fbpx
Wikipedia

Photovoltaics

April 20, 2023

Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors.

The Solar Settlement, a sustainable housing community project in Freiburg, Germany
Charging station in France that provides energy for electric cars using solar energy
Solar panels on the International Space Station

A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating. The mount may be fixed or use a solar tracker to follow the sun across the sky.

Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels. Solar PV has specific advantages as an energy source: once installed, its operation generates no pollution and no greenhouse gas emissions, it shows scalability in respect of power needs and silicon has large availability in the Earth's crust, although other materials required in PV system manufacture such as silver may constrain further growth in the technology. Other major constraints identified are competition for land use.[1] The use of PV as a main source requires energy storage systems or global distribution by high-voltage direct current power lines causing additional costs, and also has a number of other specific disadvantages such as variable power generation which have to be balanced. Production and installation does cause some pollution and greenhouse gas emissions, though only a fraction of the emissions caused by fossil fuels.

Photovoltaic systems have long been used in specialized applications as stand-alone installations and grid-connected PV systems have been in use since the 1990s.[2] Photovoltaic modules were first mass-produced in 2000, when the German government funded a one hundred thousand roof program.[3] Decreasing costs has allowed PV to grow as an energy source. This has been partially driven by massive Chinese government investment in developing solar production capacity since 2000, and achieving economies of scale. Improvements in manufacturing technology and efficiency have also led to decreasing costs.[4][5] Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have supported solar PV installations in many countries.[6] Panel prices dropped by a factor of 4 between 2004 and 2011. Module prices dropped by about 90% over the 2010s.

In 2019, worldwide installed PV capacity increased to more than 635 gigawatts (GW) covering approximately two percent of global electricity demand.[7] After hydro and wind powers, PV is the third renewable energy source in terms of global capacity. In 2019 the International Energy Agency expected a growth by 700–880 GW from 2019 to 2024.[8] In some instances, PV has offered the cheapest source of electrical power in regions with a high solar potential, with a bid for pricing as low as 0.01567 US$/kWh in Qatar in 2020.[9] In 2020 the International Energy Agency stated in its World Energy Outlook that ‘[f]or projects with low cost financing that tap high quality resources, solar PV is now the cheapest source of electricity in history.[10]

Etymology

The term "photovoltaic" comes from the Greek φῶς (phōs) meaning "light", and from "volt", the unit of electromotive force, the volt, which in turn comes from the last name of the Italian physicist Alessandro Volta, inventor of the battery (electrochemical cell). The term "photovoltaic" has been in use in English since 1849.[11]

History

George Cove may have invented a photovoltaic panel in 1909, roughly 40 years before Bell Labs did in 1950.[12] In 1989, the German Research Ministry initiated the first ever program to finance PV roofs (2200 roofs). A program led by Walter Sandtner in Bonn, Germany.[13]

In 1994, Japan followed in their footsteps and conducted a similar program with 539 residential PV systems installed.[14] Since, many countries have continued to produce and finance PV systems in an exponential speed.

Solar cells

Main article: Solar cell
 
Solar cells generate electricity directly from sunlight.
 
Photovoltaic power potential map estimates, how many kWh of electricity can be produced from a 1 kWp free-standing c-Si modules, optimally inclined towards the Equator. The resulting long-term average is calculated based on weather data of at least 10 recent years.

Photovoltaics are best known as a method for generating electric power by using solar cells to convert energy from the sun into a flow of electrons by the photovoltaic effect.[15][16]

Solar cells produce direct current electricity from sunlight which can be used to power equipment or to recharge batteries. The first practical application of photovoltaics was to power orbiting satellites and other spacecraft, but today the majority of photovoltaic modules are used for grid-connected systems for power generation. In this case an inverter is required to convert the DC to AC. There is still a smaller market for stand alone systems for remote dwellings, boats, recreational vehicles, electric cars, roadside emergency telephones, remote sensing, and cathodic protection of pipelines.

Photovoltaic power generation employs solar modules composed of a number of solar cells containing a semiconductor material.[17] Copper solar cables connect modules (module cable), arrays (array cable), and sub-fields. Because of the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years.[18][19][20]

Cells require protection from the environment and are usually packaged tightly in solar modules.

Photovoltaic module power is measured under standard test conditions (STC) in "Wp" (watts peak).[21] The actual power output at a particular place may be less than or greater than this rated value, depending on geographical location, time of day, weather conditions, and other factors.[22] Solar photovoltaic array capacity factors are typically under 25% when not coupled with storage, which is lower than many other industrial sources of electricity.[23]

Solar cell efficiencies

This section is an excerpt from Solar-cell efficiency.[edit]
 
Reported timeline of research solar cell energy conversion efficiencies since 1976 (National Renewable Energy Laboratory)

Solar-cell efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell.

The efficiency of the solar cells used in a photovoltaic system, in combination with latitude and climate, determines the annual energy output of the system. For example, a solar panel with 20% efficiency and an area of 1 m2 will produce 200 kWh/yr at Standard Test Conditions if exposed to the Standard Test Condition solar irradiance value of 1000 W/m2 for 2.74 hours a day. Usually solar panels are exposed to sunlight for longer than this in a given day, but the solar irradiance is less than 1000 W/m2 for most of the day. A solar panel can produce more when the sun is high in the sky and will produce less in cloudy conditions or when the sun is low in the sky, usually the sun is lower in the sky in the winter.

Two location dependant factors that affect solar PV efficiency are the dispersion and intensity of solar radiation. These two variables can vary greatly between each country.[24] The global regions that have high radiation levels throughout the year are the middle east, Northern Chile, Australia, China, and Southwestern USA.[24][25] In a high-yield solar area like central Colorado, which receives annual insolation of 2000 kWh/m2/year,[26] a panel can be expected to produce 400 kWh of energy per year. However, in Michigan, which receives only 1400 kWh/m2/year,[26] annual energy yield will drop to 280 kWh for the same panel. At more northerly European latitudes, yields are significantly lower: 175 kWh annual energy yield in southern England under the same conditions.[27]

 
Schematic of charge collection by solar cells. Light transmits through transparent conducting electrode creating electron hole pairs, which are collected by both the electrodes. The absorption and collection efficiencies of a solar cell depend on the design of transparent conductors and active layer thickness.[28]
Several factors affect a cell's conversion efficiency, including its reflectance, thermodynamic efficiency, charge carrier separation efficiency, charge carrier collection efficiency and conduction efficiency values.[29][28] Because these parameters can be difficult to measure directly, other parameters are measured instead, including quantum efficiency, open-circuit voltage (VOC) ratio, and § Fill factor. Reflectance losses are accounted for by the quantum efficiency value, as they affect "external quantum efficiency". Recombination losses are accounted for by the quantum efficiency, VOC ratio, and fill factor values. Resistive losses are predominantly accounted for by the fill factor value, but also contribute to the quantum efficiency and VOC ratio values. In 2019, the world record for solar cell efficiency at 47.1% was achieved by using multi-junction concentrator solar cells, developed at National Renewable Energy Laboratory, Golden, Colorado, USA.[30]

Performance and degradation

 
This chart illustrates the effect of clouds on solar energy production.

Module performance is generally rated under standard test conditions (STC): irradiance of 1,000 W/m2, solar spectrum of AM 1.5 and module temperature at 25 °C.[31] The actual voltage and current output of the module changes as lighting, temperature and load conditions change, so there is never one specific voltage at which the module operates. Performance varies depending on geographic location, time of day, the day of the year, amount of solar irradiance, direction and tilt of modules, cloud cover, shading, soiling, state of charge, and temperature. Performance of a module or panel can be measured at different time intervals with a DC clamp meter or shunt and logged, graphed, or charted with a chart recorder or data logger.

For optimum performance, a solar panel needs to be made of similar modules oriented in the same direction perpendicular to direct sunlight. Bypass diodes are used to circumvent broken or shaded panels and optimize output. These bypass diodes are usually placed along groups of solar cells to create a continuous flow.[32]

Electrical characteristics include nominal power (PMAX, measured in W), open-circuit voltage (VOC), short-circuit current (ISC, measured in amperes), maximum power voltage (VMPP), maximum power current (IMPP), peak power (watt-peak, Wp), and module efficiency (%).

Open-circuit voltage or VOC is the maximum voltage the module can produce when not connected to an electrical circuit or system.[33] VOC can be measured with a voltmeter directly on an illuminated module's terminals or on its disconnected cable.

The peak power rating, Wp, is the maximum output under standard test conditions (not the maximum possible output). Typical modules, which could measure approximately 1 by 2 metres (3 ft × 7 ft), will be rated from as low as 75 W to as high as 600 W, depending on their efficiency. At the time of testing, the test modules are binned according to their test results, and a typical manufacturer might rate their modules in 5 W increments, and either rate them at +/- 3%, +/-5%, +3/-0% or +5/-0%.[34][35][36]

Influence of temperature

The performance of a photovoltaic (PV) module depends on the environmental conditions, mainly on the global incident irradiance G in the plane of the module. However, the temperature T of the p–n junction also influences the main electrical parameters: the short circuit current ISC, the open circuit voltage VOC and the maximum power Pmax. In general, it is known that VOC shows a significant inverse correlation with T, while for ISC this correlation is direct, but weaker, so that this increase does not compensate for the decrease in VOC. As a consequence, Pmax decreases when T increases. This correlation between the power output of a solar cell and the working temperature of its junction depends on the semiconductor material, and is due to the influence of T on the concentration, lifetime, and mobility of the intrinsic carriers, i.e., electrons and gaps. inside the photovoltaic cell.

Temperature sensitivity is usually described by temperature coefficients, each of which expresses the derivative of the parameter to which it refers with respect to the junction temperature. The values ​​of these parameters, which can be found in any data sheet of the photovoltaic module, are the following:

- β: VOC variation coefficient with respect to T, given by ∂VOC/∂T.

- α: Coefficient of variation of ISC with respect to T, given by ∂ISC/∂T.

- δ: Coefficient of variation of Pmax with respect to T, given by ∂Pmax/∂T.

Techniques for estimating these coefficients from experimental data can be found in the literature [37]

Degradation

The ability of solar modules to withstand damage by rain, hail, heavy snow load, and cycles of heat and cold varies by manufacturer, although most solar panels on the U.S. market are UL listed, meaning they have gone through testing to withstand hail.[38]

Potential-induced degradation (also called PID) is a potential-induced performance degradation in crystalline photovoltaic modules, caused by so-called stray currents.[39] This effect may cause power loss of up to 30%.[40]

The largest challenge for photovoltaic technology is the purchase price per watt of electricity produced. Advancements in photovoltaic technologies have brought about the process of "doping" the silicon substrate to lower the activation energy thereby making the panel more efficient in converting photons to retrievable electrons.[41]

Chemicals such as boron (p-type) are applied into the semiconductor crystal in order to create donor and acceptor energy levels substantially closer to the valence and conductor bands.[42] In doing so, the addition of boron impurity allows the activation energy to decrease twenty-fold from 1.12 eV to 0.05 eV. Since the potential difference (EB) is so low, the boron is able to thermally ionize at room temperatures. This allows for free energy carriers in the conduction and valence bands thereby allowing greater conversion of photons to electrons.

The power output of a photovoltaic (PV) device decreases over time. This decrease is due to its exposure to solar radiation as well as other external conditions. The degradation index, which is defined as the annual percentage of output power loss, is a key factor in determining the long-term production of a photovoltaic plant. To estimate this degradation, the percentage of decrease associated with each of the electrical parameters. The individual degradation of a photovoltaic module can significantly influence the performance of a complete string. Furthermore, not all modules in the same installation decrease their performance at exactly the same rate. Given a set of modules exposed to long-term outdoor conditions, the individual degradation of the main electrical parameters and the increase in their dispersion must be considered. As each module tends to degrade differently, the behavior of the modules will be increasingly different over time, negatively affecting the overall performance of the plant.

There are several studies dealing with the power degradation analysis of modules based on different photovoltaic technologies available in the literature. According to a recent study,[43] the degradation of crystalline silicon modules is very regular, oscillating between 0.8% and 1.0% per year.

On the other hand, if we analyze the performance of thin-film photovoltaic modules, an initial period of strong degradation is observed (which can last several months and up to two years), followed by a later stage in which the degradation stabilizes, being then comparable to that of crystalline silicon.[44] Strong seasonal variations are also observed in such thin-film technologies because the influence of the solar spectrum is much greater. For example, for modules of amorphous silicon, micromorphic silicon or cadmium telluride, we are talking about annual degradation rates for the first years of between 3% and 4%.[45] However, other technologies, such as CIGS, show much lower degradation rates, even in those early years.

Manufacturing of PV systems

See also: List of photovoltaics companies

Overall the manufacturing process of creating solar photovoltaics is simple in that it does not require the culmination of many complex or moving parts. Because of the solid-state nature of PV systems, they often have relatively long lifetimes, anywhere from 10 to 30 years. To increase the electrical output of a PV system, the manufacturer must simply add more photovoltaic components. Because of this, economies of scale are important for manufacturers as costs decrease with increasing output.[46]

While there are many types of PV systems known to be effective, crystalline silicon PV accounted for around 90% of the worldwide production of PV in 2013. Manufacturing silicon PV systems has several steps. First, polysilicon is processed from mined quartz until it is very pure (semi-conductor grade). This is melted down when small amounts of boron, a group III element, are added to make a p-type semiconductor rich in electron holes. Typically using a seed crystal, an ingot of this solution is grown from the liquid polycrystalline. The ingot may also be cast in a mold. Wafers of this semiconductor material are cut from the bulk material with wire saws, and then go through surface etching before being cleaned. Next, the wafers are placed into a phosphorus vapor deposition furnace which lays a very thin layer of phosphorus, a group V element, which creates an n-type semiconducting surface. To reduce energy losses, an anti-reflective coating is added to the surface, along with electrical contacts. After finishing the cell, cells are connected via electrical circuit according to the specific application and prepared for shipping and installation.[47]

Environmental costs of manufacture

Solar photovoltaic power is not entirely "clean energy": production produces greenhouse gas emissions, materials used to build the cells are potentially unsustainable and will run out eventually, the technology uses toxic substances which cause pollution, and there are no viable technologies for recycling solar waste.[48] Data required to investigate their impact are sometimes affected by a rather large amount of uncertainty. The values of human labor and water consumption, for example, are not precisely assessed due to the lack of systematic and accurate analyses in the scientific literature.[1] One difficulty in determining impacts due to PV is to determine if the wastes are released to the air, water, or soil during the manufacturing phase.[49] Life-cycle assessments, which look at all different environment impacts ranging from global warming potential, pollution, water depletion and others, are unavailable for PV. Instead, studies have tried to estimate the impact and potential impacts of various types of PV, but these estimates are usually restricted to simply assessing energy costs of the manufacture and/or transport, because these are new technologies and the total environmental impacts of their components and disposal methods are unknown, even for commercially available first generation solar cells, let alone experimental prototypes with no commercial viability.[50]

Thus, estimates of the environmental impacts of PV have focused on carbon dioxide equivalents per kWh or energy pay-back time (EPBT). The EPBT describes the timespan a PV system needs to operate in order to generate the same amount of energy that was used for its manufacture.[51] Another study includes transport energy costs in the EPBT.[52] The EPBT has also been defined completely differently as "the time needed to compensate for the total renewable- and non-renewable primary energy required during the life cycle of a PV system" in another study, which also included installation costs.[53] This energy amortization, given in years, is also referred to as break-even energy payback time.[54] The lower the EPBT, the lower the environmental cost of solar power. The EPBT depends vastly on the location where the PV system is installed (e.g. the amount of sunlight available and the efficiency of the electrical grid)[52] and on the type of system, namely the system's components.[51]

A 2015 review of EPBT estimates of first and second-generation PV suggested that there was greater variation in embedded energy than in efficiency of the cells implying that it was mainly the embedded energy that needs to reduce to have a greater reduction in EPBT.[55]

In general, the most important component of solar panels, which accounts for much of the energy use and greenhouse gas emissions, is the refining of the polysilicon.[51] As to how much percentage of the EPBT this silicon depends on the type of system. A fully autarkic system requires additional components ('Balance of System', the power inverters, storage, etc.) which significantly increase the energy cost of manufacture, but in a simple rooftop system, some 90% of the energy cost is from silicon, with the remainder coming from the inverters and module frame.[51]

In an analysis by Alsema et al. from 1998, the energy payback time was higher than 10 years for the former system in 1997, while for a standard rooftop system the EPBT was calculated as between 3.5 and 8 years.[51][56]

The EPBT relates closely to the concepts of net energy gain (NEG) and energy returned on energy invested (EROI). They are both used in energy economics and refer to the difference between the energy expended to harvest an energy source and the amount of energy gained from that harvest. The NEG and EROI also take the operating lifetime of a PV system into account and a working life of 25 to 30 years is typically assumed. From these metrics, the Energy payback Time can be derived by calculation.[57][58]

EPBT improvements

PV systems using crystalline silicon, by far the majority of the systems in practical use, have such a high EPBT because silicon is produced by the reduction of high-grade quartz sand in electric furnaces. This coke-fired smelting process occurs at high temperatures of more than 1000 °C and is very energy intensive, using about 11 kilowatt-hours (kWh) per produced kilogram of silicon.[59] The energy requirements of this process makes the energy cost per unit of silicon produced relatively inelastic, which means that the production process itself will not become more efficient in the future.

Nonetheless, the energy payback time has shortened significantly over the last years, as crystalline silicon cells became ever more efficient in converting sunlight, while the thickness of the wafer material was constantly reduced and therefore required less silicon for its manufacture. Within the last ten years, the amount of silicon used for solar cells declined from 16 to 6 grams per watt-peak. In the same period, the thickness of a c-Si wafer was reduced from 300 μm, or microns, to about 160–190 μm. The sawing techniques that slice crystalline silicon ingots into wafers have also improved by reducing the kerf loss and making it easier to recycle the silicon sawdust.[60][61]

Key parameters for material and energy efficiency
Parameter Mono-Si CdTe
Cell efficiency 16.5% 15.6%
Derate cell to module efficiency 8.5% 13.9%
Module efficiency 15.1% 13.4%
Wafer thickness / layer thickness 190 μm 4.0 μm
Kerf loss 190 μm –
Silver per cell 9.6 g/m2 –
Glass thickness 4.0 mm 3.5 mm
Operational lifetime 30 years 30 years
Source: IEA-PVPS, Life Cycle Assessment, March 2015[62]

Impacts from first generation PV

Crystalline silicon modules are the most extensively studied PV type in terms of LCA since they are the most commonly used. Mono-crystalline silicon photovoltaic systems (mono-si) have an average efficiency of 14.0%.[63] The cells tend to follow a structure of front electrode, anti-reflection film, n-layer, p-layer, and back electrode, with the sun hitting the front electrode. EPBT ranges from 1.7 to 2.7 years.[64] The cradle to gate of CO2-eq/kWh ranges from 37.3 to 72.2 grams when installed in Southern Europe.[65]

Techniques to produce multi-crystalline silicon (multi-si) photovoltaic cells are simpler and cheaper than mono-si, however tend to make less efficient cells, an average of 13.2%.[63] EPBT ranges from 1.5 to 2.6 years.[64] The cradle to gate of CO2-eq/kWh ranges from 28.5 to 69 grams when installed in Southern Europe.[65]

Assuming that the following countries had a high-quality grid infrastructure as in Europe, in 2020 it was calculated it would take 1.28 years in Ottawa, Canada, for a rooftop photovoltaic system to produce the same amount of energy as required to manufacture the silicon in the modules in it (excluding the silver, glass, mounts and other components), 0.97 years in Catania, Italy, and 0.4 years in Jaipur, India. Outside of Europe, where net grid efficiencies are lower, it would take longer. This 'energy payback time' can be seen as the portion of time during the useful lifetime of the module in which the energy production is polluting. At best, this means that a 30-year old panel has produced clean energy for 97% of its lifetime, or that the silicon in the modules in a solar panel produce 97% less greenhouse gas emissions than a coal-fired plant for the same amount of energy (assuming and ignoring many things).[52] Some studies have looked beyond EPBT and GWP to other environmental impacts. In one such study, conventional energy mix in Greece was compared to multi-si PV and found a 95% overall reduction in impacts including carcinogens, eco-toxicity, acidification, eutrophication, and eleven others.[66]

Impacts from second generation PV

Cadmium telluride (CdTe) is one of the fastest-growing thin film based solar cells which are collectively known as second-generation devices. This new thin-film device also shares similar performance restrictions (Shockley-Queisser efficiency limit) as conventional Si devices but promises to lower the cost of each device by both reducing material and energy consumption during manufacturing. The global market share of CdTe was 4.7% in 2008.[49] This technology's highest power conversion efficiency is 21%.[67] The cell structure includes glass substrate (around 2 mm), transparent conductor layer, CdS buffer layer (50–150 nm), CdTe absorber and a metal contact layer.

CdTe PV systems require less energy input in their production than other commercial PV systems per unit electricity production. The average CO2-eq/kWh is around 18 grams (cradle to gate). CdTe has the fastest EPBT of all commercial PV technologies, which varies between 0.3 and 1.2 years.[68]

Impacts from third generation PV

Third-generation PVs are designed to combine the advantages of both the first and second generation devices and they do not have Shockley-Queisser limit, a theoretical limit for first and second generation PV cells. The thickness of a third generation device is less than 1 μm.[69]

Two new promising thin film technologies are copper zinc tin sulfide (Cu2ZnSnS4 or CZTS),[50] zinc phosphide (Zn3P2)[50] and single-walled carbon nano-tubes (SWCNT).[70] These thin films are currently only produced in the lab but may be commercialized in the future. The manufacturing of CZTS and (Zn3P2) processes are expected to be similar to those of current thin film technologies of CIGS and CdTe, respectively. While the absorber layer of SWCNT PV is expected to be synthesized with CoMoCAT method.[71] by Contrary to established thin films such as CIGS and CdTe, CZTS, Zn3P2, and SWCNT PVs are made from earth abundant, nontoxic materials and have the potential to produce more electricity annually than the current worldwide consumption.[72][73] While CZTS and Zn3P2 offer good promise for these reasons, the specific environmental implications of their commercial production are not yet known. Global warming potential of CZTS and Zn3P2 were found 38 and 30 grams CO2-eq/kWh while their corresponding EPBT were found 1.85 and 0.78 years, respectively.[50] Overall, CdTe and Zn3P2 have similar environmental impacts but can slightly outperform CIGS and CZTS.[50] A study on environmental impacts of SWCNT PVs by Celik et al., including an existing 1% efficient device and a theoretical 28% efficient device, found that, compared to monocrystalline Si, the environmental impacts from 1% SWCNT was ∼18 times higher due mainly to the short lifetime of three years.[70]

Economics

See also: Photovoltaic system § Costs and economy

Source: Apricus[74]

There have been major changes in the underlying costs, industry structure and market prices of solar photovoltaics technology, over the years, and gaining a coherent picture of the shifts occurring across the industry value chain globally is a challenge. This is due to: "the rapidity of cost and price changes, the complexity of the PV supply chain, which involves a large number of manufacturing processes, the balance of system (BOS) and installation costs associated with complete PV systems, the choice of different distribution channels, and differences between regional markets within which PV is being deployed". Further complexities result from the many different policy support initiatives that have been put in place to facilitate photovoltaics commercialisation in various countries.[2]

Renewable energy technologies have generally gotten cheaper since their invention.[75][76][77] Renewable energy systems have become cheaper to build than fossil fuel power plants across much of the world, thanks to advances in wind and solar energy technology, in particular.[78]

Hardware costs

 
Price per watt history for conventional (c-Si) solar cells since 1977

In 1977 crystalline silicon solar cell prices were at $76.67/W.[79]

Although wholesale module prices remained flat at around $3.50 to $4.00/W in the early 2000s due to high demand in Germany and Spain afforded by generous subsidies and shortage of polysilicon, demand crashed with the abrupt ending of Spanish subsidies after the market crash of 2008, and the price dropped rapidly to $2.00/W. Manufacturers were able to maintain a positive operating margin despite a 50% drop in income due to innovation and reductions in costs. In late 2011, factory-gate prices for crystalline-silicon photovoltaic modules suddenly dropped below the $1.00/W mark, taking many in the industry by surprise, and has caused a number of solar manufacturing companies to go bankrupt throughout the world. The $1.00/W cost is often regarded in the PV industry as marking the achievement of grid parity for PV, but most experts do not believe this price point is sustainable. Technological advancements, manufacturing process improvements, and industry re-structuring, may mean that further price reductions are possible.[2] The average retail price of solar cells as monitored by the Solarbuzz group fell from $3.50/watt to $2.43/watt over the course of 2011.[80] In 2013 wholesale prices had fallen to $0.74/W.[79] This has been cited as evidence supporting 'Swanson's law', an observation similar to the famous Moore's Law, which claims that solar cell prices fall 20% for every doubling of industry capacity.[79] The Fraunhofer Institute defines the 'learning rate' as the drop in prices as the cumulative production doubles, some 25% between 1980 and 2010. Although the prices for modules have dropped quickly, current inverter prices have dropped at a much lower rate, and in 2019 constitute over 61% of the cost per kWp, from a quarter in the early 2000s.[52]

Note that the prices mentioned above are for bare modules, another way of looking at module prices is to include installation costs. In the US, according to the Solar Energy Industries Association, the price of installed rooftop PV modules for homeowners fell from $9.00/W in 2006 to $5.46/W in 2011. Including the prices paid by industrial installations, the national installed price drops to $3.45/W. This is markedly higher than elsewhere in the world, in Germany homeowner rooftop installations averaged at $2.24/W. The cost differences are thought to be primarily based on the higher regulatory burden and lack of a national solar policy in the US.[81]

By the end of 2012 Chinese manufacturers had production costs of $0.50/W in the cheapest modules.[82] In some markets distributors of these modules can earn a considerable margin, buying at factory-gate price and selling at the highest price the market can support ('value-based pricing').[2]

In California PV reached grid parity in 2011, which is usually defined as PV production costs at or below retail electricity prices (though often still above the power station prices for coal or gas-fired generation without their distribution and other costs).[83] Grid parity had been reached in 19 markets in 2014.[84][85]

Levelised cost of electricity

 
AWM Munich ETFE Cushions-Photovoltaics

The levelised cost of electricity (LCOE) is the cost per kWh based on the costs distributed over the project lifetime, and is thought to be a better metric for calculating viability than price per wattage. LCOEs vary dramatically depending on the location.[2] The LCOE can be considered the minimum price customers will have to pay the utility company in order for it to break even on the investment in a new power station.[4] Grid parity is roughly achieved when the LCOE falls to a similar price as conventional local grid prices, although in actuality the calculations are not directly comparable.[86] Large industrial PV installations had reached grid parity in California in 2011.[77][86] Grid parity for rooftop systems was still believed to be much farther away at this time.[86] Many LCOE calculations are not thought to be accurate, and a large amount of assumptions are required.[2][86] Module prices may drop further, and the LCOE for solar may correspondingly drop in the future.[87]

Because energy demands rise and fall over the course of the day, and solar power is limited by the fact that the sun sets, solar power companies must also factor in the additional costs of supplying a more stable alternative energy supplies to the grid in order to stabilize the system, or storing the energy somehow (current battery technology cannot store enough power). These costs are not factored into LCOE calculations, nor are special subsidies or premiums that may make buying solar power more attractive.[4] The unreliability and temporal variation in generation of solar and wind power is a major problem. Too much of these volatile power sources can cause instability of the entire grid.[88]

As of 2017 power-purchase agreement prices for solar farms below $0.05/kWh are common in the United States, and the lowest bids in some Persian Gulf countries were about $0.03/kWh.[89] The goal of the United States Department of Energy is to achieve a levelised cost of energy for solar PV of $0.03/kWh for utility companies.[90]

Subsidies and financing

Financial incentives for photovoltaics, such as feed-in tariffs (FITs), have often been offered to electricity consumers to install and operate solar-electric generating systems, and in some countries such subsidies are the only way photovoltaics can remain economically profitable. In Germany FIT subsidies are generally around €0.13 above the normal retail price of a kWh (€0.05).[91] PV FITs have been crucial for the adoption of the industry, and are available to consumers in over 50 countries as of 2011. Germany and Spain have been the most important countries regarding offering subsidies for PV, and the policies of these countries have driven demand in the past.[2] Some US solar cell manufacturing companies have repeatedly complained that the dropping prices of PV module costs have been achieved due to subsidies by the government of China, and the dumping of these products below fair market prices. US manufacturers generally recommend high tariffs on foreign supplies to allow them remain profitable. In response to these concerns, the Obama administration began to levy tariffs on US consumers of these products in 2012 to raise prices for domestic manufacturers.[2] The USA, however, also subsidies the industry, offering consumers a 30% federal tax credit to purchase modules. In Hawaii federal and state subsidies chop off up to two thirds of the installation costs.[81]

Some environmentalists have promoted the idea that government incentives should be used in order to expand the PV manufacturing industry to reduce costs of PV-generated electricity much more rapidly to a level where it is able to compete with fossil fuels in a free market. This is based on the theory that when the manufacturing capacity doubles, economies of scale will cause the prices of the solar products to halve.[4]

In many countries there is access to capital is lacking to develop PV projects. To solve this problem, securitization has been proposed to accelerate development of solar photovoltaic projects.[83][92] For example, SolarCity offered the first U.S. asset-backed security in the solar industry in 2013.[93]

Other

Photovoltaic power is also generated during a time of day that is close to peak demand (precedes it) in electricity systems with high use of air conditioning. Since large-scale PV operation requires back-up in the form of spinning reserves, its marginal cost of generation in the middle of the day is typically lowest, but not zero, when PV is generating electricity. This can be seen in Figure 1 of this paper:.[94] For residential properties with private PV facilities networked to the grid, the owner may be able earn extra money when the time of generation is included, as electricity is worth more during the day than at night.[95]

One journalist theorised in 2012 that if the energy bills of Americans were forced upwards by imposing an extra tax of $50/ton on carbon dioxide emissions from coal-fired power, this could have allowed solar PV to appear more cost-competitive to consumers in most locations.[80]

Growth

Main article: Growth of photovoltaics
 
Worldwide growth of photovoltaics on a semi-log plot since 1992

Solar photovoltaics formed the largest body of research among the seven sustainable energy types examined in a global bibliometric study, with the annual scientific output growing from 9,094 publications in 2011 to 14,447 publications in 2019.[96]

Likewise, the application of solar photovoltaics is growing rapidly and worldwide installed capacity reached about 515 gigawatts (GW) by 2018.[97] The total power output of the world's PV capacity in a calendar year is now beyond 500 TWh of electricity. This represents 2% of worldwide electricity demand. More than 100 countries use solar PV.[98][99] China is followed by the United States and Japan, while installations in Germany, once the world's largest producer, have been slowing down.

Honduras generated the highest percentage of its energy from solar in 2019, 14.8%.[100] As of 2019, Vietnam has the highest installed capacity in Southeast Asia, about 4.5 GW.[101] The annualized installation rate of about 90 W per capita per annum places Vietnam among world leaders.[101] Generous Feed-in tariff (FIT) and government supporting policies such as tax exemptions were the key to enable Vietnam's solar PV boom. Underlying drivers include the government's desire to enhance energy self-sufficiency and the public's demand for local environmental quality.[101]

A key barrier is limited transmission grid capacity.[101]

China has the world's largest solar power capacity, with 253 GW of installed capacity at the end-2020 compared with about 151 GW in the European Union, according to International Energy Agency data.[102]

Top 10 PV countries in 2019 (MW)
Installed and total solar power capacity in 2019 (MW)[103]
# Nation Total capacity Added capacity
1   China 204,700 30,100
2   United States 75,900 13,300
3   Japan 63,000 7,000
4   Germany 49,200 3,900
5   India 42,800 9,900
6   Italy 20,800 600
7   Australia 15,928 3,700
8   United Kingdom 13,300 233
9   South Korea 11,200 3,100
10   France 9,900 900

Data: IEA-PVPS Snapshot of Global PV Markets 2020 report, April 2020[103]
Also see Solar power by country for a complete and continuously updated list

In 2017 it was thought probable that by 2030 global PV installed capacities could be between 3,000 and 10,000 GW.[89] Greenpeace in 2010 claimed that 1,845 GW of PV systems worldwide could be generating approximately 2,646 TWh/year of electricity by 2030, and by 2050 over 20% of all electricity could be provided by PV.[104]

Applications

Main article: Applications of photovoltaics

There are many practical applications for the use of solar panels or photovoltaics covering every technological domain under the sun. From the fields of the agricultural industry as a power source for irrigation to its usage in remote health care facilities to refrigerate medical supplies. Other applications include power generation at various scales and attempts to integrate them into homes and public infrastructure. PV modules are used in photovoltaic systems and include a large variety of electrical devices.

Photovoltaic systems

Main article: Photovoltaic system

A photovoltaic system, or solar PV system is a power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and directly convert sunlight into electricity, a solar inverter to change the electric current from DC to AC, as well as mounting, cabling and other electrical accessories. PV systems range from small, roof-top mounted or building-integrated systems with capacities from a few to several tens of kilowatts, to large utility-scale power stations of hundreds of megawatts. Nowadays, most PV systems are grid-connected, while stand-alone systems only account for a small portion of the market.

Photo sensors

Main article: Photodetectors

Photosensors are sensors of light or other electromagnetic radiation.[105] A photo detector has a p–n junction that converts light photons into current. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy.

Experimental technology

Crystalline silicon photovoltaics are only one type of PV, and while they represent the majority of solar cells produced currently there are many new and promising technologies that have the potential to be scaled up to meet future energy needs. As of 2018, crystalline silicon cell technology serves as the basis for several PV module types, including monocrystalline, multicrystalline, mono PERC, and bifacial.[106]

Another newer technology, thin-film PV, are manufactured by depositing semiconducting layers of perovskite, a mineral with semiconductor properties, on a substrate in vacuum. The substrate is often glass or stainless-steel, and these semiconducting layers are made of many types of materials including cadmium telluride (CdTe), copper indium diselenide (CIS), copper indium gallium diselenide (CIGS), and amorphous silicon (a-Si). After being deposited onto the substrate the semiconducting layers are separated and connected by electrical circuit by laser scribing.[107][108] Perovskite solar cells are a very efficient solar energy converter and have excellent optoelectronic properties for photovoltaic purposes, but their upscaling from lab-sized cells to large-area modules is still under research.[109] Thin-film photovoltaic materials may possibly become attractive in the future, because of the reduced materials requirements and cost to manufacture modules consisting of thin-films as compared to silicon-based wafers.[110] In 2019 university labs at Oxford, Stanford and elsewhere reported perovskite solar cells with efficiencies of 20-25%.[111]

CIGS

Main article: Copper indium gallium selenide

Copper indium gallium selenide (CIGS) is a thin film solar cell based on the copper indium diselenide (CIS) family of chalcopyrite semiconductors. CIS and CIGS are often used interchangeably within the CIS/CIGS community. The cell structure includes soda lime glass as the substrate, Mo layer as the back contact, CIS/CIGS as the absorber layer, cadmium sulfide (CdS) or Zn (S,OH)x as the buffer layer, and ZnO:Al as the front contact.[112] CIGS is approximately 1/100th the thickness of conventional silicon solar cell technologies. Materials necessary for assembly are readily available, and are less costly per watt of solar cell. CIGS based solar devices resist performance degradation over time and are highly stable in the field.

Reported global warming potential impacts of CIGS ranges 20.5–58.8 grams CO2-eq/kWh of electricity generated for different solar irradiation (1,700 to 2,200 kWh/m2/y) and power conversion efficiency (7.8 – 9.12%).[113] EPBT ranges from 0.2 to 1.4 years,[68] while harmonized value of EPBT was found 1.393 years.[55] Toxicity is an issue within the buffer layer of CIGS modules because it contains cadmium and gallium.[50][114] CIS modules do not contain any heavy metals.

Perovskite solar cells

This section is an excerpt from Perovskite solar cell.[edit]
 
Perovskite solar cells
 
Solar cell efficiencies of various cell technologies (including both single-crystal and thin film technologies) as tracked by NREL

A perovskite solar cell (PSC) is a type of solar cell that includes a perovskite-structured compound, most commonly a hybrid organic–inorganic lead or tin halide-based material as the light-harvesting active layer.[115][116] Perovskite materials, such as methylammonium lead halides and all-inorganic caesium lead halide, are cheap to produce and simple to manufacture.

Efficiencies of laboratory-scale devices using these materials have increased from 3.8% in 2009[117] to 25.7% in 2021 in single-junction architectures,[118][119] and, in silicon-based tandem cells, to 29.8%,[118][120] exceeding the maximum efficiency achieved in single-junction silicon solar cells. Perovskite solar cells have therefore been the fastest-advancing solar technology as of 2016.[115] With the potential of achieving even higher efficiencies and very low production costs, perovskite solar cells have become commercially attractive. Core problems and research subjects include their short- and long-term stability.[121]

Dye-Sensitized Solar Cells

Dye-sensitized Solar Cells (DSCs) are a novel thin film solar cell. These solar cells operate under ambient light better than other photovoltaic technologies. They work with light being absorbed in a sensitizing dye between two charge transport materials. Dye surrounds TiO2 nanoparticles which are in a sintered network.[122] TiO2 acts as conduction band in an n-type semiconductor; the scaffold for adorned dye molecules and transports elections during excitation. For TiO2 DSC technology, sample preparation at high temperatures is very effective because higher temperatures produce more suitable textural properties. Another example of DSCs is the copper complex with Cu (II/I) as a redox shuttle with TMBY (4,4',6,6'-tetramethyl-2,2'bipyridine). DSCs show great performance with artificial and indoor light. From a range of 200 lux to 2,000 lux, these cells operate at conditions of a maximum efficiency of 29.7%.[123]

However, there have been issues with DSCs, many of which come from the liquid electrolyte. The solvent is hazardous, and will permeate most plastics. Because it is liquid, it is unstable to temperature variation, leading to freezing in cold temperatures and expansion in warm temperatures causing failure.[124] Another disadvantage is that the solar cell is not ideal for large scale application because of its low efficiency. Some of the benefits for DSC is that it can be used in a variety of light levels (including cloudy conditions), it has a low production cost, and it does not degrade under sunlight, giving it a longer lifetime then other types of thin film solar cells.

OPV

Other possible future PV technologies include organic, dye-sensitized and quantum-dot photovoltaics.[125] Organic photovoltaics (OPVs) fall into the thin-film category of manufacturing, and typically operate around the 12% efficiency range which is lower than the 12–21% typically seen by silicon-based PVs. Because organic photovoltaics require very high purity and are relatively reactive they must be encapsulated which vastly increases the cost of manufacturing and means that they are not feasible for large scale-up. Dye-sensitized PVs are similar in efficiency to OPVs but are significantly easier to manufacture. However, these dye-sensitized photovoltaics present storage problems because the liquid electrolyte is toxic and can potentially permeate the plastics used in the cell. Quantum dot solar cells are solution-processed, meaning they are potentially scalable, but currently they peak at 12% efficiency.[109]

Organic and polymer photovoltaic (OPV) are a relatively new area of research. The tradition OPV cell structure layers consist of a semi-transparent electrode, electron blocking layer, tunnel junction, holes blocking layer, electrode, with the sun hitting the transparent electrode. OPV replaces silver with carbon as an electrode material lowering manufacturing cost and making them more environmentally friendly.[126] OPV are flexible, low weight, and work well with roll-to roll manufacturing for mass production.[127] OPV uses "only abundant elements coupled to an extremely low embodied energy through very low processing temperatures using only ambient processing conditions on simple printing equipment enabling energy pay-back times".[128] Current efficiencies range 1–6.5%,[53][129] however theoretical analyses show promise beyond 10% efficiency.[128]

Many different configurations of OPV exist using different materials for each layer. OPV technology rivals existing PV technologies in terms of EPBT even if they currently present a shorter operational lifetime. A 2013 study analyzed 12 different configurations all with 2% efficiency, the EPBT ranged from 0.29 to 0.52 years for 1 m2 of PV.[130] The average CO2-eq/kWh for OPV is 54.922 grams.[131]

Thermophotovoltaics

This section is an excerpt from Thermophotovoltaic energy conversion.[edit]

Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons. A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being admitted from the hot object.[132]

As TPV systems generally work at lower temperatures than solar cells, their efficiencies tend to be low. Offsetting this through the use of multi-junction cells based on non-silicon materials is common, but generally very expensive. This currently limits TPV to niche roles like spacecraft power and waste heat collection from larger systems like steam turbines.

Solar module alignment

A number of solar modules may also be mounted vertically above each other in a tower, if the zenith distance of the Sun is greater than zero, and the tower can be turned horizontally as a whole and each module additionally around a horizontal axis. In such a tower the modules can follow the Sun exactly. Such a device may be described as a ladder mounted on a turnable disk. Each step of that ladder is the middle axis of a rectangular solar panel. In case the zenith distance of the Sun reaches zero, the "ladder" may be rotated to the north or the south to avoid a solar module producing a shadow on a lower one. Instead of an exactly vertical tower one can choose a tower with an axis directed to the polar star, meaning that it is parallel to the rotation axis of the Earth. In this case the angle between the axis and the Sun is always larger than 66 degrees. During a day it is only necessary to turn the panels around this axis to follow the Sun. Installations may be ground-mounted (and sometimes integrated with farming and grazing)[133] or built into the roof or walls of a building (building-integrated photovoltaics).

Where land may be limited, PV can be deployed as floating solar. In 2008 the Far Niente Winery pioneered the world's first "floatovoltaic" system by installing 994 photovoltaic solar panels onto 130 pontoons and floating them on the winery's irrigation pond.[134][135] A benefit of the set up is that the panels are kept at a lower temperature than they would be on land, leading to a higher efficiency of solar energy conversion. The floating panels also reduce the amount of water lost through evaporation and inhibit the growth of algae.[136]

Concentrator photovoltaics is a technology that contrary to conventional flat-plate PV systems uses lenses and curved mirrors to focus sunlight onto small, but highly efficient, multi-junction solar cells. These systems sometimes use solar trackers and a cooling system to increase their efficiency.

Efficiency

Main article: Solar cell efficiency
 
Best research-cell efficiencies

In 2019, the world record for solar cell efficiency at 47.1% was achieved by using multi-junction concentrator solar cells, developed at National Renewable Energy Laboratory, Colorado, USA.[137] The highest efficiencies achieved without concentration include a material by Sharp Corporation at 35.8% using a proprietary triple-junction manufacturing technology in 2009,[138] and Boeing Spectrolab (40.7% also using a triple-layer design).

There is an ongoing effort to increase the conversion efficiency of PV cells and modules, primarily for competitive advantage. In order to increase the efficiency of solar cells, it is important to choose a semiconductor material with an appropriate band gap that matches the solar spectrum. This will enhance the electrical and optical properties. Improving the method of charge collection is also useful for increasing the efficiency. There are several groups of materials that are being developed. Ultrahigh-efficiency devices (η>30%)[139] are made by using GaAs and GaInP2 semiconductors with multijunction tandem cells. High-quality, single-crystal silicon materials are used to achieve high-efficiency, low cost cells (η>20%).

Recent developments in organic photovoltaic cells (OPVs) have made significant advancements in power conversion efficiency from 3% to over 15% since their introduction in the 1980s.[140] To date, the highest reported power conversion efficiency ranges 6.7–8.94% for small molecule, 8.4–10.6% for polymer OPVs, and 7–21% for perovskite OPVs.[141][142] OPVs are expected to play a major role in the PV market. Recent improvements have increased the efficiency and lowered cost, while remaining environmentally-benign and renewable.

Several companies have begun embedding power optimizers into PV modules called smart modules. These modules perform maximum power point tracking (MPPT) for each module individually, measure performance data for monitoring, and provide additional safety features. Such modules can also compensate for shading effects, wherein a shadow falling across a section of a module causes the electrical output of one or more strings of cells in the module to decrease.[143]

One of the major causes for the decreased performance of cells is overheating. The efficiency of a solar cell declines by about 0.5% for every 1 degree Celsius increase in temperature. This means that a 100 degree increase in surface temperature could decrease the efficiency of a solar cell by about half. Self-cooling solar cells are one solution to this problem. Rather than using energy to cool the surface, pyramid and cone shapes can be formed from silica, and attached to the surface of a solar panel. Doing so allows visible light to reach the solar cells, but reflects infrared rays (which carry heat).[144]

Advantages

  • Pollution and energy in production

The 122 PW of sunlight reaching the Earth's surface is plentiful—almost 10,000 times more than the 13 TW equivalent of average power consumed in 2005 by humans.[145] This abundance leads to the suggestion that it will not be long before solar energy will become the world's primary energy source.[146] Additionally, solar electric generation has the highest power density (global mean of 170 W/m2) among renewable energies.[145]

Solar power is pollution-free during use, which enables it to cut down on pollution when it is substituted for other energy sources. For example, MIT estimated that 52,000 people per year die prematurely in the U.S. from coal-fired power plant pollution[147] and all but one of these deaths could be prevented from using PV to replace coal.[148][149] Production end-wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development[150] and policies are being produced that encourage recycling from producers.[151]

PV installations could ideally operate for 100 years or even more[152] with little maintenance or intervention after their initial set-up, so after the initial capital cost of building any solar power plant, operating costs are extremely low compared to existing power technologies.

Grid-connected solar electricity can be used locally thus reducing transmission/distribution losses (transmission losses in the US were approximately 7.2% in 1995).[153]

  • Solar cell research investment

Compared to fossil and nuclear energy sources, very little research money has been invested in the development of solar cells, so there is considerable room for improvement. Nevertheless, experimental high efficiency solar cells already have efficiencies of over 40% in case of concentrating photovoltaic cells[154] and efficiencies are rapidly rising while mass-production costs are rapidly falling.[155]

  • Housing subsidies

In some states of the United States, much of the investment in a home-mounted system may be lost if the homeowner moves and the buyer puts less value on the system than the seller. The city of Berkeley developed an innovative financing method to remove this limitation, by adding a tax assessment that is transferred with the home to pay for the solar panels.[156] Now known as PACE, Property Assessed Clean Energy, 30 U.S. states have duplicated this solution.[157]

Disadvantages

  • Impact on electricity network
 
Grids with high penetration of renewable energy sources generally need more flexible generation rather than baseload generation.

For behind-the-meter rooftop photovoltaic systems, the energy flow becomes two-way. When there is more local generation than consumption, electricity is exported to the grid, allowing for net metering. However, electricity networks traditionally are not designed to deal with two-way energy transfer, which may introduce technical issues. An over-voltage issue may come out as the electricity flows from these PV households back to the network.[158] There are solutions to manage the over-voltage issue, such as regulating PV inverter power factor, new voltage and energy control equipment at electricity distributor level, re-conductor the electricity wires, demand side management, etc. There are often limitations and costs related to these solutions.

High generation during the middle of the day reduces the net generation demand, but higher peak net demand as the sun goes down can require rapid ramping of utility generating stations, producing a load profile called the duck curve.

  • Implications for electricity bill management and energy investment

There is no silver bullet in electricity or energy demand and bill management, because customers (sites) have different specific situations, e.g. different comfort/convenience needs, different electricity tariffs, or different usage patterns. Electricity tariff may have a few elements, such as daily access and metering charge, energy charge (based on kWh, MWh) or peak demand charge (e.g. a price for the highest 30min energy consumption in a month). PV is a promising option for reducing energy charges when electricity prices are reasonably high and continuously increasing, such as in Australia and Germany. However, for sites with peak demand charge in place, PV may be less attractive if peak demands mostly occur in the late afternoon to early evening, for example in residential communities. Overall, energy investment is largely an economic decision and it is better to make investment decisions based on systematic evaluation of options in operational improvement, energy efficiency, onsite generation and energy storage.[159][160]

See also

 
Wikimedia Commons has media related to Photovoltaics.

References

  1. ^ a b Lo Piano, Samuele; Mayumi, Kozo (2017). "Toward an integrated assessment of the performance of photovoltaic systems for electricity generation". Applied Energy. 186 (2): 167–74. doi:10.1016/j.apenergy.2016.05.102. S2CID 156783885.
  2. ^ a b c d e f g h Bazilian, M.; Onyeji, I.; Liebreich, M.; MacGill, I.; Chase, J.; Shah, J.; Gielen, D.; Arent, D.; Landfear, D.; Zhengrong, S. (2013). (PDF). Renewable Energy. 53: 329–338. CiteSeerX 10.1.1.692.1880. doi:10.1016/j.renene.2012.11.029. Archived from the original (PDF) on 31 May 2014. Retrieved 4 September 2015.
  3. ^ Palz, Wolfgang (2013). Solar Power for the World: What You Wanted to Know about Photovoltaics. CRC Press. pp. 131–. ISBN 978-981-4411-87-5.
  4. ^ a b c d "Why did renewables become so cheap so fast?". Our World in Data. 1 December 2020.
  5. ^ Shubbak, Mahmood H. (2019). "The technological system of production and innovation: The case of photovoltaic technology in China". Research Policy. 48 (4): 993–1015. doi:10.1016/j.respol.2018.10.003. S2CID 158742469.
  6. ^ Renewable Energy Policy Network for the 21st century (REN21), Renewables 2010 Global Status Report, Paris, 2010, pp. 1–80.
  7. ^ "PHOTOVOLTAICS REPORT" (PDF). Fraunhofer Institute for Solar Energy Systems. 16 September 2020. p. 4.
  8. ^ "Renewables 2019". IEA. Retrieved 26 January 2020.
  9. ^ "KAHRAMAA and Siraj Energy Sign Agreements for Al-Kharsaah Solar PV Power Plant". Qatar General Electricity & Water Corporation "KAHRAMAA". 20 January 2020. Retrieved 26 January 2020.
  10. ^ Sunil Prasad Lohani, Andrew Blakers: 100% renewable energy with pumped-hydro-energy storage in Nepal. In: Clean Energy 5, 2, 2021, 243–253, doi:10.1093/ce/zkab011.
  11. ^ Smee, Alfred (1849). Elements of electro-biology,: or the voltaic mechanism of man; of electro-pathology, especially of the nervous system; and of electro-therapeutics. London: Longman, Brown, Green, and Longmans. p. 15.
  12. ^ "How to Build a Low-tech Solar Panel?". LOW-TECH MAGAZINE. Retrieved 20 October 2021.
  13. ^ Palz, Wolfgang (21 October 2013). Solar Power for the World: What You Wanted to Know about Photovoltaics. CRC Press. ISBN 978-981-4411-87-5.
  14. ^ Noguchi, Masa. "Number of Residential PV Installation in Japan: 1994-2003".
  15. ^ Photovoltaic Effect 14 July 2011 at the Wayback Machine. Mrsolar.com. Retrieved 12 December 2010
  16. ^ The photovoltaic effect 12 October 2010 at the Wayback Machine. Encyclobeamia.solarbotics.net. Retrieved on 12 December 2010.
  17. ^ Jacobson, Mark Z. (2009). "Review of Solutions to Global Warming, Air Pollution, and Energy Security". Energy & Environmental Science. 2 (2): 148–173. Bibcode:2009GeCAS..73R.581J. CiteSeerX 10.1.1.180.4676. doi:10.1039/B809990C.
  18. ^ German PV market. Solarbuzz.com. Retrieved on 3 June 2012.
  19. ^ BP Solar to Expand Its Solar Cell Plants in Spain and India 26 September 2007 at the Wayback Machine. Renewableenergyaccess.com. 23 March 2007. Retrieved on 3 June 2012.
  20. ^ Bullis, Kevin (23 June 2006). Large-Scale, Cheap Solar Electricity. Technologyreview.com. Retrieved on 3 June 2012.
  21. ^ Luque, Antonio & Hegedus, Steven (2003). Handbook of Photovoltaic Science and Engineering. John Wiley and Sons. ISBN 978-0-471-49196-5.
  22. ^ The PVWatts Solar Calculator Retrieved on 7 September 2012
  23. ^ Massachusetts: a Good Solar Market 12 September 2012 at the Wayback Machine. Remenergyco.com. Retrieved on 31 May 2013.
  24. ^ a b Kannan, Nadarajah; Vakeesan, Divagar (1 September 2016). "Solar energy for future world: - A review". Renewable and Sustainable Energy Reviews. 62: 1092–1105. doi:10.1016/j.rser.2016.05.022. ISSN 1364-0321.
  25. ^ Köberle, Alexandre C.; Gernaat, David E. H. J.; van Vuuren, Detlef P. (1 September 2015). "Assessing current and future techno-economic potential of concentrated solar power and photovoltaic electricity generation". Energy. 89: 739–756. doi:10.1016/j.energy.2015.05.145. hdl:1874/319865. ISSN 0360-5442. S2CID 108996432.
  26. ^ a b Billy Roberts (20 October 2008). "Photovoltaic Solar Resource of the United States". National Renewable Energy Laboratory. Retrieved 17 April 2017.
  27. ^ David J. C. MacKay. "Sustainable Energy - without the hot air". inference.org.uk. Retrieved 20 November 2017. Solar photovoltaics: data from a 25-m2 array in Cambridgeshire in 2006
  28. ^ a b Kumar, Ankush (3 January 2017). "Predicting efficiency of solar cells based on transparent conducting electrodes". Journal of Applied Physics. 121 (1): 014502. Bibcode:2017JAP...121a4502K. doi:10.1063/1.4973117. ISSN 0021-8979.
  29. ^ "Photovoltaic Cell Conversion Efficiency Basics". U.S. Department of Energy. Retrieved 6 September 2014.
  30. ^ Geisz, John F.; France, Ryan M.; Schulte, Kevin L.; Steiner, Myles A.; Norman, Andrew G.; Guthrey, Harvey L.; Young, Matthew R.; Song, Tao; Moriarty, Thomas (April 2020). "Six-junction III–V solar cells with 47.1% conversion efficiency under 143 Suns concentration". Nature Energy. 5 (4): 326–335. Bibcode:2020NatEn...5..326G. doi:10.1038/s41560-020-0598-5. ISSN 2058-7546. OSTI 1659948. S2CID 216289881.
  31. ^ Dunlop, James P. (2012). Photovoltaic systems. National Joint Apprenticeship and Training Committee for the Electrical Industry (3rd ed.). Orland Park, IL: American Technical Publishers, Inc. ISBN 978-1-935941-05-7. OCLC 828685287.
  32. ^ Bowden, Stuart; Honsberg, Christiana. "Bypass Diodes". Photovoltaic Education. Retrieved 29 June 2021.
  33. ^ "Open-Circuit Voltage (Battery)". Electrical School. 13 June 2018. Retrieved 30 June 2021.
  34. ^ "REC Alpha Black Series Factsheet" (PDF).
  35. ^ (PDF). Archived from the original (PDF) on 29 October 2013. Retrieved 4 June 2012.
  36. ^ "LBS Poly 260 275 Data sheet" (PDF). Retrieved 9 January 2018.
  37. ^ Piliougine, M.; Oukaja, A.; Sidrach‐de‐Cardona, M.; Spagnuolo, G. (2021). Temperature coefficients of degraded crystalline silicon photovoltaic modules at outdoor conditions. Progress in Photovoltaics. Vol. 29. pp. 558–570. doi:10.1002/pip.3396. S2CID 233976803.
  38. ^ "Are Solar Panels Affected by Weather? - Energy Informative". Energy Informative. Retrieved 14 March 2018.
  39. ^ "Solarplaza Potential Induced Degradation: Combatting a Phantom Menace". www.solarplaza.com. Retrieved 4 September 2017.
  40. ^ (www.inspire.cz), INSPIRE CZ s.r.o. "What is PID? — eicero". eicero.com. Retrieved 4 September 2017.
  41. ^ "How Solar Cells Work". HowStuffWorks. April 2000. Retrieved 9 December 2015.
  42. ^ "Bonding in Metals and Semiconductors". 2012books.lardbucket.org. Retrieved 9 December 2015.
  43. ^ Piliougine, M.; Oukaja, A.; Sánchez-Friera, P.; Petrone, G.; Sánchez-Pacheco, J.F.; Spagnuolo, G.; Sidrach-de-Cardona, M. (2021). Analysis of the degradation of single-crystalline silicon modules after 21 years of operation. Progress in Photovoltaics. Vol. 29. pp. 907–919. doi:10.1002/pip.3409. S2CID 234831264.
  44. ^ Piliougine, M.; Oukaja, A.; Sidrach‐de‐Cardona, M.; Spagnuolo, G. (2022). Analysis of the degradation of amorphous silicon-based modules after 11 years of exposure by means of IEC60891:2021 procedure 3. Progress in Photovoltaics. Vol. 30. pp. 1176–1187. doi:10.1002/pip.3567. hdl:10630/24064. S2CID 248487635.
  45. ^ Piliougine, M.; Sánchez-Friera, P.; Petrone, G.; Sánchez-Pacheco, J.F.; Spagnuolo, G.; Sidrach-de-Cardona, M. (2022). "New model to study the outdoor degradation of thin-film photovoltaic modules". Renewable Energy. 193: 857–869. doi:10.1016/j.renene.2022.05.063. S2CID 248926054.
  46. ^ Platzer, Michael (27 January 2015). "U.S. Solar Photovoltaic Manufacturing: Industry Trends, Global Competition, Federal Support". Congressional Research Service.
  47. ^ "How PV Cells Are Made". www.fsec.ucf.edu. Retrieved 5 November 2015.
  48. ^ "Are we headed for a solar waste crisis?". Environmentalprogress.org. Retrieved 30 December 2017.
  49. ^ a b Fthenakis, V. M., Kim, H. C. & Alsema, E. (2008). "Emissions from photovoltaic life cycles". Environmental Science & Technology. 42 (6): 2168–2174. Bibcode:2008EnST...42.2168F. doi:10.1021/es071763q. hdl:1874/32964. PMID 18409654. S2CID 20850468.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  50. ^ a b c d e f Collier, J., Wu, S. & Apul, D. (2014). "Life cycle environmental impacts from CZTS (copper zinc tin sulfide) and Zn3P2 (zinc phosphide) thin film PV (photovoltaic) cells". Energy. 74: 314–321. doi:10.1016/j.energy.2014.06.076.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  51. ^ a b c d e "An analysis of the energy efficiency of photovoltaic cells in reducing CO2 emissions" (PDF). clca.columbia.edu. 31 May 2009. Archived (PDF) from the original on 25 March 2015.
  52. ^ a b c d "PHOTOVOLTAICS REPORT" (PDF). Fraunhofer Institute for Solar Energy Systems. 16 September 2020. pp. 36, 43, 46.
  53. ^ a b Anctil, A., Babbitt, C. W., Raffaelle, R. P. & Landi, B. J. (2013). "Cumulative energy demand for small molecule and polymer photovoltaics". Progress in Photovoltaics: Research and Applications. 21 (7): 1541–1554. doi:10.1002/pip.2226. S2CID 94279905.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  54. ^ Ibon Galarraga, M. González-Eguino, Anil Markandya (1 January 2011). Handbook of Sustainable Energy. Edward Elgar Publishing. p. 37. ISBN 978-0857936387. Retrieved 9 May 2017 – via Google Books.{{cite book}}: CS1 maint: multiple names: authors list (link)
  55. ^ a b Bhandari, K. P., Collier, J. M., Ellingson, R. J. & Apul, D. S. (2015). "Energy payback time (EPBT) and energy return on energy invested (EROI) of solar photovoltaic systems: A systematic review and meta-analysis". Renewable and Sustainable Energy Reviews. 47: 133–141. doi:10.1016/j.rser.2015.02.057.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  56. ^ "An analysis of the energy efficiency of photovoltaic cells in reducing CO2 emissions". University of Portsmouth. 31 May 2009. Archived from the original on 25 March 2015. Energy Pay Back time comparison for Photovoltaic Cells (Alsema, Frankl, Kato, 1998, p. 5
  57. ^ Marco Raugei, Pere Fullana-i-Palmer and Vasilis Fthenakis (March 2012). "The Energy Return on Energy Investment (EROI) of Photovoltaics: Methodology and Comparisons with Fossil Fuel Life Cycles" (PDF). www.bnl.gov/. (PDF) from the original on 8 March 2016.{{cite web}}: CS1 maint: uses authors parameter (link)
  58. ^ Vasilis Fthenakis, Rolf Frischknecht, Marco Raugei, Hyung Chul Kim, Erik Alsema, Michael Held and Mariska de Wild-Scholten (November 2011). "Methodology Guidelines on Life Cycle Assessment of Photovoltaic Electricity" (PDF). www.iea-pvps.org/. IEA-PVPS. pp. 8–10. (PDF) from the original on 24 September 2015.{{cite web}}: CS1 maint: uses authors parameter (link)
  59. ^ . www.simcoa.com.au. Simcoa Operations. Archived from the original on 19 June 2014. Retrieved 17 September 2014.
  60. ^ "Reaching kerf loss below 100 μm by optimizations" (PDF). Fraunhofer ISE, 24th European PV Solar Energy Conference and Exhibition. September 2009.
  61. ^ "Silicon kerf loss recycling". HZDR - Helmholtz-Zentrum Dresden-Rossendorf. 4 April 2014.
  62. ^ "Life Cycle Assessment of Future Photovoltaic Electricity Production from Residential-scale Systems Operated in Europe". IEA-PVPS. 13 March 2015.
  63. ^ a b Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics, National Renewable Energy Laboratory, U.S. Department of Energy, 2012, 1–2.
  64. ^ a b Krebs, F. C. (2009). "Fabrication and processing of polymer solar cells: a review of printing and coating techniques". Solar Energy Materials and Solar Cells. 93 (4): 394–412. doi:10.1016/j.solmat.2008.10.004.
  65. ^ a b Yue D.; You F.; Darling S. B. (2014). "Domestic and overseas manufacturing scenarios of silicon-based photovoltaics: Life cycle energy and environmental comparative analysis". Solar Energy. 105: 669–678. Bibcode:2014SoEn..105..669Y. doi:10.1016/j.solener.2014.04.008.
  66. ^ Gaidajis, G. & Angelakoglou, K. (2012). "Environmental performance of renewable energy systems with the application of life-cycle assessment: a multi-Si photovoltaic module case study". Civil Engineering and Environmental Systems. 29 (4): 231–238. doi:10.1080/10286608.2012.710608. S2CID 110058349.
  67. ^ Photovoltaics Report. (Fraunhofer Institute for Solar Energy Systems, ISE, 2015).
  68. ^ a b Goe, M. & Gaustad, G. (2014). "Strengthening the case for recycling photovoltaics: An energy payback analysis". Applied Energy. 120: 41–48. doi:10.1016/j.apenergy.2014.01.036.
  69. ^ Brown, G. F. & Wu, J. (2009). "Third generation photovoltaics". Laser & Photonics Reviews. 3 (4): 394–405. Bibcode:2009LPRv....3..394B. doi:10.1002/lpor.200810039. S2CID 13179665.
  70. ^ a b Celik, I., Mason, B. E., Phillips, A. B., Heben, M. J., & Apul, D. S. (2017). Environmental Impacts from Photovoltaic Solar Cells Made with Single Walled Carbon Nanotubes. Environmental Science & Technology.
  71. ^ Agboola, A. E. Development and model formulation of scalable carbon nanotube processes: HiPCO and CoMoCAT process models;Louisiana State University, 2005.
  72. ^ Wadia, C., Alivisatos, A. P. & Kammen, D. M. (2009). "Materials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment". Environmental Science and Technology. 43 (6): 2072–2077. Bibcode:2009EnST...43.2072W. doi:10.1021/es8019534. PMID 19368216.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  73. ^ Alharbi, Fahhad; Bass, John D.; Salhi, Abdelmajid; Alyamani, Ahmed; Kim, Ho-Cheol; Miller, Robert D. (2011). "Abundant non-toxic materials for thin film solar cells: Alternative to conventional materials". Renewable Energy. 36 (10): 2753–2758. doi:10.1016/j.renene.2011.03.010.
  74. ^ . Apricus Solar. Archived from the original on 17 April 2012. Retrieved 14 April 2012.
  75. ^ Renewable energy costs drop in '09 Reuters, 23 November 2009.
  76. ^ Solar Power 50% Cheaper By Year End – Analysis. Reuters, 24 November 2009.
  77. ^ a b Harris, Arno (31 August 2011). "A Silver Lining in Declining Solar Prices". Renewable Energy World.
  78. ^ Renewable Power Generation Costs in 2019. Abu Dhabi: International Renewable Energy Agency. 2020. ISBN 978-92-9260-244-4.
  79. ^ a b c "Sunny Uplands: Alternative energy will no longer be alternative". The Economist. 21 November 2012. Retrieved 28 December 2012.
  80. ^ a b Quiggin, John (3 January 2012). "The End of the Nuclear Renaissance". National Interest.
  81. ^ a b Wells, Ken (25 October 2012). . Bloomberg Businessweek. Archived from the original on 27 October 2012. Retrieved 1 November 2012.
  82. ^ Solar PV Module Costs to Fall to 36 Cents per Watt by 2017. Greentechmedia.com (2013-06-18). Retrieved on 2015-04-15.
  83. ^ a b Alafita, T.; Pearce, J. M. (2014). "Securitization of residential solar photovoltaic assets: Costs, risks and uncertainty". Energy Policy. 67: 488–498. doi:10.1016/j.enpol.2013.12.045. S2CID 11079398.
  84. ^ Liebreich, Michael (29 January 2014). "A YEAR OF CRACKING ICE: 10 PREDICTIONS FOR 2014". Bloomberg New Energy Finance. Retrieved 24 April 2014.
  85. ^ "2014 Outlook: Let the Second Gold Rush Begin" (PDF). Deutsche Bank Markets Research. 6 January 2014. (PDF) from the original on 29 November 2014. Retrieved 22 November 2014.
  86. ^ a b c d Branker, K.; Pathak, M.J.M.; Pearce, J.M. (2011). "A Review of Solar Photovoltaic Levelized Cost of Electricity". Renewable and Sustainable Energy Reviews. 15 (9): 4470–4482. doi:10.1016/j.rser.2011.07.104. hdl:1974/6879. S2CID 73523633.
  87. ^ "Renewables Investment Breaks Records". Renewable Energy World. 29 August 2011.
  88. ^ Hockenos, Paul (10 February 2021). "Is Germany Making Too Much Renewable Energy?". Foreign Policy. Retrieved 7 March 2021.
  89. ^ a b Nancy M. Haegel (2017). "Terawatt-scale photovoltaics: Trajectories and challenges". Science. 356 (6334): 141–143. Bibcode:2017Sci...356..141H. doi:10.1126/science.aal1288. hdl:10945/57762. OSTI 1352502. PMID 28408563. S2CID 206654326.
  90. ^ Adeh, Elnaz H.; Good, Stephen P.; Calaf, M.; Higgins, Chad W. (7 August 2019). "Solar PV Power Potential is Greatest Over Croplands". Scientific Reports. 9 (1): 11442. Bibcode:2019NatSR...911442A. doi:10.1038/s41598-019-47803-3. ISSN 2045-2322. PMC 6685942. PMID 31391497.
  91. ^ TROMMSDORFF, Maximillian (2016). "An economic analysis of agrophotovoltaics: Opportunities, risks and strategies towards a more efficient land use" (PDF). The Constitutional Economics Network Working Papers.
  92. ^ Lowder, T., & Mendelsohn, M. (2013). The Potential of Securitization in Solar PV Finance.[page needed]
  93. ^ "Done Deal: The First Securitization Of Rooftop Solar Assets". Forbes. 21 November 2013
  94. ^ Matar, Walid; Anwer, Murad (2017). "Jointly reforming the prices of industrial fuels and residential electricity in Saudi Arabia". Energy Policy. 109: 747–756. doi:10.1016/j.enpol.2017.07.060.
  95. ^ Utilities' Honest Assessment of Solar in the Electricity Supply. Greentechmedia.com (7 May 2012). Retrieved on 31 May 2013.
  96. ^ Straza; Schneegans (11 June 2021). Are we using science for smarter development?. Paris: UNESCO. ISBN 978-92-3-100450-6.
  97. ^ "Snapshot of Global Photovoltaic Markets 2017" (PDF). report. International Energy Agency. 19 April 2017. Retrieved 11 July 2017.
  98. ^ "Snapshot of Global PV 1992–2014" (PDF). International Energy Agency — Photovoltaic Power Systems Programme. 30 March 2015. from the original on 7 April 2015.
  99. ^ "Renewables 2011: Global Status Report". REN21. 2011. p. 22.
  100. ^ "Snapshot 2020". IEA-PVPS.
  101. ^ a b c d Do, Thang Nam; Burke, Paul J.; Baldwin, Kenneth G. H.; Nguyen, Chinh The (1 September 2020). "Underlying drivers and barriers for solar photovoltaics diffusion: The case of Vietnam". Energy Policy. 144: 111561. doi:10.1016/j.enpol.2020.111561. hdl:1885/206307. ISSN 0301-4215. S2CID 225245522.
  102. ^ "China to add 55-65 GW of solar power capacity in 2021 -industry body". Reuters. 23 July 2021. Retrieved 15 October 2022.
  103. ^ a b "Snapshot 2020 – IEA-PVPS". iea-pvps.org. Retrieved 10 May 2020.
  104. ^ Solar Photovoltaic Electricity Empowering the World 22 August 2012 at the Wayback Machine. Epia.org (22 September 2012). Retrieved on 31 May 2013.
  105. ^ Haugan, H. J.; Elhamri, S.; Szmulowicz, F.; Ullrich, B.; Brown, G. J.; Mitchel, W. C. (2008). "Study of residual background carriers in midinfrared InAs/GaSb superlattices for uncooled detector operation". Applied Physics Letters. 92 (7): 071102. Bibcode:2008ApPhL..92g1102H. doi:10.1063/1.2884264. S2CID 39187771.
  106. ^ "Solar PV Modules". www.targray.com. Retrieved 3 October 2018.
  107. ^ Kosasih, Felix Utama; Rakocevic, Lucija; Aernouts, Tom; Poortmans, Jef; Ducati, Caterina (11 December 2019). "Electron Microscopy Characterization of P3 Lines and Laser Scribing-Induced Perovskite Decomposition in Perovskite Solar Modules". ACS Applied Materials & Interfaces. 11 (49): 45646–45655. doi:10.1021/acsami.9b15520. PMID 31663326. S2CID 204967452.
  108. ^ Di Giacomo, Francesco; Castriotta, Luigi A.; Kosasih, Felix U.; Di Girolamo, Diego; Ducati, Caterina; Di Carlo, Aldo (20 December 2020). "Upscaling Inverted Perovskite Solar Cells: Optimization of Laser Scribing for Highly Efficient Mini-Modules". Micromachines. 11 (12): 1127. doi:10.3390/mi11121127. PMC 7767295. PMID 33419276.
  109. ^ a b Matteocci, Fabio; Vesce, Luigi; Kosasih, Felix Utama; Castriotta, Luigi Angelo; Cacovich, Stefania; Palma, Alessandro Lorenzo; Divitini, Giorgio; Ducati, Caterina; Di Carlo, Aldo (17 July 2019). "Fabrication and Morphological Characterization of High-Efficiency Blade-Coated Perovskite Solar Modules". ACS Applied Materials & Interfaces. 11 (28): 25195–25204. doi:10.1021/acsami.9b05730. PMID 31268662. S2CID 206497286.
  110. ^ "Thin Film Photovoltaics". www.fsec.ucf.edu. Retrieved 5 November 2015.
  111. ^ Best Research Cell Efficiences. nrel.gov (16 September 2019). Retrieved on 31 October 2019.
  112. ^ Eisenberg, D. A., Yu, M., Lam, C. W., Ogunseitan, O. A. & Schoenung, J. M. (2013). "Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics". Journal of Hazardous Materials. 260: 534–542. doi:10.1016/j.jhazmat.2013.06.007. PMID 23811631. S2CID 26540719.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  113. ^ Kim, H. C., Fthenakis, V., Choi, J. K. & Turney, D. E. (2012). "Life cycle greenhouse gas emissions of thin-film photovoltaic electricity generation". Journal of Industrial Ecology. 16: S110–S121. doi:10.1111/j.1530-9290.2011.00423.x. S2CID 153386434.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  114. ^ Werner, Jürgen H.; Zapf-Gottwick, R.; Koch, M.; Fischer, K. (2011). Toxic substances in photovoltaic modules. Proceedings of the 21st International Photovoltaic Science and Engineering Conference. Vol. 28. Fukuoka, Japan.
  115. ^ a b Manser, Joseph S.; Christians, Jeffrey A.; Kamat, Prashant V. (2016). "Intriguing Optoelectronic Properties of Metal Halide Perovskites". Chemical Reviews. 116 (21): 12956–13008. doi:10.1021/acs.chemrev.6b00136. PMID 27327168.
  116. ^ Hamers, Laurel (26 July 2017). "Perovskites power up the solar industry". Science News.
  117. ^ Kojima, Akihiro; Teshima, Kenjiro; Shirai, Yasuo; Miyasaka, Tsutomu (6 May 2009). "Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells". Journal of the American Chemical Society. 131 (17): 6050–6051. doi:10.1021/ja809598r. PMID 19366264.
  118. ^ a b "Best Research-Cell Efficiencies" (PDF). National Renewable Energy Laboratory. 5 April 2023. Retrieved 14 April 2023.
  119. ^ Min, Hanul; Lee, Do Yoon; Kim, Junu; Kim, Gwisu; Lee, Kyoung Su; Kim, Jongbeom; Paik, Min Jae; Kim, Young Ki; Kim, Kwang S.; Kim, Min Gyu; Shin, Tae Joo; Il Seok, Sang (21 October 2021). "Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes". Nature. 598 (7881): 444–450. Bibcode:2021Natur.598..444M. doi:10.1038/s41586-021-03964-8. PMID 34671136. S2CID 239052065.
  120. ^ Helmholtz-Zentrum Berlin für Materialien und Energie. "World record again at HZB: Almost 30 % efficiency for next-generation tandem solar cells". HZB Website.
  121. ^ Sun, Kai; Wang, Yanyan; Xu, Haoyuan; Zhang, Jing; Zhu, Yuejin; Hu, Ziyang (2019). "Short-Term Stability of Perovskite Solar Cells Affected by In Situ Interface Modification". Solar RRL. 3 (9): 1900089. doi:10.1002/solr.201900089. S2CID 202229877.
  122. ^ Goodson, Flynt (2014). "Supramolecular Multichromophoric Dye Sensitized Solar Cells". from the original on 9 December 2022. {{cite journal}}: Cite journal requires |journal= (help)
  123. ^ Freitag, Marina; Teuscher, Joël; Saygili, Yasemin; Zhang, Xiaoyu; Giordano, Fabrizio; Liska, Paul; Hua, Jianli; Zakeeruddin, Shaik M.; Moser, Jacques-E.; Grätzel, Michael; Hagfeldt, Anders (17 June 2017). "Dye-sensitized solar cells for efficient power generation under ambient lighting". Nature Photonics. 11 (6): 372–378. Bibcode:2017NaPho..11..372F. doi:10.1038/nphoton.2017.60. S2CID 10780585 – via www.nature.com.
  124. ^ Raga, Sonia R.; Fabregat-Santiago, Francisco (23 January 2013). "Temperature effects in dye-sensitized solar cells". Physical Chemistry Chemical Physics. 15 (7): 2328–2336. Bibcode:2013PCCP...15.2328R. doi:10.1039/C2CP43220J. PMID 23295858 – via pubs.rsc.org.
  125. ^ Nikolaidou, Katerina; Sarang, Som; Ghosh, Sayantani (2019). "Nanostructured photovoltaics". Nano Futures. 3 (1): 012002. Bibcode:2019NanoF...3a2002N. doi:10.1088/2399-1984/ab02b5. S2CID 162176556.
  126. ^ Dos Reis Benatto, Gisele A.; Roth, Bérenger; Madsen, Morten V.; Hösel, Markus; Søndergaard, Roar R.; Jørgensen, Mikkel; Krebs, Frederik C. (2014). "Carbon: The Ultimate Electrode Choice for Widely Distributed Polymer Solar Cells". Advanced Energy Materials. 4 (15): n/a. doi:10.1002/aenm.201400732. S2CID 96990654.
  127. ^ Lattante, Sandro (2014). "Electron and Hole Transport Layers: Their Use in Inverted Bulk Heterojunction Polymer Solar Cells". Electronics. 3: 132–164. doi:10.3390/electronics3010132.
  128. ^ a b Krebs, Frederik C.; Jørgensen, Mikkel (2013). "Polymer and organic solar cells viewed as thin film technologies: What it will take for them to become a success outside academia". Solar Energy Materials and Solar Cells. 119: 73–76. doi:10.1016/j.solmat.2013.05.032.
  129. ^ Espinosa, Nieves; García-Valverde, Rafael; Urbina, Antonio; Krebs, Frederik C. (2011). "A life cycle analysis of polymer solar cell modules prepared using roll-to-roll methods under ambient conditions". Solar Energy Materials and Solar Cells. 95 (5): 1293–1302. doi:10.1016/j.solmat.2010.08.020.
  130. ^ Espinosa, Nieves; Lenzmann, Frank O.; Ryley, Stephen; Angmo, Dechan; Hösel, Markus; Søndergaard, Roar R.; Huss, Dennis; Dafinger, Simone; Gritsch, Stefan; Kroon, Jan M.; Jørgensen, Mikkel; Krebs, Frederik C. (2013). "OPV for mobile applications: An evaluation of roll-to-roll processed indium and silver free polymer solar cells through analysis of life cycle, cost and layer quality using inline optical and functional inspection tools". Journal of Materials Chemistry A. 1 (24): 7037. doi:10.1039/C3TA01611K.
  131. ^ García-Valverde, R.; Miguel, C.; Martínez-Béjar, R.; Urbina, A. (2009). "Life cycle assessment study of a 4.2k Wp stand-alone photovoltaic system". Solar Energy. 83 (9): 1434–1445. Bibcode:2009SoEn...83.1434G. doi:10.1016/j.solener.2009.03.012.
  132. ^ Thermophotovoltaics. Green Energy and Technology. 2011. doi:10.1007/978-3-642-19965-3. ISBN 978-3-642-19964-6.
  133. ^ GE Invests, Delivers One of World's Largest Solar Power Plants. Huliq.com (12 April 2007). Retrieved on 3 June 2012.
  134. ^ Winery goes solar with 'Floatovoltaics'. SFGate (29 May 2008). Retrieved on 31 May 2013.
  135. ^ NAPA VALLEY'S FAR NIENTE WINERY INTRODUCES FIRST-EVER "FLOATOVOLTAIC" SOLAR ARRAY 16 March 2015 at the Wayback Machine. farniente.com
  136. ^ Napa Winery Pioneers Solar Floatovoltaics. Forbes (18 April 2012). Retrieved on 31 May 2013.
  137. ^ Geisz, John F.; France, Ryan M.; Schulte, Kevin L.; Steiner, Myles A.; Norman, Andrew G.; Guthrey, Harvey L.; Young, Matthew R.; Song, Tao; Moriarty, Thomas (April 2020). "Six-junction III–V solar cells with 47.1% conversion efficiency under 143 Suns concentration". Nature Energy. 5 (4): 326–335. Bibcode:2020NatEn...5..326G. doi:10.1038/s41560-020-0598-5. ISSN 2058-7546. OSTI 1659948. S2CID 216289881.
  138. ^ Sharp Develops Solar Cell with World's Highest Conversion Efficiency of 35.8%. Physorg.com. 22 October 2009. Retrieved on 3 June 2012.
  139. ^ Deb, Satyen K. (May 2000) Recent Developments in High Efficiency PV cells. nrel.gov
  140. ^ Yu, J.; Zheng, Y.; Huang, J. (2014). "Towards High Performance Organic Photovoltaic Cells: A Review of Recent Development in Organic Photovoltaics". Polymers. 6 (9): 2473–2509. doi:10.3390/polym6092473.
  141. ^ Sun, Y.; Welch, G. C.; Leong, W. L.; Takacs, C. J.; Bazan, G. C.; Heeger, A. J. (2011). "Solution-processed small-molecule solar cells with 6.7% efficiency". Nature Materials. 11 (1): 44–8. Bibcode:2012NatMa..11...44S. doi:10.1038/nmat3160. PMID 22057387.
  142. ^ EPFL Achieves 21% Efficiency for Perovskites. dyesol.com (8 December 2015)
  143. ^ St. John, Jeff (23 August 2012) Solar Electronics, Panel Integration and the Bankability Challenge. greentechmedia.com
  144. ^ Self-cooling Solar Cells. CNN. 2014-09-18
  145. ^ a b Smil, Vaclav (2006) Energy at the Crossroads. oecd.org. Retrieved on 3 June 2012.
  146. ^ Renewable Energy: Is the Future in Nuclear? 16 January 2014 at the Wayback Machine Prof. Gordon Aubrecht (Ohio State at Marion) TEDxColumbus, The Innovators – 18 October 2012
  147. ^ "Study: Air pollution causes 200,000 early deaths each year in the U.S". News.mit.edu. Retrieved 30 December 2017.
  148. ^ "The US could prevent a lot of deaths by switching from coal to solar". USA TODAY. Retrieved 30 December 2017.
  149. ^ Potential lives saved by replacing coal with solar photovoltaic electricity production in the U.S. Renewable and Sustainable Energy Reviews 80 (2017), pp. 710–715. open access
  150. ^ Nieuwlaar, Evert and Alsema, Erik. Environmental Aspects of PV Power Systems. IEA PVPS Task 1 Workshop, 25–27 June 1997, Utrecht, The Netherlands
  151. ^ McDonald, N.C.; Pearce, J.M. (2010). "Producer Responsibility and Recycling Solar Photovoltaic Modules" (PDF). Energy Policy. 38 (11): 7041–7047. doi:10.1016/j.enpol.2010.07.023.
  152. ^ Advantages and disadvantages of solar energy 26 December 2013 at the Wayback Machine. Retrieved on 25 December 2013.
  153. ^ U.S. Climate Change Technology Program – Transmission and Distribution Technologies 27 September 2007 at the Wayback Machine. (PDF) . Retrieved on 3 June 2012.
  154. ^ Fraunhofer: 41.1% efficiency multi-junction solar cells. renewableenergyfocus.com (28 January 2009).
  155. ^ Study Sees Solar Cost-Competitive In Europe By 2015. Solar Cells Info (16 October 2007). Retrieved on 3 June 2012.
  156. ^ . cityofberkeley.info. Archived from the original on 2 June 2013. Retrieved 9 February 2009.
  157. ^ DSIRE Solar Portal 9 March 2012 at the Wayback Machine. Dsireusa.org (4 April 2011). Retrieved on 3 June 2012.
  158. ^ Miller, Wendy; Liu, Aaron; Amin, Zakaria; Wagner, Andreas (2018). "Power Quality and Rooftop-Photovoltaic Households: An Examination of Measured Data at Point of Customer Connection". Sustainability. 10 (4): 1224. doi:10.3390/su10041224.
  159. ^ L. Liu, W. Miller, and G. Ledwich. (2017) Solutions for reducing facilities electricity costs. Australian Ageing Agenda. 39-40. Available: https://www.australianageingagenda.com.au/2017/10/27/solutions-reducing-facility-electricity-costs/ 20 May 2019 at the Wayback Machine
  160. ^ Miller, Wendy; Liu, Lei Aaron; Amin, Zakaria; Gray, Matthew (2018). "Involving occupants in net-zero-energy solar housing retrofits: An Australian sub-tropical case study". Solar Energy. 159: 390–404. Bibcode:2018SoEn..159..390M. doi:10.1016/j.solener.2017.10.008.

Further reading

April 20, 2023
photovoltaics, conversion, light, into, electricity, using, semiconducting, materials, that, exhibit, photovoltaic, effect, phenomenon, studied, physics, photochemistry, electrochemistry, photovoltaic, effect, commercially, used, electricity, generation, photo. Photovoltaics PV is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect a phenomenon studied in physics photochemistry and electrochemistry The photovoltaic effect is commercially used for electricity generation and as photosensors The Solar Settlement a sustainable housing community project in Freiburg Germany Charging station in France that provides energy for electric cars using solar energy Solar panels on the International Space StationA photovoltaic system employs solar modules each comprising a number of solar cells which generate electrical power PV installations may be ground mounted rooftop mounted wall mounted or floating The mount may be fixed or use a solar tracker to follow the sun across the sky Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels Solar PV has specific advantages as an energy source once installed its operation generates no pollution and no greenhouse gas emissions it shows scalability in respect of power needs and silicon has large availability in the Earth s crust although other materials required in PV system manufacture such as silver may constrain further growth in the technology Other major constraints identified are competition for land use 1 The use of PV as a main source requires energy storage systems or global distribution by high voltage direct current power lines causing additional costs and also has a number of other specific disadvantages such as variable power generation which have to be balanced Production and installation does cause some pollution and greenhouse gas emissions though only a fraction of the emissions caused by fossil fuels Photovoltaic systems have long been used in specialized applications as stand alone installations and grid connected PV systems have been in use since the 1990s 2 Photovoltaic modules were first mass produced in 2000 when the German government funded a one hundred thousand roof program 3 Decreasing costs has allowed PV to grow as an energy source This has been partially driven by massive Chinese government investment in developing solar production capacity since 2000 and achieving economies of scale Improvements in manufacturing technology and efficiency have also led to decreasing costs 4 5 Net metering and financial incentives such as preferential feed in tariffs for solar generated electricity have supported solar PV installations in many countries 6 Panel prices dropped by a factor of 4 between 2004 and 2011 Module prices dropped by about 90 over the 2010s In 2019 worldwide installed PV capacity increased to more than 635 gigawatts GW covering approximately two percent of global electricity demand 7 After hydro and wind powers PV is the third renewable energy source in terms of global capacity In 2019 the International Energy Agency expected a growth by 700 880 GW from 2019 to 2024 8 In some instances PV has offered the cheapest source of electrical power in regions with a high solar potential with a bid for pricing as low as 0 01567 US kWh in Qatar in 2020 9 In 2020 the International Energy Agency stated in its World Energy Outlook that f or projects with low cost financing that tap high quality resources solar PV is now the cheapest source of electricity in history 10 Contents 1 Etymology 2 History 3 Solar cells 3 1 Solar cell efficiencies 4 Performance and degradation 4 1 Influence of temperature 4 2 Degradation 5 Manufacturing of PV systems 5 1 Environmental costs of manufacture 5 1 1 EPBT improvements 5 1 2 Impacts from first generation PV 5 1 3 Impacts from second generation PV 5 1 4 Impacts from third generation PV 6 Economics 6 1 Hardware costs 6 2 Levelised cost of electricity 6 3 Subsidies and financing 6 4 Other 7 Growth 8 Applications 8 1 Photovoltaic systems 8 2 Photo sensors 9 Experimental technology 9 1 CIGS 9 2 Perovskite solar cells 9 3 Dye Sensitized Solar Cells 9 4 OPV 9 5 Thermophotovoltaics 9 6 Solar module alignment 9 7 Efficiency 10 Advantages 11 Disadvantages 12 See also 13 References 14 Further readingEtymology EditThe term photovoltaic comes from the Greek fῶs phōs meaning light and from volt the unit of electromotive force the volt which in turn comes from the last name of the Italian physicist Alessandro Volta inventor of the battery electrochemical cell The term photovoltaic has been in use in English since 1849 11 History EditGeorge Cove may have invented a photovoltaic panel in 1909 roughly 40 years before Bell Labs did in 1950 12 In 1989 the German Research Ministry initiated the first ever program to finance PV roofs 2200 roofs A program led by Walter Sandtner in Bonn Germany 13 In 1994 Japan followed in their footsteps and conducted a similar program with 539 residential PV systems installed 14 Since many countries have continued to produce and finance PV systems in an exponential speed Solar cells EditMain article Solar cell Solar cells generate electricity directly from sunlight Photovoltaic power potential map estimates how many kWh of electricity can be produced from a 1 kWp free standing c Si modules optimally inclined towards the Equator The resulting long term average is calculated based on weather data of at least 10 recent years Photovoltaics are best known as a method for generating electric power by using solar cells to convert energy from the sun into a flow of electrons by the photovoltaic effect 15 16 Solar cells produce direct current electricity from sunlight which can be used to power equipment or to recharge batteries The first practical application of photovoltaics was to power orbiting satellites and other spacecraft but today the majority of photovoltaic modules are used for grid connected systems for power generation In this case an inverter is required to convert the DC to AC There is still a smaller market for stand alone systems for remote dwellings boats recreational vehicles electric cars roadside emergency telephones remote sensing and cathodic protection of pipelines Photovoltaic power generation employs solar modules composed of a number of solar cells containing a semiconductor material 17 Copper solar cables connect modules module cable arrays array cable and sub fields Because of the growing demand for renewable energy sources the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years 18 19 20 Cells require protection from the environment and are usually packaged tightly in solar modules Photovoltaic module power is measured under standard test conditions STC in Wp watts peak 21 The actual power output at a particular place may be less than or greater than this rated value depending on geographical location time of day weather conditions and other factors 22 Solar photovoltaic array capacity factors are typically under 25 when not coupled with storage which is lower than many other industrial sources of electricity 23 Solar cell efficiencies Edit This section is an excerpt from Solar cell efficiency edit Reported timeline of research solar cell energy conversion efficiencies since 1976 National Renewable Energy Laboratory Solar cell efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell The efficiency of the solar cells used in a photovoltaic system in combination with latitude and climate determines the annual energy output of the system For example a solar panel with 20 efficiency and an area of 1 m2 will produce 200 kWh yr at Standard Test Conditions if exposed to the Standard Test Condition solar irradiance value of 1000 W m2 for 2 74 hours a day Usually solar panels are exposed to sunlight for longer than this in a given day but the solar irradiance is less than 1000 W m2 for most of the day A solar panel can produce more when the sun is high in the sky and will produce less in cloudy conditions or when the sun is low in the sky usually the sun is lower in the sky in the winter Two location dependant factors that affect solar PV efficiency are the dispersion and intensity of solar radiation These two variables can vary greatly between each country 24 The global regions that have high radiation levels throughout the year are the middle east Northern Chile Australia China and Southwestern USA 24 25 In a high yield solar area like central Colorado which receives annual insolation of 2000 kWh m2 year 26 a panel can be expected to produce 400 kWh of energy per year However in Michigan which receives only 1400 kWh m2 year 26 annual energy yield will drop to 280 kWh for the same panel At more northerly European latitudes yields are significantly lower 175 kWh annual energy yield in southern England under the same conditions 27 Schematic of charge collection by solar cells Light transmits through transparent conducting electrode creating electron hole pairs which are collected by both the electrodes The absorption and collection efficiencies of a solar cell depend on the design of transparent conductors and active layer thickness 28 Several factors affect a cell s conversion efficiency including its reflectance thermodynamic efficiency charge carrier separation efficiency charge carrier collection efficiency and conduction efficiency values 29 28 Because these parameters can be difficult to measure directly other parameters are measured instead including quantum efficiency open circuit voltage VOC ratio and Fill factor Reflectance losses are accounted for by the quantum efficiency value as they affect external quantum efficiency Recombination losses are accounted for by the quantum efficiency VOC ratio and fill factor values Resistive losses are predominantly accounted for by the fill factor value but also contribute to the quantum efficiency and VOC ratio values In 2019 the world record for solar cell efficiency at 47 1 was achieved by using multi junction concentrator solar cells developed at National Renewable Energy Laboratory Golden Colorado USA 30 Performance and degradation Edit This chart illustrates the effect of clouds on solar energy production Module performance is generally rated under standard test conditions STC irradiance of 1 000 W m2 solar spectrum of AM 1 5 and module temperature at 25 C 31 The actual voltage and current output of the module changes as lighting temperature and load conditions change so there is never one specific voltage at which the module operates Performance varies depending on geographic location time of day the day of the year amount of solar irradiance direction and tilt of modules cloud cover shading soiling state of charge and temperature Performance of a module or panel can be measured at different time intervals with a DC clamp meter or shunt and logged graphed or charted with a chart recorder or data logger For optimum performance a solar panel needs to be made of similar modules oriented in the same direction perpendicular to direct sunlight Bypass diodes are used to circumvent broken or shaded panels and optimize output These bypass diodes are usually placed along groups of solar cells to create a continuous flow 32 Electrical characteristics include nominal power PMAX measured in W open circuit voltage VOC short circuit current ISC measured in amperes maximum power voltage VMPP maximum power current IMPP peak power watt peak Wp and module efficiency Open circuit voltage or VOC is the maximum voltage the module can produce when not connected to an electrical circuit or system 33 VOC can be measured with a voltmeter directly on an illuminated module s terminals or on its disconnected cable The peak power rating Wp is the maximum output under standard test conditions not the maximum possible output Typical modules which could measure approximately 1 by 2 metres 3 ft 7 ft will be rated from as low as 75 W to as high as 600 W depending on their efficiency At the time of testing the test modules are binned according to their test results and a typical manufacturer might rate their modules in 5 W increments and either rate them at 3 5 3 0 or 5 0 34 35 36 Influence of temperature Edit The performance of a photovoltaic PV module depends on the environmental conditions mainly on the global incident irradiance G in the plane of the module However the temperature T of the p n junction also influences the main electrical parameters the short circuit current ISC the open circuit voltage VOC and the maximum power Pmax In general it is known that VOC shows a significant inverse correlation with T while for ISC this correlation is direct but weaker so that this increase does not compensate for the decrease in VOC As a consequence Pmax decreases when T increases This correlation between the power output of a solar cell and the working temperature of its junction depends on the semiconductor material and is due to the influence of T on the concentration lifetime and mobility of the intrinsic carriers i e electrons and gaps inside the photovoltaic cell Temperature sensitivity is usually described by temperature coefficients each of which expresses the derivative of the parameter to which it refers with respect to the junction temperature The values of these parameters which can be found in any data sheet of the photovoltaic module are the following b VOC variation coefficient with respect to T given by VOC T a Coefficient of variation of ISC with respect to T given by ISC T d Coefficient of variation of Pmax with respect to T given by Pmax T Techniques for estimating these coefficients from experimental data can be found in the literature 37 Degradation Edit The ability of solar modules to withstand damage by rain hail heavy snow load and cycles of heat and cold varies by manufacturer although most solar panels on the U S market are UL listed meaning they have gone through testing to withstand hail 38 Potential induced degradation also called PID is a potential induced performance degradation in crystalline photovoltaic modules caused by so called stray currents 39 This effect may cause power loss of up to 30 40 The largest challenge for photovoltaic technology is the purchase price per watt of electricity produced Advancements in photovoltaic technologies have brought about the process of doping the silicon substrate to lower the activation energy thereby making the panel more efficient in converting photons to retrievable electrons 41 Chemicals such as boron p type are applied into the semiconductor crystal in order to create donor and acceptor energy levels substantially closer to the valence and conductor bands 42 In doing so the addition of boron impurity allows the activation energy to decrease twenty fold from 1 12 eV to 0 05 eV Since the potential difference EB is so low the boron is able to thermally ionize at room temperatures This allows for free energy carriers in the conduction and valence bands thereby allowing greater conversion of photons to electrons The power output of a photovoltaic PV device decreases over time This decrease is due to its exposure to solar radiation as well as other external conditions The degradation index which is defined as the annual percentage of output power loss is a key factor in determining the long term production of a photovoltaic plant To estimate this degradation the percentage of decrease associated with each of the electrical parameters The individual degradation of a photovoltaic module can significantly influence the performance of a complete string Furthermore not all modules in the same installation decrease their performance at exactly the same rate Given a set of modules exposed to long term outdoor conditions the individual degradation of the main electrical parameters and the increase in their dispersion must be considered As each module tends to degrade differently the behavior of the modules will be increasingly different over time negatively affecting the overall performance of the plant There are several studies dealing with the power degradation analysis of modules based on different photovoltaic technologies available in the literature According to a recent study 43 the degradation of crystalline silicon modules is very regular oscillating between 0 8 and 1 0 per year On the other hand if we analyze the performance of thin film photovoltaic modules an initial period of strong degradation is observed which can last several months and up to two years followed by a later stage in which the degradation stabilizes being then comparable to that of crystalline silicon 44 Strong seasonal variations are also observed in such thin film technologies because the influence of the solar spectrum is much greater For example for modules of amorphous silicon micromorphic silicon or cadmium telluride we are talking about annual degradation rates for the first years of between 3 and 4 45 However other technologies such as CIGS show much lower degradation rates even in those early years Manufacturing of PV systems EditSee also List of photovoltaics companies Overall the manufacturing process of creating solar photovoltaics is simple in that it does not require the culmination of many complex or moving parts Because of the solid state nature of PV systems they often have relatively long lifetimes anywhere from 10 to 30 years To increase the electrical output of a PV system the manufacturer must simply add more photovoltaic components Because of this economies of scale are important for manufacturers as costs decrease with increasing output 46 While there are many types of PV systems known to be effective crystalline silicon PV accounted for around 90 of the worldwide production of PV in 2013 Manufacturing silicon PV systems has several steps First polysilicon is processed from mined quartz until it is very pure semi conductor grade This is melted down when small amounts of boron a group III element are added to make a p type semiconductor rich in electron holes Typically using a seed crystal an ingot of this solution is grown from the liquid polycrystalline The ingot may also be cast in a mold Wafers of this semiconductor material are cut from the bulk material with wire saws and then go through surface etching before being cleaned Next the wafers are placed into a phosphorus vapor deposition furnace which lays a very thin layer of phosphorus a group V element which creates an n type semiconducting surface To reduce energy losses an anti reflective coating is added to the surface along with electrical contacts After finishing the cell cells are connected via electrical circuit according to the specific application and prepared for shipping and installation 47 Environmental costs of manufacture Edit Solar photovoltaic power is not entirely clean energy production produces greenhouse gas emissions materials used to build the cells are potentially unsustainable and will run out eventually the technology uses toxic substances which cause pollution and there are no viable technologies for recycling solar waste 48 Data required to investigate their impact are sometimes affected by a rather large amount of uncertainty The values of human labor and water consumption for example are not precisely assessed due to the lack of systematic and accurate analyses in the scientific literature 1 One difficulty in determining impacts due to PV is to determine if the wastes are released to the air water or soil during the manufacturing phase 49 Life cycle assessments which look at all different environment impacts ranging from global warming potential pollution water depletion and others are unavailable for PV Instead studies have tried to estimate the impact and potential impacts of various types of PV but these estimates are usually restricted to simply assessing energy costs of the manufacture and or transport because these are new technologies and the total environmental impacts of their components and disposal methods are unknown even for commercially available first generation solar cells let alone experimental prototypes with no commercial viability 50 Thus estimates of the environmental impacts of PV have focused on carbon dioxide equivalents per kWh or energy pay back time EPBT The EPBT describes the timespan a PV system needs to operate in order to generate the same amount of energy that was used for its manufacture 51 Another study includes transport energy costs in the EPBT 52 The EPBT has also been defined completely differently as the time needed to compensate for the total renewable and non renewable primary energy required during the life cycle of a PV system in another study which also included installation costs 53 This energy amortization given in years is also referred to as break even energy payback time 54 The lower the EPBT the lower the environmental cost of solar power The EPBT depends vastly on the location where the PV system is installed e g the amount of sunlight available and the efficiency of the electrical grid 52 and on the type of system namely the system s components 51 A 2015 review of EPBT estimates of first and second generation PV suggested that there was greater variation in embedded energy than in efficiency of the cells implying that it was mainly the embedded energy that needs to reduce to have a greater reduction in EPBT 55 In general the most important component of solar panels which accounts for much of the energy use and greenhouse gas emissions is the refining of the polysilicon 51 As to how much percentage of the EPBT this silicon depends on the type of system A fully autarkic system requires additional components Balance of System the power inverters storage etc which significantly increase the energy cost of manufacture but in a simple rooftop system some 90 of the energy cost is from silicon with the remainder coming from the inverters and module frame 51 In an analysis by Alsema et al from 1998 the energy payback time was higher than 10 years for the former system in 1997 while for a standard rooftop system the EPBT was calculated as between 3 5 and 8 years 51 56 The EPBT relates closely to the concepts of net energy gain NEG and energy returned on energy invested EROI They are both used in energy economics and refer to the difference between the energy expended to harvest an energy source and the amount of energy gained from that harvest The NEG and EROI also take the operating lifetime of a PV system into account and a working life of 25 to 30 years is typically assumed From these metrics the Energy payback Time can be derived by calculation 57 58 EPBT improvements Edit PV systems using crystalline silicon by far the majority of the systems in practical use have such a high EPBT because silicon is produced by the reduction of high grade quartz sand in electric furnaces This coke fired smelting process occurs at high temperatures of more than 1000 C and is very energy intensive using about 11 kilowatt hours kWh per produced kilogram of silicon 59 The energy requirements of this process makes the energy cost per unit of silicon produced relatively inelastic which means that the production process itself will not become more efficient in the future Nonetheless the energy payback time has shortened significantly over the last years as crystalline silicon cells became ever more efficient in converting sunlight while the thickness of the wafer material was constantly reduced and therefore required less silicon for its manufacture Within the last ten years the amount of silicon used for solar cells declined from 16 to 6 grams per watt peak In the same period the thickness of a c Si wafer was reduced from 300 mm or microns to about 160 190 mm The sawing techniques that slice crystalline silicon ingots into wafers have also improved by reducing the kerf loss and making it easier to recycle the silicon sawdust 60 61 Key parameters for material and energy efficiency Parameter Mono Si CdTeCell efficiency 16 5 15 6 Derate cell to module efficiency 8 5 13 9 Module efficiency 15 1 13 4 Wafer thickness layer thickness 190 mm 4 0 mmKerf loss 190 mm Silver per cell 9 6 g m2 Glass thickness 4 0 mm 3 5 mmOperational lifetime 30 years 30 yearsSource IEA PVPS Life Cycle Assessment March 2015 62 Impacts from first generation PV Edit Crystalline silicon modules are the most extensively studied PV type in terms of LCA since they are the most commonly used Mono crystalline silicon photovoltaic systems mono si have an average efficiency of 14 0 63 The cells tend to follow a structure of front electrode anti reflection film n layer p layer and back electrode with the sun hitting the front electrode EPBT ranges from 1 7 to 2 7 years 64 The cradle to gate of CO2 eq kWh ranges from 37 3 to 72 2 grams when installed in Southern Europe 65 Techniques to produce multi crystalline silicon multi si photovoltaic cells are simpler and cheaper than mono si however tend to make less efficient cells an average of 13 2 63 EPBT ranges from 1 5 to 2 6 years 64 The cradle to gate of CO2 eq kWh ranges from 28 5 to 69 grams when installed in Southern Europe 65 Assuming that the following countries had a high quality grid infrastructure as in Europe in 2020 it was calculated it would take 1 28 years in Ottawa Canada for a rooftop photovoltaic system to produce the same amount of energy as required to manufacture the silicon in the modules in it excluding the silver glass mounts and other components 0 97 years in Catania Italy and 0 4 years in Jaipur India Outside of Europe where net grid efficiencies are lower it would take longer This energy payback time can be seen as the portion of time during the useful lifetime of the module in which the energy production is polluting At best this means that a 30 year old panel has produced clean energy for 97 of its lifetime or that the silicon in the modules in a solar panel produce 97 less greenhouse gas emissions than a coal fired plant for the same amount of energy assuming and ignoring many things 52 Some studies have looked beyond EPBT and GWP to other environmental impacts In one such study conventional energy mix in Greece was compared to multi si PV and found a 95 overall reduction in impacts including carcinogens eco toxicity acidification eutrophication and eleven others 66 Impacts from second generation PV Edit Cadmium telluride CdTe is one of the fastest growing thin film based solar cells which are collectively known as second generation devices This new thin film device also shares similar performance restrictions Shockley Queisser efficiency limit as conventional Si devices but promises to lower the cost of each device by both reducing material and energy consumption during manufacturing The global market share of CdTe was 4 7 in 2008 49 This technology s highest power conversion efficiency is 21 67 The cell structure includes glass substrate around 2 mm transparent conductor layer CdS buffer layer 50 150 nm CdTe absorber and a metal contact layer CdTe PV systems require less energy input in their production than other commercial PV systems per unit electricity production The average CO2 eq kWh is around 18 grams cradle to gate CdTe has the fastest EPBT of all commercial PV technologies which varies between 0 3 and 1 2 years 68 Impacts from third generation PV Edit Third generation PVs are designed to combine the advantages of both the first and second generation devices and they do not have Shockley Queisser limit a theoretical limit for first and second generation PV cells The thickness of a third generation device is less than 1 mm 69 Two new promising thin film technologies are copper zinc tin sulfide Cu2ZnSnS4 or CZTS 50 zinc phosphide Zn3P2 50 and single walled carbon nano tubes SWCNT 70 These thin films are currently only produced in the lab but may be commercialized in the future The manufacturing of CZTS and Zn3P2 processes are expected to be similar to those of current thin film technologies of CIGS and CdTe respectively While the absorber layer of SWCNT PV is expected to be synthesized with CoMoCAT method 71 by Contrary to established thin films such as CIGS and CdTe CZTS Zn3P2 and SWCNT PVs are made from earth abundant nontoxic materials and have the potential to produce more electricity annually than the current worldwide consumption 72 73 While CZTS and Zn3P2 offer good promise for these reasons the specific environmental implications of their commercial production are not yet known Global warming potential of CZTS and Zn3P2 were found 38 and 30 grams CO2 eq kWh while their corresponding EPBT were found 1 85 and 0 78 years respectively 50 Overall CdTe and Zn3P2 have similar environmental impacts but can slightly outperform CIGS and CZTS 50 A study on environmental impacts of SWCNT PVs by Celik et al including an existing 1 efficient device and a theoretical 28 efficient device found that compared to monocrystalline Si the environmental impacts from 1 SWCNT was 18 times higher due mainly to the short lifetime of three years 70 Economics EditSee also Photovoltaic system Costs and economy Source Apricus 74 There have been major changes in the underlying costs industry structure and market prices of solar photovoltaics technology over the years and gaining a coherent picture of the shifts occurring across the industry value chain globally is a challenge This is due to the rapidity of cost and price changes the complexity of the PV supply chain which involves a large number of manufacturing processes the balance of system BOS and installation costs associated with complete PV systems the choice of different distribution channels and differences between regional markets within which PV is being deployed Further complexities result from the many different policy support initiatives that have been put in place to facilitate photovoltaics commercialisation in various countries 2 Renewable energy technologies have generally gotten cheaper since their invention 75 76 77 Renewable energy systems have become cheaper to build than fossil fuel power plants across much of the world thanks to advances in wind and solar energy technology in particular 78 Hardware costs Edit Price per watt history for conventional c Si solar cells since 1977 In 1977 crystalline silicon solar cell prices were at 76 67 W 79 Although wholesale module prices remained flat at around 3 50 to 4 00 W in the early 2000s due to high demand in Germany and Spain afforded by generous subsidies and shortage of polysilicon demand crashed with the abrupt ending of Spanish subsidies after the market crash of 2008 and the price dropped rapidly to 2 00 W Manufacturers were able to maintain a positive operating margin despite a 50 drop in income due to innovation and reductions in costs In late 2011 factory gate prices for crystalline silicon photovoltaic modules suddenly dropped below the 1 00 W mark taking many in the industry by surprise and has caused a number of solar manufacturing companies to go bankrupt throughout the world The 1 00 W cost is often regarded in the PV industry as marking the achievement of grid parity for PV but most experts do not believe this price point is sustainable Technological advancements manufacturing process improvements and industry re structuring may mean that further price reductions are possible 2 The average retail price of solar cells as monitored by the Solarbuzz group fell from 3 50 watt to 2 43 watt over the course of 2011 80 In 2013 wholesale prices had fallen to 0 74 W 79 This has been cited as evidence supporting Swanson s law an observation similar to the famous Moore s Law which claims that solar cell prices fall 20 for every doubling of industry capacity 79 The Fraunhofer Institute defines the learning rate as the drop in prices as the cumulative production doubles some 25 between 1980 and 2010 Although the prices for modules have dropped quickly current inverter prices have dropped at a much lower rate and in 2019 constitute over 61 of the cost per kWp from a quarter in the early 2000s 52 Note that the prices mentioned above are for bare modules another way of looking at module prices is to include installation costs In the US according to the Solar Energy Industries Association the price of installed rooftop PV modules for homeowners fell from 9 00 W in 2006 to 5 46 W in 2011 Including the prices paid by industrial installations the national installed price drops to 3 45 W This is markedly higher than elsewhere in the world in Germany homeowner rooftop installations averaged at 2 24 W The cost differences are thought to be primarily based on the higher regulatory burden and lack of a national solar policy in the US 81 By the end of 2012 Chinese manufacturers had production costs of 0 50 W in the cheapest modules 82 In some markets distributors of these modules can earn a considerable margin buying at factory gate price and selling at the highest price the market can support value based pricing 2 In California PV reached grid parity in 2011 which is usually defined as PV production costs at or below retail electricity prices though often still above the power station prices for coal or gas fired generation without their distribution and other costs 83 Grid parity had been reached in 19 markets in 2014 84 85 Levelised cost of electricity Edit AWM Munich ETFE Cushions Photovoltaics The levelised cost of electricity LCOE is the cost per kWh based on the costs distributed over the project lifetime and is thought to be a better metric for calculating viability than price per wattage LCOEs vary dramatically depending on the location 2 The LCOE can be considered the minimum price customers will have to pay the utility company in order for it to break even on the investment in a new power station 4 Grid parity is roughly achieved when the LCOE falls to a similar price as conventional local grid prices although in actuality the calculations are not directly comparable 86 Large industrial PV installations had reached grid parity in California in 2011 77 86 Grid parity for rooftop systems was still believed to be much farther away at this time 86 Many LCOE calculations are not thought to be accurate and a large amount of assumptions are required 2 86 Module prices may drop further and the LCOE for solar may correspondingly drop in the future 87 Because energy demands rise and fall over the course of the day and solar power is limited by the fact that the sun sets solar power companies must also factor in the additional costs of supplying a more stable alternative energy supplies to the grid in order to stabilize the system or storing the energy somehow current battery technology cannot store enough power These costs are not factored into LCOE calculations nor are special subsidies or premiums that may make buying solar power more attractive 4 The unreliability and temporal variation in generation of solar and wind power is a major problem Too much of these volatile power sources can cause instability of the entire grid 88 As of 2017 power purchase agreement prices for solar farms below 0 05 kWh are common in the United States and the lowest bids in some Persian Gulf countries were about 0 03 kWh 89 The goal of the United States Department of Energy is to achieve a levelised cost of energy for solar PV of 0 03 kWh for utility companies 90 Subsidies and financing Edit Financial incentives for photovoltaics such as feed in tariffs FITs have often been offered to electricity consumers to install and operate solar electric generating systems and in some countries such subsidies are the only way photovoltaics can remain economically profitable In Germany FIT subsidies are generally around 0 13 above the normal retail price of a kWh 0 05 91 PV FITs have been crucial for the adoption of the industry and are available to consumers in over 50 countries as of 2011 Germany and Spain have been the most important countries regarding offering subsidies for PV and the policies of these countries have driven demand in the past 2 Some US solar cell manufacturing companies have repeatedly complained that the dropping prices of PV module costs have been achieved due to subsidies by the government of China and the dumping of these products below fair market prices US manufacturers generally recommend high tariffs on foreign supplies to allow them remain profitable In response to these concerns the Obama administration began to levy tariffs on US consumers of these products in 2012 to raise prices for domestic manufacturers 2 The USA however also subsidies the industry offering consumers a 30 federal tax credit to purchase modules In Hawaii federal and state subsidies chop off up to two thirds of the installation costs 81 Some environmentalists have promoted the idea that government incentives should be used in order to expand the PV manufacturing industry to reduce costs of PV generated electricity much more rapidly to a level where it is able to compete with fossil fuels in a free market This is based on the theory that when the manufacturing capacity doubles economies of scale will cause the prices of the solar products to halve 4 In many countries there is access to capital is lacking to develop PV projects To solve this problem securitization has been proposed to accelerate development of solar photovoltaic projects 83 92 For example SolarCity offered the first U S asset backed security in the solar industry in 2013 93 Other Edit Photovoltaic power is also generated during a time of day that is close to peak demand precedes it in electricity systems with high use of air conditioning Since large scale PV operation requires back up in the form of spinning reserves its marginal cost of generation in the middle of the day is typically lowest but not zero when PV is generating electricity This can be seen in Figure 1 of this paper 94 For residential properties with private PV facilities networked to the grid the owner may be able earn extra money when the time of generation is included as electricity is worth more during the day than at night 95 One journalist theorised in 2012 that if the energy bills of Americans were forced upwards by imposing an extra tax of 50 ton on carbon dioxide emissions from coal fired power this could have allowed solar PV to appear more cost competitive to consumers in most locations 80 Growth EditMain article Growth of photovoltaics Worldwide growth of photovoltaics on a semi log plot since 1992 Solar photovoltaics formed the largest body of research among the seven sustainable energy types examined in a global bibliometric study with the annual scientific output growing from 9 094 publications in 2011 to 14 447 publications in 2019 96 Likewise the application of solar photovoltaics is growing rapidly and worldwide installed capacity reached about 515 gigawatts GW by 2018 97 The total power output of the world s PV capacity in a calendar year is now beyond 500 TWh of electricity This represents 2 of worldwide electricity demand More than 100 countries use solar PV 98 99 China is followed by the United States and Japan while installations in Germany once the world s largest producer have been slowing down Honduras generated the highest percentage of its energy from solar in 2019 14 8 100 As of 2019 Vietnam has the highest installed capacity in Southeast Asia about 4 5 GW 101 The annualized installation rate of about 90 W per capita per annum places Vietnam among world leaders 101 Generous Feed in tariff FIT and government supporting policies such as tax exemptions were the key to enable Vietnam s solar PV boom Underlying drivers include the government s desire to enhance energy self sufficiency and the public s demand for local environmental quality 101 A key barrier is limited transmission grid capacity 101 China has the world s largest solar power capacity with 253 GW of installed capacity at the end 2020 compared with about 151 GW in the European Union according to International Energy Agency data 102 Top 10 PV countries in 2019 MW Installed and total solar power capacity in 2019 MW 103 Nation Total capacity Added capacity1 China 204 700 30 1002 United States 75 900 13 3003 Japan 63 000 7 0004 Germany 49 200 3 9005 India 42 800 9 9006 Italy 20 800 6007 Australia 15 928 3 7008 United Kingdom 13 300 2339 South Korea 11 200 3 10010 France 9 900 900Data IEA PVPS Snapshot of Global PV Markets 2020 report April 2020 103 Also see Solar power by country for a complete and continuously updated listIn 2017 it was thought probable that by 2030 global PV installed capacities could be between 3 000 and 10 000 GW 89 Greenpeace in 2010 claimed that 1 845 GW of PV systems worldwide could be generating approximately 2 646 TWh year of electricity by 2030 and by 2050 over 20 of all electricity could be provided by PV 104 Applications EditMain article Applications of photovoltaics There are many practical applications for the use of solar panels or photovoltaics covering every technological domain under the sun From the fields of the agricultural industry as a power source for irrigation to its usage in remote health care facilities to refrigerate medical supplies Other applications include power generation at various scales and attempts to integrate them into homes and public infrastructure PV modules are used in photovoltaic systems and include a large variety of electrical devices Photovoltaic systems Edit Main article Photovoltaic system A photovoltaic system or solar PV system is a power system designed to supply usable solar power by means of photovoltaics It consists of an arrangement of several components including solar panels to absorb and directly convert sunlight into electricity a solar inverter to change the electric current from DC to AC as well as mounting cabling and other electrical accessories PV systems range from small roof top mounted or building integrated systems with capacities from a few to several tens of kilowatts to large utility scale power stations of hundreds of megawatts Nowadays most PV systems are grid connected while stand alone systems only account for a small portion of the market Photo sensors Edit Main article Photodetectors Photosensors are sensors of light or other electromagnetic radiation 105 A photo detector has a p n junction that converts light photons into current The absorbed photons make electron hole pairs in the depletion region Photodiodes and photo transistors are a few examples of photo detectors Solar cells convert some of the light energy absorbed into electrical energy Experimental technology EditCrystalline silicon photovoltaics are only one type of PV and while they represent the majority of solar cells produced currently there are many new and promising technologies that have the potential to be scaled up to meet future energy needs As of 2018 crystalline silicon cell technology serves as the basis for several PV module types including monocrystalline multicrystalline mono PERC and bifacial 106 Another newer technology thin film PV are manufactured by depositing semiconducting layers of perovskite a mineral with semiconductor properties on a substrate in vacuum The substrate is often glass or stainless steel and these semiconducting layers are made of many types of materials including cadmium telluride CdTe copper indium diselenide CIS copper indium gallium diselenide CIGS and amorphous silicon a Si After being deposited onto the substrate the semiconducting layers are separated and connected by electrical circuit by laser scribing 107 108 Perovskite solar cells are a very efficient solar energy converter and have excellent optoelectronic properties for photovoltaic purposes but their upscaling from lab sized cells to large area modules is still under research 109 Thin film photovoltaic materials may possibly become attractive in the future because of the reduced materials requirements and cost to manufacture modules consisting of thin films as compared to silicon based wafers 110 In 2019 university labs at Oxford Stanford and elsewhere reported perovskite solar cells with efficiencies of 20 25 111 CIGS Edit Main article Copper indium gallium selenide Copper indium gallium selenide CIGS is a thin film solar cell based on the copper indium diselenide CIS family of chalcopyrite semiconductors CIS and CIGS are often used interchangeably within the CIS CIGS community The cell structure includes soda lime glass as the substrate Mo layer as the back contact CIS CIGS as the absorber layer cadmium sulfide CdS or Zn S OH x as the buffer layer and ZnO Al as the front contact 112 CIGS is approximately 1 100th the thickness of conventional silicon solar cell technologies Materials necessary for assembly are readily available and are less costly per watt of solar cell CIGS based solar devices resist performance degradation over time and are highly stable in the field Reported global warming potential impacts of CIGS ranges 20 5 58 8 grams CO2 eq kWh of electricity generated for different solar irradiation 1 700 to 2 200 kWh m2 y and power conversion efficiency 7 8 9 12 113 EPBT ranges from 0 2 to 1 4 years 68 while harmonized value of EPBT was found 1 393 years 55 Toxicity is an issue within the buffer layer of CIGS modules because it contains cadmium and gallium 50 114 CIS modules do not contain any heavy metals Perovskite solar cells Edit This section is an excerpt from Perovskite solar cell edit Perovskite solar cells Solar cell efficiencies of various cell technologies including both single crystal and thin film technologies as tracked by NREL A perovskite solar cell PSC is a type of solar cell that includes a perovskite structured compound most commonly a hybrid organic inorganic lead or tin halide based material as the light harvesting active layer 115 116 Perovskite materials such as methylammonium lead halides and all inorganic caesium lead halide are cheap to produce and simple to manufacture Efficiencies of laboratory scale devices using these materials have increased from 3 8 in 2009 117 to 25 7 in 2021 in single junction architectures 118 119 and in silicon based tandem cells to 29 8 118 120 exceeding the maximum efficiency achieved in single junction silicon solar cells Perovskite solar cells have therefore been the fastest advancing solar technology as of 2016 update 115 With the potential of achieving even higher efficiencies and very low production costs perovskite solar cells have become commercially attractive Core problems and research subjects include their short and long term stability 121 Dye Sensitized Solar Cells Edit Dye sensitized Solar Cells DSCs are a novel thin film solar cell These solar cells operate under ambient light better than other photovoltaic technologies They work with light being absorbed in a sensitizing dye between two charge transport materials Dye surrounds TiO2 nanoparticles which are in a sintered network 122 TiO2 acts as conduction band in an n type semiconductor the scaffold for adorned dye molecules and transports elections during excitation For TiO2 DSC technology sample preparation at high temperatures is very effective because higher temperatures produce more suitable textural properties Another example of DSCs is the copper complex with Cu II I as a redox shuttle with TMBY 4 4 6 6 tetramethyl 2 2 bipyridine DSCs show great performance with artificial and indoor light From a range of 200 lux to 2 000 lux these cells operate at conditions of a maximum efficiency of 29 7 123 However there have been issues with DSCs many of which come from the liquid electrolyte The solvent is hazardous and will permeate most plastics Because it is liquid it is unstable to temperature variation leading to freezing in cold temperatures and expansion in warm temperatures causing failure 124 Another disadvantage is that the solar cell is not ideal for large scale application because of its low efficiency Some of the benefits for DSC is that it can be used in a variety of light levels including cloudy conditions it has a low production cost and it does not degrade under sunlight giving it a longer lifetime then other types of thin film solar cells OPV Edit Other possible future PV technologies include organic dye sensitized and quantum dot photovoltaics 125 Organic photovoltaics OPVs fall into the thin film category of manufacturing and typically operate around the 12 efficiency range which is lower than the 12 21 typically seen by silicon based PVs Because organic photovoltaics require very high purity and are relatively reactive they must be encapsulated which vastly increases the cost of manufacturing and means that they are not feasible for large scale up Dye sensitized PVs are similar in efficiency to OPVs but are significantly easier to manufacture However these dye sensitized photovoltaics present storage problems because the liquid electrolyte is toxic and can potentially permeate the plastics used in the cell Quantum dot solar cells are solution processed meaning they are potentially scalable but currently they peak at 12 efficiency 109 Organic and polymer photovoltaic OPV are a relatively new area of research The tradition OPV cell structure layers consist of a semi transparent electrode electron blocking layer tunnel junction holes blocking layer electrode with the sun hitting the transparent electrode OPV replaces silver with carbon as an electrode material lowering manufacturing cost and making them more environmentally friendly 126 OPV are flexible low weight and work well with roll to roll manufacturing for mass production 127 OPV uses only abundant elements coupled to an extremely low embodied energy through very low processing temperatures using only ambient processing conditions on simple printing equipment enabling energy pay back times 128 Current efficiencies range 1 6 5 53 129 however theoretical analyses show promise beyond 10 efficiency 128 Many different configurations of OPV exist using different materials for each layer OPV technology rivals existing PV technologies in terms of EPBT even if they currently present a shorter operational lifetime A 2013 study analyzed 12 different configurations all with 2 efficiency the EPBT ranged from 0 29 to 0 52 years for 1 m2 of PV 130 The average CO2 eq kWh for OPV is 54 922 grams 131 Thermophotovoltaics Edit This section is an excerpt from Thermophotovoltaic energy conversion edit Thermophotovoltaic TPV energy conversion is a direct conversion process from heat to electricity via photons A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being admitted from the hot object 132 As TPV systems generally work at lower temperatures than solar cells their efficiencies tend to be low Offsetting this through the use of multi junction cells based on non silicon materials is common but generally very expensive This currently limits TPV to niche roles like spacecraft power and waste heat collection from larger systems like steam turbines Solar module alignment Edit A number of solar modules may also be mounted vertically above each other in a tower if the zenith distance of the Sun is greater than zero and the tower can be turned horizontally as a whole and each module additionally around a horizontal axis In such a tower the modules can follow the Sun exactly Such a device may be described as a ladder mounted on a turnable disk Each step of that ladder is the middle axis of a rectangular solar panel In case the zenith distance of the Sun reaches zero the ladder may be rotated to the north or the south to avoid a solar module producing a shadow on a lower one Instead of an exactly vertical tower one can choose a tower with an axis directed to the polar star meaning that it is parallel to the rotation axis of the Earth In this case the angle between the axis and the Sun is always larger than 66 degrees During a day it is only necessary to turn the panels around this axis to follow the Sun Installations may be ground mounted and sometimes integrated with farming and grazing 133 or built into the roof or walls of a building building integrated photovoltaics Where land may be limited PV can be deployed as floating solar In 2008 the Far Niente Winery pioneered the world s first floatovoltaic system by installing 994 photovoltaic solar panels onto 130 pontoons and floating them on the winery s irrigation pond 134 135 A benefit of the set up is that the panels are kept at a lower temperature than they would be on land leading to a higher efficiency of solar energy conversion The floating panels also reduce the amount of water lost through evaporation and inhibit the growth of algae 136 Concentrator photovoltaics is a technology that contrary to conventional flat plate PV systems uses lenses and curved mirrors to focus sunlight onto small but highly efficient multi junction solar cells These systems sometimes use solar trackers and a cooling system to increase their efficiency Efficiency Edit Main article Solar cell efficiency Best research cell efficiencies In 2019 the world record for solar cell efficiency at 47 1 was achieved by using multi junction concentrator solar cells developed at National Renewable Energy Laboratory Colorado USA 137 The highest efficiencies achieved without concentration include a material by Sharp Corporation at 35 8 using a proprietary triple junction manufacturing technology in 2009 138 and Boeing Spectrolab 40 7 also using a triple layer design There is an ongoing effort to increase the conversion efficiency of PV cells and modules primarily for competitive advantage In order to increase the efficiency of solar cells it is important to choose a semiconductor material with an appropriate band gap that matches the solar spectrum This will enhance the electrical and optical properties Improving the method of charge collection is also useful for increasing the efficiency There are several groups of materials that are being developed Ultrahigh efficiency devices h gt 30 139 are made by using GaAs and GaInP2 semiconductors with multijunction tandem cells High quality single crystal silicon materials are used to achieve high efficiency low cost cells h gt 20 Recent developments in organic photovoltaic cells OPVs have made significant advancements in power conversion efficiency from 3 to over 15 since their introduction in the 1980s 140 To date the highest reported power conversion efficiency ranges 6 7 8 94 for small molecule 8 4 10 6 for polymer OPVs and 7 21 for perovskite OPVs 141 142 OPVs are expected to play a major role in the PV market Recent improvements have increased the efficiency and lowered cost while remaining environmentally benign and renewable Several companies have begun embedding power optimizers into PV modules called smart modules These modules perform maximum power point tracking MPPT for each module individually measure performance data for monitoring and provide additional safety features Such modules can also compensate for shading effects wherein a shadow falling across a section of a module causes the electrical output of one or more strings of cells in the module to decrease 143 One of the major causes for the decreased performance of cells is overheating The efficiency of a solar cell declines by about 0 5 for every 1 degree Celsius increase in temperature This means that a 100 degree increase in surface temperature could decrease the efficiency of a solar cell by about half Self cooling solar cells are one solution to this problem Rather than using energy to cool the surface pyramid and cone shapes can be formed from silica and attached to the surface of a solar panel Doing so allows visible light to reach the solar cells but reflects infrared rays which carry heat 144 Advantages EditPollution and energy in productionThe 122 PW of sunlight reaching the Earth s surface is plentiful almost 10 000 times more than the 13 TW equivalent of average power consumed in 2005 by humans 145 This abundance leads to the suggestion that it will not be long before solar energy will become the world s primary energy source 146 Additionally solar electric generation has the highest power density global mean of 170 W m2 among renewable energies 145 Solar power is pollution free during use which enables it to cut down on pollution when it is substituted for other energy sources For example MIT estimated that 52 000 people per year die prematurely in the U S from coal fired power plant pollution 147 and all but one of these deaths could be prevented from using PV to replace coal 148 149 Production end wastes and emissions are manageable using existing pollution controls End of use recycling technologies are under development 150 and policies are being produced that encourage recycling from producers 151 PV installations could ideally operate for 100 years or even more 152 with little maintenance or intervention after their initial set up so after the initial capital cost of building any solar power plant operating costs are extremely low compared to existing power technologies Grid connected solar electricity can be used locally thus reducing transmission distribution losses transmission losses in the US were approximately 7 2 in 1995 153 Solar cell research investmentCompared to fossil and nuclear energy sources very little research money has been invested in the development of solar cells so there is considerable room for improvement Nevertheless experimental high efficiency solar cells already have efficiencies of over 40 in case of concentrating photovoltaic cells 154 and efficiencies are rapidly rising while mass production costs are rapidly falling 155 Housing subsidiesIn some states of the United States much of the investment in a home mounted system may be lost if the homeowner moves and the buyer puts less value on the system than the seller The city of Berkeley developed an innovative financing method to remove this limitation by adding a tax assessment that is transferred with the home to pay for the solar panels 156 Now known as PACE Property Assessed Clean Energy 30 U S states have duplicated this solution 157 Disadvantages EditImpact on electricity network Grids with high penetration of renewable energy sources generally need more flexible generation rather than baseload generation For behind the meter rooftop photovoltaic systems the energy flow becomes two way When there is more local generation than consumption electricity is exported to the grid allowing for net metering However electricity networks traditionally are not designed to deal with two way energy transfer which may introduce technical issues An over voltage issue may come out as the electricity flows from these PV households back to the network 158 There are solutions to manage the over voltage issue such as regulating PV inverter power factor new voltage and energy control equipment at electricity distributor level re conductor the electricity wires demand side management etc There are often limitations and costs related to these solutions High generation during the middle of the day reduces the net generation demand but higher peak net demand as the sun goes down can require rapid ramping of utility generating stations producing a load profile called the duck curve Implications for electricity bill management and energy investmentThere is no silver bullet in electricity or energy demand and bill management because customers sites have different specific situations e g different comfort convenience needs different electricity tariffs or different usage patterns Electricity tariff may have a few elements such as daily access and metering charge energy charge based on kWh MWh or peak demand charge e g a price for the highest 30min energy consumption in a month PV is a promising option for reducing energy charges when electricity prices are reasonably high and continuously increasing such as in Australia and Germany However for sites with peak demand charge in place PV may be less attractive if peak demands mostly occur in the late afternoon to early evening for example in residential communities Overall energy investment is largely an economic decision and it is better to make investment decisions based on systematic evaluation of options in operational improvement energy efficiency onsite generation and energy storage 159 160 See also Edit Wikimedia Commons has media related to Photovoltaics This section may contain an excessive amount of intricate detail that may interest only a particular audience Please help by spinning off or relocating any relevant information and removing excessive detail that may be against Wikipedia s inclusion policy September 2022 Learn how and when to remove this template message Agrivoltaic American Solar Energy Society Anomalous photovoltaic effect Copper in renewable energy Solar photovoltaic power generation Cost of electricity by source Energy demand management Electromotive force Solar cell List of photovoltaics companies Photoelectrochemical cell Quantum efficiency Quantum efficiency of solar cells Renewable energy commercialization Solar cell fabric Solar module quality assurance Solar photovoltaic monitoring Solar power by country Solar thermal energy Theory of solar cellReferences Edit a b Lo Piano Samuele Mayumi Kozo 2017 Toward an integrated assessment of the performance of photovoltaic systems for electricity generation Applied Energy 186 2 167 74 doi 10 1016 j apenergy 2016 05 102 S2CID 156783885 a b c d e f g h Bazilian M Onyeji I Liebreich M MacGill I Chase J Shah J Gielen D Arent D Landfear D Zhengrong S 2013 Re considering the economics of photovoltaic power PDF Renewable Energy 53 329 338 CiteSeerX 10 1 1 692 1880 doi 10 1016 j renene 2012 11 029 Archived from the original PDF on 31 May 2014 Retrieved 4 September 2015 Palz Wolfgang 2013 Solar Power for the World What You Wanted to Know about Photovoltaics CRC Press pp 131 ISBN 978 981 4411 87 5 a b c d Why did renewables become so cheap so fast Our World in Data 1 December 2020 Shubbak Mahmood H 2019 The technological system of production and innovation The case of photovoltaic technology in China Research Policy 48 4 993 1015 doi 10 1016 j respol 2018 10 003 S2CID 158742469 Renewable Energy Policy Network for the 21st century REN21 Renewables 2010 Global Status Report Paris 2010 pp 1 80 PHOTOVOLTAICS REPORT PDF Fraunhofer Institute for Solar Energy Systems 16 September 2020 p 4 Renewables 2019 IEA Retrieved 26 January 2020 KAHRAMAA and Siraj Energy Sign Agreements for Al Kharsaah Solar PV Power Plant Qatar General Electricity amp Water Corporation KAHRAMAA 20 January 2020 Retrieved 26 January 2020 Sunil Prasad Lohani Andrew Blakers 100 renewable energy with pumped hydro energy storage in Nepal In Clean Energy 5 2 2021 243 253 doi 10 1093 ce zkab011 Smee Alfred 1849 Elements of electro biology or the voltaic mechanism of man of electro pathology especially of the nervous system and of electro therapeutics London Longman Brown Green and Longmans p 15 How to Build a Low tech Solar Panel LOW TECH MAGAZINE Retrieved 20 October 2021 Palz Wolfgang 21 October 2013 Solar Power for the World What You Wanted to Know about Photovoltaics CRC Press ISBN 978 981 4411 87 5 Noguchi Masa Number of Residential PV Installation in Japan 1994 2003 Photovoltaic Effect Archived 14 July 2011 at the Wayback Machine Mrsolar com Retrieved 12 December 2010 The photovoltaic effect Archived 12 October 2010 at the Wayback Machine Encyclobeamia solarbotics net Retrieved on 12 December 2010 Jacobson Mark Z 2009 Review of Solutions to Global Warming Air Pollution and Energy Security Energy amp Environmental Science 2 2 148 173 Bibcode 2009GeCAS 73R 581J CiteSeerX 10 1 1 180 4676 doi 10 1039 B809990C German PV market Solarbuzz com Retrieved on 3 June 2012 BP Solar to Expand Its Solar Cell Plants in Spain and India Archived 26 September 2007 at the Wayback Machine Renewableenergyaccess com 23 March 2007 Retrieved on 3 June 2012 Bullis Kevin 23 June 2006 Large Scale Cheap Solar Electricity Technologyreview com Retrieved on 3 June 2012 Luque Antonio amp Hegedus Steven 2003 Handbook of Photovoltaic Science and Engineering John Wiley and Sons ISBN 978 0 471 49196 5 The PVWatts Solar Calculator Retrieved on 7 September 2012 Massachusetts a Good Solar Market Archived 12 September 2012 at the Wayback Machine Remenergyco com Retrieved on 31 May 2013 a b Kannan Nadarajah Vakeesan Divagar 1 September 2016 Solar energy for future world A review Renewable and Sustainable Energy Reviews 62 1092 1105 doi 10 1016 j rser 2016 05 022 ISSN 1364 0321 Koberle Alexandre C Gernaat David E H J van Vuuren Detlef P 1 September 2015 Assessing current and future techno economic potential of concentrated solar power and photovoltaic electricity generation Energy 89 739 756 doi 10 1016 j energy 2015 05 145 hdl 1874 319865 ISSN 0360 5442 S2CID 108996432 a b Billy Roberts 20 October 2008 Photovoltaic Solar Resource of the United States National Renewable Energy Laboratory Retrieved 17 April 2017 David J C MacKay Sustainable Energy without the hot air inference org uk Retrieved 20 November 2017 Solar photovoltaics data from a 25 m2 array in Cambridgeshire in 2006 a b Kumar Ankush 3 January 2017 Predicting efficiency of solar cells based on transparent conducting electrodes Journal of Applied Physics 121 1 014502 Bibcode 2017JAP 121a4502K doi 10 1063 1 4973117 ISSN 0021 8979 Photovoltaic Cell Conversion Efficiency Basics U S Department of Energy Retrieved 6 September 2014 Geisz John F France Ryan M Schulte Kevin L Steiner Myles A Norman Andrew G Guthrey Harvey L Young Matthew R Song Tao Moriarty Thomas April 2020 Six junction III V solar cells with 47 1 conversion efficiency under 143 Suns concentration Nature Energy 5 4 326 335 Bibcode 2020NatEn 5 326G doi 10 1038 s41560 020 0598 5 ISSN 2058 7546 OSTI 1659948 S2CID 216289881 Dunlop James P 2012 Photovoltaic systems National Joint Apprenticeship and Training Committee for the Electrical Industry 3rd ed Orland Park IL American Technical Publishers Inc ISBN 978 1 935941 05 7 OCLC 828685287 Bowden Stuart Honsberg Christiana Bypass Diodes Photovoltaic Education Retrieved 29 June 2021 Open Circuit Voltage Battery Electrical School 13 June 2018 Retrieved 30 June 2021 REC Alpha Black Series Factsheet PDF TSM PC PM14 Datasheet PDF Archived from the original PDF on 29 October 2013 Retrieved 4 June 2012 LBS Poly 260 275 Data sheet PDF Retrieved 9 January 2018 Piliougine M Oukaja A Sidrach de Cardona M Spagnuolo G 2021 Temperature coefficients of degraded crystalline silicon photovoltaic modules at outdoor conditions Progress in Photovoltaics Vol 29 pp 558 570 doi 10 1002 pip 3396 S2CID 233976803 Are Solar Panels Affected by Weather Energy Informative Energy Informative Retrieved 14 March 2018 Solarplaza Potential Induced Degradation Combatting a Phantom Menace www solarplaza com Retrieved 4 September 2017 www inspire cz INSPIRE CZ s r o What is PID eicero eicero com Retrieved 4 September 2017 How Solar Cells Work HowStuffWorks April 2000 Retrieved 9 December 2015 Bonding in Metals and Semiconductors 2012books lardbucket org Retrieved 9 December 2015 Piliougine M Oukaja A Sanchez Friera P Petrone G Sanchez Pacheco J F Spagnuolo G Sidrach de Cardona M 2021 Analysis of the degradation of single crystalline silicon modules after 21 years of operation Progress in Photovoltaics Vol 29 pp 907 919 doi 10 1002 pip 3409 S2CID 234831264 Piliougine M Oukaja A Sidrach de Cardona M Spagnuolo G 2022 Analysis of the degradation of amorphous silicon based modules after 11 years of exposure by means of IEC60891 2021 procedure 3 Progress in Photovoltaics Vol 30 pp 1176 1187 doi 10 1002 pip 3567 hdl 10630 24064 S2CID 248487635 Piliougine M Sanchez Friera P Petrone G Sanchez Pacheco J F Spagnuolo G Sidrach de Cardona M 2022 New model to study the outdoor degradation of thin film photovoltaic modules Renewable Energy 193 857 869 doi 10 1016 j renene 2022 05 063 S2CID 248926054 Platzer Michael 27 January 2015 U S Solar Photovoltaic Manufacturing Industry Trends Global Competition Federal Support Congressional Research Service How PV Cells Are Made www fsec ucf edu Retrieved 5 November 2015 Are we headed for a solar waste crisis Environmentalprogress org Retrieved 30 December 2017 a b Fthenakis V M Kim H C amp Alsema E 2008 Emissions from photovoltaic life cycles Environmental Science amp Technology 42 6 2168 2174 Bibcode 2008EnST 42 2168F doi 10 1021 es071763q hdl 1874 32964 PMID 18409654 S2CID 20850468 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link a b c d e f Collier J Wu S amp Apul D 2014 Life cycle environmental impacts from CZTS copper zinc tin sulfide and Zn3P2 zinc phosphide thin film PV photovoltaic cells Energy 74 314 321 doi 10 1016 j energy 2014 06 076 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link a b c d e An analysis of the energy efficiency of photovoltaic cells in reducing CO2 emissions PDF clca columbia edu 31 May 2009 Archived PDF from the original on 25 March 2015 a b c d PHOTOVOLTAICS REPORT PDF Fraunhofer Institute for Solar Energy Systems 16 September 2020 pp 36 43 46 a b Anctil A Babbitt C W Raffaelle R P amp Landi B J 2013 Cumulative energy demand for small molecule and polymer photovoltaics Progress in Photovoltaics Research and Applications 21 7 1541 1554 doi 10 1002 pip 2226 S2CID 94279905 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Ibon Galarraga M Gonzalez Eguino Anil Markandya 1 January 2011 Handbook of Sustainable Energy Edward Elgar Publishing p 37 ISBN 978 0857936387 Retrieved 9 May 2017 via Google Books a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link a b Bhandari K P Collier J M Ellingson R J amp Apul D S 2015 Energy payback time EPBT and energy return on energy invested EROI of solar photovoltaic systems A systematic review and meta analysis Renewable and Sustainable Energy Reviews 47 133 141 doi 10 1016 j rser 2015 02 057 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link An analysis of the energy efficiency of photovoltaic cells in reducing CO2 emissions University of Portsmouth 31 May 2009 Archived from the original on 25 March 2015 Energy Pay Back time comparison for Photovoltaic Cells Alsema Frankl Kato 1998 p 5 Marco Raugei Pere Fullana i Palmer and Vasilis Fthenakis March 2012 The Energy Return on Energy Investment EROI of Photovoltaics Methodology and Comparisons with Fossil Fuel Life Cycles PDF www bnl gov Archived PDF from the original on 8 March 2016 a href Template Cite web html title Template Cite web cite web a CS1 maint uses authors parameter link Vasilis Fthenakis Rolf Frischknecht Marco Raugei Hyung Chul Kim Erik Alsema Michael Held and Mariska de Wild Scholten November 2011 Methodology Guidelines on Life Cycle Assessment of Photovoltaic Electricity PDF www iea pvps org IEA PVPS pp 8 10 Archived PDF from the original on 24 September 2015 a href Template Cite web html title Template Cite web cite web a CS1 maint uses authors parameter link Production Process of Silicon www simcoa com au Simcoa Operations Archived from the original on 19 June 2014 Retrieved 17 September 2014 Reaching kerf loss below 100 mm by optimizations PDF Fraunhofer ISE 24th European PV Solar Energy Conference and Exhibition September 2009 Silicon kerf loss recycling HZDR Helmholtz Zentrum Dresden Rossendorf 4 April 2014 Life Cycle Assessment of Future Photovoltaic Electricity Production from Residential scale Systems Operated in Europe IEA PVPS 13 March 2015 a b Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics National Renewable Energy Laboratory U S Department of Energy 2012 1 2 a b Krebs F C 2009 Fabrication and processing of polymer solar cells a review of printing and coating techniques Solar Energy Materials and Solar Cells 93 4 394 412 doi 10 1016 j solmat 2008 10 004 a b Yue D You F Darling S B 2014 Domestic and overseas manufacturing scenarios of silicon based photovoltaics Life cycle energy and environmental comparative analysis Solar Energy 105 669 678 Bibcode 2014SoEn 105 669Y doi 10 1016 j solener 2014 04 008 Gaidajis G amp Angelakoglou K 2012 Environmental performance of renewable energy systems with the application of life cycle assessment a multi Si photovoltaic module case study Civil Engineering and Environmental Systems 29 4 231 238 doi 10 1080 10286608 2012 710608 S2CID 110058349 Photovoltaics Report Fraunhofer Institute for Solar Energy Systems ISE 2015 a b Goe M amp Gaustad G 2014 Strengthening the case for recycling photovoltaics An energy payback analysis Applied Energy 120 41 48 doi 10 1016 j apenergy 2014 01 036 Brown G F amp Wu J 2009 Third generation photovoltaics Laser amp Photonics Reviews 3 4 394 405 Bibcode 2009LPRv 3 394B doi 10 1002 lpor 200810039 S2CID 13179665 a b Celik I Mason B E Phillips A B Heben M J amp Apul D S 2017 Environmental Impacts from Photovoltaic Solar Cells Made with Single Walled Carbon Nanotubes Environmental Science amp Technology Agboola A E Development and model formulation of scalable carbon nanotube processes HiPCO and CoMoCAT process models Louisiana State University 2005 Wadia C Alivisatos A P amp Kammen D M 2009 Materials Availability Expands the Opportunity for Large Scale Photovoltaics Deployment Environmental Science and Technology 43 6 2072 2077 Bibcode 2009EnST 43 2072W doi 10 1021 es8019534 PMID 19368216 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Alharbi Fahhad Bass John D Salhi Abdelmajid Alyamani Ahmed Kim Ho Cheol Miller Robert D 2011 Abundant non toxic materials for thin film solar cells Alternative to conventional materials Renewable Energy 36 10 2753 2758 doi 10 1016 j renene 2011 03 010 Insolation Levels Europe Apricus Solar Archived from the original on 17 April 2012 Retrieved 14 April 2012 Renewable energy costs drop in 09 Reuters 23 November 2009 Solar Power 50 Cheaper By Year End Analysis Reuters 24 November 2009 a b Harris Arno 31 August 2011 A Silver Lining in Declining Solar Prices Renewable Energy World Renewable Power Generation Costs in 2019 Abu Dhabi International Renewable Energy Agency 2020 ISBN 978 92 9260 244 4 a b c Sunny Uplands Alternative energy will no longer be alternative The Economist 21 November 2012 Retrieved 28 December 2012 a b Quiggin John 3 January 2012 The End of the Nuclear Renaissance National Interest a b Wells Ken 25 October 2012 Solar Energy Is Ready The U S Isn t Bloomberg Businessweek Archived from the original on 27 October 2012 Retrieved 1 November 2012 Solar PV Module Costs to Fall to 36 Cents per Watt by 2017 Greentechmedia com 2013 06 18 Retrieved on 2015 04 15 a b Alafita T Pearce J M 2014 Securitization of residential solar photovoltaic assets Costs risks and uncertainty Energy Policy 67 488 498 doi 10 1016 j enpol 2013 12 045 S2CID 11079398 Liebreich Michael 29 January 2014 A YEAR OF CRACKING ICE 10 PREDICTIONS FOR 2014 Bloomberg New Energy Finance Retrieved 24 April 2014 2014 Outlook Let the Second Gold Rush Begin PDF Deutsche Bank Markets Research 6 January 2014 Archived PDF from the original on 29 November 2014 Retrieved 22 November 2014 a b c d Branker K Pathak M J M Pearce J M 2011 A Review of Solar Photovoltaic Levelized Cost of Electricity Renewable and Sustainable Energy Reviews 15 9 4470 4482 doi 10 1016 j rser 2011 07 104 hdl 1974 6879 S2CID 73523633 Renewables Investment Breaks Records Renewable Energy World 29 August 2011 Hockenos Paul 10 February 2021 Is Germany Making Too Much Renewable Energy Foreign Policy Retrieved 7 March 2021 a b Nancy M Haegel 2017 Terawatt scale photovoltaics Trajectories and challenges Science 356 6334 141 143 Bibcode 2017Sci 356 141H doi 10 1126 science aal1288 hdl 10945 57762 OSTI 1352502 PMID 28408563 S2CID 206654326 Adeh Elnaz H Good Stephen P Calaf M Higgins Chad W 7 August 2019 Solar PV Power Potential is Greatest Over Croplands Scientific Reports 9 1 11442 Bibcode 2019NatSR 911442A doi 10 1038 s41598 019 47803 3 ISSN 2045 2322 PMC 6685942 PMID 31391497 TROMMSDORFF Maximillian 2016 An economic analysis of agrophotovoltaics Opportunities risks and strategies towards a more efficient land use PDF The Constitutional Economics Network Working Papers Lowder T amp Mendelsohn M 2013 The Potential of Securitization in Solar PV Finance page needed Done Deal The First Securitization Of Rooftop Solar Assets Forbes 21 November 2013 Matar Walid Anwer Murad 2017 Jointly reforming the prices of industrial fuels and residential electricity in Saudi Arabia Energy Policy 109 747 756 doi 10 1016 j enpol 2017 07 060 Utilities Honest Assessment of Solar in the Electricity Supply Greentechmedia com 7 May 2012 Retrieved on 31 May 2013 Straza Schneegans 11 June 2021 Are we using science for smarter development Paris UNESCO ISBN 978 92 3 100450 6 Snapshot of Global Photovoltaic Markets 2017 PDF report International Energy Agency 19 April 2017 Retrieved 11 July 2017 Snapshot of Global PV 1992 2014 PDF International Energy Agency Photovoltaic Power Systems Programme 30 March 2015 Archived from the original on 7 April 2015 Renewables 2011 Global Status Report REN21 2011 p 22 Snapshot 2020 IEA PVPS a b c d Do Thang Nam Burke Paul J Baldwin Kenneth G H Nguyen Chinh The 1 September 2020 Underlying drivers and barriers for solar photovoltaics diffusion The case of Vietnam Energy Policy 144 111561 doi 10 1016 j enpol 2020 111561 hdl 1885 206307 ISSN 0301 4215 S2CID 225245522 China to add 55 65 GW of solar power capacity in 2021 industry body Reuters 23 July 2021 Retrieved 15 October 2022 a b Snapshot 2020 IEA PVPS iea pvps org Retrieved 10 May 2020 Solar Photovoltaic Electricity Empowering the World Archived 22 August 2012 at the Wayback Machine Epia org 22 September 2012 Retrieved on 31 May 2013 Haugan H J Elhamri S Szmulowicz F Ullrich B Brown G J Mitchel W C 2008 Study of residual background carriers in midinfrared InAs GaSb superlattices for uncooled detector operation Applied Physics Letters 92 7 071102 Bibcode 2008ApPhL 92g1102H doi 10 1063 1 2884264 S2CID 39187771 Solar PV Modules www targray com Retrieved 3 October 2018 Kosasih Felix Utama Rakocevic Lucija Aernouts Tom Poortmans Jef Ducati Caterina 11 December 2019 Electron Microscopy Characterization of P3 Lines and Laser Scribing Induced Perovskite Decomposition in Perovskite Solar Modules ACS Applied Materials amp Interfaces 11 49 45646 45655 doi 10 1021 acsami 9b15520 PMID 31663326 S2CID 204967452 Di Giacomo Francesco Castriotta Luigi A Kosasih Felix U Di Girolamo Diego Ducati Caterina Di Carlo Aldo 20 December 2020 Upscaling Inverted Perovskite Solar Cells Optimization of Laser Scribing for Highly Efficient Mini Modules Micromachines 11 12 1127 doi 10 3390 mi11121127 PMC 7767295 PMID 33419276 a b Matteocci Fabio Vesce Luigi Kosasih Felix Utama Castriotta Luigi Angelo Cacovich Stefania Palma Alessandro Lorenzo Divitini Giorgio Ducati Caterina Di Carlo Aldo 17 July 2019 Fabrication and Morphological Characterization of High Efficiency Blade Coated Perovskite Solar Modules ACS Applied Materials amp Interfaces 11 28 25195 25204 doi 10 1021 acsami 9b05730 PMID 31268662 S2CID 206497286 Thin Film Photovoltaics www fsec ucf edu Retrieved 5 November 2015 Best Research Cell Efficiences nrel gov 16 September 2019 Retrieved on 31 October 2019 Eisenberg D A Yu M Lam C W Ogunseitan O A amp Schoenung J M 2013 Comparative alternative materials assessment to screen toxicity hazards in the life cycle of CIGS thin film photovoltaics Journal of Hazardous Materials 260 534 542 doi 10 1016 j jhazmat 2013 06 007 PMID 23811631 S2CID 26540719 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Kim H C Fthenakis V Choi J K amp Turney D E 2012 Life cycle greenhouse gas emissions of thin film photovoltaic electricity generation Journal of Industrial Ecology 16 S110 S121 doi 10 1111 j 1530 9290 2011 00423 x S2CID 153386434 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Werner Jurgen H Zapf Gottwick R Koch M Fischer K 2011 Toxic substances in photovoltaic modules Proceedings of the 21st International Photovoltaic Science and Engineering Conference Vol 28 Fukuoka Japan a b Manser Joseph S Christians Jeffrey A Kamat Prashant V 2016 Intriguing Optoelectronic Properties of Metal Halide Perovskites Chemical Reviews 116 21 12956 13008 doi 10 1021 acs chemrev 6b00136 PMID 27327168 Hamers Laurel 26 July 2017 Perovskites power up the solar industry Science News Kojima Akihiro Teshima Kenjiro Shirai Yasuo Miyasaka Tsutomu 6 May 2009 Organometal Halide Perovskites as Visible Light Sensitizers for Photovoltaic Cells Journal of the American Chemical Society 131 17 6050 6051 doi 10 1021 ja809598r PMID 19366264 a b Best Research Cell Efficiencies PDF National Renewable Energy Laboratory 5 April 2023 Retrieved 14 April 2023 Min Hanul Lee Do Yoon Kim Junu Kim Gwisu Lee Kyoung Su Kim Jongbeom Paik Min Jae Kim Young Ki Kim Kwang S Kim Min Gyu Shin Tae Joo Il Seok Sang 21 October 2021 Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes Nature 598 7881 444 450 Bibcode 2021Natur 598 444M doi 10 1038 s41586 021 03964 8 PMID 34671136 S2CID 239052065 Helmholtz Zentrum Berlin fur Materialien und Energie World record again at HZB Almost 30 efficiency for next generation tandem solar cells HZB Website Sun Kai Wang Yanyan Xu Haoyuan Zhang Jing Zhu Yuejin Hu Ziyang 2019 Short Term Stability of Perovskite Solar Cells Affected by In Situ Interface Modification Solar RRL 3 9 1900089 doi 10 1002 solr 201900089 S2CID 202229877 Goodson Flynt 2014 Supramolecular Multichromophoric Dye Sensitized Solar Cells Archived from the original on 9 December 2022 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Freitag Marina Teuscher Joel Saygili Yasemin Zhang Xiaoyu Giordano Fabrizio Liska Paul Hua Jianli Zakeeruddin Shaik M Moser Jacques E Gratzel Michael Hagfeldt Anders 17 June 2017 Dye sensitized solar cells for efficient power generation under ambient lighting Nature Photonics 11 6 372 378 Bibcode 2017NaPho 11 372F doi 10 1038 nphoton 2017 60 S2CID 10780585 via www nature com Raga Sonia R Fabregat Santiago Francisco 23 January 2013 Temperature effects in dye sensitized solar cells Physical Chemistry Chemical Physics 15 7 2328 2336 Bibcode 2013PCCP 15 2328R doi 10 1039 C2CP43220J PMID 23295858 via pubs rsc org Nikolaidou Katerina Sarang Som Ghosh Sayantani 2019 Nanostructured photovoltaics Nano Futures 3 1 012002 Bibcode 2019NanoF 3a2002N doi 10 1088 2399 1984 ab02b5 S2CID 162176556 Dos Reis Benatto Gisele A Roth Berenger Madsen Morten V Hosel Markus Sondergaard Roar R Jorgensen Mikkel Krebs Frederik C 2014 Carbon The Ultimate Electrode Choice for Widely Distributed Polymer Solar Cells Advanced Energy Materials 4 15 n a doi 10 1002 aenm 201400732 S2CID 96990654 Lattante Sandro 2014 Electron and Hole Transport Layers Their Use in Inverted Bulk Heterojunction Polymer Solar Cells Electronics 3 132 164 doi 10 3390 electronics3010132 a b Krebs Frederik C Jorgensen Mikkel 2013 Polymer and organic solar cells viewed as thin film technologies What it will take for them to become a success outside academia Solar Energy Materials and Solar Cells 119 73 76 doi 10 1016 j solmat 2013 05 032 Espinosa Nieves Garcia Valverde Rafael Urbina Antonio Krebs Frederik C 2011 A life cycle analysis of polymer solar cell modules prepared using roll to roll methods under ambient conditions Solar Energy Materials and Solar Cells 95 5 1293 1302 doi 10 1016 j solmat 2010 08 020 Espinosa Nieves Lenzmann Frank O Ryley Stephen Angmo Dechan Hosel Markus Sondergaard Roar R Huss Dennis Dafinger Simone Gritsch Stefan Kroon Jan M Jorgensen Mikkel Krebs Frederik C 2013 OPV for mobile applications An evaluation of roll to roll processed indium and silver free polymer solar cells through analysis of life cycle cost and layer quality using inline optical and functional inspection tools Journal of Materials Chemistry A 1 24 7037 doi 10 1039 C3TA01611K Garcia Valverde R Miguel C Martinez Bejar R Urbina A 2009 Life cycle assessment study of a 4 2k Wp stand alone photovoltaic system Solar Energy 83 9 1434 1445 Bibcode 2009SoEn 83 1434G doi 10 1016 j solener 2009 03 012 Thermophotovoltaics Green Energy and Technology 2011 doi 10 1007 978 3 642 19965 3 ISBN 978 3 642 19964 6 GE Invests Delivers One of World s Largest Solar Power Plants Huliq com 12 April 2007 Retrieved on 3 June 2012 Winery goes solar with Floatovoltaics SFGate 29 May 2008 Retrieved on 31 May 2013 NAPA VALLEY S FAR NIENTE WINERY INTRODUCES FIRST EVER FLOATOVOLTAIC SOLAR ARRAY Archived 16 March 2015 at the Wayback Machine farniente com Napa Winery Pioneers Solar Floatovoltaics Forbes 18 April 2012 Retrieved on 31 May 2013 Geisz John F France Ryan M Schulte Kevin L Steiner Myles A Norman Andrew G Guthrey Harvey L Young Matthew R Song Tao Moriarty Thomas April 2020 Six junction III V solar cells with 47 1 conversion efficiency under 143 Suns concentration Nature Energy 5 4 326 335 Bibcode 2020NatEn 5 326G doi 10 1038 s41560 020 0598 5 ISSN 2058 7546 OSTI 1659948 S2CID 216289881 Sharp Develops Solar Cell with World s Highest Conversion Efficiency of 35 8 Physorg com 22 October 2009 Retrieved on 3 June 2012 Deb Satyen K May 2000 Recent Developments in High Efficiency PV cells nrel gov Yu J Zheng Y Huang J 2014 Towards High Performance Organic Photovoltaic Cells A Review of Recent Development in Organic Photovoltaics Polymers 6 9 2473 2509 doi 10 3390 polym6092473 Sun Y Welch G C Leong W L Takacs C J Bazan G C Heeger A J 2011 Solution processed small molecule solar cells with 6 7 efficiency Nature Materials 11 1 44 8 Bibcode 2012NatMa 11 44S doi 10 1038 nmat3160 PMID 22057387 EPFL Achieves 21 Efficiency for Perovskites dyesol com 8 December 2015 St John Jeff 23 August 2012 Solar Electronics Panel Integration and the Bankability Challenge greentechmedia com Self cooling Solar Cells CNN 2014 09 18 a b Smil Vaclav 2006 Energy at the Crossroads oecd org Retrieved on 3 June 2012 Renewable Energy Is the Future in Nuclear Archived 16 January 2014 at the Wayback Machine Prof Gordon Aubrecht Ohio State at Marion TEDxColumbus The Innovators 18 October 2012 Study Air pollution causes 200 000 early deaths each year in the U S News mit edu Retrieved 30 December 2017 The US could prevent a lot of deaths by switching from coal to solar USA TODAY Retrieved 30 December 2017 Potential lives saved by replacing coal with solar photovoltaic electricity production in the U S Renewable and Sustainable Energy Reviews 80 2017 pp 710 715 open access Nieuwlaar Evert and Alsema Erik Environmental Aspects of PV Power Systems IEA PVPS Task 1 Workshop 25 27 June 1997 Utrecht The Netherlands McDonald N C Pearce J M 2010 Producer Responsibility and Recycling Solar Photovoltaic Modules PDF Energy Policy 38 11 7041 7047 doi 10 1016 j enpol 2010 07 023 Advantages and disadvantages of solar energy Archived 26 December 2013 at the Wayback Machine Retrieved on 25 December 2013 U S Climate Change Technology Program Transmission and Distribution Technologies Archived 27 September 2007 at the Wayback Machine PDF Retrieved on 3 June 2012 Fraunhofer 41 1 efficiency multi junction solar cells renewableenergyfocus com 28 January 2009 Study Sees Solar Cost Competitive In Europe By 2015 Solar Cells Info 16 October 2007 Retrieved on 3 June 2012 Berkeley FIRST Solar Financing City of Berkeley CA cityofberkeley info Archived from the original on 2 June 2013 Retrieved 9 February 2009 DSIRE Solar Portal Archived 9 March 2012 at the Wayback Machine Dsireusa org 4 April 2011 Retrieved on 3 June 2012 Miller Wendy Liu Aaron Amin Zakaria Wagner Andreas 2018 Power Quality and Rooftop Photovoltaic Households An Examination of Measured Data at Point of Customer Connection Sustainability 10 4 1224 doi 10 3390 su10041224 L Liu W Miller and G Ledwich 2017 Solutions for reducing facilities electricity costs Australian Ageing Agenda 39 40 Available https www australianageingagenda com au 2017 10 27 solutions reducing facility electricity costs Archived 20 May 2019 at the Wayback Machine Miller Wendy Liu Lei Aaron Amin Zakaria Gray Matthew 2018 Involving occupants in net zero energy solar housing retrofits An Australian sub tropical case study Solar Energy 159 390 404 Bibcode 2018SoEn 159 390M doi 10 1016 j solener 2017 10 008 Further reading EditPortals Energy Renewable energy Environment Retrieved from https en wikipedia org w index php title Photovoltaics amp oldid 1149748613, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.