Pumped-storage hydroelectricity

"Hydro-storage" redirects here. For storage of water for other purposes, see Reservoir.

Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential energy of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process make the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest. If the upper lake collects significant rainfall or is fed by a river then the plant may be a net energy producer in the manner of a traditional hydroelectric plant.

Diagram of the TVA pumped storage facility at Raccoon Mountain Pumped-Storage Plant in Tennessee, United States

Shaded-relief topo map of the Taum Sauk pumped storage plant in Missouri, United States. The lake on the mountain is built upon a flat surface, requiring a dam around the entire perimeter.

Pumped-storage hydroelectricity allows energy from intermittent sources (such as solar, wind) and other renewables, or excess electricity from continuous base-load sources (such as coal or nuclear) to be saved for periods of higher demand.^[1][2] The reservoirs used with pumped storage are quite small when compared to conventional hydroelectric dams of similar power capacity, and generating periods are often less than half a day.

Pumped storage is by far the largest-capacity form of grid energy storage available, and, as of 2020, the United States Department of Energy Global Energy Storage Database reports that PSH accounts for around 95% of all active tracked storage installations worldwide, with a total installed throughput capacity of over 181 GW, of which about 29 GW are in the United States, and a total installed storage capacity of over 1.6 TWh, of which about 250 GWh are in the United States.^[3] The round-trip energy efficiency of PSH varies between 70%–80%,^[4][5][6][7] with some sources claiming up to 87%.^[8]

The main requirement for PSH is hilly country. The global greenfield pumped hydro atlas lists more than 600,000 potential sites around the world, which is about 100 times more than needed to support 100% renewable electricity. Most are closed loop systems away from rivers. For example, the United States has about 35,000 potential sites.Areas of natural beauty and new dams on rivers can be avoided because of the very large number of potential sites. Some projects utilise existing reservoirs (dubbed "bluefield") such as the 350 Gigawatt-hour Snowy 2.0 scheme under construction in Australia. Some recently proposed projects propose to take advantage of "brownfield" locations such as disused mines such as the Kidston project under construction in Australia.^[9]

Water requirements for PSH are small: about 1 Gigalitre of initial fill water per Gigawatt-hour of storage. This water is recycled uphill and downhill for many decades. Land requirements are also small: about 10 Hectares per Gigawatt-hour of storage, which is much smaller than the land occupied by the solar and windfarms that the storage supports. Closed loop (off-river) pumped hydro storage has the smallest carbon emissions per unit of storage of all candidates for large scale energy storage.

Overview

Basic principle

 

Power distribution, over a day, of a pumped-storage hydroelectricity facility. Green represents power consumed in pumping; red is power generated.

At times of low electrical demand, excess generation capacity is used to pump water into the upper reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity. Reversible turbine/generator assemblies act as a combined pump and turbine generator unit (usually a Francis turbine design).^[10] Variable speed operation further optimize the round trip efficiency in pumped hydro storage plants.^[11][12] In micro-PSH applications, a group of pumps and Pump As Turbine (PAT) could be implemented respectively for pumping and generating phases.^[13] The same pump could be used in both modes by changing rotational direction and speed:^[13] the operation point in pumping usually differs from the operation point in PAT mode.

Types: natural or man-made reservoirs

In open-loop systems, pure pumped-storage plants store water in an upper reservoir with no natural inflows, while pump-back plants utilize a combination of pumped storage and conventional hydroelectric plants with an upper reservoir that is replenished in part by natural inflows from a stream or river. Plants that do not use pumped-storage are referred to as conventional hydroelectric plants; conventional hydroelectric plants that have significant storage capacity may be able to play a similar role in the electrical grid as pumped storage by deferring output until needed.

Economic efficiency

Taking into account evaporation losses from the exposed water surface and conversion losses, energy recovery of 70–80% or more can be achieved.^[14] This technique is currently the most cost-effective means of storing large amounts of electrical energy, but capital costs and the presence of appropriate geography are critical decision factors in selecting pumped-storage plant sites.

The relatively low energy density of pumped storage systems requires either large flows and/or large differences in height between reservoirs. The only way to store a significant amount of energy is by having a large body of water located relatively near, but as high as possible above, a second body of water. In some places this occurs naturally, in others one or both bodies of water were man-made. Projects in which both reservoirs are artificial and in which no natural inflows are involved with either reservoir are referred to as "closed loop" systems.^[15]

These systems may be economical because they flatten out load variations on the power grid, permitting thermal power stations such as coal-fired plants and nuclear power plants that provide base-load electricity to continue operating at peak efficiency, while reducing the need for "peaking" power plants that use the same fuels as many base-load thermal plants, gas and oil, but have been designed for flexibility rather than maximal efficiency. Hence pumped storage systems are crucial when coordinating large groups of heterogeneous generators. Capital costs for pumped-storage plants are relatively high, although this is somewhat mitigated by their proven long service life of decades - and in some cases over a century,^[16][17] which is three to five times longer than utility-scale batteries. When electricity prices become negative, pumped hydro operators may earn twice - when "buying" the electricity to pump the water to the upper reservoir at negative spot prices and again when selling the electricity at a later time when prices are high.

 

The upper reservoir (Llyn Stwlan) and dam of the Ffestiniog Pumped Storage Scheme in North Wales. The lower power station has four water turbines which generate 360 MW of electricity within 60 seconds of the need arising.

Along with energy management, pumped storage systems help control electrical network frequency and provide reserve generation. Thermal plants are much less able to respond to sudden changes in electrical demand, potentially causing frequency and voltage instability. Pumped storage plants, like other hydroelectric plants, can respond to load changes within seconds.

The most important use for pumped storage has traditionally been to balance baseload powerplants, but may also be used to abate the fluctuating output of intermittent energy sources. Pumped storage provides a load at times of high electricity output and low electricity demand, enabling additional system peak capacity. In certain jurisdictions, electricity prices may be close to zero or occasionally negative on occasions that there is more electrical generation available than there is load available to absorb it; although at present this is rarely due to wind or solar power alone, increased wind and solar generation will increase the likelihood of such occurrences.^{[citation needed]} It is particularly likely that pumped storage will become especially important as a balance for very large scale photovoltaic and wind generation.^[18] Increased long distance transmission capacity combined with significant amounts of energy storage will be a crucial part of regulating any large-scale deployment of intermittent renewable power sources.^[19] The high non-firm renewable electricity penetration in some regions supplies 40% of annual output, but 60% may be reached before additional storage is necessary.^[20][21][22]

Small-scale facilities

Smaller pumped storage plants cannot achieve the same economies of scale as larger ones, but some do exist, including a recent 13 MW project in Germany. Shell Energy has proposed a 5 MW project in Washington State. Some have proposed small pumped storage plants in buildings, although these are not yet economical.^[23] Also, it is difficult to fit large reservoirs into the urban landscape.^[23] Nevertheless, some authors defend the technological simplicity and security of water supply as important externalities.^[23]

History

The first use of pumped storage was in 1907 in Switzerland, at the Engeweiher pumped storage facility near Schaffhausen, Switzerland.^[24][25] In the 1930s reversible hydroelectric turbines became available. These turbines could operate as both turbine-generators and in reverse as electric motor driven pumps. The latest in large-scale engineering technology are variable speed machines for greater efficiency. These machines operate in synchronization with the network frequency when generating, but operate asynchronously (independent of the network frequency) when pumping.

The first use of pumped-storage in the United States was in 1930 by the Connecticut Electric and Power Company, using a large reservoir located near New Milford, Connecticut, pumping water from the Housatonic River to the storage reservoir 70 metres (230 ft) above.^[26]

Worldwide use

See also: List of pumped-storage hydroelectric power stations and United States Department of Energy Global Energy Storage Database

 

Kruonis Pumped Storage Plant, Lithuania

In 2009, world pumped storage generating capacity was 104 GW,^[27] while other sources claim 127 GW, which comprises the vast majority of all types of utility grade electric storage.^[28] The EU had 38.3 GW net capacity (36.8% of world capacity) out of a total of 140 GW of hydropower and representing 5% of total net electrical capacity in the EU. Japan had 25.5 GW net capacity (24.5% of world capacity).^[27]

In 2010 the United States had 21.5 GW of pumped storage generating capacity (20.6% of world capacity).^[29] PSH contributed 21,073 GWh of energy in 2020 in the United States, but −5,321 GWh (net) because more energy is consumed in pumping than is generated.^[30] Nameplate pumped storage capacity had grown to 21.6 GW by 2014, with pumped storage comprising 97% of grid-scale energy storage in the United States. As of late 2014, there were 51 active project proposals with a total of 39 GW of new nameplate capacity across all stages of the FERC licensing process for new pumped storage hydroelectric plants in the United States, but no new plants were currently under construction in the United States at the time.^[31][32]

The five largest operational pumped-storage plants are listed below (for a detailed list see List of pumped-storage hydroelectric power stations):

Station	Country	Location	Installed generation capacity (MW)	Storage capacity (GWh)	Refs
Fengning Pumped Storage Power Station	China	41°39′58″N 116°31′44″E / 41.66611°N 116.52889°E / 41.66611; 116.52889 (Fengning Pumped Storage Power Station)	3,600	40	^[33]^[34]
Bath County Pumped Storage Station	United States	38°12′32″N 79°48′00″W / 38.20889°N 79.80000°W / 38.20889; -79.80000 (Bath County Pumped-storage Station)	3,003	24	^[35]
Guangdong Pumped Storage Power Station	China	23°45′52″N 113°57′12″E / 23.76444°N 113.95333°E / 23.76444; 113.95333 (Guangzhou Pumped Storage Power Station)	2,400		^[36]^[37]
Huizhou Pumped Storage Power Station	China	23°16′07″N 114°18′50″E / 23.26861°N 114.31389°E / 23.26861; 114.31389 (Huizhou Pumped Storage Power Station)	2,400		^[38]^[39]^[40]^[41]
Okutataragi Pumped Storage Power Station	Japan	35°14′13″N 134°49′55″E / 35.23694°N 134.83194°E / 35.23694; 134.83194 (Okutataragi Hydroelectric Power Station)	1,932		^[42]
Ludington Pumped Storage Power Plant	United States	43°53′37″N 86°26′43″W / 43.89361°N 86.44528°W / 43.89361; -86.44528 (Ludington Pumped Storage Power Plant)	1,872	20	^[43]^[44]
Note: this table shows the power-generating capacity in megawatts as is usual for power stations. However, the overall energy-storage capacity in megawatt-hours (MWh) is a different intrinsic property and can not be derived from the above given figures.

Countries with the largest power pumped-storage hydro capacity in 2017^[45]

Country	Pumped storage generating capacity (GW)	Total installed generating capacity (GW)^[46]	Pumped storage/ total generating capacity
China	32.0	1646.0	1.9%
Japan	28.3	322.2	8.8%
United States	22.6	1074.0	2.1%
Spain	8.0	106.7	7.5%
Italy	7.1	117.0	6.1%
India	6.8	308.8	2.2%
Germany	6.5	204.1	3.2%
Switzerland	6.4	19.6	32.6%
France	5.8	129.3	4.5%
Austria	4.7	25.2	18.7%
South Korea	4.7	103.0	4.6%
Portugal	3.5	19.6	17.8%
Ukraine	3.1	56.9	5.4%
South Africa	2.9	56.6	5.1%
United Kingdom	2.8	94.6	3.0%
Australia	2.6	67.0	3.9%
Russia	2.2	263.5	0.8%
Poland	1.7	37.3	4.6%
Thailand	1.4	41.0	3.4%
Bulgaria	1.4	12.5	9.6%
Belgium	1.2	21.2	5.7%

Australia

Australia has 15GW of pumped storage under construction or in development. Examples include:

In June 2018 the Australian federal government announced that 14 sites had been identified in Tasmania for pumped storage hydro, with the potential of adding 4.8GW to the national grid if a second interconnector beneath Bass Strait was constructed.

The Snowy 2.0 project will link two existing dams in the New South Wales Snowy Mountains to provide 2,000 MW of capacity and 350,000 MWh of storage.^[47]

In September 2022, a pumped hydro electric storage (PHES) scheme was announced at Pioneer-Burdekin in central Queensland which has the potential to be the largest PHES in the world at 5GW.

Norway

There are 9 power stations capable of pumping with a total installed capacity of 1344 MW and an average annual production of 2247 GWh. The pumped storage hydro power in Norway is built a bit different from the rest of the world. They are designed for seasonal pumping. Most of them can also not cycle the water endlessly, but only pump and reuse once. The reason for this is the design of the tunnels and elevation of lower and upper reservoir. Some, like Nygard power station, pump water from several river intakes up to a reservoir.

The largest one, Saurdal, which is part of the Ulla-Førre complex, have four 160 MW Francis turbines, but only two are reversible. The lower reservoir is at higher elevation than the station itself, and thus the water pumped up can only be used once before it has to flow to the next station, Kvilldal, further down the tunnel system. And in addition to the lower reservoir it will receive water that can be pumped up from 23 river/stream and small reservoir intakes. Some which have already gone through a smaller power station on its way.

Pump-back hydroelectric dams

Conventional hydroelectric dams may also make use of pumped storage in a hybrid system that both generates power from water naturally flowing into the reservoir as well as storing water pumped back to the reservoir from below the dam. The Grand Coulee Dam in the United States was expanded with a pump-back system in 1973.^[48] Existing dams may be repowered with reversing turbines thereby extending the length of time the plant can operate at capacity. Optionally a pump back powerhouse such as the Russell Dam (1992) may be added to a dam for increased generating capacity. Making use of an existing dam's upper reservoir and transmission system can expedite projects and reduce costs.

In January 2019, the State Grid Corporation of China announced plans to invest US$5.7 billion in five pumped hydro storage plants with a total 6 GW capacity, to be located in Hebei, Jilin, Zhejiang, Shandong provinces, and in Xinjiang Autonomous Region. China is seeking to build 40 GW of pumped hydro capacity installed by 2020.^[49]

Potential technologies

Seawater

Pumped storage plants can operate with seawater, although there are additional challenges compared to using fresh water, such as saltwater corrosion and barnacle growth.^[50] Inaugurated in 1966, the 240 MW Rance tidal power station in France can partially work as a pumped-storage station. When high tides occur at off-peak hours, the turbines can be used to pump more seawater into the reservoir than the high tide would have naturally brought in. It is the only large-scale power plant of its kind.

In 1999, the 30 MW Yanbaru project in Okinawa was the first demonstration of seawater pumped storage. It has since been decommissioned. A 300 MW seawater-based Lanai Pumped Storage Project was considered for Lanai, Hawaii, and seawater-based projects have been proposed in Ireland.^[51] A pair of proposed projects in the Atacama Desert in northern Chile would use 600 MW of photovoltaic solar (Skies of Tarapacá) together with 300 MW of pumped storage (Mirror of Tarapacá) raising seawater 600 metres (2,000 ft) up a coastal cliff.^[52][53]

Freshwater coastal reservoirs

Freshwater from the river floods is stored in the sea area replacing seawater by constructing coastal reservoirs. The stored river water is pumped to uplands by constructing a series of embankment canals and pumped storage hydroelectric stations for the purpose of energy storage, irrigation, industrial, municipal, rejuvenation of exploited rivers, etc. These multipurpose coastal reservoir projects create massive pumped storage hydroelectric potential to utilize the variable and intermittent solar and wind power which are carbon neutral, clean, and renewable energy sources.^[54]

Underground reservoirs

The use of underground reservoirs has been investigated.^[55] Recent examples include the proposed Summit project in Norton, Ohio, the proposed Maysville project in Kentucky (underground limestone mine), and the Mount Hope project in New Jersey, which was to have used a former iron mine as the lower reservoir. The proposed energy storage at the Callio site in Pyhäjärvi (Finland) would utilize the deepest base metal mine in Europe, with 1,450 metres (4,760 ft) elevation difference.^[56] Several new underground pumped storage projects have been proposed. Cost-per-kilowatt estimates for these projects can be lower than for surface projects if they use existing underground mine space. There are limited opportunities involving suitable underground space, but the number of underground pumped storage opportunities may increase if abandoned coal mines prove suitable.^[57]

In Bendigo, Victoria, Australia, the Bendigo Sustainability Group has proposed the use of the old gold mines under Bendigo for Pumped Hydro Energy Storage.^[58] Bendigo has the greatest concentration of deep shaft hard rock mines anywhere in the world with over 5,000 shafts sunk under Bendigo in the second half of the 19th Century. The deepest shaft extends 1,406 metres vertically underground. A recent pre-feasibility study has shown the concept to be viable with a generation capacity of 30 MW and a run time of 6 hours using a water head of over 750 metres.

US-based start-up Quidnet Energy is exploring using abandoned oil and gas wells for pumped-storage. If successful, they hope to scale up to using many or most of the 3 million abandoned wells in the US.^[59][60]

Decentralised systems

Small (or micro) applications for pumped-storage could be built on streams and within infrastructures, such as drinking water networks^[61] and artificial snow making infrastructures. In this regard, a storm-water basin has been concretely implemented as a cost-effective solution for a water reservoir in a micro pumped hydro energy storage.^[13] Such plants provide distributed energy storage and distributed flexible electricity production and can contribute to the decentralized integration of intermittent renewable energy technologies, such as wind power and solar power. Reservoirs that can be used for small pumped-storage hydropower plants could include^[62] natural or artificial lakes, reservoirs within other structures such as irrigation, or unused portions of mines or underground military installations. In Switzerland one study suggested that the total installed capacity of small pumped-storage hydropower plants in 2011 could be increased by 3 to 9 times by providing adequate policy instruments.^[62]

Underwater reservoirs

Further information: Stored Energy at Sea

In March 2017 the research project StEnSea (Storing Energy at Sea) announced their successful completion of a four-week test of a pumped storage underwater reservoir. In this configuration a hollow sphere submerged and anchored at great depth acts as the lower reservoir, while the upper reservoir is the enclosing body of water. Electricity is created when water is let in via a reversible turbine integrated into the sphere. During off-peak hours the turbine changes direction and pumps the water out again, using "surplus" electricity from the grid. The quantity of power created when water is let in grows proportionally to the height of the column of water above the sphere, in other words: the deeper the sphere is located, the more densely it can store energy. As such the energy storage capacity of the submerged reservoir is not governed by the gravitational energy in the traditional sense, but rather by the vertical pressure variation.

Home use

Using a pumped-storage system of cisterns and small generators, pico hydro may also be effective for "closed loop" home energy generation systems.^[63][64]

Fracking

Using hydraulic fracturing pressure can be stored underground in strata such as shale. The shale used contains no hydrocarbons.^[65]

Electrolysis

One idea to reduce pumping energy requirements is to use electricity to split water at a low elevation, and then pipe the lighter-than-air hydrogen to a high elevation where it could be burned with atmospheric oxygen to produce water. This high-elevation water could then be returned to the low elevation, potentially more than recovering efficiency losses by harvesting the gravitational potential energy of higher-altitude atmospheric oxygen (which is later harmlessly re-mixed by sun-powered wind).^[66]

High-density pumped hydro

RheEnergise^[67] aim to improve the efficiency of pumped storage by using fluid 2.5x denser than water ("a fine-milled suspended solid in water"^[68]), such that "projects can be 2.5x smaller for the same power."^[69]

See also

•  Energy portal
•  Renewable energy portal
•  Water portal

• Compressed-air energy storage
• Gravity battery
• Hydropower
• Tide mill
• List of energy storage power plants

References

1. "Storage for a secure Power Supply from Wind and Sun" (PDF). (PDF) from the original on 23 February 2011. Retrieved 21 January 2011.
2. Rehman, Shafiqur; Al-Hadhrami, Luai; Alam, Md (30 April 2015). "Pumped hydro energy storage system: A technological review". Renewable and Sustainable Energy Reviews. 44: 586–598. doi:10.1016/j.rser.2014.12.040. from the original on 8 February 2022. Retrieved 15 November 2016 – via ResearchGate.
3. "DOE OE Global Energy Storage Database". U.S. Department of Energy Energy Storage Systems Program. Sandia National Laboratories. 8 July 2020. from the original on 9 July 2021. Retrieved 12 July 2020.
4. "Energy storage - Packing some power". The Economist. 3 March 2011. from the original on 6 March 2020. Retrieved 11 March 2012.
5. Jacob, Thierry (7 July 2011). (PDF). Stucky. Archived from the original (PDF) on 7 July 2011. Retrieved 13 February 2012.
6. Levine, Jonah G. (December 2007). (PDF). University of Colorado. p. 6. Archived from the original (PDF) on 1 August 2014.
7. Yang, Chi-Jen (11 April 2016). Pumped Hydroelectric Storage. Duke University. ISBN 9780128034491.
8. . Archived from the original on 18 November 2015. Retrieved 26 February 2017.
9. (PDF). 17 July 2019. p. 188. Archived from the original (PDF) on 17 July 2019.
10. "Pumped-Hydro Energy Storage" (PDF). (PDF) from the original on 31 October 2020. Retrieved 28 August 2020.
11. "Variable Speed Is Key To World's Biggest Pumped Hydro Energy Storage Project, China's Fengning Plant". 4 July 2018. from the original on 7 August 2020. Retrieved 28 August 2020.
12. Joseph, Anto; Chelliah, Thanga; Lee, Sze; Lee, Kyo-Beum (2018). "Reliability of Variable Speed Pumped-Storage Plant". Electronics. 7 (10): 265. doi:10.3390/electronics7100265.
13. Morabito, Alessandro; Hendrick, Patrick (7 October 2019). "Pump as turbine applied to micro energy storage and smart water grids: A case study". Applied Energy. 241: 567–579. doi:10.1016/j.apenergy.2019.03.018.
14. . energystorage.org. Archived from the original on 19 January 2019. Retrieved 15 January 2017.
15. . www.ferc.gov. Archived from the original on 20 July 2017. Retrieved 15 January 2017.
16. "Pumping power: Pumped storage stations around the world". 30 December 2020. from the original on 19 November 2021. Retrieved 19 November 2021.
17. "Erneuter Abschreiber beim Pumpspeicher Engeweiher". 28 June 2017. from the original on 20 April 2021. Retrieved 9 March 2020.
18. Kurokawa, K.; Komoto, K.; van der Vleuten, P.; Faiman, D. (eds.). . Earthscan. Archived from the original on 13 June 2007 – via IEA Photovoltaic Power Systems Programme.
19. "Reducing Wind Curtailment through Transmission Expansion in a Wind Vision Future" (PDF). (PDF) from the original on 16 January 2017. Retrieved 14 January 2017.
20. "German grid operator sees 70% wind + solar before storage needed". Renew Economy. 7 December 2015. from the original on 2 February 2017. Retrieved 20 January 2017. Schucht says, in the region he is operating in, 42 percent of the power supply (in output, not capacity), came from wind and solar – about the same as South Australia. Schucht believes that integration of 60 to 70 percent variable renewable energy – just wind and solar – could be accommodated within the German market without the need for additional storage. Beyond that, storage will be needed.
21. Dehmer, Dagmar (8 June 2016). "German electricity transmission CEO: '80% renewables is no problem'". Der Tagesspiegel / EurActiv.com. from the original on 18 October 2016. Retrieved 1 February 2017. There are a certain number of myths in the energy industry. One of them is that we need more flexibility in the system to integrate renewables, like energy storage, interruptible loads or backup power plants. That's a myth. We are well on track to having a system that can accommodate between 70-80% renewable energy without the need for more flexibility options.
22. . Energinet.dk. 15 January 2016. Archived from the original on 25 January 2016.
23. de Oliveira e Silva, Guilherme; Hendrick, Patrick (1 October 2016). "Pumped hydro energy storage in buildings". Applied Energy. 179: 1242–1250. doi:10.1016/j.apenergy.2016.07.046.
24. Jung, Daniel (June 2017). . Archived from the original on 20 April 2021.
25. Institution of Civil Engineers. Institution of Civil Engineers (Great Britain). April 1990. p. 1. ISBN 9780727715869.
26. "A Ten-Mile Storage Battery". Popular Science. July 1930. p. 60 – via Google Books.
27. "International Energy Statistics". www.eia.gov. from the original on 27 April 2017. Retrieved 4 May 2019.
28. Rastler (2010). . et al. Palo Alto, Calif.: EPRI. Archived from the original on 17 August 2011.
29. . Archived from the original on 28 May 2010. Retrieved 29 October 2010.
30. "Table 3.27 Gross/Net Generation by Energy Storage Technology: Total (All Sectors), 2010 - 2020". US Energy Information Administration. from the original on 15 November 2021. Retrieved 4 January 2022.
31. "2014 Hydropower Market Report Highlights" (PDF). U.S. Department of Energy. (PDF) from the original on 20 February 2017. Retrieved 19 February 2017.
32. "2014 Hydropower Market Report" (PDF). U.S. Department of Energy. (PDF) from the original on 1 February 2017. Retrieved 19 February 2017.
33. "Clean power plant online to ensure sound Beijing Winter Olympics". China Daily. 31 December 2021. Retrieved 23 January 2023.
34. "China's State Grid powers up 3.6-GW pumped-storage hydro complex". Renewablesnow.com. Retrieved 10 March 2022.
35. , archived from the original on 3 January 2012, retrieved 30 December 2011
36. Pumped-storage hydroelectric power stations in China, archived from the original on 8 December 2012, retrieved 25 June 2010
37. (PDF). Archived from the original (PDF) on 7 July 2011. Retrieved 25 June 2010.
38. (PDF) (in Chinese). Archived from the original (PDF) on 7 July 2011.
39. (PDF) (in Chinese). Archived from the original (PDF) on 7 July 2011.
40. (PDF) (in Chinese). Archived from the original (PDF) on 7 July 2011.
41. Huizhou Pumped-storage Power Station, retrieved 25 June 2010^{[permanent dead link]}
42. (PDF). Japan Nuclear. Archived from the original (PDF) on 4 June 2013. Retrieved 1 September 2010.
43. , archived from the original on 21 October 2007, retrieved 1 September 2010
44. , archived from the original on 11 July 2011, retrieved 1 September 2010
45. . Abu Dhabi: International Renewable Energy Agency. 2017. p. 30. Archived from the original (PDF) on 31 August 2018.
46. "Electricity – installed generating capacity". The World Factbook. from the original on 26 September 2021. Retrieved 26 September 2021.
47. "How could pumped hydro energy storage power our future?". ARENAWIRE. Australian Renewable Energy Agency. 18 January 2021. from the original on 19 January 2021. Retrieved 18 January 2021.
48. Lehr, Jay H.; Keeley, Jack, eds. (2016). Alternative Energy and Shale Gas Encyclopedia (1st ed.). Wiley. p. 424. ISBN 978-0470894415.
49. Shen, Feifei (9 January 2019). "China's State Grid to Spend $5.7 Billion on Pumped Hydro Plants". Bloomberg.com. from the original on 19 January 2019. Retrieved 18 January 2019.
50. Richard A. Dunlap (5 February 2020). Renewable Energy: Combined Edition. Morgan & Claypool Publishers. ISBN 978-1-68173-600-6. OL 37291231M. Wikidata Q107212803.
51. "Massive Energy Storage, Courtesy of West Ireland". sciencemag.org. 18 February 2012. from the original on 8 September 2017. Retrieved 21 June 2017.
52. "Project Espejo de Tarapacá". Valhalla. 11 March 2015. from the original on 18 June 2017. Retrieved 19 June 2017.
53. "The Mirror of Tarapaca: Chilean power project harnesses both sun and sea". 4 May 2016. from the original on 4 May 2019. Retrieved 4 May 2019.
54. Sasidhar, Nallapaneni (May 2023). "Multipurpose Freshwater Coastal Reservoirs and Their Role in Mitigating Climate Change" (PDF). Indian Journal of Environment Engineering. 3 (1): 30–45. doi:10.54105/ijee.A1842.053123. ISSN 2582-9289. S2CID 258753397. Retrieved 23 May 2023.
55. Pummer, Elena (2016). Hybrid Modelling of the Hydrodynamic Processes in Underground Pumped Storage Plants (PDF). Aachen, Germany: RWTH Aachen University. (PDF) from the original on 4 November 2020. Retrieved 19 May 2020.
56. "Energy storage". Callio Pyhäjärvi. from the original on 15 March 2018. Retrieved 14 March 2018.
57. "German Coal Mine to Be Reborn as Giant Pumped Storage Hydro Facility". 17 March 2017. from the original on 9 July 2019. Retrieved 20 March 2017.
58. Smith, Trevor. "Bendigo Mines Pumped Hydro Project". Bendigo Sustainability Group. from the original on 15 July 2018. Retrieved 13 July 2020.
59. Lo, Chris (27 November 2016). "Could depleted oil wells be the next step in energy storage?". Retrieved 16 May 2022.
60. "Press Release: CPS Energy & Quidnet Energy Announce Landmark Agreement to Build Grid-Scale, Long Duration, Geomechanical Pumped Storage Project in Texas". quidnetenergy.com. Retrieved 16 May 2022.
61. "Senator Wash". www.iid.com. Imperial Irrigation District. from the original on 26 June 2016. Retrieved 6 August 2016.
62. Crettenand, N. (2012). (PhD Thesis N° 5356.). Ecole Polytechnique Fédérale de Lausanne. Archived from the original on 13 September 2018.
63. . Science Daily. 24 October 2016. Archived from the original on 10 May 2017. Retrieved 6 September 2018.
64. Root, Ben (December 2011 – January 2012). . Vol. 146. Home Power. p. 77. Archived from the original on 5 September 2018. Retrieved 6 September 2018.
65. Russell Gold (21 September 2021). "Fracking Has a Bad Rep, but Its Tech Is Powering a Clean Energy Shift Texas start-ups are harnessing know-how born of the shale boom in pursuit of a greener future". Texas Monthly. from the original on 24 September 2021. Retrieved 23 September 2021.
66. Charles I. Clausing (May 2003). "Recharging the power grid". Technology Review. p. 13.
67. RheEnergise company website
68. [1]Institution of Mechanical Engineers article
69. [2] RheEnergise 'how it works' article

External links

 

Look up pumped hydro in Wiktionary, the free dictionary.

 

Wikimedia Commons has media related to Pumped-storage hydroelectric power plants.

• Pumped-storage hydroelectricity at Curlie
• Global pumped hydro atlas, with over 600K potential sites