Pumped-storage hydroelectricity: Difference between revisions

===Decentralised systems===

Small (or micro) applications for pumped storage could be built on streams and within infrastructures, such as drinking water networks<ref>{{Cite web |title=Senator Wash |url=http://www.iid.com/water/water-transportation-system/colorado-river-facilities/senator-wash |url-status=live |archive-url=https://web.archive.org/web/20160626043856/http://www.iid.com/water/water-transportation-system/colorado-river-facilities/senator-wash |archive-date=26 June 2016 |access-date=6 August 2016 |website=www.iid.com |publisher=Imperial Irrigation District |language=en}}</ref> 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.<ref name=":1a" /> 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<ref name="Thesis">{{Cite book |last=Crettenand |first=N. |url=https://infoscience.epfl.ch/record/176337?ln=en |title=The facilitation of mini and small hydropower in Switzerland: shaping the institutional framework. With a particular focus on storage and pumped-storage schemes |publisher=Ecole Polytechnique Fédérale de Lausanne |year=2012 |archive-url=https://web.archive.org/web/20180913040049/https://infoscience.epfl.ch/record/176337?ln=en |archive-date=13 September 2018 |type=PhD Thesis N° 5356.}}</ref> 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 [[Market-based environmental policy instruments|policy instruments]].<ref name="Thesis" />

 

===Underwater reservoirs===

{{Further|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.

 

As such, the energy storage capacity of the submerged reservoir is not governed by the [[gravitational energy]] in the traditional sense, but by the [[vertical pressure variation]].

 

Using [[hydraulic fracturing]] pressure can be stored underground in [[Permeability_(Earth_sciences)|impermeable]] strata such as shale.<ref>{{cite journal|title= Is Hydraulic Fracturing the Next Big Breakthrough in Battery Tech?|journal= [[Society_of_Petroleum_Engineers#Magazines|Journal of Petroleum Technology]]|publisher= [[Society of Petroleum Engineers]]|volume= 75|number =10|date =October 2023|pages= 36–41|last= Jacobs|first= Trent}}</ref> The shale used contains no hydrocarbons.<ref name="TM91221">{{Cite news |last=Russell Gold |date=September 21, 2021 |title=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. |work=Texas Monthly |url=https://www.texasmonthly.com/news-politics/fracking-clean-energy-geothermal/ |url-status=live |access-date=September 23, 2021 |archive-url=https://web.archive.org/web/20210924171206/https://www.texasmonthly.com/news-politics/fracking-clean-energy-geothermal/ |archive-date=24 September 2021}}</ref>

 

===High-density pumped hydro===