A new technology is gaining ground across the globe – Pumped storage hydropower (PSH) – a type of hydroelectric energy storage.
Over the past century, hydroelectric power has been synonymous with gigantic dams, like the Hoover Dam in the U.S. or the Three Gorges Dam in China. And while the feats of engineering provide renewable energy, they in turn displace communities and destroy ecosystems.
However, new research released last week by Global Energy Monitor reveals a transformation underway in hydroelectric projects. Instead of conventional dams, a new technology called pumped storage hydropower is rapidly expanding, using the same gravitational qualities of water.
Is it a lake or a battery?
Pumped storage hydropower (PSH) is a type of hydroelectric energy storage. It is a configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other (discharge), passing through a turbine.
The system also requires power as it pumps water back into the upper reservoir (recharge). PSH turns the upper reservoir into a giant storage battery because it can store power and then release it when needed.
The first known use cases of PSH were found in Italy and Switzerland in the 1890s, and PSH was first used in the United States in 1930. Now, PSH facilities can be found all around the world.
Pumped Storage Hydropower can be further defined as being an open-loop or closed-loop system. Open-loop PSH has an ongoing hydrologic connection to a natural body of water. With closed-loop PSH, reservoirs are not connected to an outside body of water.
As you can see, both of these systems involve two reservoirs: one on top of a hill and another at the bottom. When electricity generated from nearby power plants exceeds demand, it’s used to pump water uphill, essentially filling the upper reservoir as a battery. Later, when electricity demand spikes, water is released to the lower reservoir through a turbine, generating power.
Pumped storage is a crucial component of the global energy transition, as the worldwide growth in variable renewable energy sources like wind and solar increases the need for energy storage solutions.
Modeling by IRENA suggests that 420 GW of total installed pumped storage hydropower will be needed in order to allow the world to meet the Paris Agreement’s climate goals by 2050.
