Pumped Storage

Pumped storage strengthens the grid

Pumped Storage Plant

Pumped storage provides vital support to our nation’s electricity grid, helping to balance the flow of power across transmission networks by absorbing excess when electricity demand is low and releasing it when demand increases. With an ability to respond almost instantaneously to changes in the amount of electricity running through the grid, pumped storage is an essential component of the nation’s electricity network. Pumped storage is a proven grid-scale energy storage technology that can also enable the U.S. to grow its renewable energy portfolio. The more grid energy storage we have — using tested technologies like pumped storage — the more new energy resources we can bring online.

Pumped storage has been available since the 1930s, but with renewable energy mandates in place in 30 states, variable generation is coming online rapidly and our infrastructure needs electricity storage capacity more than ever.

While benefits of expanding pumped storage capacity are clear, current market structures and regulatory frameworks do not present an effective means of achieving this goal.  Policy changes are needed to support the timely development of additional grid-scale energy storage. NHA has developed a series of recommendations to guide the energy industry and policy makers. For more information, see NHA’s white paper: Challenges and Opportunities for New Pumped Storage Development.

The right policies can help increase pumped storage capacity

Tax credits have helped to ramp up other renewables by creating stable market conditions and providing certainty for investors — which in turn drives the capital expenditures necessary to bring facilities online. Congress should establish that same market stability for pumped storage by moving forward on a proposal for a 20% investment tax credit and CREBs eligibility for energy storage technologies. This would jump-start the pumped storage projects on the drawing board today.

Closed-loop off-river systems, which have minimal impacts, need a new regulatory process. The long development timelines for these large, capital-intensive projects do not allow developers to use incentives designed for projects with shorter lead times.

Project Highlight: New York Power Authority’s Blenheim-Gilboa facility

Nestled in the Catskill Mountains, the New York Power Authority’s (NYPA) Blenheim-Gilboa Pumped Storage Power Project is an essential part of the region’s power supply. The project saves New York consumers money, providing low-cost electricity at the times of highest demand, while also standing in reserve to back up the grid’s electricity supply. Should another facility suddenly go offline, Blenheim-Gilboa can be up and running within two minutes.

The two reservoirs at this large facility hold five billion gallons of water each. When the pumped storage plant is generating power, the water falls from the upper reservoir down a shaft that is five times higher than Niagara Falls turning generators at the bottom and producing up to 1,000MW of power during peak demand periods. When demand is low, cheap surplus power from the grid is used to pump the water back uphill and storing that electricity for use once again when it is most needed.

In May 2010, NYPA completed a $135 million, four-year modernization program that has extended the project’s lifespan. Each of Blenheim-Gilboa’s four turbines was replaced in a phased process, and in total increased the facility’s capacity by 120MW.

The closed loop project is the fifth largest pumped storage facility in the country.

Project Highlight: Eagle Crest Energy

The West is undoubtedly the nation’s hydro powerhouse and is home to some of the largest and most recognizable dams in the country and the world, such as the Hoover Dam. It is also proving to be a laboratory for new applications for hydropower technology that will benefit the nation’s electric grid as a whole.

One such technology is pumped storage. With pumped storage, the power generated by other energy sources like wind and solar can be stored and used when energy demand is high. Power generated off-peak and not needed by consumers, is used to pump water into an upper reservoir. When demand is high, the water is released downhill into a lower reservoir, running through turbines and generating electricity to send back to the grid when it is most needed.

The capacity to store large quantities of electricity makes pumped storage a key provider of what are known as ancillary services, which also include frequency control and reserve generation – two methods of controlling the way in which electricity moves through the transmission system.

In Southern California, Eagle Crest Energy is developing the Eagle Mountain pumped storage project, which will help ensure the reliability of supply in one of the fastest growing electricity markets in the country. California also has the nation’s most aggressive renewable electricity standard, a law requiring utilities to use increasing amounts of renewable energy. The Eagle Mountain project will allow utilities to meet these goals by helping the electricity grid to accommodate increasing amounts of wind and solar power. This pumped storage project will be a sustainable, as well as a reliable, energy source: the Eagle Mountain facility is being built on a previously mined site, converting disturbed land into a usable asset. As a closed-loop system, the facility does not affect any existing waterways or aquatic habitats. During operations, it will be an emissions-free source of generating 1,300 MW of firm power that can be dispatched when needed.

Pumped Storage Factsheet