Information Study for Pumped Storage Hydropower Siting

Identifying and understanding the issues and interests surrounding the siting of PSH in Washington State is needed if this proven technology is to be used to help achieve the state’s commitment to limit greenhouse gas emissions, transition off fossil fuels, and reduce the impacts of climate change.

The Washington State University Energy Program (WSU) invites Tribes and stakeholders such as local governments, land use and environmental organizations, and other interested parties to participate in a process to share their issues, concerns, and interests about the location of PSH in the state.

Kick-off Webinar

Information Study for Pumped Storage Hydropower Siting

Thursday, June 13, 2024, from 11:00 am to 12:30 pm Pacific Time
Registration required—REGISTER HERE

  • Introduce an information study designed to understand issues and interests surrounding the siting of PSH in Washington
  • Begin identifying participants' views on PSH siting opportunities, concerns, factors, and questions
  • Describe opportunities to be involved and stay updated on the study being conducted by the Washington State University Energy Program

This is an information gathering process only –
there are no PSH projects being proposed or reviewed.

Questions? ¿hablas español?
Contact Karen Janowitz, Project Lead

The state of Washington is committed to achieving an electricity supply free of greenhouse gas emissions by 2045, aiming to stem climate change and improve the health of communities while creating family-sustaining jobs. To do this, more is needed than just replacing fossil fuel sources with carbon-free renewables such as solar and wind.

Energy storage technologies ensure that there are no disruptions in the energy supply with the use of renewable resources by storing energy and then releasing it when needed. While the use of different energy storage methods and technological advancements are increasing rapidly, one of the most established, reliable, and proven methods, dating back decades, is pumped storage hydropower (PSH).

What is Pumped Storage Hydropower

Pumped Storage Hydropower acts as a battery by storing energy and releasing it when demand for electricity is high. It consists of two water reservoirs at different elevations. When energy is needed, water flows from the upper reservoir to the lower reservoir through turbines that generate electricity sent to the electrical grid. Water is pumped from the lower reservoir back up to the upper reservoir when there is an excess energy supply. PSH can provide energy at times when solar and wind resources fluctuate, such as at night or when winds are weak.

PSH is a mature and proven long-duration storage technology that can provide more hours of electricity than most other storage methods.1 As of 2022, PSH provided approximately 96% of the energy storage capacity in the United States, mostly from projects built decades ago.2 Its technology process is mechanical, so it does not rely on mined minerals such as lithium. This efficient technology can quickly respond when power is needed, and PSH’s life-cycle costs are lower than most other battery technologies due to its long lifespan.

Siting needs include specific geology and a sufficient elevation difference between the reservoirs, often between 1000 and 2000 feet – the greater the difference, the more power can be generated. Barriers to developing PSH include its high construction expense and a long construction time. Of particular interest to our information study, there are possible siting impacts to resources, including land use, environmental, and Tribal cultural resources.

The WSU study focuses on closed-loop PSH, where neither reservoir is connected to an existing water body. Most of the existing PSH plants are open loop, with the lower reservoir using water from a river or other water source. Closed-loop PSH has fewer impacts to wildlife, habitats, and the hydrologic cycle.




The information study was written into the Washington State Legislature 2023 Engrossed Second Substitute House Bill 1216 (Section 306), concerning clean energy siting, and signed into law May 3, 2023 effective July 23, 2023. A report is due to the legislature by June 30, 2024.3

The legislature directs WSU to conduct a process to identify issues and interests related to siting pumped storage projects in Washington State in order to support expanded capacity to store intermittently produced renewable energy. The bill states that “The goal of the process is to identify and understand issues and interests of various stakeholders and federally recognized Indian tribes related to areas where pumped storage might be sited, providing useful information to developers of potential projects, and for subsequent environmental reviews under the state environmental policy act.” WSU is to “provide ample opportunities for the engagement of federally recognized Indian Tribes, local governments and special purpose districts, land use and environmental organizations, and additional stakeholders that self-identify as interested in participating in the process.”

Our process

Listening to as many people as possible is key to identifying and understanding issues, interests, and concerns regarding PSH siting. To this end, we invite Tribes, agencies such as local governments and special purpose districts, land use and environmental organizations, and all other interested parties to participate in meetings and webinars to discuss, learn, and share about PSH siting. We are meeting with Tribal staff, attending Tribal conferences, and working with a WSU Tribal Liaison to offer as many methods of engagement with Tribes as possible.

To carry out this information study process, WSU has assembled a PSH Study Team consisting of the WSU Energy Program study lead, the WSU Tribal Liaison for Special Projects, facilitation and outreach professionals from Ross Strategic, and a geographic information system (GIS) consultant from Meridian Environmental.

We will hold facilitated gatherings in early fall 2024 (dates TBA). If there are In-person gatherings, they will be focused in the geographic regions where the landscape topography is more suitable for closed-loop PSH and where other factors do not impede siting. As it is not feasible for the study team to visit all suitable locations, we hope that those in regions we cannot visit will participate in the online gatherings. Our first informational webinar will be in June 2024, with more held throughout the study period.


Researchers from the National Renewable Energy Laboratory (NREL) created a map showing theoretical locations for PSH projects in the United States, using various parameters such as existing elevation data and economic factors.4 The team’s GIS consultant is reviewing and assessing this data for Washington State, and identifying other data and factors unique to Washington that will further refine locations. Some data identified during the Least-Conflict Solar Siting on the Columbia Plateau project5 may be used, however the goal of the PSH siting information process is to gather interests and concerns about PSH siting, not to create a mapping tool as was one of the outcomes of the Least-Conflict study.

How can you participate?

We invite you to sign up for our PSH Siting email distribution list below to receive updates and information about meeting dates and locations. Please let other individuals and groups who may be interested in participating know about this process. We encourage you to contact us for more information or to meet with the WSU PSH study team. Visit the Study’s webpage or to email

Join our email list here!

1 The amount of energy this amounts to depends on the rate of discharge and the maximum rating of the system.
2 U.S. Hydropower Market Report 2023 Edition
3 Laws/House/1216-S2.SL.pdf
4 Closed-Loop Pumped Storage Hydropower Resource Assessment for the United States, 2022