Today, the U.S. Department of Energy (DOE) announced selections for its Notice of Opportunity for Technical Assistance (NOTA) to perform techno-economic studies to evaluate the long-term value of two selected pumped-storage hydropower (PSH) projects. While PSH projects were initially built to balance the electricity system between period of high demand during the day and low demand at night, increases in variable renewable generation have changed how plants are operated and the value they provide to the grid. For example, instead of generating during the day and pumping at night, many plants now change operational modes multiple times per day and are relied on to provide quick ramping or frequency response. Determining the value of PSH under these changing grid conditions is a significant challenge that requires new modeling tools and analysis. These studies will provide PSH developers with improved capabilities to estimate the value of a proposed PSH project and compare financial revenue streams under current market structures relative to the economic value of PSH projects to the grid.

The techno-economic studies for the two selected projects will be carried out by a Technical Assistance team comprising subject matter experts from the following DOE national laboratories: Argonne National Laboratory, Idaho National Laboratory, National Renewable Energy Laboratory, Oak Ridge National Laboratory, and Pacific Northwest National Laboratory. The studies will support a larger multi-year research strategy to define the capabilities and estimate the value that hydropower and PSH resources contribute to electric grid resilience and reliability and how those contributions could be optimized for a rapidly evolving grid.

The Technical Assistance team has developed draft guidance—a step-by-step methodology that can be used by PSH developers, plant owners and operators, and other stakeholders to assess the economic value of existing or planned PSH projects. The methodology will be applied at the two sites below to evaluate and demonstrate the potential economic and financial value of the proposed projects. Through these studies, the team will test and refine the valuation guidance, after which the guidance and valuation tools will be made publicly available for use by the hydropower industry.

GridAmerica Holdings, Inc., Goldendale Energy Storage Project

GridAmerica Holdings’ proposed Goldendale project would be located on the border of Oregon and Washington at the northern terminus of the Pacific AC and DC intertie transmission lines. This project, if constructed, could facilitate the storage and export of the growing amount of wind energy available in the Northwest to nearby states. Using existing pumping infrastructure from an old aluminum smelting facility, the closed-loop system would include three variable-speed reversible pump-turbines for a total generating capacity of 1,200 megawatts (MW) and a total pumping capacity of 1,552 MW. The project would provide a range of services to the grid to support reliability and resilience in addition to specifically balancing variable wind generation. A preliminary permit for the project was issued by the Federal Energy Regulatory Commission (FERC) in March 2018.

Absaroka Energy, Banner Mountain Project

Absaroka Energy’s proposed Banner Mountain project would be located in central Wyoming—a region with increased development of variable renewable energy sources like wind. The project also lies along the proposed route of the Energy Gateway West 500-kilovolt (kV) transmission line, which would enable it to serve additional areas in the western and southwestern United States. Banner Mountain would be a closed-loop facility that would include three ternary units—a PSH technology that enables rapid switching between generating and pumping modes—for a total capacity of 400 MW. The project would support grid reliability and resilience by balancing variable generation and enabling improved operation of existing transmission and generation assets in the region. A preliminary permit for the project was issued by FERC in May 2018.

The Office of Energy Efficiency and Renewable Energy supports research and development of energy efficiency and renewable energy technologies to strengthen U.S. economic growth, energy security, and environmental quality. For more information on water power research, development, testing, and deployment see the EERE Water Power Technology Office’s website.