One of the oldest forms of storing electric power, relying on gravity, which gets little attention in the current discussions of how to accommodate the intermittent nature of solar and wind generation, could be headed for northwestern Colorado and a major revitalization.
A Salt Lake City renewables company working on solar, wind, and all forms of storing electricity, rPlus Energies, according to the Steamboat Pilot newspaper, is moving forward with a $1.5 billion, 600-MW pumped hydro storage project near Craig, a small city of 9,000 and the county seat of Moffatt County and not far from the legendary ski resort community of Steamboat Springs.
The company says it has completed negotiations with local land owners. According to company executive Luigi Resta, rPlus Hydro, a subsidiary of the parent company focused on pumped storage, is ready to “start engaging with our engineering firms to actually do some pre-feasibility design and engineering at the site that will look at where the underground powerhouse is and where the shafts are.”
Pumped hydro, according to the Department of Energy’s definition, “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).” When conventional technologies are generating more power than the grid requires, the power can be used to pump water uphill to the storage reservoir. When the grid needs additional power, the water can be released to run through a turbine and generate power.
According to rPlus Hydro, one of the chief advantages of pumped storage over batteries is that batteries “are well-suited for short durations (typically 2-4 hours), whereas pumped storage typically offers storage durations of 8 hours or longer.” The projects are also long-lived, with lifespans of 75 years or more.
According to a recent article in the journal Environmental Science and Technology by researchers are the Department of Energy’s National Renewable Energy Laboratory, “Results of this study suggest that pumped storage hydropower has the lowest life cycle greenhouse gas emissions compared to other energy storage options.” The NREL study notes, “Technologies such as wind and solar power contribute to electricity decarbonization goals yet are temporally variable and do not provide grid inertia; therefore, they require grid-scale storage for efficient dispatching.”
The Federal Energy Regulatory Commission licenses all U.S. hydropower, including pumped storage hydro. According to FERC, the commission “has authorized a total of 24 pumped storage projects that are constructed and in operation, with a total installed capacity of over 16,500 megawatts. Most of these projects were authorized more than 30 years ago.” The last large U.S. pumped storage facility came on line in 1995.
rPlus Hydro is aggressively developing pumped storage projects, with 10 planned, all but one in the Western U.S. (and one in Kentucky). All range from 400-MW to 1,000-MW in capacity, with in-service dates estimated for the early 2030s. Most are closed-loop projects, with upper and lower self-contained reservoirs, while two are “off-stream,” meaning the project is connected to a source of running water.
Several of the projects are in coal country, as is the case with the Craig project. The three-unit, 1,285-MW coal-fired Craig Station plant is set to close by 2030. Units 1 and 2, jointly owned by PacifiCorp, Platte River Power Authority, Salt River Project, Tri-State Generation and Transmission Association, and Xcel Energy, are scheduled to shut down in 2025 and 2028, and Tri-State’s Unit 3 in 2030. The Colowyo coal mine in nearby Meeker, Colo., will close in 2030 as a result.
rPlus Hydro’s largest project is the 1,000-MW White Pine Waterpower closed loop venture about eight miles east of Ely, Nevada, located on some 1,096 acres of Bureau of Land Management administered federal land. The project infrastructure includes “a new 25-mile-long transmission line connecting the project with the Robinson Summit Substation.” The project got a preliminary FERC approval in 2017 and submitted a final license application last February. According a FERC Federal Register notice last May, the agency anticipates a draft environmental assessment under the National Environmental Policy Act in September 2024 and a final environmental assessment on March 20,2025. The schedule from rPlus Hydro calls for 5-7 years of construction.
According to Hydro Review, “Most of the pumped storage hydro capacity in the U.S. was built between 1960 and 1990, and significant new capacity has not been added since then. In fact, no new projects have come online since 2012, according to the U.S. Energy Information Administration (EIA), when the San Diego County Water Authority’s 40-MW Lake Hodges project began operating in California.”
China is by far the most aggressive pumped storage developer in the world. The New York Times recently wrote that China accounts for over 80% of the world’s planned pumped hydro projects. Of course, China also leads the world in all new electric generation, including wind, solar, and coal.
As is the case with much energy development, not all pumped storage projects will succeed. Alabama Power July 17 withdrew its FERC notice of intent for the 1,600-MW Chandler Mountain off-stream pumped storage project. The project faced stiff local opposition from landowners fearing takings by the utility and lowering of property values, by the Alabama Rivers Alliance raising water quality impacts, and questions raised by the Cherokee Nation about the project disrupting historical cultural relicts. The tribal government said it found no instances of such disruption, but said the project should be stopped if items of cultural significance were uncovered.
–Kennedy Maize
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