Energy Storage

Milestone for Major Pumped Hydro Storage Project in Wyoming

A Utah-based company is developing a pumped hydro energy storage project in the heart of coal country, one of several renewable energy deployments being sited in Wyoming in an effort to diversify that state’s energy and power portfolio.

Officials with the 900-MW Seminoe Pumped Storage Project, being developed by rPlus Hydro, part of rPlus Energies, on Jan. 26 announced rPlus Hydro subsidiary Black Canyon Hydro has submitted a final license application to the Federal Energy Regulatory Commission (FERC). The project is sited in Carbon County, long among the largest coal-producing counties in the nation’s largest coal-producing state, and now home to some of the nation’s newest wind farms.

The Seminoe project would represent a $2.5 billion investment in renewable energy. Officials on Thursday in an email to POWER said filing the application with FERC is a “critical step only achieved by a handful of pumped storage projects in the last 20 years,” with rPlus saying only six U.S. pumped storage projects have progressed to a final license application stage since 2000.

“No matter one’s view about fossil fuels, renewable energy, electric cars, etc., everyone wants reliable power. Pumped storage has been a workhorse for reliable power around the world for a long time,” said Matthew Shapiro, CEO of rPlus Hydro. Shapiro, noting the number of wind farms coming online in the region, told POWER, “Just as it has great coal resources, Wyoming happens to have that wind energy resource that a lot of people want to use. It simply makes sense to have an energy storage project like this in a place where it can help make the most effective use of that natural resource.”

Economic Benefits

The project site is about 35 miles northeast of Rawlins, Wyoming. Officials with rPlus told POWER the Seminoe installation would bring “substantial economic benefits to the local community and will serve as an important element of Wyoming’s modernized and reliable energy infrastructure.” The company also said it expects to soon submit a final license application to FERC for rPlus’ 1,000-MW White Pine Pumped Storage project, located in White Pine County, Nevada.

This graphic shows key sites involved with the Seminoe Pumped Storage project in Wyoming. The new upper reservoir will be built to store water that will be moved to the lower, existing Seminoe Reservoir. Courtesy: rPlus Hydro

The Seminoe facility would provide 10 hours of full-output energy storage capacity, according to rPlus, a company founded in 2018 as a subsidiary of Salt Lake City-based Gardner Group. The type of pumped hydro system at the site would move water between an upper reservoir and a lower reservoir to store energy and generate power when needed. The lower reservoir of the project will be the existing Seminoe Reservoir. A new upper reservoir will be part of the construction.

The Seminoe Dam is located on the North Platte River in Wyoming, about 72 miles southwest of Casper. The dam includes a 13.5-MW power plant. Source: rPlus Hydro

The new reservoir will be about 1,000 feet above the existing reservoir, and about 10,000 feet—just under two miles—east of the Seminoe Dam. Energy for the pumping system, and for the power generated by the project, will be transmitted through a new 30-mile line connecting the facility to PacifiCorp’s existing Aeolus Substation, near Medicine Bow, Wyoming.

“As the American West sees continuation of development of renewable resources and a consolidation of the different regional balancing authorities, energy storage will play a crucial role for the security of our infrastructure system,” said Luigi Resta, president of rPlus Energies. “It’s incredibly rewarding and satisfying to see Seminoe be one of the few pumped storage projects in the U.S. that has achieved this significant milestone over the past 20 years—and we’re looking forward to ensuring this facility plays a valuable role in the clean energy transition across the Mountain West.”

Supporting State’s Wind Energy

Resta told POWER, “This project is an incredibly valuable clean energy investment for Wyoming—helping to unlock the wind resources within this part of the state while also allowing for both wind and solar resources to be viewed as a baseload dispatchable resource rather than a variable resource.”

“Seminoe Pumped Storage will be an ideal match for Wyoming’s excellent wind energy resource, and will support Wyoming’s role as an energy leader,” said Shapiro. “It can also help ensure efficient utilization of new transmission lines that are, or will soon be, under construction, such as the Gateway lines and TransWest Express.”

Officials have said the project, in addition to the new reservoir, will include construction of underground tunnels and an underground powerhouse. An intake-outlet structure will be added in the Seminoe Reservoir.

The Wyoming pumped hydro storage project has been in the works since 2019, with the onset of environmental surveys, along with agency and community meetings. Engineering and design of the project is ongoing as it moves through the permitting phase. Construction could begin as early as 2025, and the facility could begin operating as soon as 2030. Thursday’s license application filing will mark the start of an environmental review and licensing process with local, state, and federal agencies.

Officials on Thursday said the project is expected to create as many as 500 jobs during its four- to six-year construction phase. The facility is expected to provide about 35 full-time jobs once operational, and generate about $9 million in annual tax revenue for local and state governments.

Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).

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