Giant 1GW pumped-hydro energy storage project enters final review

Planned for White Pine County, Nevada by developer rPlus, it would be one of the first large-scale pumped-hydro projects built in the U.S. in decades.
By Julian Spector

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A desert vista with a highway and mountains in background. In the foreground is a road sign that reads welcome to Nevada
White Pine County, Nevada, the site of a planned pumped-hydro energy storage project (Famartin/CC BY-SA 4.0)

One of the biggest planned clean-energy storage projects in the country just got one step closer to becoming reality.

Clean-energy developer rPlus Energies filed for final licensing approval with federal regulators for the 1-gigawatt/8-gigawatt-hour White Pine pumped-hydro project in Nevada, the company announced Wednesday. If completed, this project would store enough renewable electricity to meet about one-eighth of Nevada’s peak power demand single-handedly, according to rPlus President Luigi Resta. That’s a pivotal addition for a state that aims to make its electricity supply 50 percent renewable by 2030 and 100 percent carbon-free by 2050.

Meeting these targets will require storing cheap wind and solar generation for use in hours when those resources aren’t available. Lithium-ion batteries are arriving on the market to help, but grid battery projects getting built today can deliver only a few hours of steady power. That can cover the evening hours after the sun goes down, but the state will need longer-duration storage to keep the lights on for bigger stretches of time without relying on fossil fuels.

That pumped-hydro storage works has been proven for decades. It involves using excess power to pump water to a higher elevation, where it’s stored in a reservoir. When the power is needed, water flows back down, generating electricity along the way. The White Pine site will use two yet-to-be-made reservoirs with a 2,200-foot elevation gap between them, which generates more power with the same amount of water compared to locations with a lower height differential. Another advantage of this design is that it doesn’t interfere with existing waterways.

A video rendering of the proposed project’s site and design (rPlus)

Pumped-hydro storage still accounts for the vast majority of grid storage capacity in the U.S., despite the rapid growth in battery installations in the last few years. But the U.S. hasn’t built any new large-scale pumped hydro in decades.

The process requires arduous, years-long permitting, then years of construction. In the past, regulated utilities would foot the hefty upfront bill for this kind of project, but eventually, they switched to preferring gas plants for on-demand power. Independent developers haven’t been able to finance and build pumped hydro on their own — yet.

You have a proven technology that’s been financed but hasn’t been built recently,” explained Resta. But power markets are changing due to the influx of cheap, albeit variable, wind and solar. The time has come now [for new pumped hydro]. The utilities know it, and it solves many issues with the grid.”

A small but dedicated group of pumped storage developers agrees. They gained a critical victory in the Inflation Reduction Act, which included pumped-hydro storage in the new 30 percent investment tax credit for standalone grid storage. Projects can gain an additional 10 percent credit by meeting requirements for domestic materials. Pumped storage is well positioned to access that bonus since it relies on civil engineering and equipment that is already produced in the U.S., as opposed to batteries, which are largely manufactured overseas.

That’s resonating with utilities, Resta said, who currently is developing 13 pumped-hydro projects around the country.

What the IRA passage does is reduce the capital cost that will be passed on to the ratepayers,” he said. It makes it much more attractive.”

But, even after years of engineering studies and environmental impact analyses, and securing water rights from White Pine County, rPlus has plenty more to do before White Pine is operational. The Federal Energy Regulatory Commission will now oversee a multi-agency evaluation of the 9,000-page application, which could take two years to resolve.

White Pine is one of just a handful of current pumped-hydro developments to even reach this stage, Resta said. If it gets final approval, excavating two purpose-built reservoirs and installing all the necessary pumps and generating equipment will take five and a half years. If all goes well, White Pine could start storing clean energy in 2031.

A few other pumped-hydro projects have final approvals in hand and could get built before then, including Rye Development’s Swan Lake project and Absaroka Energy’s Gordon Butte. But developers still need to figure out what kind of contract they can sign with a customer at this point in time that gives their financiers the confidence to move forward. These developers bet that the fundamental needs of a decarbonizing grid will break the pumped-hydro impasse, sooner or later.

Julian Spector is a senior reporter at Canary Media. He reports on batteries, long-duration energy storage, low-carbon hydrogen and clean energy breakthroughs around the world.