One of the country’s biggest planned clean-energy storage projects just filed for final licensing approval. 

The project would store enough renewable energy to power one-eighth of Nevada’s peak power demand single-handedly.

Most electro-chemical batteries can storage energy for a few hours – good enough to time-shift solar PV production to evenings when it’s needed most. 

But with renewables scaling up, there’s now a corresponding need for much more battery storage to come online, time-shifting the production of renewables’ affordable but intermittent production. 

Pumped hydropower is by far the most common type of energy storage in the U.S., with the largest capacity and longest duration possibilities. This, despite lithium ion technology’s gains in recent years. 

On a dispatch command, a dam drains its reservoir down through turbines to supply the power grid, and then replenishes itself during low-cost off-peak electricity hours. Some power is required to pump water back uphill, but this resource still has efficiency rates over 80%. 

The more sloped the penstock or water sluice gate in terms of high-low elevation difference, the more efficiently potential energy converts to kinetic. 

It has been decades since new large-scale pumped hydro has been constructed – there are only so many places for it to be built, and permitting and capital costs are substantial. 

However pumped hydro scored a critical victory in the Inflation Reduction Act by being included in the new 30% tax credit for standalone grid storage, with a 10% adder available for using domestic materials. Previously, battery projects had to be paired with a renewable like solar PV to co-claim its credit. 

With long time scales involved, we should hope to start seeing more such projects soon; Nevada’s proposed White Pine project should start being ready to store clean energy by 2031. 

More information on the Nevada project is available at:

The U.S. Department of Energy’s “Closed-Loop Pumped Storage Hydropower Resource Assessment for the United States is available at: