Alaska has 1,800 suitable sites for pumped storage with a total capacity of 4 TWh: DOE labs

This story was originally published on Utility Dive. To receive daily news and insights, subscribe to our free daily Utility Dive newsletter.

Alaska contains around 1,800 sites with the specific geography necessary to host pumped storage hydropower plants which could significantly bolster the state’s grid, according to a newly highlighted study from Argonne National Laboratory and the National Renewable Energy Laboratory.

“Alaska is warming faster than any other state, according to the U.S. Department of Agriculture,” the Department of Energy said in a March 14 release. “Although most Alaskans get their energy from the state’s two largest power systems, the Railbelt and Southeast Alaska, more than 150 isolated communities rely on smaller systems that operate like microgrids.”

Across all 1,800 potential sites, the total energy storage capacity was about 4 TWh, according to the study.

A facility for pumped storage hydropower, or PSH, requires two reservoirs positioned at different elevations. Energy is stored by pumping water into the higher reservoir, and when that energy is needed, the water is “released and flows back down, spinning turbines and generating electricity,” DOE said.

“Because the team identified more than 1,800 sites with the necessary geography, their findings demonstrate that Alaska has huge potential to develop more of these energy storage facilities to support a clean and resilient power system,” DOE said.

Researchers found that PSH sites “were part of the optimal capacity expansion solution in all scenarios analyzed for the Railbelt system.” Currently, around 80% of the Railbelt system’s generation is from natural gas.

The researchers’ grid integration model of how the Railbelt would absorb an influx of clean energy generation found that both long and short-term energy storage would be needed. 

“While batteries could provide short-term storage, the team also found that the long-term storage offered by PSH facilities could help integrate more variable renewable resources, like wind energy and solar power, into the grid and ensure it remains reliable even during periods when wind and solar energy resources wane,” DOE said.

However, the study noted that traditional hydropower often comes with “large upfront capital costs that often deter small hydropower development.” To compensate, the researchers suggest that Alaska could deploy modular pumped storage hydropower to “reduce costs by standardizing the design, manufacturing, construction, and operation, while also reducing the environmental impacts and site requirements.”

“For Alaska applications, the availability of small, transportable modular systems would help address the high construction and transportation costs that communities throughout Alaska experience,” the study said.