A Maine company plans to build the state's first pumped storage hydropower facility in Oxford County.
Western Maine Energy Storage filed a preliminary permit with the Federal Energy Regulatory Commission to evaluate the potential of constructing a 500 megawatt development in Dixfield.
Hydropower storage works by shifting water through turbines between two large reservoirs, said company spokesperson Tom Brennan. It's a technology with a long track record in the U.S. and across the world.
"There's two dozen or more operating systems in the U.S.," Brennan said. "What it essentially is is a water battery."
A typical system pumps water into a huge storage pool at times when electric prices and demand are low. Then when demand peaks, water is released to flow downhill, generating electricity, according to Brennan.
Installing energy storage systems will provide generation when other renewable sources such as wind and solar are not creating electricity, Brennan said.
Brennan said that Pittsfield-based Cianbro Corp. construction company is the managing partner of Western Maine Energy Storage.
Maine has a legal goal of adding 300 megawatts of energy storage by 2025. In a February 2024 report the Maine Governor's Energy Office noted that pumped hydropower storage have typically larger capacity than lithium-ion batteries, but require federal licensing, can be challenging to site and "consume more energy than they store when pumping water uphill."
No hydropower storage systems have been installed in the U.S. since 2012, according to the report.
In its permit application, Western Maine Energy Storage said its system would include two 100-acre reservoirs connected with a enclosed pipe to deliver water to a powerhouse with two turbines.
The company wants a four-year permit to examine the feasibility of the plan, conduct environmental studies and complete engineering plans.
