A $1 billion energy storage project aimed at stabilizing Maine’s electricity supply is being proposed for western Maine.
A new company, Western Maine Energy Storage, said Wednesday that it plans to build Maine’s first so-called pumped storage hydropower facility on private land between Dixfield and Canton in Oxford County. The project will move water between two manmade reservoirs to generate power in response to demand on the electricity grid.
The company was formed in May 2024 and is based at the headquarters of construction company Cianbro Corp. of Pittsfield, according to filings with Secretary of State Shenna Bellows’ office. A company arm that initiates projects will manage the start of the facility. A Western Maine Energy Storage spokesperson would not comment on who the additional partners are, but said it will need to bring in more investors going forward.
The idea is to store about 500 megawatts of renewable energy for when it is needed. Power generated by solar and wind facilities is intermittent, depending on sunshine, tides and time of day.
When the grid has excess power, the facility will pump water from the lower reservoir through a floodgate and into the upper reservoir for storage. When there is high demand for power on the grid, water from the upper reservoir will be released through turbines that generate electricity down to the lower reservoir for distribution on the grid. There will be a connection to Central Maine Power’s infrastructure nearby and a generator housed between the two ponds to help move the water.
The two ponds would be about 100 acres each, Western Maine Energy Storage spokesperson Thomas Brennan said. They will be filled by water from the Androscoggin River, a process that could take up to one year. Afterward, the water levels will be maintained by runoff precipitation, he said.
The demand for electricity is growing in Maine and nationwide. Popular heat pumps have electrified heating and cooling, more electric vehicle chargers are being installed throughout the state and artificial intelligence applications are expected to increase demand for electricity.
Pumped storage hydropower has been around for several decades, and the current 24 facilities in operation account for more than 90 percent of utility-scale energy storage in the country, according to federal data. The closest plants to Maine are two in Massachusetts.
The western Maine project will be regulated by the Federal Energy Regulatory Commission. It still needs a licensing application approval, public comment sessions and technical studies before getting final approval by FERC. If all goes according to plan, construction is expected to be completed in 2033.
Large energy projects have encountered public opposition by Mainers in the past, including for potential harm to the environment. Construction and legal issues in August 2023 also initially delayed CMP’s massive, $1 billion hydropower corridor through western Maine for months at an extra cost of $500 million.
In December 2024, Maine energy regulators said they would kill a developer’s plan to build an Aroostook County wind transmission line and request new bids due to price uncertainties around the project.
Lori Valigra reports on the environment for the BDN’s Maine Focus investigative team. Reach her at lvaligra@bangordailynews.com. Support for this reporting is provided by the Unity Foundation, a fund at the Maine Community Foundation and donations by BDN readers.