An aerial drone image shows Key Capture Energy's battery storage development in Pflugerville, Texas, on Oct. 13, 2022. This is a 100 megawatt project that participates in the Electric Reliability Council of Texas market. Credit: Courtesy of Kevin Farley via Key Capture Energy

Maine is in the early stages of developing battery storage for excess renewable energy, but it will need more storage capacity as the state transitions to clean energy to meet statutory climate goals, energy policy experts said.

Maine is just the ninth state to set energy storage goals. But so far it has reached only 21 percent of its goal for 2025.

Maine has 63 megawatts of operational battery energy storage, according to the Governor’s Energy Office. But the state has statutory targets to deploy 300 megawatts of battery energy storage by 2025 and 400 megawatts by 2030.

Battery energy storage systems are a relatively new, developing technology. The current technology stores excess electricity in large lithium ion batteries — similar to those used in cell phones or cars — to provide power either when less electricity is being generated or when backup is needed during a power outage.

“We can’t move very fast towards greener energy if we don’t include battery energy storage in the mix,” said Sen. Eloise Vitelli, D-Arrowsick, at a panel discussion on battery energy storage deployment organized by the Environmental and Energy Technology Council of Maine, or E2Tech, on Monday. “Renewable sources such as wind and solar are intermittent, and we need to do something in those interim times when the sun isn’t shining and the wind isn’t blowing.”

On a commercial scale, battery systems are set up in large containers. Inside the containers are racks with battery modules on them, which look like bookcases stacked with large briefcases, said Paul Williamson, the senior development manager at Key Capture Energy, a New York-based company that builds and operates battery energy storage systems. The battery systems can come in various sizes and can be deployed on a grid scale or feed into smaller poles and wires.

Batteries can store anywhere from hundreds of megawatts to thousands of megawatts of electricity, Williamson said, but it depends on whether the local infrastructure, or transmission lines and substations, can support them.

The Maine Public Utilities Commission recognizes that battery energy storage will be increasingly important and may require a different process to interconnect to the grid than other energy resources, Phil Bartlett, the PUC’s chairperson, said.

Apart from the green benefits of storing and using excess renewable power, battery energy storage systems can also help prevent expensive upgrades to the grid, Bartlett said.

“Battery energy storage may be useful for grid reliability and could help us avoid the need for more expensive upgrades at a substation or as a part of the distribution circuit,” he said.

In Maine, there are several companies working to develop and build these systems. There are more than 450 megawatts planned to be installed in Maine, according to Dan Burgess, the director of the Governor’s Energy Office. He didn’t elaborate on the timeframe for when the battery energy storage systems can be expected to be installed.

“We need some larger projects to be developed in order to meet these targets, and we need to be looking at programs and initiatives to get there,” he said at E2Tech’s event on Monday.

One of the companies, Key Capture Energy, is currently awaiting approval from ISO-New England, the regional grid operator, for the three battery systems it plans to develop in the state.

“There are up to 10 companies that are active in developing standalone battery energy storage systems in Maine, and there are also several companies that are developing battery energy storage systems to be paired with their solar projects,” Williamson said.

Mehr Sher is a Report for America corps member. Additional support for this reporting is provided by the Unity Foundation and donations by BDN readers.


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Mehr Sher

Mehr Sher reports on the Maine environment. She is a Report for America corps member. Additional support for her reporting is provided by the Unity Foundation and donations by BDN readers.