Dec. 24 -- Gov. Janet Mills is taking steps to increase Maine's renewable energy storage capacity, a critical support for wind and solar power in the state.
The Governor's Energy Office recommended in a new report Monday that the state Public Utilities Commission establish programs that would add 200 megawatts to be built by developers. The PUC is reviewing the report and has not yet begun soliciting public comment, a spokeswoman said.
State legislation in 2021 established energy storage goals of 300 megawatts of power capacity by the end of 2025, enough to provide electricity to 300,000 homes, and 400 MW by the close of 2030.
With 63 MW of storage capacity already operating at six sites in Cumberland, Oxford, Penobscot, York and other counties, a pending 175-MW project in Gorham and hundreds of megawatts of planned projects, Maine could exceed its goal if enough storage is proposed, approved and online in the coming years.
Storage capacity holds and releases solar and wind power and reduces demand on the electricity grid and the need for costly upgrades.
To pay for new storage projects a customer of Central Maine Power should expect to pay an average $5.90 a month more in the first year the program is in effect; the bill would decrease $3.41 a month in the following year, according to the Governor's Energy Office.
Over the first 10 years of the program, CMP residential customers would pay $1.77 a month less, on average. Residential customers of Versant Power would pay $4.89 a month more in the first year, and the amount would decrease in the following years starting at $2.83 a month beginning in year two. Over 10 years, monthly bills would decline by $1.50.
The estimates are based on a ratio of upfront and pay-for-performance incentives.
Costs are estimates based on the difference between storage costs and revenue of selling power, tax incentives, capital invested by developers, administration costs and other factors.
Among its recommendations, the report issued Monday by the Governor's Energy Office suggested that regulators consider designing rates according to the time of day when customers use electricity and clarify utility ownership of energy storage.
The Public Utilities Commission, directed by a 2023 state law, is considering whether CMP and Versant may own battery storage, which hasn't been possible since the Legislature deregulated the utilities more than 25 years ago. Environmentalists and others have urged regulators to allow for competitive energy storage markets.
Maine hopes to capitalize on rising demand for energy storage. "With declining costs and increasingly clear value to be captured from energy storage capabilities, the regional electricity system is poised for significant new energy storage deployment," the report said.
ISO-New England, the region's grid operator, reports that battery storage comprises 46% of the proposed new power sources looking to connect to the grid, the Governor's Energy Office said.