ISO New England, the region's power grid operator, forecasts that electricity consumption in Maine and across New England will increase by approximately 9 percent over the next ten years, according to a report released on May 1. This anticipated growth, fueled by the adoption of heat pumps and electric vehicles, marks a reversal from two decades of declining or flat demand due to energy efficiency gains and behind-the-meter solar generation.
Conservative Projections Amid Policy Changes
While still predicting overall growth, this year's forecast is more conservative than recent estimates. Last year, ISO New England projected an 11 percent rise. The downward revision largely stems from changes in federal climate and energy policies under the Trump administration, which let key tax credits from the Inflation Reduction Act expire at the end of 2025. However, state-level programs in Maine remain unaffected, according to the Efficiency Maine Trust.
"We've had years of relatively flat demand, thanks to states investing in energy efficiency," said Mary Cate Colapietro, an ISO New England spokesperson. "But looking ahead, there is going to be a shift as electrification of heating and transportation accelerates."
Key Drivers: Heat Pumps and Electric Vehicles
The two main factors driving demand growth are the switch from fossil fuels to electric heat pumps and the rising number of electric vehicles. Although these technologies are more efficient than their traditional counterparts, they still increase overall grid load. ISO New England's forecasts incorporate data on home and business consumption, EV registrations, heat pump installations, and behind-the-meter solar generation. This year, the models also included, for the first time, estimates from large users like data centers and behind-the-meter battery storage systems.
Michael Stoddard, executive director of Efficiency Maine, believes past projections were too aggressive regarding EV and heat pump adoption but considers this year's numbers "more reasonable." He still thinks estimates of heat pump electricity consumption are too high and hopes forecasters "start to take a harder look." ISO New England updated its assumptions for heat pump demand this year and factored in reduced demand from building weatherization.
State vs. Federal Incentives
Maine has legally mandated goals: at least 115,000 households fully heated by heat pumps and 130,000 partially heated by 2030, plus 220,000 battery electric and plug-in hybrid vehicles. The state offers rebates through Efficiency Maine, funded by utility energy efficiency programs, ISO New England's forward capacity market, and the Regional Greenhouse Gas Initiative. This consistent funding has allowed contractors to expand, with over 200,000 heat pumps already installed. EV adoption has been slower, with only about 9,700 registered in Maine as of 2024, representing 0.8% of all vehicles.
"Increases to the grid cost money," Stoddard said. "You want to build it to the right size at the right time."
Grid Planning and Costs
Maine's grid has some capacity to absorb growth, especially after mill closures, but winter demand from heat pumps will require investment. Utilities Versant and Central Maine Power have submitted integrated grid plans to the Public Utilities Commission, relying partly on previous ISO New England forecasts. Versant built in flexibility, so the new conservative forecast should not disrupt its plan.
Rising demand does not necessarily mean skyrocketing bills, according to Francesca Hsie of the think tank Third Way. "It depends on the energy supply mix, what we invest in, and how much we expand the grid," she said. Smarter grid technologies, advanced conductors, and building more solar and wind—cheaper than new gas plants—can lower costs. However, federal hurdles are slowing such projects. Maine's electric bills have risen at the third highest rate nationally in recent years.
In addition to the integrated grid planning process, the Maine Department of Energy Resources has begun drafting the next Maine Energy Plan, updated every two years.
This story was originally published by The Maine Monitor and distributed through a partnership with The Associated Press.
