Grid operators expect to have a sufficient supply of electricity to meet heightened demand this summer, and that public conservation or controlled outages will not be needed.
ISO New England projects that consumer electric demand will peak at 25,228 megawatts under normal weather conditions and could grow to 26,473 MW under very hot and humid weather this summer. The operator said it expects to have 28,717 MW of total resources available, though the forecast published late last month noted that the higher demand estimate “could present challenging operating conditions, particularly if combined with an unexpected loss of generation or other factors.”
“Should these conditions materialize — as they did last summer, when demand reached the highest level in the region in more than a decade — ISO New England grid operators have several tools available to maintain reliability on the system,” including increasing imports and tapping stand-by units, the organization said.
Summer 2025 grid demand peaked at 26,586 MW on June 24. Since then, significant new resources have connected into the region’s grid, including the New England Clean Energy Connect transmission line bringing in Canadian hydropower, more of the Vineyard Wind offshore wind farm, and several grid-scale battery projects. And behind-the-meter solar panels are projected to reduce demand by more than 1,700 MW during the peak hour of demand on days with normal weather conditions.
“Instead of peaking in the mid-afternoon, as was common during summers before widespread solar panel installations, New England grid demand now peaks in the early evening hours, around 5 p.m. to 6 p.m.,” ISO-NE said. “The region has more than 8,000 MW of [behind-the-meter solar] which effectively push the peak hour of grid demand later in the day, when the sun is lower in the sky and production from solar PV systems is reduced.”
During peak demand periods, dirtier fuels like oil are often pressed into service so reducing demand during those times can have a greater impact on emissions avoidance by limiting the use of high-emitting power generators, according to the Metropolitan Area Planning Council. MAPC offers a summer peak demand program to alert municipalities on days when peak demand is within reach and encourage them to reduce their consumption to save money on electric bills.
The all-time record for peak demand in New England was set on Aug. 2, 2006, when demand reached 28,130 MW after a prolonged heat wave, ISO New England said.
Colin Young is the deputy editor for State House News Service and State Affairs Pro Massachusetts. Reach him at colin.young@statehousenews.com.
