New England power system prepared for summer heat 

ISO New England, operator of the region’s electric grid, expects sufficient energy supplies this summer, when the region typically sees its highest demand for electricity. 

The ISO projects consumer demand will peak at 25,228 megawatts (MW) under normal weather conditions. 

Very hot and humid weather could drive demand to 26,473 MW, which 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.

Meeting summer demand 

The ISO expects nearly 29,000 MW to be available this summer to meet consumer demand for electricity and required reserves. New England relies on a variety of generating resources, including wind, solar, natural gas, oil, nuclear, hydro, and biomass. Imports from New York and Canada, as well as resources paid to reduce energy usage, also help keep supply and demand balanced.  

Since last summer, several new large resources have connected to the region’s power system, specifically the New England Clean Energy Connect (NECEC) transmission line, the Vineyard Wind offshore wind farm, and several grid-scale battery projects.  

Behind-the-meter solar photovoltaic installations (BTM PV) continue to grow in the region and are projected to reduce demand by more than 1,700 MW this summer 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. The region has more than 8,000 MW of BTM PV 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. 

Preparing for summer 

Ahead of each summer, ISO New England compares anticipated contributions from the region’s fleet of resources against projected consumer demand for electricity across a variety of weather scenarios. In recent years, the ISO has enhanced its modeling capabilities to better account for the changing power system, with both consumer demand and generating resources becoming more weather dependent. The results of these analyses indicate the region is well positioned entering the summer months.  

The ISO also coordinates with resource and transmission owners, government officials, and neighboring regions ahead of the summer season to improve situational awareness. 

Managing the unexpected 

ISO New England’s system operators are prepared to manage unexpected situations and abnormal conditions that may arise and affect energy demand or supply. ISO system operators undergo rigorous training to ensure the reliability of the grid in New England, completing 200 hours of continuing education every three years to maintain their certifications. This training includes hands-on simulations that prepare them for handling various scenarios during all types of weather conditions. 

System operators have numerous tools to balance supply and demand, including increasing production of online generation, dispatching stand-by units, requesting deferral of scheduled maintenance, increasing imports, and voluntary reductions of energy use and other energy conserving measures. Depending on the severity of the issues, the expected duration of the event and the level of risk to the power system, system operators can use additional tools such as requesting public conservation or implementing controlled power outages. 

ISO New England does not anticipate public conservation or controlled outages will be needed this summer. 

2026 Summer Fast Facts 

• Summer peak forecast: 25,228 MW under normal weather conditions; 26,473 MW under above average temperatures. 
• Total resources available: 28,717 MW 
• Last summer’s demand peaked at 26,586 MW on June 24, 2025. 
• All-time peak demand: 28,130 MW, on Aug. 2, 2006.