The North American Electric Reliability Corp. (NERC) is warning of potential energy supply shortfalls in parts of the U.S. this summer during periods of extreme weather amid climbing electricity demand and a changing resource mix.
The warnings were part of NERC’s 2025 Summer Reliability Assessment released May 14, which evaluated generation resource and transmission system adequacy for June through September.
All areas studied by NERC are expected to have adequate resources for normal summer peak load conditions. But, several regions are at risk of electricity supply shortfalls during periods of more extreme summer weather, including New England, parts of the Midwest, the Southwest Power Pool and Texas.
According to the report, weather services anticipate above-average temperatures across much of North America this summer and below-average precipitation in the Northwest and Midwest.
Total peak electricity demand for the areas that NERC assesses has risen by over 10 gigawatts since last summer, more than double the previous year-to-year increase. At the same time, more than 7.4 GW of generation capacity has retired or become inactive for the upcoming summer, most of it natural gas- and coal-fired generation.
“As demand expands, grid planners and operators are doing more than ever, but they’re doing it under tighter reserve margins,” said John Moura, NERC’s director of reliability assessment and performance analysis, on a May 14 webinar discussing the report. “While we’re adding a lot more resources — solar, batteries and other emerging technologies — the pace and performance of that buildout doesn’t yet fully align with the reliability needs of a rapidly electrifying economy.”
“Once again, NERC identifies continuing threats to the electric grid that leave a large area of the country vulnerable to power supply disruptions during periods of extreme summer conditions,” said National Rural Electric Cooperative Association CEO Jim Matheson. “Demand is surging, supply isn’t keeping up, and the resources being added to the grid aren’t as flexible or reliable as the always-available generation they’re replacing.
“Now more than ever, we need smart energy policies that prioritize reliability, affordability and put American consumers first. We look forward to continuing to work with policymakers to meet this challenge and keep the lights on across the nation.”
NERC said its summer findings are consistent with risks and issues that it observed in its latest Long-Term Reliability Assessment, released in December 2024.
That report said more than half of North America is at risk of energy shortfalls in the next 10 years amid surging electricity demand and thermal plant retirements. NERC projected that capacity additions to the bulk power system in the next decade will fall short of demand growth.
