The North American Electric Reliability Corporation’s 2026 Summer Reliability Assessment, released May 19th, finds that every assessment area should be able to meet normal peak summer demand. Three regions carry what NERC calls elevated risk for the summer: New England, the Canadian province of Saskatchewan, and the Pacific Northwest.
That is half the number of regions of last year’s assessment, when parts of the Midwest, Texas, and the central U.S. were all at an elevated risk. Elevated risk means resources should be adequate under typical summer conditions, but could fall short and lead to blackouts during a worse-than-forecast heat wave, an unexpected loss of generation, or unusually low wind or solar output. As NERC’s director of reliability assessments put it, “The improved conditions we’re seeing shouldn’t be interpreted as saying that overall reliability risk is declining.”
The grid’s buildout since last year is record-breaking, but only a fraction can be counted on to show up when it’s needed. More than 58 gigawatts (GW) of capacity have been added since last year, but because wind and solar only produce power when weather conditions allow, NERC discounts their contribution to what they can be reasonably expected to produce: 16.4 GW from solar, 14.7 GW from battery storage, 6.7 GW from natural gas, and 1.6 GW from wind, totaling only 39.4 GW.
Solar accounts for most of the gap. NERC reports 30.5 GW of solar added, but only 16.4 GW counts at peak demand, because the grid’s riskiest hours now fall in the evening after sunset, when solar output is declining or gone. In winter, solar is much less useful to the grid. NERC’s November assessment showed 11 GW of new solar contributed just 1.2 GW at winter peak, an 89% derate. Natural gas is the only major addition that reliably produces near its rated capacity whenever it’s called on. Batteries and wind also depend on weather conditions or, in the case of batteries, on having been charged in the preceding hours. Wind drought, prolonged periods of low wind output, is a recurring reliability concern for NERC.
Demand grew faster than it did a year ago. Aggregated peak demand across all assessment areas climbed more than 11 GW, exceeding the 10 GW year-on-year jump that preceded last summer. Several assessment areas revised forecasts downward because data centers are connecting to the grid slower than expected, but the demand may still materialize if projects are merely delayed, rather than cancelled.
Section 202(c) of the Federal Power Act allows the Department of Energy to order power plants to keep running when grid reliability is at risk. The DOE has used its authority to keep six coal and gas plants running through late May and June, covering the spring-to-summer transition that NERC identifies as growing harder to manage. These plants were not even counted in NERC’s anticipated resources for summer; they’re only still available to the grid because DOE stepped in.
The summer outlook is better than last year’s. But NERC’s own data show that most of what’s being added to the grid cannot be counted on at peak demand. As NERC’s director of reliability assessments put it: “Increasing risks for early fall and winter seasons reinforce the need for additional firm and dispatchable resources to maintain reliability and meet rising electricity demand.” Unfortunately, the grid is still not building the firm and dispatchable resources that NERC says it needs.