NERC says solar and batteries strengthen summer reliability

A new summer reliability assessment from NERC forecasts the U.S. grid is better prepared for an unusually hot season, crediting record additions of solar and battery storage—even as some regions still face elevated risk and the Trump administration’s forced fo

For a summer that’s shaping up to be unusually hot, the U.S. grid heads into the season with a key advantage: new solar and batteries are piling up faster than the risk models can catch up.

That’s the central takeaway of a new summer reliability assessment from the North American Electric Reliability Corp. which oversees the United States and Canadian electric systems. NERC said “record resource additions have strengthened readiness for the summer season. ” pointing to “a substantial influx of solar and battery” as well as “some new natural gas-fired generators.”.

The assessment lands in direct tension with the Trump administration’s public argument that aging fossil-fueled power plants are necessary to prevent blackouts. Over the last year. the Department of Energy has forced five coal plants and one oil- and gas-fired power plant to stay online past their planned retirements. citing an energy emergency that grid experts say does not exist. That approach is now being challenged in court.

But the reliability picture that NERC lays out is built less on keeping older plants running and more on the speed and scale of new clean capacity. Crucially. NERC’s latest summer assessment reached its conclusions without including any of the plants the Department of Energy compelled to remain in service. The report states: “These plants and units were not incorporated into the anticipated resources of their corresponding assessment areas for Summer 2026.” It adds: “This report reflects the conclusion that renewables are significant contributors to reducing risk on the system today.”.

Public Citizen’s Tyson Slocum. director of the energy program at the nonprofit watchdog group. said in a Thursday statement that the report confirms what the group has long argued. “Delaying the retirement of outdated coal plants that require millions of dollars in upgrades and maintenance to keep them operational only prevents more reliable sources from being added to the grid.”.

Still. “better” doesn’t mean “risk-free.” NERC’s report is clear that some parts of the system could face trouble if heat drives demand higher than normal. It singled out New England. the Pacific Northwest. West Texas. and Canada’s Saskatchewan province. warning of potential electricity shortfalls under “abnormal summer conditions. ” such as elevated temperatures that push up air-conditioning needs. In the Pacific Northwest, drought conditions have also hampered hydropower—the backbone of power supply in that region.

The news is sharper when compared with last year’s forecast. NERC says the summer assessment for 2025 projected elevated risk across six U.S. regions during abnormally hot and dry conditions. including “a wide swath of the middle of the country from Texas to the Canadian border.” Those areas are no longer at risk this summer.

The report also notes which places have moved out of the worry zone, naming the 15 U.S. states from Louisiana to North Dakota. Canada’s Manitoba province is included as well. and the report ties that improvement to how the grid is managed by the Midcontinent Independent System Operator. which provides power to about 45 million people.

MISO matters here because it also hosts several of the coal-fired power plants in Michigan and Indiana that the Department of Energy has forced to stay online.

Even with the presence of those plants in the background political fight. the numbers in NERC’s reliability math tilt strongly toward renewables. NERC tracked about 7 gigawatts of new fossil gas generation added since last summer. but that addition was dwarfed by 30.5 gigawatts of solar generation capacity added in the same period.

Solar, of course, doesn’t behave like a steady supply. It doesn’t provide its full nameplate generation capacity during morning and evening hours. and it generates nothing at night or when clouds roll in. But NERC found that the 30.5 gigawatts of new solar are contributing 16.4 gigawatts of capacity during times of peak summer demand.

Batteries are doing the rest of the work—capturing excess power and holding it for later when the system is under stress. NERC tallied more than 16 gigawatts of battery capacity added since last summer.

Where those batteries are coming online also matters for the real-world test of a heatwave. NERC says most of the battery buildout has been in Texas and California. along with other parts of the U.S. West. In recent years. solar-charged batteries have helped save the California and Texas grids from summer shortfalls and have “dramatically” reduced the risk of heatwave-driven blackouts.

Yet the reliability lift isn’t confined to those states. NERC says “MISO’s capacity resources have improved since Summer 2025. ” and that the new additions there are “made up of predominantly solar resource installations. along with smaller amounts of natural gas. wind. and battery storage resources.”.

The assessment also gave fuel to advocates who have argued for years that reliability and renewables aren’t enemies. Jessi Eidbo. a senior adviser at the Sierra Club and a member of NERC’s Large Loads Working Group. said the report underscores that point. “This is not a conversation about renewables being tied to reliability risk,” she said. “This report reflects the conclusion that renewables are significant contributors to reducing risk on the system today.”.

To show how much renewables can deliver when the system is actually stressed, Eidbo pointed to a section of NERC’s report that calculates what proportion of total capacity from solar, wind, hydropower, and battery storage is available to serve the peak demand hour in a given area.

In MISO. NERC found that the 20.4 gigawatts of solar available can provide 60 percent of their nameplate generation capacity during peak hours. For storage. the numbers are even stronger: NERC’s assessment of the peak load contribution of MISO’s fleet of roughly 3.6 gigawatts of battery storage rated it at 97 percent.

The Southwest Power Pool—an operator serving 14 Midwestern and Great Plains states—showed similar trends, though slightly lower. NERC assigned a 54 percent peak contribution rating to the Southwest Power Pool’s 3.9 gigawatts of solar. and an 84 percent peak contribution rating to the region’s 1.3 gigawatts of battery storage.

Eidbo highlighted that both MISO-adjacent comparisons track a major shift since summer 2025: both regions moved from “elevated” risk to “normal” risk from summer 2025 to summer 2026, and both now have “very high percentages of nameplate capacity from energy storage systems.”

All of this is part of what makes the coming summer feel different. NERC’s assessment suggests solar and batteries—technologies that can be built more quickly and at lower cost than gas plants—can supply the grid in the moments when heat pushes demand to its highest point.

NERC summer reliability assessment solar battery storage electric grid Department of Energy coal plants natural gas generators Public Citizen Sierra Club MISO Southwest Power Pool heatwave risk