How Solar and Storage Help the Power Grid Withstand Summer Heat
Article Summary
A growing integration of solar energy and battery storage has helped some of North America's power grids withstand record summer heat. This trend highlights the increasing role of renewables in managing rising electricity demand and ensuring grid reliability.
Key Takeaways
- Texas managed its highest electricity demand without emergency measures, with solar providing about a third of the state’s power during a recent heat wave.
- Regions with lower renewable shares faced much higher price spikes, emphasizing the cost benefits of renewables.
- With U.S. electricity demand projected to rise 39% by 2035, solar and storage, which accounted for 91% of new capacity in early 2026, are key to supporting grid stability and affordability.
It has been a hot summer across North America, with many cities in the United States and Canada setting new temperature records, which has left residents rushing to crank up their air conditioners.
One unexpected outcome of the heat wave has been that power grids once thought to be stretched to the limit have avoided sustained outages even as AC usage spiked. That’s due in large part to an evolving grid increasingly powered by record levels of new solar energy and battery energy storage capacity.
Texas offsets surge thanks to renewable energy capacity
Texas, long America’s energy capital, offers a window into what’s possible if the country continues to build more solar, storage and supporting infrastructure. In 2024 and 2025, Texas passed California as the nation’s leading solar producer on an annual basis, and it ranks second to California in overall storage capacity.1
The Electric Reliability Council of Texas (ERCOT), the organization that operates the state’s grid, was able to manage its summer 2026 surge without raising prices or taking emergency actions. That was not the case with grids in the Mid-Atlantic and Great Plains regions, according to a Politico report2, and what sets Texas apart is its renewable energy capacity.
During a stretch of triple-digit heat, Texas set a new electricity-use record, as widespread air-conditioning demand drove consumption sharply upward — the highest demand peak in the state’s history. That milestone underscores both the pressure of extreme weather and the state’s growing electricity demand.
Solar supplied roughly a third of ERCOT’s electricity during the recent heat wave. In 2025, solar generation in Texas surpassed coal-fired power for the first time, and improved battery storage has extended solar’s usefulness later into the evening.
The highest price on ERCOT’s record-setting day was $364 per megawatt-hour, reached around 10:30 p.m. That’s a high number, but still way below the $9,000 per MWh record during Winter Storm Uri in 2021 and far below what PJM Interconnection experienced this summer. Today wind, solar and batteries account for 50% of ERCOT’s installed capacity, and their low operating costs help keep power affordable even during extreme heat.
PJM, which serves 13 Mid-Atlantic states, is tied for the nation’s lowest renewable share at just 13%. During its own near-record demand surge on July 2, prices peaked above $2,000 per MWh.
As electricity demand continues to rise, solar offers a solution
ICF projects U.S. electricity demand to rise 39% by 20353, with wholesale energy prices potentially spiking by as much as 74%. There is reason for optimism that more solar and storage can ease some stress on people’s pocketbooks and the power grid.
The Solar Energy Industries Association and Wood Mackenzie found that solar and storage are dominating new electricity generation capacity so far this year. In the first quarter of 2026, 91% of all new grid capacity came from solar and storage4 — the highest quarterly share on record.
Mortenson is diversifying energy options in Texas and beyond. The company has built more than 20 solar projects totaling over 5 gigawatts of electric generating capacity in the Lone Star State, and more than 120 solar projects totaling over 17 GW of capacity nationwide, across 19 states. Mortenson has also installed more than 45 gigawatt-hours of battery storage capacity throughout the U.S.
This work is at the forefront of a trend to deploy renewable energy sources and energy storage to address rising temperatures, support local economies, and boost grid performance and reliability. Mortenson’s Solar Energy group sees this every day, as customers seek out solutions that pair solar with storage to help relieve pressure on power grids and independent system operators (ISOs).
Solar has been America’s largest source of new electricity-generation capacity for the past five years, accounting for 169 GW, enough to power roughly 28 million homes, according to SEIA and Wood Mackenzie data. That’s a meaningful buffer during a heat wave, and battery storage, which can be deployed exactly when it’s needed most, is providing added support.
Utilities, businesses and investors continue to choose these technologies because they are among the lowest-cost and fastest-to-deploy energy resources available.
More heat waves are on the horizon. If this year is any guide, the solar and storage capacity already on the grid — and the capacity still to come — will be a big reason the lights stay on.