Arizona’s largest electric utilities set new demand records this summer while keeping the grid operating through the state’s most taxing heat, according to a September 23 review by the Arizona Corporation Commission. The new peaks put both Arizona Public Service and Salt River Project above 9,000 megawatts for the first time, extending a multiyear rise in the amount of electricity needed during the hottest hours. The commission reported no rolling outages during the record-setting peak periods.
APS reached 9,164 megawatts between 6 and 7 p.m. on August 2, topping the record it had set just nine days earlier. The utility’s own post-summer account says the system continued to serve customers reliably and explains that one megawatt is roughly enough for 160 average Arizona homes. APS serves about 1.5 million homes and businesses in 11 of the state’s 15 counties, so even a small percentage increase in peak demand translates into hundreds of megawatts of added load.
SRP’s peak arrived July 24, when demand hit 9,072 megawatts between 5 and 6 p.m. The utility said it broke its previous record on multiple days as extreme temperatures coincided with continued customer growth. The commission reported that SRP’s 2025 record was 8,542 megawatts, while APS’s was 8,648 megawatts. In other words, each utility added more than 500 megawatts to its annual high in a single summer.
The records are not the same as a supply emergency. Utilities plan generating resources, purchases and reserves around expected peaks, and the commission’s summer-preparedness review found that Arizona providers had arranged capacity above their forecasts. The result matters because the highest-demand hour, rather than average use, often determines how much generation and transmission must be ready. A system can have ample electricity most of the year and still require costly infrastructure for a relatively short stretch of extreme heat.
Additional generation helped create that margin. The commission said Arizona added nearly 2,800 megawatts of new generating capacity during the first six months of 2026, citing the U.S. Energy Information Administration. The federal agency’s monthly inventory of new electric generating units provides the underlying project data. New capacity does not eliminate every operational risk: fuel availability, transmission constraints, plant outages and the timing of solar production can all affect whether nameplate capacity is available at the hour it is needed.
The practical lesson is that Arizona’s grid passed this summer’s test, but the benchmark moved sharply higher. The commission’s figures and the utilities’ separate reports point to the same pressures—extreme heat and customer growth—while the state continues adding power plants and grid equipment. For regulators, the next question is not simply whether enough electricity was available in 2026, but whether planned investments can keep pace without shifting avoidable costs or reliability risks to customers.
