Energy demand

The U.S. is nearing the end of one of its hottest summers on record. Across the nation, heat waves have driven peak electricity demand on some days to levels far exceeding seasonal averages. Grid operators rely on so-called “peaker” plants to ensure they will have enough supply to meet these demand surges. Peaker units can start up quickly and at relatively low cost, but they typically burn more fuel per unit of electricity produced than other types of fossil fuel units. Because they are less efficient than other plants, peakers typically run only during high-demand periods. Historically, peakers have run for less than 10% of the year, often for just a few hours at a stretch. Nonetheless, their higher emissions per unit of electricity produced raise environmental and health concerns. As of 2021, there were 999 peaker plants across the U.S., in all 50 states. About 70% of these plants burned natural gas, and the rest were powered by oil and coal. To reduce air p...