Heat Wave Is Pushing Power Grids to Their Limit

The nation's power system is getting a punishing stress test. A heat dome is settling over the Midwest and East Coast this week, with temperatures expected to top 100 degrees from Boston to Washington, DC, pushing electricity demand toward record highs and raising the risk of rolling outages, Reuters reports. Extreme heat warnings were issued in Michigan, Illinois, Ohio, Indiana, Kentucky, and Iowa on Tuesday, with the heat expected to hit the Northeast through the Fourth of July holiday, reports the AP. Grid operators say the surge in air-conditioning use is hitting a system already strained by rapid growth from data centers and electric vehicles—and by aging coal and gas plants that run less efficiently in extreme heat.

The nation's largest electrical grid, Northeast PJM Interconnection, which serves 67 million people from the Mid-Atlantic through parts of the South and Midwest, expects demand to hit a summer record of 166.3 gigawatts Thursday evening, just above its 2006 record. It's planning for "unlikely but plausible" demand of up to 169 GW, backed by 180.2 GW of generation and programs that pay customers to cut usage in emergencies. On Tuesday, the Trump administration, granting a request from PJM, declared a power emergency for the grid, Bloomberg reports. The order allows power plants in the region to exceed environmental regulations while operating at maximum capacity.

New York's grid operator says peak demand there could near its 34 GW record, while Midwestern operator MISO may also test its all-time high and will lean on PJM for help. PJM warns of a "fundamental mismatch" between fast-rising demand and slow-to-build new plants. On Monday evening, in a sign of the strain on PJM, wholesale prices briefly spiked from less than $40 per megawatt-hour earlier in the day to above $1,600 amid severe transmission congestion, Reuters reports.