Largest US power grid PJM escalates emergency actions to avoid blackouts

PJM, operator of the largest U.S. power grid, escalated emergency measures on July 3 to help avert blackouts while it faced generator outages, heavy transmission-line overloading, and soaring air-conditioning demand during extreme heat. The company said it is operating under a federal alert to cut electricity consumption across its service territory, and it instructed utilities to reduce supply to customers who have contracts requiring emergency curtailment. PJM serves about 67 million people across the Mid-Atlantic, South and the Washington, D.C. area. In northern Virginia, home to a dense concentration of data centers, spot wholesale prices this week rose above $2,000 per megawatt hour, versus roughly $40 per MWh when PJM is not under strain. Analysts cited congestion on high-voltage lines as a key driver.