California Zaps Power-Use Record

Californians used a record amount of electricity in one day, with peak demand hitting roughly 44,900 megawatts at about 4 p.m. Monday in the areas served by Southern California Edison, Pacific Gas & Electric and San Diego Gas & Electric, according to the California Independent System Operator, the nonprofit corporation that operates the state’s power transmission grid. The previous record of 44,650 megawatts was set about a year ago. Customers of San Francisco-based PG&E; were largely responsible for the record, pushing peak demand to 22,914 megawatts at about 2 p.m. Edison and SDG&E; territories didn’t post records. The ISO declared a “stage one” emergency in which utilities are asked to urge customers to conserve energy. On July 28, the ISO declared the system’s first “stage two” emergency, in which utilities are allowed to interrupt the power supply to commercial and industrial customers that have selected that option in exchange for lower rates. Although usage was lower on July 28 than it was Monday, supply was constrained because of plant malfunctions and an inability to import power from nearby states, which were grappling with their own heat waves.