PJM sets all-time electricity demand record

PJM Interconnection said July 2 demand reached an estimated 168,158 megawatts, setting an all-time peak for the grid operator during a heat wave that pushed temperatures across parts of its footprint into the 90s. The previous record was 165,563 MW, set on Aug. 2, 2006, according to PJM. The operator said the July 2 figure was preliminary and reflected demand that would have been served absent curtailment through demand response programs. PJM’s service territory spans 13 states and the District of Columbia, making it the largest power grid operator in the United States. ### How high did demand actually get? PJM said in a July 14 operations update that the grid “reached an all-time peak load estimated at 168,158 MW on July 2,” based on preliminary figures that include the effect of demand response suppressing load. PJM said the prior record of 165,563 MW had stood since 2006. A July 2 PJM operations update had forecast a peak of 166,241 MW for that day, which at the time would have exceeded the standing summer hourly integrated peak. (insidelines.pjm.com) PJM said then that calling demand response resources could suppress the preliminary peak totals. ### Why do some accounts mention both July 2 and July 3? PJM kept hot weather alerts in place through at least July 3 and issued a Maximum Generation Alert and Load Management Alert as the heat persisted. (insidelines.pjm.com) The operator’s July 3 update said it expected elevated peak loads to continue through the holiday weekend, even as forecasts shifted. (insidelines.pjm.com) An Aug. 3 PJM presentation on the July 2-3 events described the period as an “all-time record” load-management event tied to the June 29-July 5 heat wave. The presentation said July 2 was the hottest day across the regional transmission organization and showed load-weighted temperature-humidity readings well above the 2015-2025 summer average. (insidelines.pjm.com) ### What role did demand response play? PJM said demand response customers cut usage by an estimated 6,113 MW on July 2 and 5,037 MW on July 3. The operator said the July 2 peak estimate reflected the “true demand” the system would have needed to serve without those curtailment actions. Demand response is a program under which customers are paid in advance for a commitment to reduce electricity use during system emergencies, PJM said. (pjm.com) That means the record figure is not the same as the metered load actually served in real time; it is PJM’s estimate of underlying demand during the emergency event. ### What was happening on the grid during the heat wave? (insidelines.pjm.com) July 1 and July 2 brought multiple emergency procedures as PJM prepared for heavy air-conditioning use. PJM said a Hot Weather Alert remained in effect for the full region, while Maximum Generation Alerts and Load Management Alerts were used to prepare generation and transmission personnel for high demand. (insidelines.pjm.com) The InForum letter published Aug. 5 cited the July heat wave and said temperatures were near 97 degrees as regional power supplies were strained. That account matched PJM’s own description of a prolonged heat event that drove demand to record levels. ### Where did PJM publish the record and what comes next? PJM published the record in its Inside Lines operations updates on July 14 and July 15 and in committee materials posted in early August. (insidelines.pjm.com) The operator’s public data tools continue to show current and historical load information, while its emergency procedures dashboard posts active grid alerts. (inforum.com) As of Aug. 6, PJM’s public postings included current load data and active emergency notices, and its committee presentation from Aug. 3 remained available with the July 2-3 hot weather review. Those records are the next reference points for any updated accounting of the July peak or later summer stress events. (pjm.com) (insidelines.pjm.com)