PJM Averts Blackout During Unusual Heat Wave Using Demand Response

An unusual extreme heat wave spanning two days this week combined with local equipment issues in Indiana, Michigan, Ohio, and Pennsylvania forced regional grid operator PJM Interconnection to take localized emergency measures to avoid the possibility of an uncontrolled blackout over a larger area.

Soaring temperatures on Tuesday (Sept. 11) and Wednesday (Sept. 12) pushed power use to record levels for the month of September, said the grid operator whose service region encompasses Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia.

Demand for power in PJM’s region soared to 144, 370 MW on Tuesday, forcing the operator to direct local utilities in Indiana, Michigan, Ohio, and Pennsylvania to immediately and temporarily cut back demand by 150 MW to avoid the risk of a cascading blackout.

Demand was headed even higher on Wednesday until PJM called for demand response, asking customers to voluntarily reduce their electricity use in exchange for payment, the entity said. The peak demand for electricity on Wednesday was 142,071 MW. By comparison, peak demand for this summer on July 18—the hottest day this summer—was 157,509 MW. Last year, the highest demand for electricity in September was 129,959 MW.

Demand response resources act like generation resources on the system. “An estimated 5,949 MW of demand response resources (the largest amount of demand response PJM has ever received) were called on Wednesday, comparable to five nuclear plants or generators,” PJM said.

Sources: POWER, PJM