Electricity Demand Increases in Eastern and Midwestern U.S. in June Due to Heatwaves: EIA

Electricity demand increased in the eastern and midwestern region of the U.S due to a heatwave, according to a July 1 report published by the U.S. Energy Information Administration. Demand across the Eastern interconnection hit a high of 502,670 megawatts (MW) during a single hour on June 21, in comparison to an hourly June peak of 467,609 MW during 2023.

Weather is a key driver of power demand across the U.S., particularly during the summer since households and businesses use power for air conditioning. Regions within the Eastern Interconnection reached record or close to record temperatures during June. On June 20, Bangor touched 96 degrees, whilst Delaware, South Jersey and Philadelphia saw 20 heat records broken between June 19 and June 24. Record high temperatures were also evident during June 22 and 23 in the Baltimore- Washington D.C. area.

There are a number of independent system operators and regional transmission operators across the East interconnection, all of which manage electricity dispatch across large areas. PJM Interconnection LLC, Midcontinent Independent System Operator (MISO), the Independent System Operator for New England (ISO-NE) and the New York Independent System Operator (NYISO), were most impacted by the recent heatwave.

Power demand across the PJM region hit a high of 147,976 MW on June 21, 19 percent higher than the hourly peak during June 2023. Peak electricity demand per day during the heatwave was between one percent and 24 percent higher than the maximum of any June day during the previous five years.

The northern part of MISO witnessed higher demand than usual. Power demand in the northern part of the operating area was greater than in the southern part for each hour between June 18 until midday June 20. Demand in the ISO-NE power grid hit a high on June 20 at 23,266 MW and NYISO reached a high on June 21 at 28,245 MW.