PJM Serves High Weekend Load Through Record Heat and Humidity


PJM and its utility partners reliably served customers over a weekend that likely set records for Saturday electricity use.

With temperatures at or near 100 degrees for much of the weekend in the PJM footprint spanning 13 states and Washington, D.C., electricity demand was highest on Friday, July 19, with regular work-day needs driving usage over 152,000 MW (which would be the high for the year), according to preliminary load estimates.  

Heavy electricity demand continued through Saturday, peaking past 150,000 MW, a level that likely breaks PJM’s all-time high for a weekend day, when there is less commercial and industrial activity than a typical weekday.

The previous weekend record for electricity usage was 149,644 MW peak recorded on July 7, 2012.

PJM’s all-time, one-day highest power use was recorded in the summer of 2006 at 165,563 MW.

Electricity demand eased Sunday as a more moderate air mass crept into the western part of the PJM footprint. That front trimmed Sunday’s electricity demand to result in a preliminary peak just over 140,000 MW.

Preliminary peaks are calculated daily from raw telemetry data and are approximate values.

PJM issued Hot Weather Alerts during the heatwave to prepare transmission and generation personnel and facilities for extreme heat and/or humidity that may cause capacity problems on the grid.

How PJM Ensures Reliable Electricity in Hot Weather

PJM meets electricity needs by procuring enough resources to satisfy peak demand, plus required reserves, at the lowest cost through its competitive markets. PJM works with its members to ensure that power flows where it is needed and holds resources, such as generating plants, to strict standards to deliver electricity as promised. PJM also has resources on reserve to cover generation that is unexpectedly unavailable or demand that is higher than forecasted.