PJM Issues Maximum Generation Alert as September Heatwave and 36 GW Maintenance Outages Challenge Grid Reliability

The largest US grid operator triggers emergency load management alerts, demand response protocols, and obtains a DOE Section 202(c) emergency order allowing ...

PJM Issues Maximum Generation Alert as September Heatwave and 36 GW Maintenance Outages Challenge Grid Reliability

The largest US grid operator triggers emergency load management alerts, demand response protocols, and obtains a DOE Section 202(c) emergency order allowing power plants to waive emissions caps and directing data centers to backup generators.

Convergence of Unseasonable Heat and Fall Maintenance Outage Season

PJM Interconnection, which coordinates the movement of wholesale electricity in 13 Mid-Atlantic and Midwestern states and the District of Columbia, issued a Maximum Generation Alert and Load Management Alert for September 17, 2026. The emergency notice was spurred by late-season triple-digit heat index figures driving power demand into peak summer territory.

The strain was severely amplified by timing: mid-September is the traditional start of the fall shoulder outage season, with approximately 35,000 to 36,000 MW of power generation and transmission capacity offline for scheduled overhaul and maintenance.

Emergency Operating Directives and DOE Section 202(c) Environmental Waivers

To preserve grid frequency and prevent transmission line sagging under elevated thermal ratings, PJM instructed generation and transmission asset owners to immediately cancel or defer non-essential maintenance and keep all operational capacity synchronized to the grid.

Simultaneously, the U.S. Department of Energy granted PJM a temporary emergency order under Section 202(c) of the Federal Power Act, authorizing power plants to exceed hourly environmental permit limits and directing hyperscale data center operators to switch to on-site backup generators during peak hours to preserve public supply.