PJM Interconnection, the grid operator that keeps the lights on for a large stretch of the Mid-Atlantic and Midwest, called on demand-response customers and secured emergency federal authority on September 17, 2026, after forecasting that electricity demand across its footprint would peak at approximately 132,000 megawatts. The forecast, issued as of noon that day, arrived alongside unusually warm September weather colliding with the seasonal maintenance schedule that idles part of the grid’s generating capacity every fall.
To keep the system stable, PJM activated demand-response programs, deferred equipment maintenance where it could, and asked the U.S. Department of Energy for special authority to direct large power users, including data centers, onto backup generators if conditions worsened. Washington granted that authority the same day.
A grid told to prepare for 132,000 megawatts of demand
According to PJM’s own operations update, the grid operator activated Pre-Emergency Demand Response in every zone except ComEd and the Mid-Atlantic, and called additional Emergency Demand Response in the BGE, PepCo, and Dominion zones, to build reserves ahead of the September 17 evening peak. Demand response programs pay customers in advance to reduce electricity use when PJM calls on them, and PJM said the calls were needed to cover the forecast peak of approximately 132,000 megawatts.
PJM also issued a Maximum Generation and Load Management Alert, instructing transmission and generation owners to defer or cancel any equipment maintenance that could be put off. The grid operator said it had already recalled or canceled outages where possible, but approximately 36,000 megawatts of generation and transmission work remained sidelined even after that recall effort, on top of demand pushing toward the 132,000-megawatt peak. PJM also expected to curtail electricity exports to neighboring grid systems to the south and west, where hotter weather was driving even higher demand.
The federal order that let PJM commandeer backup power
The U.S. Department of Energy issued emergency Order No. 202-26-45 on September 17, acting under section 202(c) of the Federal Power Act in response to an application PJM had filed the day before. The order directed PJM to dispatch specific generating units as needed and authorized PJM, working with its transmission owners and electric distribution companies, to order data centers and other large-load customers onto backup generation as a last resort, either just before or during a top-tier Energy Emergency Alert. It also granted temporary relief from environmental permit limits on generating units. The order itself took effect immediately and expired the following day, September 18.
“Today’s order will help secure reliable electricity access for millions of American families and businesses across the Mid-Atlantic by making additional power generation, including back-up power, available to use as needed,” U.S. Secretary of Energy Chris Wright said in a statement announcing the order. Wright pointed to reduced solar output as the days shorten and warned that the North American Electric Reliability Corporation had flagged the danger of late-summer temperature spikes hitting a grid that has already retired reliable power sources. The Department of Energy estimated more than 35 gigawatts of backup generation remained available nationwide that PJM could draw on if needed.
Why September, not August, produced the emergency
PJM’s outage season typically runs from mid-September through December, when transmission and generation equipment is taken offline for maintenance so it can be fully available during winter demand peaks. That schedule collided this year with an unseasonably warm stretch, pushing demand toward levels the grid normally sees only in mid-summer while a meaningful share of its generating and transmission capacity sat offline for planned work.
Wright’s statement placed part of the blame on policy rather than weather alone, arguing that past leaders’ “energy subtraction policies” had made the grid more vulnerable to blackouts when the sun doesn’t shine or the wind doesn’t blow. Whatever the cause, the immediate fix was operational: PJM said it worked to recall as many deferred maintenance outages as it could before September 17, even though thousands of megawatts of scheduled work could not be reversed in time.
Data centers, neighboring grids, and who pays for the order
The most consequential piece of the order, for now, is the authority it gives PJM over large electricity users rather than power plants. Data centers and other large-load customers can be ordered onto their own backup generators if PJM needs the relief, a tool aimed squarely at facilities whose electricity demand has grown fast enough to strain the grid on its own. PJM’s emergency procedures documentation describes a dedicated team of grid operators who monitor supply and demand around the clock and can escalate through a series of alert levels before an Energy Emergency Alert 3 is ever declared.
PJM did not report reaching that top alert level on September 17. The combination of demand response, deferred maintenance, and export curtailments was enough to manage the forecast 132,000-megawatt peak without forcing any data center onto backup power under the new federal authority, leaving that tool untested for the moment even though the order authorizing it remained in effect through the following evening.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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