Breaking: Warm October and Heavy Outages Triggered Rare Grid Alert
Unseasonable heat combined with 70,000 megawatts of scheduled maintenance to force the first ever Capacity Advisory and a Maximum Generation Alert.
By Sakura Ellis ·
The U.S. Department of Energy declared a power grid emergency across 13 states and the District of Columbia on Sunday October 12, 2026. Energy Secretary Chris Wright issued the order under section 202(c) of the Federal Power Act. The order granted PJM Interconnection temporary emergency authority to keep the regional grid stable from October 13 through October 16, 2026. This action was taken to prevent interruptions rather than to announce scheduled blackouts. No blackouts occurred during this period and no mandatory conservation orders were issued for households.
The primary driver of the emergency was a collision between unusually warm October weather and the fall shoulder season. This period is when generator and transmission owners take equipment offline for maintenance and upgrades ahead of winter. Most scheduled outages are prohibited in the summer, so the summer peak period ended in mid-September. On Friday October 9, PJM issued a Capacity Advisory for Monday October 12 and Tuesday October 13. This was the first ever use of that procedure, which PJM members endorsed in June 2026 for circumstances when projected conditions indicate an approaching capacity shortfall.
PJM’s load forecast was about 102,000 megawatts of peak demand on Monday and about 104,000 megawatts on Tuesday. These figures were set against previously scheduled generation outages of about 70,000 megawatts plus planned transmission outages. Paul Dajewski, PJM’s senior manager for dispatch, told stakeholders that this volume of outages is typical for the shoulder season. The combination of high demand and significant maintenance created a tight balance for the system operators.
On Monday October 12, PJM issued a Maximum Generation Alert and a Load Management Alert for October 13. The grid operator also extended the Capacity Advisory through October 14 and issued a Maintenance Outage Recall for October 14. This escalation followed a forecast of approximately 111,500 megawatts or higher for demand. On October 13, PJM extended the Maximum Generation Alert and Load Management Alert through October 14. The operator called on Demand Response programs, which pay customers who sign up in advance to cut electricity use when the grid is stressed. PJM said these alerts required no action from customers.
A Maximum Generation Alert tells transmission and generation owners that conditions will be tight. This allows them to defer or cancel equipment maintenance and testing. It also tells neighboring grid operators that exports from PJM may be curtailed. Scheduled transmission line outages also limited how much electricity could move between zones. Generation was bottled in some areas because of transmission limits. This was particularly true for resources serving congested zones in Washington D.C., Maryland, and Virginia, specifically the BGE, Pepco, and Dominion zones.
The Department of Energy said PJM wanted to deploy auxiliary, standby, directly connected, or battery storage resources at data centers. This included hyperscaler facilities and other large industrial and commercial customer sites. PJM coordinates wholesale electricity across all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia. This region serves about 67 million people. The order allowed PJM to direct designated generation units to produce electricity and, in limited circumstances, to use backup power reserves.
PJM says the shoulder-season reprieve is not what it used to be. Most of the new, rapidly growing demand comes from data centers and other energy-intensive large-load customers. Their consumption does not fall with the weather; it is a 12-month, 24/7 phenomenon. That expanding demand is outpacing new transmission and electricity supply coming onto the system. Unseasonably hot or cold weather now arrives outside the traditional peak seasons, adding further strain to the infrastructure.
PJM had also used Department of Energy emergency orders during two unseasonably warm September periods, August 31 to September 4 and September 15 to 18. These orders let eligible resources keep operating beyond normal limits. After sunset on those days, PJM had to cover net load as solar output fell faster than electricity use. The recent emergency highlighted the fragility of the grid under record demand and the critical role of data centers in modern electricity consumption patterns across the affected states.
