(The Center Square) – Despite ongoing concerns over electricity demand and grid reliability, PJM Interconnection says the region should have enough power to get through the summer – though national reliability officials warn that longer-term risks are mounting as data centers and other large energy users reshape grid planning.
PJM’s Summer Outlook 2026 projects adequate reserves to maintain reliability under expected conditions, even with hotter-than-normal weather in the forecast and peak demand projected at near-historic levels. The organization is responsible for controlling the flow of power across 13 different states and the nation's capital.
Demand is expected to reach about 156,400 MW, with 180,200 MW of generation capacity available, along with 7,800 MW of contracted demand response from customers who have agreed to reduce electricity use during system emergencies.
The North American Electric Reliability Corporation’s Summer Assessment largely aligns with that near-term outlook, citing recently added solar, battery, and natural gas resources that have improved summer readiness. But NERC also recently issued a Level 3 alert focused on reliability risks tied to large computational loads, including data centers, which can behave differently than traditional electricity demand.
The summer outlook focuses on whether enough resources are available to meet peak demand this year. NERC’s alert focuses on whether grid operators, utilities, and planners have the modeling, communications, and operating procedures needed to manage sudden changes from large, voltage-sensitive loads in the near future.
PJM says demand response helped control peak electricity use six times last summer during an early season heat wave. Summer peak reached approximately 161,300 MW on June 23 and 160,900 MW on June 24 – the third- and fifth-highest summer peaks in its history. The all-time summer peak was 165,563 MW in 2006.
For this summer, planning scenarios include unlikely but plausible demand of up to 169,100 MW of demand. The report notes an expected installed reserve margin of about 26%, exceeding the 18.6% margin needed to meet the one-day-in-10-years reliability standard.
Still, operating margins are tightening. The report says PJM has traditionally exported power to neighboring systems during extreme weather emergencies and has also relied on neighbors for support, but tighter margins may mean fewer resources are available to export during emergencies.
“While we expect to operate reliably this summer, the outlook resembles last year’s and reflects a new reality – continued load growth driven by data centers that is outpacing the addition of new generation,” said Michael Bryson, PJM senior vice president of operations. “This results in tightening operating reserve margins and greater risk.”
NERC officials echoed that broader concern.
Mark Olson, NERC’s manager of Reliability Assessments, told the Center Square that Level 3 alerts are for urgent reliability concerns and not frequently issued. Since 2020, only two have been issued: one in 2025 on inverter-based resources – including solar and battery – that can disconnect from the grid during disturbances, and the other in 2023 for cold-weather preparedness.
Olson said issuing an alert is intended to push the industry to act quickly while longer-term fixes, including new standards, technical guidance, and direct coordination with large power users, are developed.
He explained that grid operators use models and real-time monitoring to keep the system stable. Large loads like data centers behave differently, so existing tools must be updated with accurate information.
“We are in better shape than we have been in the past,” Olson said, “but we recognize risks are growing in other time periods.”
He said new solar and battery resources have strengthened summer readiness because they perform well in hot weather. But risks are shifting to fall and winter, when demand still rises and some resources are less aligned to perform during those times.
Although Virginia is known as “Data Center Alley” because it is home to the densest concentration of data centers in the world – the PJM region is one of the highest growth areas for large computational loads.
Olson said PJM has experience with the types of performance issues the NERC alert is meant to address. The alert calls on operators to improve modeling, establish communications with data center owners and operators, and ensure they have the information needed to manage sudden load reductions or disconnections.
The summer assessment recommends that operators review the linked materials and incident reports. That awareness can help shape operating plans, ensure sufficient resources are available to manage load and frequency disturbances, and support grid stability during similar events.
