America's biggest grid can now order data centers off the grid

The U.S. Department of Energy gave PJM Interconnection emergency authority this summer to direct large power users, including data centers, to switch to backup generators before blackouts hit. During the July heat wave, PJM prepared to curtail large loads in the BGE, PEPCO and Dominion zones and set a new all-time peak-demand record the same day, even though the final curtailment step was never triggered.

For engineers planning AI infrastructure, this is a signal worth internalizing: cloud contracts promise uptime, but the grid underneath now treats data center load as interruptible in an emergency. PJM's own forecasts show summer peak demand growing 3.6% a year, driven largely by data centers, while capacity market costs and wholesale power prices have already climbed sharply, with one market monitor citing wholesale prices up more than 75% year over year.

Northern Virginia's Data Center Alley is where this pressure is most visible. Hyperscalers like Amazon and Microsoft have moved to lock in dedicated power through nuclear deals (Talen/Susquehanna, Constellation/Three Mile Island), but private power contracts don't solve the underlying transmission and timing mismatch facing the regional grid.

The practical takeaway: any serious AI infrastructure announcement now needs to show real megawatt numbers, interconnection timelines, and a credible answer for what happens on the hottest day of the year — not just GPU counts and capex figures.