A Real Mid-Atlantic Grid Emergency Just Tested the Rule PJM Doesn't Have

On October 12, Energy Secretary Chris Wright invoked emergency authority under Section 202(c) of the Federal Power Act to protect the grid run by PJM Interconnection, the nation's largest wholesale power market, spanning 13 states and Washington, D.C. and serving more than 67 million people. The order ran from October 13 through October 16 and let PJM push specific generating units beyond their normal operating or permit limits and tap backup generation if conditions deteriorated. The Department of Energy said more than 35 gigawatts of unused backup capacity was available nationwide if needed.

The trigger was not a storm or an equipment failure. PJM had forecast demand near 111,500 megawatts for October 13, and roughly 61,591 megawatts of generation were already offline or scheduled for maintenance outages on October 14 — work utilities normally front-load into fall because it is historically PJM's slackest season. Unusually warm fall weather across the Mid-Atlantic collapsed that cushion: DOE's own numbers put the system within about 900 megawatts of its reserve margin. The most acute strain showed up in the BGE, PEPCO, and Dominion zones — the utility footprints that cover Baltimore, Washington, D.C., and Northern Virginia, the latter widely described as the densest concentration of data centers on earth.

The curtailment rule that doesn't exist

The emergency landed almost immediately after the Federal Energy Regulatory Commission rejected the mechanism PJM had built specifically for moments like this one. PJM's Interim Resource Adequacy Service, filed to address demand growth that is outpacing new generation, would have let the grid operator curtail large new loads — chiefly data centers that hadn't brought their own backing generation — ahead of ordinary residential and commercial customers during a supply shortfall. FERC sent the plan back, ruling that key provisions intruded on states' authority over retail electricity service and that PJM hadn't adequately justified singling out large loads for different treatment. It approved only a narrower piece: a registry to track loads of 50 megawatts or more.

That left PJM without a settled, pre-agreed order of operations for exactly the scenario that materialized this week. The October 12 order gave PJM authority to direct large loads, including data centers, onto backup generation only as what DOE's order itself frames as a last resort before PJM would have to declare a full Energy Emergency Alert 3 — the most severe tier, one step from directed outages. It did not give PJM, or anyone else, standing authority to curtail data center demand first and automatically. Any such request still runs through voluntary mechanisms like data centers' Ratepayer Protection Pledge commitments, not a binding tariff rule.

David Rosner, FERC commissioner, concurring in the order rejecting PJM's plan: "in an emergency, data centers not serving critical functions should be shut off before ordinary customers."

A federal order is not a market rule

The gap matters because of how the two mechanisms differ. A Section 202(c) emergency order is a blunt, temporary instrument DOE issues plant-by-plant or region-by-region when conditions already look dangerous — it can keep an aging gas unit running past its limits or unlock idle backup capacity, but it says nothing about which customers get protected first. A FERC-approved curtailment tariff would have been a standing rule, built into PJM's market design, that applies automatically every time the system gets tight, regardless of the weather. Right now PJM is governed by the emergency order, not the rule, and this week's episode is the clearest evidence yet that the two are not substitutes: DOE had to reach for generators rather than load, even in zones where data center demand is itself a documented driver of the tightening margin.

That is a structural problem heading into the rest of 2026. PJM's own filings attribute the deteriorating reserve margin to demand growth it links to data centers and electrification outpacing new generation, even as federal regulators keep PJM from building standing authority to curtail that same demand during stress events. Virginia alone — home to Loudoun County, which officials there estimate carries up to 70 percent of global internet traffic on a given day — sits inside the Dominion zone DOE flagged as among the most acute this week. PJM has said it will refile a revised version of its curtailment plan, addressing FERC's objections about state authority and load-specific treatment, but regulatory counsel following the docket expect the rewrite to take months, not weeks, and PJM has other near-term priorities competing for its attention.

Until a revised rule clears FERC, every tight week in PJM territory gets handled the same way this one was: ad hoc emergency orders that extend plant permits and unlock backup diesel and gas units, while the underlying question — whether data centers get cut before households when the math runs out — stays open. DOE has said it does not expect blackouts and that residential customers don't need to change behavior. But each new order is also a reminder that the fix is temporary and plant-specific, not a rule the market can count on the next time fall weather or a heat wave collides with maintenance season.