PJM Manual 13 / Capacity Advisory new emergency procedure / Markets and Reliability Committee Jun 24 / effective immediately / fires on >1pp shortfall from target reserve margin / up to 5 days advance notice / first non-weather-driven emergency procedure / data center load growth now an independent reliability variable

Plain-English version of what happened. PJM Interconnection is the regional transmission organization (RTO) — the federally regulated nonprofit that physically dispatches the electric grid for 13 states and DC, covering 67 million people from New Jersey through Virginia, Ohio, Maryland, parts of North Carolina, and out to Chicago. PJM publishes operating procedures in a series of manuals; Manual 13 is the one that defines emergency procedures — the rules PJM follows when it needs to keep the lights on under stress. Until this week, every emergency procedure in Manual 13 was scaffolded around weather. The 'Hot Weather Alert' fires when forecast temperatures will push air-conditioning load above a threshold. The 'Maximum Generation Alert' fires when PJM expects to call on every available generator to meet demand on a peak summer or winter day. The 'Cold Weather Alert' fires during deep-freeze events. The logic was: a normal-temperature day in PJM has enough reserve generation to absorb forecast errors, generator trips, and economic dispatch glitches; emergencies happen on weather days. That has been the implicit reliability physics of PJM since the RTO was founded in 1997. On June 24, 2026, PJM's Markets and Reliability Committee endorsed an addition to Manual 13: the 'Capacity Advisory.' It is a brand-new emergency procedure, effective immediately. The Capacity Advisory fires when forecasted or actual capacity deficits appear OUTSIDE of extreme hot or cold periods — i.e., on a normal-weather day, when historically PJM would not have expected a shortfall. PJM's stated rationale, in its own words: 'PJM is now seeing forecasted or actual capacity deficits outside of extreme hot or cold periods and expects these instances to increase as demand growth outpaces the addition of new power resources.' The trigger threshold uses an existing PJM concept. PJM has a 'target reserve margin' — the amount of generation it should have available above expected peak demand to maintain reliability standards. The number is set annually by the Reserve Requirement Study and is currently about 17.8% above peak. Per PJM's Open Access Transmission Tariff (the legal document FERC approves that defines what services PJM provides and at what price), a shortfall of more than one percentage point below that target reserve margin triggers an investigation into the cause — and if the shortfall persists across two more Base Residual Auctions (the annual capacity auction), it triggers a Reliability Backstop Auction (essentially an emergency procurement). The new Capacity Advisory uses the same '>1 percentage-point shortfall' trigger, but the operational mechanism is different: the Advisory can be issued up to 5 days in advance when day-ahead forecasts show generation approaching demand. It's a pre-positioning tool — PJM telling its members 'tighten up your maintenance scheduling, hold available generation, get ready to dispatch demand response' — before the situation becomes a Maximum Generation Alert. What PJM is admitting in plain language. The whole legacy reliability framework assumed normal-weather = surplus. PJM is now writing into Manual 13 that normal-weather can equal deficit, because the cumulative load growth from data centers (PJM's own 5-year forecast shows ~35-40 GW of data-center load growth on a system that peaks around 165 GW) is faster than the new-generation queue can absorb. The Capacity Advisory is the operational acknowledgment that this is the steady-state reality, not an episodic stress case.

Primary source · PJM Inside Lines — PJM Adds Emergency Procedures to Maintain Reliability (Jun 24 2026) ↗