A key generator serving Virginia tripped the morning of the September emergency

RICHMOND, Va. - On the morning the federal government declared a grid emergency for Virginia and 12 other states, a power plant supporting the region's most strained areas abruptly stopped running. More than a month later, its name is still not public.

PJM Interconnection disclosed the outage in a two-page letter to Energy Secretary Chris Wright dated Sept. 17. "This morning, a critical generation facility that supports the affected Zones identified in PJM's September 16 application unexpectedly went offline," wrote Frederick "Stu" Bresler, PJM's chief operating officer. "It is unclear whether it will return to service by today's evening peak, exacerbating the already tight system conditions and potential shortage of energy to supply the forecast load."

The "affected Zones" in PJM's application were the BGE, Pepco and Dominion zones, which cover central Maryland, the D.C. area and most of Virginia.

What the public record shows

The letter does not give the plant's name, location, owner, fuel or size. It does not say what caused the outage or when the plant returned. DOE posted the letter on its docket page for Order No. 202-26-45 as "Supplemental Information Supporting Request for Emergency Order."

A review of PJM's posted documents for the event, including its Sept. 17 operations update, its demand response summary, Exhibit A and its Sept. 17 compliance report, along with DOE's docket and news coverage available online, did not identify the facility. PJM's operations update mentioned outages generally but not this one.

PJM hasn't named it.

Why it mattered

PJM had already told DOE the system was on a knife's edge. Its Sept. 16 application forecast demand "at or around 133,285 MW (or higher)" and a shortfall of "approximately 700 MW below its reserve margin." It said about 33,191 megawatts of generation was out, much of it for fall maintenance, and that north-to-south power transfers were "being limited by loading on the Conastone-Peach Bottom 5012 500 kV facility."

That transmission limit is why a single plant inside the affected zones could matter so much. Power from elsewhere in PJM could help only up to what the lines could carry. The application said that if "unforeseen contingencies - like generation or line losses - were to arise, the reliability impacts to the PJM system could be significant." The next morning, one did.

Wright signed the emergency order the same day. That afternoon PJM called emergency demand response in the BGE, Pepco and Dominion zones, deployed between 2:30 and 4 p.m. and released at 10 p.m., according to a PJM summary.

What ran instead

The order let PJM run listed plants past environmental permit limits and direct backup generators at large power users to run. PJM's Sept. 17 compliance report shows units that ran in reliance on the order, including Mount Storm units 3 and 1 in West Virginia, listed under PJM's Dominion-zone "VP" prefix, at 12 hours and 1 hour, and six diesel backup units in Ashburn at 8 to 10 hours each. Listed Virginia combustion turbines in Louisa, Fauquier and Hanover counties do not appear on that report.

How it could be identified

Generator owners report outages to PJM, but PJM's public postings for this event do not include unit-level outage data. PJM's market monitor, Monitoring Analytics, publishes reports on market events, and owners of large plants sometimes disclose unplanned outages in regulatory or investor filings. Any FERC filings seeking cost recovery under the order, which says rate recovery "is available," could also shed light on which units were involved in the emergency.

The Virginia State Corporation Commission, which regulates Dominion Energy Virginia, was copied on the order. No public SCC statement about the outage was found.

Documents

The order, PJM's application, its supplemental letter and Exhibit A are posted on the Department of Energy's 202(c) page for Order No. 202-26-45 at energy.gov. PJM's daily compliance report for Sept. 17 is posted at pjm.com.