PJM Interconnection has introduced new emergency procedures to maintain reliability amid tightening supply margins, rising demand, and more frequent extreme weather events, according to a filing and market notice issued on Wednesday.
The changes, adopted to PJM Manual 13 and endorsed by stakeholders at a June 24 Markets and Reliability Committee meeting, take effect immediately and expand coordination among the grid operator, transmission owners, generators, and large electricity users.
The US grid operator said it is increasingly seeing forecast or actual capacity shortfalls outside traditional periods of extreme heat or cold, as demand growth accelerates and new power resources fail to keep pace.
The trend is also being driven by a higher share of intermittent renewable generation on the system.
Under the new framework, PJM has introduced a 'Capacity Advisory' alert, which can be issued up to 5 days in advance when projected system conditions indicate that available generation is approaching the required demand levels across PJM zones.
The advisory is designed to give market participants an earlier warning of potential tight conditions.
The Capacity Advisory framework allows PJM to take steps, including recalling or rescheduling generation and transmission maintenance outages, alerting neighboring grid operators to reduce expected imports, and requesting updated information from generators on fuel availability, environmental constraints, and operational status.
PJM said that, in more severe conditions, it may also activate a separate emergency protocol allowing the use of on-site backup generators at large industrial users, including data centers, under coordination with the US Department of Energy.
The "Emergency Use of Backup Generators Warning" would prompt planning by PJM, utilities, and large customers to estimate how much load could be served by backup generation in each transmission zone.
PJM could issue an "Emergency Use of Backup Generator Action" if conditions worsen, requiring large loads to switch to backup power within 15 minutes.
The grid operator said the measure would be deployed only after all available generation resources and demand-response tools have been exhausted, and before more severe actions such as voltage reductions or manual load shedding.
PJM said multiple emergency procedures may be issued simultaneously, depending on system conditions, underscoring what it described as the increasing complexity of maintaining grid reliability during periods of stressed supply and rising demand.