US Power Grid Emergency Order Authorises Data Centre Backup Generators as Last Resort Across 13 States

The US Department of Energy has authorised the operator of a regional electricity grid serving 13 states and Washington, DC to direct data centres and other large power users to switch to backup generation as a last resort during a four-day emergency period.

Energy Secretary Chris Wright issued the order on 12 October after PJM Interconnection forecast demand of around 111,500 megawatts or more on 13 October, with 61,591 megawatts of generating capacity expected to be unavailable. PJM also warned that available capacity could come within 900 megawatts of its reserve margin on 14 October.

The order took effect on 13 October and remains in force through 16 October. It gives PJM additional options amid elevated demand, planned maintenance and transmission constraints. The authorisation does not, by itself, establish that all eligible backup generators have been activated or that blackouts are occurring.

What the Emergency Order Allows

Order No. 202-26-50 was issued under Section 202(c) of the Federal Power Act, which allows the Energy Department to take temporary action during electricity emergencies.

It directs PJM to operate specified generating units as needed to maintain reliability and authorises the last-resort use of backup resources before declaring an Energy Emergency Alert Level 3, or during that alert.

Energy Emergency Alert Level 3 is the stage at which an electricity operator may need to interrupt customers' electricity supply, or shed firm load, to address an energy shortfall. Issuing the federal order does not, by itself, mean PJM has declared that alert.

Large users can ease pressure on the grid by running eligible on-site backup resources instead of drawing electricity from the network. The order covers resources at data centres and other large industrial and commercial facilities, including standby generators and battery storage, whether or not they are connected to the wider grid.

The authority excludes backup resources serving critical reliability or backup needs. Examples include resources supporting hospitals, emergency services, air traffic control, 911 call centres, water and wastewater facilities, and certain natural gas infrastructure.

The order also provides limited flexibility where emergency operation would conflict with environmental operating restrictions. Resources must comply with environmental requirements to the maximum extent practicable, and PJM must report daily which resources operated under the allowances. The provisions do not amount to an unrestricted exemption from environmental requirements.

Why PJM Requested Federal Intervention

PJM's 11 October application cited planned autumn maintenance and construction that had contributed to substantial generation outages. These coincided with transmission outages, firm electricity export obligations and constraints that could limit the movement of power between regions.

The forecast of 61,591 megawatts of unavailable generating capacity describes power plants expected to be out of service, not electricity already lost by customers.

Electricity operators also need capacity beyond expected demand to maintain reliability. PJM's warning about approaching its reserve margin concerned forecast operating conditions, rather than a finding that the grid had run out of electricity.

PJM identified the most acute concerns in its Baltimore Gas and Electric, PEPCO and Dominion zones, which cover parts of Maryland, Virginia, the Washington metropolitan area and neighbouring regions.

What the Order Means for Residents

PJM coordinates wholesale electricity markets and manages the high-voltage grid across all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia, as well as Washington, DC.

Ahead of the forecast pressure on supply, the operator issued a Maximum Generation Alert and a Load Management Alert for 13 October and extended its Capacity Advisory through 14 October.

These operational measures are distinct from an instruction for households to reduce electricity use. PJM's capacity advisory said residential customers did not need to take action and described recalling or rescheduling maintenance outages as possible steps to maintain adequate resources.

PJM also clarified that identifying resources for reliability purposes under the emergency order did not automatically require them to operate at maximum output or full load.

Earlier Emergency Measures

The October directive follows earlier PJM emergency orders this year. A September order, effective on 17–18 September, similarly authorised specified generation and the last-resort use of backup resources before or during an Energy Emergency Alert Level 3.

The latest directive gives PJM temporary flexibility to manage the immediate pressures from demand, generation outages and transmission constraints.

Separately, PJM has warned that capacity pressures could become more frequent as electricity demand grows faster than new power resources are added. The four-day order addresses the immediate reliability concern rather than the longer-term challenge of ensuring sufficient electricity supply.