America’s largest power grid has struggled to cope with an onslaught of data centers. Now, after an auction to add more generation capacity failed, grid operator PJM Interconnection has said it will take data centers and other large users offline during power outages.

The decision comes as the breakneck pace of data center construction has grid operators scrambling to generate power. By 2035, data centers are expected to use 4 times more electricity than today.

PJM will not begin reducing supply until June 2027, and the cuts will only apply to data centers of 50 megawatts or larger. The grid operator is organizing another auction for new generation capacity.

Like other demand response programs, which have been around for decades and typically include large users such as manufacturers, customers who have their power cut off will be compensated. These programs typically give customers advance notice, anywhere from 30 minutes to a few days, depending on anticipated demand.

The move will likely spur many new (and potentially existing) data centers to establish their own on-site power sources. Those that do not will likely rely on backup generators, which tend to be more expensive and often more polluting to operate.

Many data centers prefer diesel generators as the fuel is widely available and can be stored on site. Federal regulations allow such generators to be used up to 50 hours per year for demand response events and up to 100 hours per year for events such as emergencies and maintenance.

This week, Vantage Data Centers came under fire for its apparent coordination with Virginia environmental regulators to cast doubt on a report that said diesel backup generators could contribute tens of millions of dollars in annual health damage to people living near a 96-megawatt data center in northern Virginia.

PJM has been criticized in recent months for the way it has managed new generation capacity and large new users, including data centres. The network operator’s territory stretches from Virginia to Illinois and covers 67 million customers. Over the past year, wholesale electricity prices have nearly doubled, and independent market monitor PJM blamed data centers for much of the increase.