Data centers across 13 states recently received emergency permission to switch to diesel backup generators during a record heat wave, a move that highlights the growing tension between AI infrastructure demands and grid reliability. The U.S. Department of Energy granted this authorization to PJM Interconnection, the regional grid operator serving over 67 million people, after the organization warned of potential blackouts as electricity demand hit an all-time peak of 168,158 megawatts on July 2.

The emergency order, initially in effect from June 30 through July 3 and later extended through July 7, allowed data centers and other large industrial users to rely on their onsite backup generators instead of drawing power from the grid during peak demand periods. While PJM ultimately did not need to activate this emergency measure, the authorization itself signals a fundamental shift in how the nation manages power during extreme weather as data center construction accelerates.

What's Driving This Emergency Authorization?

The request came as temperatures soared into the 90s and above 100 degrees across PJM's 13-state territory, which includes Pennsylvania, Ohio, Virginia, Maryland, New Jersey, and other major population centers. PJM warned that the region faced an all-time peak electricity load during the heat wave, and the North American Electric Reliability Corporation's 2025 long-term assessment identified the PJM region as facing high risk for energy shortfalls over the next five years.

The core problem is straightforward: new power generation projects cannot keep pace with escalating demand, especially as data centers consume enormous amounts of electricity 24/7 to power computing hardware and cooling systems. Data center campuses operate continuously, unlike traditional industrial facilities that may have variable demand patterns.

How Much Power Do These Data Centers Actually Need?

The scale of data center power consumption is staggering. A single proposed facility in Archbald, Pennsylvania, the Wildcat Ridge Data Center Campus, plans to use 1.6 gigawatts, or 1,600 megawatts, to power 14 data centers. To put that in perspective, the Lackawanna Energy Center, the largest power plant in Lackawanna County, produces only 1,485 megawatts.

To maintain operations during power outages, the Wildcat Ridge facility would rely on 588 diesel generators that would collectively produce more electricity than the county's largest power plant. This backup generation capacity exists at data centers nationwide, and the Department of Energy noted that "tens of gigawatts of readily available backup generation have remained largely untapped".

Why Are Local Communities Concerned About Diesel Generators?

Backup generators have emerged as one of the most contentious issues in communities where data centers are proposed. Unlike traditional power plants, which operate under strict environmental permitting rules, backup generators are governed with more lenient pollution standards. During the recent heat wave, the Department of Energy also temporarily allowed power generators to exceed their environmental permitting limits to maintain grid reliability.

A screening-level air quality assessment conducted by Harvard University environmental health scientist Michael Cork examined the potential health impacts from Wildcat Ridge's nearly 600 generators. Using U.S. Environmental Protection Agency modeling, Cork estimated that the facility's generators could cause anywhere from $3.3 million to $124 million in annual health damages across Lackawanna County and would emit hundreds of thousands of pounds of air pollutants each year.

"It is essentially installing the cheapest and dirtiest type of power plant," said Tom Schuster, Sierra Club Pennsylvania Chapter Director.

Tom Schuster, Sierra Club Pennsylvania Chapter Director

What Are the Key Concerns About This Trend?

Community opposition to data center development centers on several interconnected issues:

• Pollution and Health Impacts: Backup generators emit significant air pollutants, and the emergency authorization during heat waves could extend generator runtime beyond what municipalities previously anticipated, increasing cumulative emissions.
• Noise Pollution: Local governments typically exempt data centers from noise limits when they rely on backup generators, meaning residents near facilities could experience increased noise during emergencies.
• Fuel Storage and Safety: Data centers maintain large volumes of diesel fuel on site to sustain generators, raising concerns about storage safety and environmental contamination risks.
• Grid Strain Acceleration: As data center development outpaces new power generation construction, future heat emergencies may be triggered at lower temperatures, meaning more frequent and longer-duration generator use.

In Archbald alone, developers propose 51 data centers across six projects, with 30 buildings confined to roughly a one-mile stretch. This concentration of facilities would create unprecedented demand on local infrastructure and emergency systems.

How Might This Change Future Emergency Response?

The authorization to use data center backup generators during grid emergencies represents a significant policy shift. Previously, discussions about generator use focused on mandatory quarterly testing and maintenance schedules, plus operation during actual power outages. Now, generators may run during peak demand periods even when the grid remains operational, fundamentally changing the environmental and health calculus for communities hosting these facilities.

Experts warn that if data center development continues outpacing power generation construction, future heat emergencies will likely last longer and be triggered by lower temperatures. This means backup generators could become a routine part of summer grid management rather than a true emergency measure.

The tension between AI infrastructure needs and grid reliability will likely intensify as companies race to build data centers for artificial intelligence and cloud computing workloads. While the recent emergency authorization prevented blackouts, it also exposed the vulnerability of a power system struggling to keep pace with technological demand.