Key Takeaways

  • PJM Interconnection asked the US Department of Energy to require data centres to switch to backup generators during grid emergencies
  • Historic heatwave exposes rising tensions between AI data centre expansion and stressed electricity and water systems
  • Lawmakers and utilities signal growing bipartisan support for stricter oversight of data centre siting and resource use

A scorching heatwave stretching across much of the United States is providing a real‑time stress test of the country's power and water systems, and PJM Interconnection has stepped into the spotlight with an unusually direct request. The grid operator asked the US Department of Energy to require data centres in its territory to transition to backup generators within fifteen minutes of an emergency alert. That quick handoff could free up enough electricity for homes and core services during the heat dome now gripping the Eastern Seaboard.

This comes at a moment when the US is accelerating construction of thousands of AI‑oriented data centres. These facilities are energy hungry, and they lean heavily on local water supplies as well. The tension between that growth and infrastructure capacity has been building for years, but this heatwave has exposed the physical limits of existing utility grids.

A look at the political response shows how quickly the issue is shifting. The Texas governor called for banning data centre construction in rural areas during a recent campaign stop, adding to an earlier stance that facilities should generate their own power and reuse water. On the opposite end of the political spectrum, prominent federal lawmakers are pushing for a moratorium on new data centre development. It is rare for both ends of US politics to converge on the same topic, but local opposition is now common. A recent Gallup survey found that 70% of Americans are against data centre construction near their communities.

This public sentiment is forming just as grid demand from AI accelerates. The US Department of Energy estimates that data centres account for 4% of total electricity demand today and could hit 9% by 2030. That rise is occurring alongside electrified transportation and new manufacturing loads. Utilities have warned that peak demand growth is returning after decades of stability.

Research from the University of Calgary described similar concerns north of the border, noting that typical hyperscale AI facilities can draw levels of power comparable to a small city. The University of Calgary sustainability group, cited in the ucalgary.ca research, pointed to global trends where AI‑oriented hyperscale sites regularly consume around 100 MW.

Some of the highest profile analyses of data centre resource use have come from consumer‑oriented publications as well. Reporting from Consumer Reports explained how water demand scales sharply for AI workloads. Large AI facilities can use up to 5 million gallons per day. During heatwaves, these same facilities often rely on evaporative cooling systems that do not cycle water back into the system.

State and local governments are already feeling the pressure. Earlier this year, around 50,000 customers near Lake Tahoe were forced to switch power providers due to rising data centre load. Henrico County in Virginia asked schools to reduce electricity usage because local data centres were pushing the grid close to its limits. Virginia leads the country in operating data centres with 398 facilities and another 287 planned. Texas follows with 296 open and 170 planned. These concentrations of infrastructure require significant regional grid upgrades to maintain baseline reliability.

Globally, this story is not unique. Work from the Lincoln Institute of Land Policy, noted in the lincolninst.edu analysis, highlighted how data centre clusters can create localized heat islands. A University of Cambridge study cited in the article found temperature increases of 2 degrees Celsius near data centres, with spikes up to 9.2 degrees Celsius immediately adjacent to cooling infrastructure.

During normal temperatures, cooling systems already account for up to 40% of a data centre's electricity use, according to analyst comments in the source report. When temperatures rise, that share increases. The heat dome now affecting Washington, DC, New York, and much of the eastern United States has pushed feel‑like temperatures above 38.9 degrees Celsius in major metro areas. It has also tilted more facilities into maximum cooling mode, which only adds to the stress PJM Interconnection is trying to manage.

Not all of the strain is coming from electricity. Water is another pressure point. AI facilities concentrate their water demand at precisely the wrong moments for local communities. Nearly 80% of potable water used in evaporative cooling evaporates instead of recirculating. Cities in drought‑prone regions are watching this trend closely. Corpus Christi, Texas, is a striking example. Local officials are concerned the region could soon face fresh water shortages. Some reservoirs are below 10% capacity after five years of drought, and one planned data centre development north of the city has complicated emergency supply planning.

Despite these challenges, utilities and policymakers are not moving in lockstep. Some regions are delaying the retirement of older power plants while others are exploring unconventional cooling technologies. Analysts at Bloomberg have covered these debates closely, noting how capital markets are beginning to price in long‑term grid expansion requirements. In the background, the International Energy Agency has forecast that global data centre water consumption could grow from roughly 560 billion litres annually to as much as 1,200 billion litres by 2030. Those numbers are often cited, but the heatwave is giving them immediate operational relevance.

PJM Interconnection's request to the Department of Energy offers a glimpse of how operators may handle these peak stress moments in the future. Whether this becomes a standard emergency tool or a temporary fix is still unclear. What is clear is that AI growth is landing squarely on existing infrastructure, and this summer’s conditions are forcing grid operators to implement emergency load-balancing measures.