Texas data center boom could erase decades of progress on air quality

This article first appeared on The Texas Tribune.

Texas’ rapidly growing data center industry could reverse much of the state’s progress on air quality by the end of the decade, according to a new report released Tuesday.

The air emissions report published by the Houston Advanced Research Center revealed that the industry’s impact on air quality depends heavily on how data centers are powered. The outlook is far worse if the facilities rely on natural gas plants.

“What we are showcasing here is that there is a significant increase in different pollutant emissions that needs to be addressed because otherwise this could have strong implications for the population and environment,” said Carlos Gamarra, vice president for energy, air and IT for HARC, whose team produced the air quality impact scenarios.

Between 2002 and 2024, Texas sharply cut its major air pollutants — particularly from transportation, industry and the power generation sectors — even as the state’s population grew by millions and its economy roughly doubled, according to the report, which used federal and state agencies’ data on air emissions.

At least 288 data center projects are planned across the state, according to a recent Texas Tribune analysis. The scale of the projected data center build-out means that the sector's future emissions trajectory now depends heavily on how electricity is supplied. According to the report’s modeling, emissions could plausibly range from a marginal increase to a reversal of two decades of progress in reducing air emissions.

By 2031, the report projects that statewide nitrogen oxide emissions could rise 35% — even under a cleaner “net zero” scenario where data centers connect to the grid and deploy wind and solar on site. Under a different scenario where data centers choose traditional on-site natural-gas power sources, those emissions could increase nearly 400%. Such emissions can damage the human respiratory system with long-term exposure, causing chronic lung disease.

“We need to treat data centers as the industrial facilities they are … to hold them accountable to the same industrial and power generation emissions standards that produced Texas progress,” Gamarra said.

The report’s researchers argue that it’s not too late to stop this outcome. Instead of relying on the cheapest, fastest power options, Gamarra said, Texas lawmakers and industry leaders have the opportunity to shape the state’s air quality by choosing cleaner choices like renewable and wind and implementing regulation that could help reduce the impact.

How do data centers impact air quality?

Data centers need electricity to keep their servers running. Those servers also need cooling systems to avoid overheating, and some of the most water-efficient technologies use the most electricity to operate. As AI computing chips get more powerful and run at hotter temperatures, the need for cooling increases — and that means more energy.

Data centers can get that electricity in a number of ways. Historically, the most common method has been connecting to the Texas power grid. But there’s a wait to get connected. The Electric Reliability Council of Texas, the grid operator, in the last two years received over 500 requests to connect large electricity users, many of which are data centers, compared to two dozen such requests the year before that, according to state records from this summer.

Proposed data centers in Texas range from five to 11,000 megawatts in planned capacity, which reflects the maximum power an individual facility could use in any given moment. The estimated electricity that large projects could need from the grid added up to 439 gigawatts — which would equal roughly a third of all the power generation in America.

Data center developers and operators that can’t wait for a grid connection look for alternatives.

“The challenge right now is for these data centers when they try to connect to the grid, they have long timelines, like three to five years, and they cannot wait,” Gamarra said. “So they start deploying their own on-site energy systems, and they don't always pick the cleanest version of on-site generation because of timelines.”

He also notes that cleaner, more renewable technologies cannot always provide continuous energy to the data centers. Operators that choose cleaner technologies pay a higher price.

Going back on Texas air quality progress

Researchers modeled how four power supply scenarios could affect air pollutant levels over the next five years, based on projections of data center energy demand. The report studied a number of scenarios, comparing pollution from data centers connected to the grid versus combinations of on-site generation, including natural gas, solar and wind.

Gamarra attributed Texas’s declining emissions over the past two decades to changes in the electricity mix, especially the growth of wind and solar, pollution controls across power generation for industry and transportation, and the retirement of coal-fired generation.

That progress could be reversed if natural gas plants are the primary power sources for data centers.

Levels of nitrogen oxides would increase 136% by 2031 and approach the level they were at in 2004. Volatile organic compounds would exceed their 2002 level by 32%. Levels of particulate matter, microscopic particles that can penetrate deep into the lungs and enter the bloodstream, would increase to levels not seen since 2006.

Some scientists call particulate matter the deadliest form of air pollution because it can trigger health problems such as asthma attacks, irregular heartbeat and respiratory diseases.

The report also found that the power sources of data centers can drive enormous swings in air pollution. On-site natural gas engines emit about four times as much nitrogen oxides as grid power for the same data center, according to Gamarra.

At least 32 natural gas-fired power plants are planned in Texas — more than any other state — according to the nonprofit Environmental Integrity Project.

Nitrogen oxide emissions from data center power generation could be two to 10 times higher if all new demand were met with combustion instead of grid supply paired with solar and wind, depending on which demand forecast is used.

Major metros like Houston, Dallas-Fort Worth, San Antonio and Austin frequently struggle to meet federal air pollution standards already, mainly due to intense traffic, vehicle exhaust and high summer temperatures.

Even under the cleanest power supply scenario, the report found that the sheer volume of data center power demand leads to an increase in emissions.

“If the industry grows as is expected to grow, we need to be careful with air quality. We need to pay attention to it because we don't want to go back to the emissions levels we had in the early 2000s,” Gamarra said.

There’s also a role for data center operators to play, Gamarra added. Operators could choose cleaner power when possible and meet existing pollution-control standards. They could also disclose electricity use, power sources and resulting pollution so communities can assess impacts before development decisions are made.

Disclosure: Houston Advanced Research Center has been a financial supporter of The Texas Tribune within the past five years. The Texas Tribune is a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in our journalism. Find a complete list of them and more information about our financial and disclosure policies here.