Texas Data Center Power Demand Could Reverse Air Quality Gains, HARC Report Finds

Texas’ emissions gains face a new test

The central issue in Texas’ data center surge is how the facilities get their power. A report released Tuesday by the Houston Advanced Research Center (HARC) finds that emissions could rise modestly or erase much of the state’s air quality progress, depending on the energy mix. The report’s scenarios suggest that natural gas powered data centers carry the greatest risk.

Texas cut major air pollutants between 2002 and 2024, even as its population grew by millions and the economy roughly doubled. The reductions came from transportation, industry and power generation, according to federal and state emissions data cited in the report. Now, at least 288 data center projects are planned statewide, based on a recent Texas Tribune analysis. The scale makes the power supply choices consequential.

By 2031, nitrogen oxide emissions could climb 35% in the report’s “net zero” scenario, where data centers connect to the grid and add wind and solar on site. If operators instead rely on traditional on-site natural gas, the increase could approach 400%. Long-term exposure to nitrogen oxides can harm the respiratory system and contribute to chronic lung disease.

“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, HARC’s vice president for energy, air and IT. His team developed the air quality scenarios. Gamarra argues data centers should face the industrial and power generation emissions standards that helped drive Texas’ earlier reductions.

Power demand is colliding with grid delays

Data centers draw electricity for servers and cooling. Some water efficient cooling systems consume more power, and increasingly powerful AI chips run hotter, adding to cooling needs. The demand is arriving as grid connections take time: the Electric Reliability Council of Texas (ERCOT) received more than 500 requests from large electricity users in the last two years, many from data centers, compared with two dozen the year before, according to state records from this summer.

Planned Texas facilities range from 5 megawatts to 11,000 megawatts of capacity, the maximum power a site could draw at a given moment. Estimated grid demand from large projects totals 439 gigawatts, roughly a third of all U.S. power generation. Gov. Greg Abbott has temporarily paused new data center grid connections while an audit examines power needs, water and cooling use, public financial assistance and community impacts.

For developers facing grid delays of three to five years, waiting may not be viable. Some build on-site power instead, and Gamarra says schedules can push them toward dirtier options. Cleaner renewable systems can also cost more and may not provide continuous power. That’s the practical bind: the fastest supply choice can carry a higher emissions cost.

Natural gas could reverse earlier gains

Researchers modeled four electricity supply scenarios over the next five years, comparing grid power with combinations of on-site natural gas, solar and wind. Gamarra credits Texas’ past emissions decline to a changing electricity mix, growth in wind and solar, pollution controls across power generation, industry and transportation, and the retirement of coal plants. The report suggests that reliance on natural gas could undo part of that progress.

Under the natural gas scenario, nitrogen oxide emissions could rise 136% by 2031, nearing 2004 levels. Volatile organic compound emissions could exceed their 2002 level by 32%, while particulate matter could return to levels last seen in 2006. These microscopic particles can penetrate deep into the lungs and enter the bloodstream. Some scientists describe particulate matter as the deadliest form of air pollution; it can trigger asthma attacks, irregular heartbeat and respiratory disease.

The power source matters sharply. Gamarra says on-site natural gas engines emit about four times as much nitrogen oxide as grid power for the same data center. Across different demand forecasts, nitrogen oxide emissions from data center power generation could be two to 10 times higher if new demand is met with combustion rather than grid supply paired with solar and wind. Texas has at least 32 natural gas fired power plants planned, more than any other state, according to the Environmental Integrity Project.

Houston, Dallas-Fort Worth, San Antonio and Austin already often struggle to meet federal air pollution standards, with traffic, vehicle exhaust and hot summers contributing to the problem. Even the report’s cleanest power scenario produces higher emissions because projected data center demand is so large. The obvious read is that cleaner power solves the problem. It doesn’t; it can limit the increase, but the modeled demand still adds pollution.

Choices remain open

Gamarra says lawmakers and industry leaders can still influence the outcome by favoring cleaner power, including wind and other renewables, and setting rules to reduce pollution. Operators can choose cleaner sources where feasible, meet existing emissions controls, and disclose electricity use, power sources and resulting pollution. That information would let communities weigh local effects before development decisions are made.

“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.

Disclosure: HARC has financially supported The Texas Tribune within the past five years. The Tribune is a nonprofit, nonpartisan news organization funded in part by donations from members, foundations and corporate sponsors; financial supporters have no role in its journalism. Its full list of supporters and disclosure policies are available here. This article first appeared in The Texas Tribune.

Topic: Texas