Texas data centers could send air pollution soaring

For more than 20 years, the US state of Texas has cut several major air pollutants, even as its population and economy have grown. Now researchers fear that trend could reverse as a large number of data centers need power.

Data centers are the large buildings filled with computers used to train and run AI, among other things. They consume enormous amounts of electricity.

Four scenarios for power

The Houston Advanced Research Center (HARC) published a report in mid-October on the impact of data centers on air quality through 2031. The report models four scenarios for how data centers could get their power. The figures below come from a summary in the Texas Tribune, and they are model estimates, not measured emissions.

If data centers connect to the grid and use on-site wind and solar, total nitrogen oxide (NOx) emissions in Texas could rise by 35 percent. NOx is a group of air-polluting gases formed by combustion, among other processes.

If data centers instead use conventional natural gas on-site, the increase could reach nearly 400 percent. According to the article, on-site gas engines emit roughly four times as much NOx as grid-connected power for the same data center.

In a full natural gas scenario, NOx from the power sector could rise by 136 percent and approach 2004 levels. Emissions of volatile organic compounds would then be 32 percent above 2002 levels, and particulate pollution (soot) would reach its highest level since 2006.

Many projects in the pipeline

At least 288 data center projects are planned in Texas. Their combined expected demand is about 439 gigawatts, which the article says is roughly a third of US electricity generation. Grid operator ERCOT received more than 500 interconnection requests in two years, compared with 24 previously. Governor Abbott has temporarily halted new grid connections until a review is completed.

At least 32 gas-fired power plants for data centers are also planned in Texas, more than in any other state. Houston, Dallas, San Antonio and Austin already struggle to meet federal air quality standards.

A separate analysis from the Environmental Integrity Project shows that if the 32 power plants ran at full capacity, they could emit more than 287 million tons of greenhouse gases, more than 14,000 tons of fine particulate matter, about 20,000 tons of NOx and about 8,000 tons of volatile organic compounds per year. Nearly 90 percent of the proposed plants in Texas are located in counties where average life expectancy is lower than the US average of 77 years.

Carlos Gamarra, vice president at HARC, says: "There is a significant increase in emissions of various pollutants that will need to be addressed."

It is unclear how many of the planned projects will actually be built.