Texas data centers could reverse decades of air quality gains

By 2031, smog-forming nitrogen oxide emissions in Texas could climb 136 percent and approach their 2004 volume, according to a Houston Advanced Research Center report covered this week by The Verge. Fine particulate matter known as PM2.5 would return to the volume last seen in 2006.

The driver is the state's data center buildout, and how operators power it. HARC modeled a scenario in which facilities connect to the grid and deploy wind and solar on site; even then, "statewide nitrogen oxide emissions could rise 35%" by 2031. Under a scenario where data centers lean on traditional on-site natural gas, those emissions could increase nearly 400 percent.

"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.

The gap between the two paths is wide. Nitrogen oxide emissions from data center power would be two to 10 times higher if all new demand were met by on-site combustion rather than by the grid paired with solar and wind, depending on the demand forecast. On-site natural gas engines emit about four times as much NOx as grid power for the same data center, according to Gamarra.

A Texas Tribune analysis found at least 288 planned data center projects statewide, with proposed sizes ranging from 5 to 11,000 megawatts. Gamarra wants them "treated as the industrial facilities they are," he told the Tribune, to hold them accountable to the same emissions standards that produced the state's air quality progress.