xAI has been granted permission to run a permanent installation of 15 gas turbines at its Memphis data center.

Shelby County Health Department gave the company a permit for the turbines, which the company says will act as a backup power source for the data center, at a meeting on Tuesday.

Elon Musk’s firm has been using gas turbines at the site, on Paul Lowry Road in Memphis, since it opened last year to supply part of its primary power.

The turbines have been a source of much controversy, with campaigners claiming that they negatively impact air quality in the area and that xAI has been operating without the correct permits.

Elon gets gassed up

Under the permit, which covers the period to 1 January 2027, xAI will be allowed to run 15 turbines generating 247.2MW of electricity.

In terms of emissions, the turbines must not exceed 13.71 tons of hazardous air pollutants or 9.79 tons of formaldehyde over a 12-month period, the health department said.

The Memphis data center, which is home to xAI’s Colossus supercomputer, went live in July 2024 with an initial capacity of 150MW, covered by an 8MW grid connection and gas turbines. It received a permit for a temporary installation of 15 turbines.

Power company Memphis Light, Gas, Water increased the data center’s grid power allocation to 150MW last November. However, in April, it was revealed that xAI had also doubled the number of gas turbines at the facility to a reported 35, in apparent violation of its permit.

The company said in May that it had started removing turbines from the site, and that once a second 150MW electrical substation comes online in the Fall, it will use gas power for backup only.

Given that 247MW is unlikely to satisfy the entire backup power needs of the data center, xAI will need other options too, and has apparently been installing battery Megapacks from Tesla, another of Musk’s companies, to help manage its power.

DCD has contacted xAI for comment on the decision, but the Memphis Chamber of Commerce welcomed news of the permit being granted.

“This approval demonstrates Shelby County’s commitment to evidence-based decision-making that balances economic growth with environmental stewardship,” said Ted Townsend, president and CEO of the Greater Memphis Chamber. “We’re pleased that our Shelby County Health Department has thoroughly evaluated the scientific data and recognized the exceptional environmental standards of these turbines.”

While natural gas is less damaging to the environment than other fossil fuels, it remains a pollutant with a carbon footprint that is significantly higher than renewable energy sources. Despite this, many in the data center industry are turning to gas to power their new facilities.

Campaigners dismay at xAI permits

Campaign group the Southern Environmental Law Center (SELC) has previously accused xAI of violating the Clean Air Act through its use of gas turbines.

SELC says satellite imagery taken on July 1 shows that there are currently 24 turbines operating at the Memphis data center.

“The decision to give xAI an air permit for its polluting gas turbines flies in the face of the hundreds of Memphians who spoke out against the company’s permit request,” SELC senior attorney Amanda Garcia said.

“Instead of confronting long-standing air pollution problems in South Memphis, the Shelby County Health Department is turning a blind eye to obvious Clean Air Act violations in order to allow another polluter to set up shop in this already-overburdened community without appropriate protections. We are evaluating our options moving forward.”

SELC and the National Association for the Advancement of Colored People (NAACP) announced in June that they intended to sue xAI over possible Clean Air Act violations, with the NAACP calling for the data center to be shut down while the allegations are investigated.