Microsoft and Enchanted Rock signed a contract for a 99 MW natural gas-fueled backup system to supply the massive company’s data center in San Jose when Pacific Gas & Electric shuts off or loses power. The plan includes installing 224 gas-fueled units of 0.45 MW each, two diesel units of 1.25 MW and 0.5 MW that include emissions controls.

During an evidentiary hearing at the California Energy Commission last month, there was no opposition to the company’s request to waive state permitting for the backup system, unlike that faced by numerous other diesel backup systems seeking exemption from state certifications.

“We need more projects like this that supply power much cleaner than the petroleum diesel generators that are plaguing our communities,” said Bill Magavern, policy director for the Coalition for Clean Air, said of the June 15 announcement of the Microsoft- Enchanted Rock agreement.

The Environmental Impact Report on the project found emissions from the natural gas units would be more than 99% below those produced by diesel-fueled backup engines that meet Tier 2 or Tier 4 emission standards. In addition, particulate matter would be 95% lower, carbon monoxide emissions 86% less, and sulfur dioxide emissions 56% lower.

Enchanted Rock will offset the natural gas used at Microsoft’s San Jose campus with renewable natural gas bought from a project certified by the California Air Resources Board under its Low Carbon Fuel Standard program, according to Jim Kelly, Director of Natural Gas at Enchanted Rock.

RNG is produced from facilities that emit methane, such as food waste and agricultural operations.

The site where the gas will be produced has not yet been identified, Kelly said.

The alternative natural gas fuel cannot be injected directly into Pacific Gas & Electric’s gas lines, which serve the area, because of concerns about purity.

The photo is courtesy of Enchanted Rock