US operator ECL has announced a new 35MW data center in California that will utilize hydrogen as one of its power sources.

The facility, in Santa Clara, Northern California, will combine on-grid electricity and natural gas with the company’s behind-the-meter hydrogen power blocks, and support rack densities ranging from 75kW to 270kW. The first phase of development will offer 2.5MW of IT capacity.

Dubbed CSC-1, the data center will use ECL’s FlexGrid architecture, which allows different power sources to ensure what ECL describes as “always-on, grid-independent operation.”

By using the hydrogen power blocks, ECL says customers can avoid long wait times for grid connections. The company has been a pioneer of using hydrogen as a data center power source, and already has a 1MW data center, MV-1, powered by hydrogen operating at its California headquarters in Mountain View. AI cloud firm Lambda is a known customer of the site.

Proponents of hydrogen say it could offer a low-carbon alternative to traditional forms of electricity used by data centers, and ease pressure on the grid caused by the AI boom. But obtaining and storing it can be tricky, and there is not yet a widespread network of hydrogen pipelines in the US.

By-product water from hydrogen generation can supply the data center’s cooling loop, ECL said. It is touting Power Usage Effectiveness (PUE) of less than 1.15 for the new facility

“A 35MW facility delivered in Santa Clara in under a year would have been unthinkable through traditional grid-connected development,” said Yuval Bachar, co-founder and CEO of ECL.

“Every major AI operator in the Bay Area is staring at the same math, with years-long interconnection queues pitted against AI deployment needs that are growing by the minute. By phasing growth through modular power blocks, ECL matches infrastructure deployment to the actual pace of AI demand rather than forcing customers to overbuild or wait.

“This site demonstrates that power architecture itself can become the enabling layer for AI scale rather than the constraint.”

ECL has previously outlined plans for a 1GW hydrogen-powered campus in Texas, but the status of the project is unclear.