Ambrosia Energy will build a 10 GWh factory in Texas to make batteries for off-grid data centers

Ambrosia Energy has begun work on a massive, 10 gigawatt-hour battery factory near Austin, Texas, co-founder and CEO Ben Longmier announced on stage Tuesday at TechCrunch Disrupt in San Francisco.

“That allows us to build about a 300 megawatt power plant per year out at our field sites,” he said.

The factory will occupy 150,000 square feet, and Longmier said that Ambrosia plans to reach full production in two to three years.

The startup emerged from stealth in June to build power plants for data centers at a cost of $100 per megawatt hour. Longmier and his co-founder, Sara Spangelo had settled on solar plus batteries as the cheapest option that’s the fastest to deploy. Solar panels power the load during the day and charge the batteries, which discharge at night and on cloudy days to keep the data center operating round the clock.

Longmier and Spangelo previously founded the satellite constellation startup Swarm, which they sold to SpaceX.

Ambrosia is also beginning work on its first commercial power plant in West Texas later this year, Longmier said. The facility will pair 300 megawatts of solar panels with 660 megawatt-hours of batteries to deliver 30 megawatts of continuous power, with a goal of 99.3% uptime.

Even with “overbuilding” solar and batteries to deliver continuous uptime, Longmier said the company can be profitable at $100 per megawatt-hour, making it competitive with natural gas turbines that many hyperscalers are planning to use to power their data centers.

Sections of Ambrosia’s first pilot-scale power plant have been operating continuously for more than 100 days, Longmier said. The pilot is capable of generating 200 kilowatts of electricity 24/7.

To hit its cost targets, Ambrosia has been finding ways to simplify its components, including solar mounts and battery packs. By reducing part counts, and manufacturing many components in a factory, the startup has been able to reduce costs relative to buying from outside suppliers.

“We buy existing cells and we make our own pack in-house, and it has the fewest parts by a factor of about 100 compared to any other competitor we’ve seen,” Longmier said. ”We’ve been able to get to about 1.3x the cost of the bare cell compared to about a 5- or 7x for most stationary storage systems.”