Ambrosia Energy Starts Building 10 GWh Battery Factory in Texas

Ambrosia Energy has started work on a 10 gigawatt-hour battery factory near Austin, Texas, co-founder and CEO Ben Longmier announced Tuesday at TechCrunch Disrupt in San Francisco. The 150,000-square-foot plant will supply batteries for off-grid data centers, and Longmier said the company plans to reach full production in two to three years.

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

Who is behind Ambrosia?

Longmier and co-founder Sara Spangelo previously founded the satellite constellation startup Swarm, which they sold to SpaceX. Ambrosia emerged from stealth in June with a narrow thesis: build power plants for data centers at a cost of $100 per megawatt hour.

The pair settled on solar plus batteries as the cheapest option that deploys fastest. Solar panels carry the load during the day and charge the batteries. The batteries discharge at night and on cloudy days, keeping a data center running round the clock.

What does the factory change?

The Texas plant gives Ambrosia control over its own battery supply, and that control is central to its cost math. To hit its targets, the company has been simplifying components, including solar mounts and battery packs. Fewer parts, plus in-house manufacturing, cut 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."

That spread is the mechanism. If a finished pack costs only 1.3 times the cell inside it, while competitors' systems run five to seven times, the factory converts into a structural cost advantage measured in dollars per megawatt hour.

Does the technology already work?

Sections of Ambrosia's first pilot-scale power plant have run continuously for more than 100 days, Longmier said. The pilot generates 200 kilowatts of electricity 24/7.

The company will also begin its first commercial power plant in West Texas later this year. That facility pairs 300 megawatts of solar panels with 660 megawatt-hours of batteries to deliver 30 megawatts of continuous power, with a target of 99.3% uptime.

Can it beat natural gas?

Even with "overbuilding" solar and batteries to guarantee continuous uptime, Longmier said Ambrosia can be profitable at $100 per megawatt hour. That price makes it competitive with the natural gas turbines many hyperscalers plan to use for their data centers.

The West Texas plant serves as the first commercial test. If it holds 99.3% uptime at the claimed cost, the Austin factory's 10 GWh of annual cell capacity becomes the constraint on how fast Ambrosia can scale to hyperscaler demand.