Ambrosia Energy is building a 10 gigawatt-hour battery factory near Austin, Texas, wagering that making battery packs itself will help solar-powered data centers compete against gas turbines. Ben Longmier, the company’s co-founder and CEO, disclosed the project Tuesday during an onstage appearance at TechCrunch Disrupt in San Francisco.
Longmier expects the factory, which will cover 150,000 square feet, to reach full production within two to three years. “That allows us to build about a 300 megawatt power plant per year out at our field sites,” he said.
Ambrosia’s approach to lowering costs relies heavily on manufacturing. Rather than purchasing complete battery systems from outside suppliers, it buys cells and assembles them into packs with simpler designs. The startup is reducing part counts in other components, including solar mounts, and moving much of the production into a factory to bring costs down.
“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.”
In June, Ambrosia came out of stealth with plans for data center power plants costing $100 per megawatt-hour. Solar paired with batteries was the choice of Longmier and co-founder Sara Spangelo, who viewed it as both the least expensive option and the quickest to deploy. Before Ambrosia, they founded Swarm, a satellite constellation startup they later sold to SpaceX.
During the day, the solar panels supply the data center and charge the batteries at the same time. At night, or when clouds limit sunlight, the batteries release their stored energy. The aim is to run the facility around the clock without depending on the grid.
For this arrangement to work commercially, solar capacity must substantially exceed the continuous load being supplied. Work on Ambrosia’s first commercial power plant is scheduled to begin in West Texas later this year. According to Longmier, 300 megawatts of solar panels and 660 megawatt-hours of batteries will supply 30 megawatts continuously, targeting 99.3% uptime.
Even after “overbuilding” the solar and battery capacity needed for continuous operation, Ambrosia can make a profit at $100 per megawatt-hour, Longmier said. He said that price would let it compete against natural gas turbines, which many hyperscalers intend to use for their data centers’ power supply.
Some operating experience from a pilot-scale plant supports the plan, though it doesn’t establish that the commercial targets can be met. Parts of Ambrosia’s first pilot power plant have run without interruption for more than 100 days, according to Longmier. That pilot is capable of supplying 200 kilowatts of electricity 24/7.
Whether the simpler hardware Ambrosia makes in-house can achieve its stated economics of $100 per megawatt-hour and its 99.3% uptime target at commercial scale will be tested in West Texas. The planned facility has not yet demonstrated either result.
