Ambrosia Energy starts building 10 GWh battery factory near Austin for off-grid data centers

Ambrosia Energy has started construction on a 10 GWh battery factory near Austin, Texas, co-founder and CEO Ben Longmier announced this week at TechCrunch Disrupt in San Francisco. The 150,000-square-foot facility "allows us to build about a 300 megawatt power plant per year out at our field sites," Longmier said. The company expects to reach full production in two to three years.

Ambrosia emerged from stealth in June to build power plants for data centers at a cost of $100 per megawatt hour. Longmier and co-founder Sara Spangelo, who previously founded satellite constellation startup Swarm and sold it to SpaceX, settled on solar plus batteries as the cheapest option that is also the fastest to deploy. Solar panels power data centers during the day while charging batteries that discharge at night and on cloudy days.

The company is also beginning work on its first commercial power plant in West Texas later this year, pairing 300 megawatts of solar with 660 megawatt-hours of batteries to deliver 30 megawatts of continuous power, with a target of 99.3% uptime. Sections of a pilot-scale plant have operated continuously for more than 100 days, generating 200 kilowatts around the clock.

Longmier said Ambrosia can be profitable at $100 per megawatt hour even with "overbuilding" solar and batteries, making it competitive with the natural gas turbines many hyperscalers are planning to use. To hit its cost targets, the company is simplifying components and manufacturing packs in-house: "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," he 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."

Analysis

Why This Matters

Data center power demand is one of the biggest constraints on AI expansion, and much of the industry's new supply is coming from natural gas.
Ambrosia claims its solar-plus-battery plants can match gas turbines on price while avoiding new fossil fuel capacity at a time when AI energy use is under scrutiny.
The factory is the linchpin of that strategy: without low-cost, mass-manufactured battery packs, the $100 per megawatt hour target falls apart.

Background

AI data centers need continuous, high-density power, and hyperscalers have been securing it through large natural gas plants. Ambrosia, founded by Sara Spangelo and Ben Longmier after they sold satellite startup Swarm to SpaceX, emerged from stealth in June arguing that solar plus batteries can deliver similar reliability more cheaply. Its plan pairs heavily overbuilt solar with utility-scale storage, and it manufactures its own battery packs in-house to cut component costs.

Key Perspectives

Ambrosia Energy: Solar plus batteries is the cheapest and fastest route to round-the-clock data center power, and in-house manufacturing is the key to hitting $100 per megawatt hour, undercutting gas turbines. Hyperscalers planning gas plants: Many of the largest cloud companies have concluded that gas turbines are the surest way to guarantee continuous power for AI workloads at scale. Critics and skeptics: A 99.3% uptime target leaves room for outages that data center customers may not tolerate, and the weather dependence of solar requires significant overbuilding, which raises land and capital costs.

What to Watch

Construction of the West Texas commercial plant, promised later this year, which is meant to deliver 30 megawatts of continuous power.
Whether the pilot's 100-plus days of continuous operation extend through a full year of weather variability.
Progress of the Austin factory toward full production in two to three years and the real-world cost of its battery packs at scale.

Analysis

Why This Matters

Background

Key Perspectives

What to Watch

Sources