Antora Energy Closes $550 Million Series C to Scale Carbon-Block Thermal Battery Manufacturing
Antora Energy raised $550 million to expand production of its carbon-block thermal batteries and build a second U.S. factory, following a 5 GWh South Dakota deployment.
Overview
Antora Energy has closed a $550 million Series C funding round to accelerate deployment of its thermal battery storage systems for industrial facilities and data centers in the US, according to Energy-Storage.News. The oversubscribed round was co-led by G2 Venture Partners and Eclipse, according to Energy-Storage.News.
What We Know
The round, announced 30 July, drew participation from new investors including Ribbit Capital, Salesforce Ventures, Activate Capital, John Doerr, Westly Group, StepStone Group, and Liberty Mutual Strategic Ventures, alongside existing backers Decarbonization Partners, Impact Science Ventures, Trust Ventures, Breakthrough Energy Ventures, and Lowercarbon Capital, according to Energy-Storage.News. Crunchbase News identifies Decarbonization Partners as a joint venture between BlackRock and Temasek, and John Doerr as affiliated with Kleiner Perkins. The company did not disclose its valuation, Crunchbase News reported.
San Jose, California-based Antora, founded in 2017, provides thermal batteries that convert low-cost, intermittent renewable electricity into reliable industrial energy, according to ESG Today. Crunchbase News reported the company has raised $770 million in equity since 2017, including a $150 million Series B in February 2024.
Antora’s thermal batteries store heat in solid carbon blocks at temperatures up to 2,400°C, charging by using electricity to resistively heat the carbon, according to Energy-Storage.News. Energy can be stored for multiple days to meet continuous industrial demand, and the company has developed thermophotovoltaic (TPV) technology that converts light from the heated carbon blocks into electricity, Energy-Storage.News reported. Canary Media described the approach as similar to “an enormous toaster,” with a large resistance heater warming blocks of solid carbon to extremely high temperatures for days at a time, which then release controlled blasts of high-intensity light usable to generate power on demand or produce steam for industrial processes.
The financing follows Antora’s deployment of Big Stone, a 5 GWh thermal battery system in South Dakota that advanced from initial construction to delivering energy in under 12 months, according to Energy-Storage.News. Antora signed a long-term heat offtake agreement for the project with POET Bioprocessing, Energy-Storage.News reported. Canary Media reported the system, located near Big Stone City, South Dakota, will turn cheap wind energy into steam that the plant needs to convert corn into ethanol, displacing some of the facility’s reliance on coal-fueled boilers, and that Antora expects the project to be one of the largest battery storage installations in the world once fully operating later this year. Antora built over 200 battery modules for the South Dakota system, according to Canary Media.
Antora’s San Jose facility has been expanded into a three-building manufacturing campus, according to Energy-Storage.News. Canary Media reported the campus ranks among the country’s largest battery factories. With the new funding, Antora plans to establish a second US manufacturing hub, expand production capacity, and strengthen its domestic supply chain, according to Energy-Storage.News. The company said it has a growing pipeline of signed agreements with hyperscalers and industrial customers spanning biofuels, chemical, and food and beverage producers, though it declined to disclose specific customer names, according to Canary Media.
Antora’s first pilot project launched in 2023: a 5-megawatt-hour system installed at a facility owned by the utility Wellhead Electric near Fresno, California, according to Canary Media.
“From factories to data centers, energy is the bottleneck to industrial growth,” Andrew Ponec, Antora’s co-founder and CEO, said in a news release quoted by Canary Media. “Antora has shown we can help break that bottleneck — delivering energy fast, at massive scale, with American innovation.”
“Our energy system is at an inflection point, and very few companies can meet soaring power demand,” said Jake Tauscher, partner at G2 Venture Partners, in the same release, according to Canary Media. “Antora is meeting that demand today. They’re deploying at scale, on budget, and on the rapid timelines customers need.”
Crunchbase News reported that investors deployed more than $15 billion into seed-through growth-stage cleantech, EV, and sustainability companies in the first half of 2026, a figure slightly above 2025 totals but well below the peaks reached in 2021 and 2022, and that Antora’s raise represents one of the year’s largest cleantech deals.
What We Don’t Know
Antora has not disclosed the names of the hyperscaler and industrial customers in its stated project pipeline, nor has it disclosed a valuation for the Series C round. The company also has not specified how much of the $550 million will go toward the new manufacturing hub versus large-scale project deployment.