Battery Storage Startup Antora Closes $550M Series C In One Of Year’s Largest Cleantech Rounds

Antora Energy , a company that provides energy through thermal batteries to data centers, announced Thursday that it has raised $550 million in a Series C funding round. G2 Venture Partners and Eclipse co-led the financing, which included participation from Decarbonization Partners ( BlackRock / Temasek ), Lowercarbon Capital , Bill Gates ’ Breakthrough Energy Ventures , John Doerr (chairman of Kleiner Perkins ), Ribbit Capital and others. With the latest round, San Jose, California-based Antora has raised $770 million since its 2017 inception, per Crunchbase. It raised $150 million in a Series B round in February of 2024. The company did not reveal its valuation. With so much data center demand amid the artificial intelligence explosion, Antora says it will use its new capital to speed up deployment of “large-scale” projects across the country “to meet surging energy demand.” It recently deployed what it describes as one of the world’s largest battery storage projects, a 5 gigawatt-hour system in South Dakota. The company says its tech is differentiated in that thermal batteries store low-cost electricity as heat in insulated blocks of solid carbon and “deliver it around the clock as heat or power.” Antora says that the same factory-built modules can serve a chemical plant, a food producer, a steelmaker, a data center, or the grid, without supply- constrained critical minerals or multi-year construction timelines. As a result, it can provide “cheap, clean energy that’s fast to deploy.” The company also claims that its San Jose, California factory ranks among the country’s largest battery gigafactories. “From factories to data centers, energy is the bottleneck to industrial growth,” said Andrew Ponec , co-founder and CEO of Antora, in a release. “Antora has shown we can help break that bottleneck—delivering energy fast, at massive scale, with American innovation. Despite surging energy demand from AI data centers, cleantech venture investment has been relatively modest in recent years , and Antora’s raise marks one of the sector’s largest this year. Crunchbase data shows investors put more than $15 billion into seed- through growth-stage rounds for companies in Crunchbase’s cleantech, EV and sustainability-focused categories in the first half of 2026. That puts this year’s funding on pace to slightly exceed the 2025 tally, though that was the lowest total in several years and well below the highs reached in 2021 and 2022. Related Crunchbase query: Global Cleantech Startup Funding In 2026 Related reading: Sector Snapshot: Cleantech Startup Funding Stabilizes As Energy Demand Grows Illustration: Dom Guzman