Antora raises $550M for AI data center batteries

San Jose-based Antora Energy has secured $550 million in a Series C funding round to scale its thermal battery technology amid the massive energy demand driven by artificial intelligence. Co-led by G2 Venture Partners and Eclipse, the round also drew investments from Decarbonization Partners, Lowercarbon Capital, Breakthrough Energy Ventures, John Doerr, and Ribbit Capital. This latest injection brings Antora's total funding to $770 million since its 2017 founding, following a $150 million Series B round in February 2024. While the company did not disclose its valuation, the capital represents one of the largest cleantech investments of the year.

Antora's technology addresses the power bottleneck by storing cheap, excess electricity as heat inside insulated blocks of solid carbon. This stored thermal energy can then be discharged continuously as either heat or electricity. The company recently deployed a massive 5 gigawatt-hour system in South Dakota, which stands as one of the largest battery storage projects in the world. Manufactured at its San Jose facility, these modular systems bypass the supply-chain constraints of traditional critical minerals and avoid multi-year construction timelines.

For AI infrastructure developers and data center operators, this development offers a viable pathway to bypass grid capacity bottlenecks. As the explosion of AI workloads strains existing electrical grids, practitioners face severe delays in securing reliable, clean power. Antora's modular carbon-block batteries can be rapidly deployed to provide continuous, zero-emission power. This allows operators to scale up data center capacity independently of traditional grid constraints, ensuring that computational expansion is not stalled by local energy shortages.

The funding arrives as cleantech investment stabilizes. Investors funneled over $15 billion into sustainability and cleantech startups during the first half of 2026, a pace slightly exceeding 2025 but remaining below the peaks of 2021 and 2022. By delivering factory-built modules that can serve data centers, steelmakers, chemical plants, and food producers, Antora aims to prove that heavy industry and high-tech computing can decarbonize rapidly.