Antora Energy secures $550 million to scale heat‑battery production

Antora Energy, a San Jose‑based startup developing solid‑carbon heat‑storage blocks, closed a $550 million Series C funding round. The round was co‑led by G2 Venture Partners and included investors such as Ribbit Capital, Salesforce Ventures, Activate Capital, John Doerr, Westly Group, StepStone Group and Liberty Mutual Strategic Ventures, alongside existing backers like Decarbonization Partners and Breakthrough Energy Ventures.

The capital will be used to build a second U.S. manufacturing plant and expand production capacity for the company’s long‑duration thermal storage systems, which can store excess renewable electricity as heat for 10–100 hours. Antora aims to decarbonise high‑energy‑use sectors such as data centres, steelmaking and other industrial processes, replacing fossil‑fuel‑based heat with renewable‑sourced thermal energy. The firm previously received ARPA‑E grants totaling $22.4 million and a $150 million Series B round in 2024.