AI data centers are consuming more electricity than ever, and one startup has secured a record cleantech round to help meet that demand. Antora Energy, a San Jose, California-based company that builds thermal batteries, announced a $550 million Series C financing led by G2 Venture Partners and Eclipse.

What You Need to Know

Antora stores low-cost electricity as heat in solid carbon blocks, releasing it as heat or power around the clock. The round includes backers such as BlackRock, Temasek, Bill Gates’ Breakthrough Energy Ventures and John Doerr. The company recently deployed a 5 gigawatt-hour system in South Dakota and says its factory ranks among the largest battery gigafactories in the U.S. The new funding will accelerate large-scale projects for data centers, chemical plants, steelmakers and more.

Investors Back a New Energy Storage Approach

Participants in the Series C include Decarbonization Partners (a BlackRock and Temasek joint venture), Lowercarbon Capital, Ribbit Capital and Kleiner Perkins chairman John Doerr. The round brings Antora’s total funding to $770 million since its 2017 founding, according to Crunchbase. The company raised $150 million in a Series B in February 2024.

Antora did not disclose its valuation. The size of the round, however, signals strong investor confidence in thermal storage as a solution for the energy-intensive AI boom.

How Thermal Batteries Work

Antora’s technology stores electricity as heat in insulated blocks of solid carbon. The same factory-built modules can serve multiple industries without requiring critical minerals or multi-year construction timelines. The company says its system is “fast to deploy” and can deliver energy 24/7.

  • Data centers: Provide reliable, clean power for AI workloads without relying on natural gas peaker plants.
  • Industrial facilities: Deliver heat or electricity for chemical plants, food producers and steelmakers.
  • Grid support: Serve as a flexible resource that can balance renewable energy supply and demand.

Why This Matters

Cleantech venture investment has been modest in recent years, with 2025 totals the lowest since 2021. Antora’s Series C is one of the largest rounds in the sector this year, and it comes at a pivotal moment. AI data centers are projected to double U.S. electricity demand by 2030, yet traditional battery storage using lithium-ion faces supply constraints. Thermal batteries offer a cheaper, faster alternative that does not depend on critical minerals. If Antora can scale its technology, it could reshape how the industrial sector and data centers meet their energy needs, cutting emissions while avoiding multi-year construction delays.

Cleantech Funding Trends

Crunchbase data shows global cleantech startup funding in the first half of 2026 exceeded $15 billion across seed through growth-stage rounds. That pace puts the year on track to slightly exceed 2025, but still well below the highs of 2021 and 2022. Antora’s massive round, however, suggests that investors are willing to make big bets on companies that can solve the energy bottleneck for AI and heavy industry. The company’s ability to deploy a 5 GWh system in South Dakota and operate a large gigafactory in San Jose, California, adds credibility to its claims of rapid scalability.