Long-duration energy storage (LDES) firm Exowatt has secured $50 million in new funding to expand US manufacturing and deployments of its P3 energy storage system, aimed at meeting the rising power demands of AI data centers and other energy-intensive facilities.
The new fundraising is an extension of the company’s $70m Series A from April 2025. The latest fundraise was led by MVP Ventures and 8090 Industries, with participation from Felicis and several other investors, including the Florida Opportunity Fund, DeepWork Capital, Dragon Global, Massive VC, and StepStone. Exowatt previously raised $20m in seed funding from backers, including OpenAI CEO Sam Altman.
Exowatt’s P3 system combines both solar and thermal storage, which the company claims provides a controllable output designed for rapid siting near load to reduce dependence on grid interconnection. Exowatt has claimed a commercial pipeline of more than 90GWh of demand, largely from data center operators and energy developers.
Its CEO, Hannan Happi, said that the additional capital would be used to support manufacturing scale-up and upcoming customer deployments.
“With the support of our investors and partners, our commercial pipeline has a current demand backlog exceeding 90GWh, spanning US data centers, energy developers, and everything in between,” said Happi. “This new capital investment will support our scaling efforts for P3 as we continue to announce customers and partners in the months ahead.”
Investors in the latest round cited data center growth and slow grid expansion as key drivers for their decision to invest. “AI demand won’t wait for new transmission interconnections,” said Andre de Baubigny of MVP Ventures.
Following the fundraiser, Exowatt now plans to ramp domestic production as data center operators search for alternatives to constrained utility capacity across the US.
Several data center companies have backed LDES developers in recent years. In May, Prometheus Hyperscale signed a deal with XL Batteries, an organic flow battery developer, to deploy its system at an undisclosed Prometheus site in 2027.
Following this, in July, Google signed its first LDES agreement with Italian CO2 battery developer Energy Dome to support a range of commercial deployments.
