Endurance Energy raises $54M to develop undersea geothermal power

Endurance Energy, a startup founded by former SpaceX engineer Andrew Redd, announced a $54 million Series A round to fund the development of geothermal power plants that would tap heat from undersea volcanoes [2]. The financing, led by Founders Fund with participation from several venture firms, is intended to accelerate the company’s plan to harvest terawatts of oceanic geothermal energy [2].

Key takeaways

• Endurance Energy raised $54 million in a Series A round led by Founders Fund [2].
• The company aims to build geothermal power plants near undersea volcanic sites [1].
• Founder Andrew Redd, a former SpaceX engineer, leads a team of 25, including 12 ex‑SpaceX staff [2].
• Investors include Ascend, Construct Capital, Felicis Ventures, First Round, Point72, Riot, and Voyager [2].
• The venture targets baseload renewable power for AI data centers, EVs, and heavy industry [2].

From rockets to the deep sea: the vision behind Endurance Energy

Andrew Redd left SpaceX after working on the Dragon and Starship programs to pursue a renewable‑energy challenge he describes as “brand new” and rooted in first‑principles thinking [2]. Drawing on his Pacific Northwest upbringing and experience with extreme heat events, Redd founded Endurance Energy last year with the goal of accessing the vast geothermal heat stored beneath the ocean floor. Unlike traditional geothermal projects that drill deep into the Earth’s crust, Endurance plans to locate its plants near undersea volcanoes where temperatures are naturally higher, potentially reducing drilling depth and cost [1].

Funding and team composition

The $54 million Series A round was closed in June 2026, with Founders Fund as lead investor and a slate of other venture partners joining the round [2]. The capital will be used to design and pilot the undersea geothermal plants, a technology the company believes can deliver continuous, baseload power without the intermittency of solar or wind [2]. Endurance’s staff has grown to 25 employees, half of whom previously worked at SpaceX, and includes a vice‑president of engineering who came from Helion Energy, a fusion startup [2].

Why it matters

Geothermal energy currently accounts for a small fraction of U.S. power generation, roughly 0.4 % [2]. Endurance Energy’s approach could expand the geographic reach of geothermal by exploiting oceanic heat sources, potentially delivering large‑scale, 24/7 renewable electricity to meet rising demand from AI data centers, electric vehicles, and heavy industry [2]. If successful, the technology may diversify the renewable‑energy mix and reduce reliance on fossil fuels, though the technical and regulatory challenges of offshore geothermal development remain to be seen.