SpaceX alum bets on subsea geothermal power for islands and data centers

A former SpaceX executive is betting the ocean floor can become a new source of firm electricity, and he is backing the pitch with money, a pilot in Tonga and claims that the market is large enough to matter for islands, industrial sites and hyperscale data centers. Endurance Energy says its subsea geothermal systems could deliver baseload power from heat beneath the seafloor, a concept that aims to turn remote underwater geology into a commercial power plant rather than a laboratory idea.

The company’s case starts with customers that have little patience for expensive diesel. Endurance says Pacific island countries can spend up to 13% of GDP on fuel imports, while electricity can cost almost seven times as much as in the United States. In Tonga, where local reporting says about 80% of electricity generation still relies on imported diesel, the government said its Tonga Energy Road Map 2021-2035 targets 100% renewable electricity by 2035. Endurance Energy Strategy Inc. signed a memorandum of understanding with Tonga to cooperate on exploration, development and deployment of subsea geothermal energy, and the government launched a subsea geothermal pilot with the company in 2026.

Endurance is also selling the idea to the power-hungry U.S. economy. The company cites the industrial sector as 33% of total U.S. energy consumption in 2022, with nearly 80% of that energy still coming from fossil fuel and coal, and points to a projected 85-gigawatt U.S. power shortfall by 2030. Its target list includes hyperscale data centers, remote islands, military bases and industrial sites, all of which need round-the-clock electricity rather than intermittent generation. That is where the comparison gets serious: subsea geothermal will have to prove it can be drilled, maintained and permitted at a cost per megawatt that can compete with nuclear, conventional geothermal and offshore wind.

The financing has moved quickly. PitchBook lists Endurance as a Seattle-based company founded in 2025 with 17 employees, and company and media references tie its fundraising to Founders Fund along with First Round Capital, Measured Ventures, Point72 Ventures and Relumin. Axios reported that Endurance had closed a seed round of about $25 million to $30 million led by Founders Fund on May 27, 2026, and TechCrunch reported on June 11, 2026 that the company had raised $54 million. Endurance says the capital will help advance seafloor hydrothermal generators designed to deliver gigawatts of baseload power to a single site, especially along the Pacific Ring of Fire. The harder test now is whether an underwater drilling program can become a dependable grid asset, not just a compelling venture pitch.