Endurance Energy Raises $54M to Tap Deep-Sea Volcanic Power

Seattle-based startup Endurance Energy has raised $54 million in a Series A funding round to advance its technology for capturing geothermal energy from undersea volcanoes [1]. Founded in 2024 by former SpaceX engineer Andrew Redd, the company aims to utilize the extreme heat found at tectonic plate boundaries on the seafloor to generate power [1].

Key takeaways

• Endurance Energy secured $54 million in funding led by Founders Fund to develop its offshore geothermal power technology [1].
• The company plans to deploy its first 100-kilowatt generator, named Adelie, at the Juan de Fuca ridge later this year [1].
• Founder Andrew Redd, who previously worked on SpaceX’s Dragon and Starship programs, claims the company’s development pace is modeled after his experience in the aerospace industry [1].
• The startup aims to reach gigawatt-scale power production and deliver electricity to the grid within two years [1].

Harnessing heat from the ocean floor

Endurance Energy is targeting geothermal sources located on the seabed, where tectonic plates diverge and magma can heat surrounding water to temperatures as high as 728 degrees Fahrenheit [1]. While traditional geothermal developers often drill on land in remote locations, the company is betting that the ocean floor offers a viable alternative for energy production [1]. Over the past year, the startup has conducted four prototype deployments, sinking test devices to depths of nearly 1,000 feet [1].

The company’s upcoming project, the Adelie system, is designed to drill into the seafloor, generate electricity from volcanic heat, and manage the transfer of that energy back to shore [1]. Redd estimates that the Pacific "Ring of Fire" could potentially support the development of 6 terawatts of power over the next five to 10 years [1]. The Series A round included participation from investors such as Felicis, Voyager Ventures, Riot Ventures, Construct Capital, Point72 Ventures, First Round Capital, and Ascend [1].

Why it matters

The funding round arrives as investor interest in geothermal energy grows, driven by the demand for carbon-free, around-the-clock power for heavy industry, electric vehicles, and data centers [1]. Despite this interest, geothermal energy currently represents only 0.4% of total U.S. power generation [1]. Endurance Energy’s goal of supporting major coastal cities along the Ring of Fire depends on its ability to scale its technology from the 100-kilowatt Adelie system to gigawatt-scale production within its two-year timeline [1].