# Endurance Energy Generates First Net-Positive Power From Underwater Volcano

> Seattle-based startup Endurance Energy successfully tested its subsea geothermal power plant, Adélie, generating net-positive electricity for 8.7 seconds at a peak of 16.5 kW from an underwater volcano off the Oregon coast in September 2026.

By PrimaryBrief newsroom · Published 2026-10-22T15:40:58.127304Z
Canonical: https://primarybrief.com/article/endurance-energy-generates-first-net-positive-power-from-underwater-volcano-f5e26c7d

Seattle-based startup Endurance Energy achieved a significant milestone in September 2026, successfully completing a "proof point" test of its subsea geothermal power plant, Adélie [1][4][5][6][7][8][9][10][11][12]. The plant generated net-positive electricity for 8.7 seconds, reaching a peak output of 16.5 kilowatts [7][12]. This event marks the first end-to-end demonstration of subsea geothermal power [1][4][6][7][10][12].

This development matters because it offers a potential source of continuous, baseload clean energy that could reduce reliance on fossil fuels, particularly for remote islands and Pacific Rim nations [1][3][4][5][6][10][12]. Subsea geothermal technology aims to provide consistent power, unlike intermittent renewable sources like solar and wind [12].

## What the Records Show

The test took place at Axial Seamount, an active underwater volcano located approximately 300 miles off the coast of Oregon [1][4][5][6][7][8][9][10][11][12]. Endurance Energy deployed its 3-ton geothermal generator, Adélie, at a depth of about 5,000 feet, which is approximately 1,500 meters [4][7][9][12]. During the deployment, the company drilled the world's first offshore geothermal well [4][6][7][10][11]. However, this newly drilled well proved too restrictive to power the plant as intended [7][9][12]. To proceed, Adélie connected to a natural hydrothermal vent that was flowing at approximately 281°C (538°F) [7][12]. The test demonstrated the full chain required for subsea geothermal power, including drilling a well, operating a power plant on the seafloor, converting heat into electricity, and communicating with the system from a remote location [4][6][10]. The power plant was operated in real-time from Seattle using a subsea fiber-optic network [4][6][7][10][12]. During the net-positive run, the turbine reached about 26,000 rotations per minute [7][12]. The operation was cut short due to a battery overcurrent protection system and a subsequent power cable failure during a restart attempt [7][9][12].

## Timeline

Endurance Energy was founded in January 2025 by Andrew Redd, a former SpaceX engineer [4][5][6][9][10][12]. The company made its first deep-sea deployment in August 2025 [4][6][10]. By June 2026, Endurance Energy had raised $63 million in total funding, which included a $54 million Series A round [5][7][9][12]. This Series A round was led by Founders Fund, with additional investments from Felicis, Voyager Ventures, Riot Ventures, and Construct Capital, and continued support from Point72 Ventures, First Round Capital, and Ascend [3]. The Adélie test at Axial Seamount occurred in September 2026 [1][4][5][6][7][8][9][10][11][12]. The company plans to deploy an upgraded system named Gentoo in winter 2026-2027 [7][12]. The ultimate goal is to deploy its first commercial 2-megawatt plant, Leopard, to deliver power in Tonga by 2027 [5][7][12].

## What Changed

The successful test of Adélie represents the first time a subsea geothermal plant has demonstrated net-positive electricity generation in an end-to-end system [1][4][6][7][10][12]. This proof point shows the potential for harnessing heat from active underwater volcanoes to provide continuous, clean electricity [1][4][6][10]. The company aims to make this technology a viable option for decarbonizing coastal regions around the Pacific and worldwide [3][4][6][10].

## What the Subject Has Said Publicly

Andrew Redd, founder and CEO of Endurance Energy, stated, "On Sept. 27, we put a power plant on an active underwater volcano and made power" [4][6][10]. He also described the event as "our first end-to-end test," adding, "We now know, firsthand, what works at depth, what needs to be improved, and how to build the next system for sustained commercial generation" [4][6][10]. Redd also remarked, "Adélie made it exist, and now we know it's possible" [5]. He expressed his aim to pursue something that is both beneficial for the world and compelling from an employee perspective [9].

## What We Could Not Confirm

We could not confirm the exact cause or detailed technical specifications of the power cable failure that ended the Adélie test [7][9][12]. We also could not confirm the duration for which future systems are expected to generate continuous power, beyond the brief net-positive period of the Adélie test [7][12].

## Evidence cited
1. Startup taps underwater volcano as energy source in "proof point" test (arstechnica.com) — https://arstechnica.com/science/2026/10/startup-taps-underwater-volcano-as-energy-source-in-proof-point-test/
2. https://geekwire.com — https://geekwire.com/
3. onestopesg.com (onestopesg.com) — https://onestopesg.com/
4. Endurance Energy Drills World's First Subsea Geothermal Well and Runs First Net-Positive Power Plant (enduranceenergy.com) — https://enduranceenergy.com/
5. Canary Media - Startup generates electricity from underwater volcano in milestone test (canarymedia.com) — https://canarymedia.com/
6. PR Newswire - Endurance Energy Drills World's First Subsea Geothermal Well and Runs First Net-Positive Power Plant (prnewswire.com) — https://prnewswire.com/
7. Renewables Now - Endurance Energy says subsea geothermal test plant made net power (renewablesnow.com) — https://renewablesnow.com/
8. EPMag - Endurance Energy drills world's first subsea geothermal well, generates net-positive power (epmag.com) — https://epmag.com/
9. Fast Company - This startup just generated power from an underwater volcano (fastcompany.com) — https://fastcompany.com/
10. Energy Global - Endurance Energy announces first end-to-end demonstration of subsea geothermal power (energyglobal.com) — https://energyglobal.com/
11. World Oil - Endurance Energy drills world’s first subsea geothermal well, generates net-positive electricity (worldoil.com) — https://worldoil.com/
12. The Watt - Endurance Energy generates electricity from subsea geothermal at Axial Seamount (thewatt.org) — https://thewatt.org/
13. https://startupfundraising.com — https://startupfundraising.com/
14. planetgraph.ai (planetgraph.ai) — https://planetgraph.ai/
15. instagram.com (instagram.com) — https://instagram.com/
16. https://www.google.com/search?q=time+in+Seattle,+WA,+US — https://www.google.com/search?q=time+in+Seattle,+WA,+US
17. indexbox.io (indexbox.io) — https://indexbox.io/
18. finsmes.com (finsmes.com) — https://finsmes.com/
19. https://datapile.co — https://datapile.co/
20. pitchbook.com (pitchbook.com) — https://pitchbook.com/