Overview
- In a late-September expedition at Axial Seamount, Endurance landed its three-ton Adélie generator on the seafloor, operated it from Seattle over the NSF Regional Cabled Array, and produced net-positive electricity for 8.7 seconds with a median output of about 2 kW and a peak of 16.5 kW.
- The company drilled and completed a 16-meter well that flowed hot fluid at roughly 260°C but the well’s flow was too limited to run the plant, so the net-positive run used a nearby natural hydrothermal vent flowing at about 281°C.
- Operations were cut short when an onboard battery overcurrent protection stopped the system and a power cable later failed during a restart attempt, exposing limits in battery management and seafloor cabling.
- Endurance conducted voluntary environmental monitoring during the deployment, reported no immediate significant changes to seafloor conditions, and sent more than 40 water and rock samples to independent labs for analysis.
- The company has raised $63 million, is readying an upgraded demonstrator called Gentoo for winter tests, is designing a 2 MW commercial unit named Leopard, and is pursuing a memorandum of understanding with Tonga that targets initial generation in 2027 while key challenges such as deeper well flow, materials durability, and permitting remain.