Turn on
To try to still operate the Adélie power plant, the team relocated it to a nearby natural vent that was already venting hydrothermal fluid at a temperature of about 538°F (281°C). On September 27th they tried.
Within nearly half a minute, the power plant’s turbine reached approximately 26,000 rpm, allowing the generator to produce 60 watt-hours of electricity.
The power plant also became net positive by producing more electricity than it consumed for about 8.7 seconds. It generated an average of around 2 kilowatts of net power and reached a peak of 16.5 kilowatts of net power.
“This is the proof,” Redd told Ars. “Net positive is the threshold that matters: the plant produced more electricity than it needed to power itself on the ocean floor, which no one had ever done before.”
The 100-kilowatt Adélie power plant is designed to generate geothermal energy from the seabed.
Photo credit: Endurance Energy
The 100-kilowatt Adélie power plant is designed to generate geothermal energy from the seabed.
Photo credit: Endurance Energy
But then a software problem brought the power outage to a standstill. Before the generator takes over, Adélie first relies on a battery to power her pumps, thrusters and controls while also turning the turbine to get it up to speed, Redd explained. A battery module registered a brief increase in current during the startup process and then stopped reporting.
This caused Adélie’s software to automatically stop the power plant for safety reasons as it continued to rely on the battery module’s old readings.
As the team restarted the power plant, a power cable to the refrigerant pump also failed because an imperfection in the cable housing allowed seawater to enter and short out two of the electrical conductors. This ended the test run, although Endurance Energy already plans to use the experience to improve the construction and testing of submarine cables.
Future missions
Placing the geothermal plant on a natural hydrothermal vent was a one-time test purely for research and demonstration purposes, Redd said. His company still plans to use drilled wells for future operations.
