NLR Advances Battery-Free Power for Remote Maritime Sensors and Navigation Aids - CleanTechnica

The National Laboratory of the Rockies (NLR), part of the U.S. Department of Energy, is developing a compact thermomagnetic generator designed to power remote maritime sensors and navigation aids without batteries. This technology, inspired by 19th-century concepts from Nikola Tesla and Thomas Edison, exploits natural temperature differences between ocean water and ambient air to generate electricity on a small scale—producing milliwatts sufficient for wireless sensor operation. The generator uses gadolinium, a rare earth element whose magnetism changes near room temperature, cycling across its Curie point as ocean and air temperatures fluctuate, thus creating a continuous electric current. After successful prototype testing in controlled freshwater environments, the NLR team is advancing toward ocean field trials, focusing on device durability and corrosion resistance in harsh marine conditions. The researchers envision these thermomagnetic generators enabling reliable, maintenance-free power for distributed ocean monitoring systems, enhancing capabilities in marine exploration and offshore applications. Funded by the Department of Energy’s Water Power Technologies Office, this