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Underwater Thermomagnetic Generator for Remote Marine Thermal Energy Harvesting and Sensing

Journal Article · · Device
Thermomagnetic generators offer a promising approach for sustainable power generation in remote marine environments. This study presents the design, thermal modeling, and experimental validation of a passively driven underwater thermomagnetic generator developed for powering ocean observation and monitoring sensors. The generator was evaluated under varying working fluids, thermal boundary conditions, and extended operation to assess real-world applicability. Two fluids, deionized water and silicone-based Thermal C5, were tested under simulated shallow- and deep-ocean conditions. Deionized water outperformed Thermal C5, especially in colder environments (~5 degrees C), achieving a peak output of 2.7 mW due to larger temperature gradients and enhanced convective-evaporative heat transfer. Long-duration tests revealed a transient evaporation-condensation cycle that temporarily reduced rotor immersion and performance before stabilizing. The generator powered commercial marine sensors for over 6 h without external batteries, demonstrating the viability of compact, passively cooled thermomagnetic systems for autonomous, off-grid marine sensing.
Research Organization:
National Laboratory of the Rockies (NLR), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Water Power Technologies Office
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
3029491
Report Number(s):
NLR/JA-5500-95747
Journal Information:
Device, Journal Name: Device Journal Issue: 2 Vol. 4
Country of Publication:
United States
Language:
English