Pacific Northwest National Laboratory (PNNL)

Thermal Gradient Energy Harvesting Device for Powering Unmanned Underwater Vehicles

There is a demand for self-powered unmanned underwater vehicles (UUVs) suitable for long-term deployments for ocean environmental monitoring. Thermal gradient energy-generation technologies for powering UUVs or autonomous sensing systems in the ocean are mainly in the research development phase, and further research related to small-scale ocean thermal gradient energy systems is needed. Phase change materials can be used to power a buoyancy engine and generate electricity, but currently have low efficiencies. This student team developed conceptual solutions for increasing the efficiency through improved mechanical architecture and design, and a benchtop prototype design for demonstrating the working principle and performance of a novel PCM-based thermal energy harvesting system that has the potential to improve energy harvesting efficiency over traditional PCM-based designs.