Affordable, Scalable, Ocean Energy Harvesting System Navy SBIR FY2014.2 Sol No.: Navy SBIR FY2014.2 Topic No.: N142-116 Topic Title: Affordable, Scalable, Ocean Energy Harvesting System Proposal No.: N142-116-0587 Firm: Maritime Applied Physics Corporation 1850 Frankfurst Avenue Baltimore, Maryland 21226-1024 Contact: Nersesse Nersessian Phone: (443) 524-3330 Web Site: www.mapcorp.com Abstract: The proposed ocean thermal energy harvesting approach is applicable to Slocum gliders, fixed-site power plants, and drifting or moored UUV charging stations. The temperature-induced buoyancy changes are driven by high-surface-area Shape Memory Alloy material that undergoes crystalline structure changes (Austinite - Martensite) when warmed or cooled by seawater. SMA produces useful linear strains of 5 to 8%. The strains can be directly used to create temperature-induced buoyancy changes by compressing and expanding a number of small spheres. SMA buoyancy engines have the potential to create a 19% buoyancy change over a 20 degree C temperature change when used in a closed thin spherical shell that is gas-precharged. Unlike a liquid-solid phase changes, the crystalline phase change contracts when heated and expands when cooled. As a result, the buoyancy changes are directly useful in ocean thermal energy harvesting. There is no need to pump a fluid in and out of a pressure vessel to get the temperature change in phase with the volume change. The high surface area per unit mass of thin shelled SMA spheres allows very high rates of heat transfer thereby dramatically improving the power output of a system that harvests ocean thermal energy. Benefits: Successful completion of Phase II would result in a compact spherical Shape Memory Alloy body that can be widely employed in the harvesting of ocean thermal energy to produce vehicle propulsion or stationary power generation using the renewable energy found in the ocean's thermoclines. Return