Ocean Surface Wave Energy Harnessing Development at Stevens Institute of Technology (SIT)

Abstract

This paper presents a system designed to harness ocean surface wave energy to generate electricity. Due to the catastrophic failures in the wave energy industry, such as the Wavegen Osprey in 1995, survivability and resilience are the highest priorities in design criteria for our research. If catastrophic failures continue in the wave energy industry, research and development funding will become more difficult to obtain. By using our patented, integrated cable reel harnessing and anchoring system, our system can be anchored in waters deep enough to eliminate the risk of system failure due to storms or large waves. Ocean surface waves make up the largest portion of the total ocean energy spectrum. Utilizing this vast resource effectively involves placing devices and systems in the high energy wave regions of the planet. Existing systems with hydraulic pistons, oscillating water columns, or linear magnets have limited stroke which prevent them from harnessing the highest energy waves that will be available. Our cable reel system will allow us to harness the largest waves available on the planet. The anchoring system will also allow for autonomous control of the Wave Energy Harnessing Device (WEHD) location in the water column. The WEHD includes a water-tight housing that holds all the electricity generating equipment that will be positioned in the water column depending on the real-time wave climate. The WEHD is tethered to a buoy, or other floating object, on the surface. The lift force on the buoy from the passing waves is transferred to the cable on the reel and then to the WEHD by a shaft fixed to the center of the reel. The design approach, highlights, and projected full-scale implementation are presented in this paper.