Wave Energy Harvesting to Power Ocean Buoys

Promotion of the Blue Economy requires a deeper understanding of the oceans to enable better management of the many aspects of oceanic sustainability. Our understanding has increased dramatically over the last 20 years in response to growing concerns about Global Climate Change, sea level rise, and the dramatic declines in many fisheries, but much more data is needed to support relevant research. The low power budgets of existing ocean observing buoys limit the amount of data that can be collected and communicated. Adding a wave energy converter (WEC) to a buoy will more than double its power budget and greatly increase the amount of data available to scientists. Triton is addressing this problem by developing a point-absorber type WEC that integrates with existing buoy designs. It uses an oscillating water column effect from buoy heave motion to drive an electrical generator. A specialized control algorithm will maximize power output from irregular ocean wave input. In Phase I we demonstrated the feasibility of using a wave energy converter to provide power for ocean observing and navigational buoys by: Demonstrating the power generating potential of the WEC by analysis and simulation using real sea state data as input, developing a detailed WEC design that addresses the critical mechanical, structural and electrical challenges present in ocean systems. In Phase II, Triton designed a fabricated a full-scale Wave energy converter prototype. Triton conducted benchtop and lab testing of a linear-to-rotary converter to characterize performance and develop control methodology. Triton conducted a short term deployment in open water to verify operation. The Phase IIA builds on the tasks that were completed during the initial Phase II effort. Triton will evaluate short-term deployment performance and design and fabricate a second iteration of the in-water prototype. The prototype will be deployed for an extended time period in a higher energetic wave site to evaluate performance. In addition to enabling larger power budgets for ocean observing buoys, the proposed WEC can be used to provide power for navigational buoys, create UAV recharging nodes, provide power for off-shore aquaculture, and provide long endurance surveillance nodes for the Navy with minimal surface presence.