A Self-reactive Marine Energy Converter to Power Ocean Aquaculture

This STTR project teams up a startup company E-Wave Technologies LLC, a leading offshore aquaculture company Innovasea Systems Inc, and a research university Virginia Tech, to co-develop an innovative solution of wave energy converter to power ocean aquaculture. Specially, the team will design and deploy a 35-40 kW flap-type WEC system hinged to the fish feed buoy, to power the feeding and monitoring systems of Innovasea’s open-ocean fish farm, with reduced cost, increased automation, and minimized environmental impacts. The proposed WEC will be integrated into the feed buoy of Innovasea’s aquaculture system with two floating flaps that are hinged to the feed buoy. Since the feed buoy of 5 meters high is moored and anchored in deep water (over 30m), it is nearly stationary in the wave motion. The flaps with optimized geometric shape will move up and down around the hinges. A tether is connected the floating flap at one end, and connected to a winch at another end. The downward of the flap rotation will pull the winch to drive the generator to produce electricity. When the flap rotates upward, the tension force in the tether will be release and the tether rope (or belt) will be rewound with the help of one-way clutch and spring, making it ready for the next wave motion to generate electricity. The WEC system is designed for easy ocean deployment for an Innovasea’s off-shore fish farm located in the Caribbean Sea, with 12 SeaStation pens of 43m diameter and 50m depth. Assume 40% capture width ration and 50% PTO efficiency, we can estimate that two flaps of 3m x 4m can provide an ~40kW power output averagely, which is sufficient for the need for feeding and monitoring of the whole fish farm, currently powered by the diesel generator. The WEC exhibits the following innovations: zero-scattering geometric flap shape for high capture with ratio through the wave-structure hydrodynamic optimization; tether based power takeoff design for simple and reliable energy conversation; efficient power electronics and control for energy storage and management, and; integration with the offshore fish farm in both mechanical and electrical aspects for significant cost reduction and deployment. This success of this project will provide invaluable solution to the electricity generation to power blue economy in the open ocean environment. For offshore fish farming, it can provide a self-sustaining unmanned operation with automatic fish feeding and intelligent farm monitoring, which is very attractive to ocean aquaculture. The cost of power generation on a feed vessel via engines and marine power plants will be significantly reduced by the proposed system. Although in general there are significant legal and environmental hurdles for ocean wave energy companies to enter this market, our team has pose significant advantage, because we target at an ocean site in Caribbean Sea that Innovasea already obtained the permit to deploy its fish farming system and this farm has operated since 2011. This co-development team is exceptionally capable to commercialize the technology to the rapidly increasing market.