Session: 09-09-02: Hybrid Energy II

Submission Number: 156292

Experimental Assessment of a Roll-Based Wave Energy Converter 

Most of the commercially viable prototypes of wave energy converters are designed for high-latitude locations with large wave heights and extreme weather conditions. Typically, these prototypes required some stiffness and/or inertia tuning mechanism to optimize its power output by matching the system’s natural frequency to that of the dominant wave. Few point absorber concepts have been proposed for long-period (swell) waves. Recently, an innovative passive tuning dual-device was proposed, at conceptual level, in a 1200 tons barge to increase its roll natural frequency to 13 seconds achieving 178 kW of mechanical power when operating in 1.5 m beam waves. This lightweight device has a conical geometry that, when submerged, entraps an amount of seawater that varies depending on its motion direction. The present work provides experimental evidence of the influence of this tuning device on the roll response to incoming waves using a 1:40 model. First, the damping coefficient and added inertia of the whole system, barge and tuning device, are estimated. Then, roll Response Amplitude Operator obtained experimentally in regular waves are used to calculate the expected power matrix. This ‘passive tuning’ method assessed can improve the efficiency of existing and novel wave energy converters operating in any sea condition without significant modifications.

Presenting Author: Jose R. Marin-Lopez ESPOL Polytechnic University

Presenting Author Biography: Researcher