Abstract
This paper describes a new configuration for a floating Oscillating Water Column (OWC) Wave Energy Converter (WEC). The WEC consists of a deeply submerged “Stabilizer”, a half-submerged, open bottom, closed top cylinder which defines the OWC, a spar which connects the Stabilizer to the OWC, and a bi-directional air turbine mounted on top of the OWC. The Stabilizer serves to anchor the WEC in the relatively motionless water deep below the surface. Unlike a spar based OWC which uses the water column as the reactive mass, this WEC has a relatively short OWC such that the natural period of the OWC is less than the lowest period waves of interest. The Stabilizer diameter is chosen to maximize the power output of the WEC for any given location and is typically such that the heave natural frequency of the WEC is about 12 seconds. For shorter wave periods, the WEC behaves more like a stationary OWC. For wave periods at or near its natural frequency it resonates. The advantages of this WEC include 1) uses a previously developed bi-directional air turbine 2) is omni-directional, 3) can be deployed in large numbers in the open ocean, 4) is light weight, with a calculated power specific mass of 93 tons/MW, 5) simulations give an annual capacity factor of 55% for a unit characteristic mass of 51 MWh/yr-ton for 1 MW, 16 meter diameter OWCs located at the AMETS Berth A Wave Buoy off the northwest coast of Ireland.