Coaxial PTO Drives for Wave, Tidal, and Oscillating Water Column Air Turbines

Abstract This technical note describes a novel self-rectifying coaxial powertrain that supports four major marine renewable energy systems: (a) surface floating buoys; (b) submerged buoys; (c) bi-directional tidal converters; and (d) Oscillating Water Column self-rectified air turbines. In each application, the coaxial power take-off mechanically rectifies bi-directional fluidic flows to spin one or more one-way generators. The mechanical drive system has two sets of impeller blades, each rotating independently of the other and are energized by the motion of waves or tides.