Our wave energy converter consists of the Salter Duck type float which is set into pendulum motion.
The wave motion causes rocking of the float on the water surface which sets the column into pendulum motion. The turbine which is rotatingly mounted to the lower end of the column, moves underwater. This results in a torque applied to the turbine. The special shape of blades causes that regardless of changing direction of turbine movement in pendulum motion, it rotates always in one direction. Then, the propeller shaft either drives the multiplier which increases the rotational speed of the shaft driving the classic generator or, without the multiplier, drives the multipolar generator which works under very low rotational speed. Electricity obtained in such a way is then sent via electric cables to the electrical grid on land.
Thanks to rigidly anchoring the float’s axis of rotation for the pendulum motion, we gather not only a considerable amount of kinetic energy of waves but also a significant amount of their potential energy (vertical movement of waves). An adequately long column enables us to attain the turbine’s velocity of more than 2m/sec under water. The turbine operating at such a speed of water’s flow on its blades starts to generate sufficiently high torque to drive the generator and therefore generate electricity.
Our invention is therefore the only solution among thousands of patents which, finally, enables us to use the turbine in order to generate electricity by direct drive of the generator. The innovative character of the solution lies in the simplicity of energy transformation process: turbine, transmission shaft, and generator. In reality, all competitive solutions, which aimed at producing electricity by means of rotational motion of the turbine, ended in failure because they used the float’s vertical movements of rising and falling on a wave. Thus, contrary to the speeds of turbine displacements in pendulum motion reached by our system, the speeds of vertical displacements are too slow and driving torque reached on the turbine is nearly zero.
A 1:5 scale prototype, which was used during tests in the Great Wave Flume (GWK) in Ship Design and Research Centre (CTO) in Gdansk.