Modelling the WITT wave energy converter

This presentation describes work undertaken as part of INNOVATE UK funding led by Witt Energy Ltd to investigate the efficacy of a novel design of wave energy converter (WEC). A sealed spherical hull is floating on the surface of the water (Fig. 2(b)) and is moored to the sea bed under a four point catenary mooring system. A mechanical device known as the WITT (Fig. 1) is housed within the hull and generates power via a heavy compound pendulum which is free to pivot independently about either horizontal axis. When waves excite the WITT WEC the motion of the pendulum is transferred into a single unidirectional output from which mechanical energy is converted into electrical energy. The device has some similarities to the SEAREV design and Wello Oy Penguin. There are signficant differences. For example, the mooring design used here is crucial in providing multiple device resonances which result in a broadbanded response in power capture characteristics. The project includes a number of partners whose combined goal is to estimate the Levelised Cost of Energy (LCOE) of a WITT WEC. The University of Bristol have developed a mathematical model of the operation of the WITT WEC in waves and have used this model to produce a numerically optimised design at different scales in a realistic wave climate and using constraints imposed from practical engineering considerations. The University of Southampton have conducted experimental tank