Construction of a wave energy prime mover

Abstract

Ocean waves are an inexhaustible source of clean energy. Wave Energy Converters (WECs) are used for the conversion of the kinetic and potential energy of waves to electrical energy. In this project, a 1:20 heaving wave energy converter model was constructed with a Power Take Off (PTO) unit, designed to extract energy from the heaving motion of a primary interface to supply a source of pressurized water. The construction of the WEC consisted of a simple lever mechanism pivoted at its centre of gravity. Its main components were a positive displacement pump, check valves, flow restrictor and a primary interface to absorb the energy from the wave. The scope of such a model was to design a simple yet durable WEC model which enabled testing of its performance under different wave conditions. Tests were conducted in the wave-making facility in the Fluids Laboratory of the Faculty of Engineering at the University of Malta. The tests were restricted to one-dimensional regular waves and experiments were done to determine the absorbing power capabilities of different floating structures in a lab environment. The performance of the wave tank was analysed and wave height sensors were designed and constructed to study the generated wave' s characteristics. The sensors constructed were designed to provide repeatable reading and to offer the minimum resistance possible to a floating buoy in the vertical plane. A comprehensive literature review was conducted to understand the limiting capabilities of different types of wave energy converters. The hydrodynamic control mechanisms needed to improve the efficiency of the WEC are introduced and three case studies which managed to arrive to pre-commercial state are examined in detail.