Wave Energy Study Breakwater Device 2Gw Power Station Reference Design 1980

Abstract

In 1978 a report was submitted by National Engineering Laboratory to the Department of Energy on a floating version of the Oscillating Water Column Wave Energy Device (Reference 1). It was apparent that such a concept, while havi~g simple and robust structure and plant, would have problems (in common with all other floating wave energy devices) with moorings and electrical umbilical systems since these lay beyond current technology. These elements amounted to approximately one fifth of the capital and maintenance costs, and it was evident that a fixed bottom mounted (breakwater type) device would therefore be 1worthy of investigation. Accordingly this report sets out the results of a study of the bottom standing concept and concludes that such a device when fully developed would have a part to play in any wave power programme. The Breakwater Device does not require the development of revolutionary technology or materials for its design, construction or operation. It eliminates the need for new and untried mooring methods or materials. Its fixity enables existing rigid type underwater electrical cables to satisfy the power transmission requirements, therefore obviating one of the main problem areas. The structure is now designed to have a low material content. There is also some potential for increased power output using active valve control. Plant and structure maintenance is greatly simplified by fixing the structure, thereby providing both a stable base for onboard work and adjacent sheltered water for crane and maintenance vessels. The design concept reported herein demonstrates both the practicability and viability of this approach and highlights areas where additional information and research would benefit the scheme.