The project proposal is prepared with the help of an Exploratory Award JO-ST-30 65 that include a Research Feasibility Study. The project objective is to de velop a technique where existing hydro turbines can be used in offshore wave en ergy converters (WEC) of the slack moored run-up type with some modification. T urbines and control equipment will be optimised for the use in the Wave Dragon - a 4 MW offshore wave energy converter. The European wave energy resource is v ery large, close to the coastline it is about 1000 TWh per year. Due to fact th at offshore WEC's could be placed in several lines with distances of 20 -30 km without loosing much efficiency because the wind generated waves are rebuilding their strength between the WEC lines, the recoverable resource (including mach ine efficiencies) is of the same magnitude. The resource is therefore not a re straint in the development of wave energy. The prime proposer has developed the Wave Dragon, and international patent application was published in 1996. This WEC combines known techniques in a new way that should lead to a competitive pr ice for the power production price from this renewable energy source, mainly be cause the capital and maintenance cost are small in comparison with the known d esigns of offshore WEC's. The design facilitates power production under North S ea conditions more than 95% of the average year. Low-head turbines of the cr oss-flow type and the Kaplan/propeller types have been in commercial use in hyd ro electric plants through decades and have an extremely long service life, but their working conditions are normally quite steady water flows and pressure he ads. The existing turbines and the control equipment are not suitable for use i n WEC's, because pressure and water flow are strongly and rapidly fluctuating i n offshore WEC's. The scientific and the technical work consists of the foll owing major elements: - Establishing reliable inflow data for the reservoir of the WEC by carrying out model test in scale 1:40 in the wave basin at Hydro Ma ritime Research Centre in Cork, Ireland. - Developing a strategy for the choic e of turbines and their regulation including the instrumentation and the automa tic control system. - Establishing the realistic outflow data and energy effic iency of the WEC by carrying out model tests on a cross section of the reservoi r in scale 1:10. The model will be equipped with a scale turbine and tested in a large wave tank at the Danish Maritime Institute to simulate the working cond itions on the WEC in 5 meter high waves, where the max. power of 4 MW will be g enerated. - Establishing the strategy for the choice of generators (AC/DC) and systems for transmission of the power to the seashore and further to the grid.
When the research project has been completed, the results will enable the n ext phase -a rather expensive test of a model in scale 1:3 or a prototype in sc ale 1:1 - of the development of the WEC before the possibility of a large scale utilisation of the huge wave energy potential is possible. Next step after pro totype tests will be to establish a power plant i the order of 600 MW in the No rth Sea.
Funding SchemeCRS - Cooperative research contracts
574 37 Vetlanda
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