1 Development of Wave Dragon from Scale 1:50 to prototype H.C. Soerensen 1 , E. Friis-Madsen 2 , W. Panhauser 3 , D. Dunce 4 , J. Nedkvintne 5 , P. Frigaard 6 , J.P. Kofoed 6 , W. Knapp 7 , S. Riemann 7 , E. Holmén 8 , A. Raulund 9 , J. Praest 10 , L.K. Hansen 11 , L. Christensen 11 , T. Nöhr- lind 12 , T. Bree 13 , P. McCullen 13 1 SPOK ApS, Copenhagen, Denmark, consult@spok.dk, 2 Löwenmark F.R.I, Copenhagen, Denmark, loewen- mark@city.dk, 3 Kössler Turbines Ges.m.b.H, St. Pölten, Austria, office@koessler.com, 4 Armstrong Technology Ltd, Tyne and Wear, UK, duncan.dunce@babcockbes.uk.com, 5 Balslev A/S, Copenhagen, Denmark, jne@balslev.dk, 6 Aalborg University, Hydraulics & Coastal Engineering Laboratory, Aalborg, Denmark, peter.frigaard@civil.auc.dk and i5jpk@civil.auc.dk, 7 Technical University Munich, Dept. of Hydraulic Machin- ery, Munich, Germany, knapp@lhm.mw.tu-muenchen.de and riemann@lhm.mw.tu-muenchen.de, 8 Veteran Kraft AB, Stockholm, Sweden, evaldholmen@chello.se, 9 NIRAS AS, Copenhagen, Denmark, aro@niras.dk, 10 Promecon A/S, Copenhagen, Denmark, jpn@promecon.dk, 11 Wave Dragon ApS, Copenhagen, Denmark, lkh@wavedragon.net and lc@wavedragon.net, 12 Nöhrlind Ltd, London, UK, tn@nohrlind.com, 13 ESB Interna- tional, Engineering, Dublin, Ireland, tommy.bree@esbi.ie ABSTRACT The Wave Dragon is a 4 to 11 MW offshore wave energy converter of the overtopping type. It basically consists of two wave reflectors focusing the waves towards a ramp, a reservoir for collecting the overtopping water and a number of hydro turbines for converting the pressure head into power. In the period from 1998 to 2001 extensive testing on a scale 1:50 model was carried out. During the last month, testing has started on a prototype of the Wave Dragon in Nissum Bredning, Denmark (wave climate in scale 1:4.5 of the North Sea). The prototype has been grid connected in June 2003 as the world’s first offshore wave energy converter. During the coming 2 years an extensive measuring program will establish the background for optimal design of the structure and regulation of the power take off system. Planning for full scale deployment of a 7 MW unit within the next 2-3 years is in progress. FUNCTIONING OF WAVE DRAGON Figure 1. The Basic principle of the Wave Dragon The Wave Dragon consists of three main elements: • Two patented wave reflectors focusing the waves towards the ramp, linked to the main structure. The wave reflectors have the verified effect of increasing the significant wave height substantially and energy capture by 70% in 3 meter significant waves (8). • The main structure consists of a patented dou- bly curved ramp and a reservoir. • A set of low head Kaplan-propeller turbines for converting the hydraulic head in the reservoir into electricity. When the waves overtop the ramp, water is filled into the reservoir at a higher level than the surround- ing sea, and this hydraulic head is utilized for power production through the hydro turbines. Wave Dragon is invented by Mr. Friis-Madsen, Löwenmark F.R.I Consulting Engineers, and cov- ered by international patent (1) and (2). The Wave Dragon consists of standard technologies combined in new ways. The Wave Dragon units each between 4 and 11 MW can be deployed in farms resulting in a power plant Reservoir Overtopping Turbine outlet