The authors describe the investigation of wind power for an offshore wind power generating system using the prediction program WAsP. The system is composed of floats that have a windmill on them and arrangement of these floats at the generating site is discussed. Studies of the wind condition on the Pacific coast of Japan's Kanto area and the southern islands are made to assess practical application.
As one of the countermeasures against the global warming problem, natural wind power energy has promising availability (Kühn 1998a, Kühn 1998b, Kühn 1998c, Cockerill 1998a, Cockerill 1998b and Ferguson 1998). Wind energy conversion systems have been developed actively in recent years in Japan (Henderson 2002). Offshore there are fewer restrictions on social conditions than on land and the authors have carried out basic investigations on offshore conversion systems paying particular attention to the geographical characteristics of the Japanese land that is surrounded by the sea. An offshore wind power generating unit that is fixed on the seabed is commonly used in a shallow sea area, but the Japanese shelf sea has a rough seabed with both shallow and deep regions. For this reason, floating type wind energy conversion systems appear most promising in Japan. The authors describe a wind power study using the prediction program WAsP (Wind Atlas Analysis and Application Program) developed by Risø National Laboratory in this paper (Mortensen 2001). An offshore wind power generating fleet was planned with the basic unit being composed of a float with a windmill on it. In this study to evaluate practical application of the unit offshore Japan, the wind conditions on the Pacific coast of the Kanto area and the southern islands were determined and the effects of geographical features around the fleet were considered based on available atmospheric and altitude data.
