Tuesday, October 9, 2012

No. 65: Present status of offshore wind generation (October 9, 2012)

Experiments of offshore wind generation are under way in several locations. Offshore wind turbines being constructed under the initiative of the New Energy and Industrial Technology Development Organization (NEDO) offshore of Chiba Prefecture will start operation in October. Local governments are developing projects to foster offshore wind generation in alliance with universities and companies. Kyushu University is operating its self-developed “wind lens turbine” that has a cover around the blades. The original turbine installed on a hexagon base collects wind and makes the wind velocity 1.5 times stronger.

Unlike in Europe, the floating wind farm anchored in the seabed with chain is dominant in Japan because water depth is mostly over 50 m off Japan. The Ministry of Environment plans to increase the output by offshore wind generation 270 times from the current 30,000 kW to 8,030,000 kW that is equivalent to the output of eight nuclear power plants by 2030. Developing the technology of the floating wind farm is critical to achieve this ambitious target.

The crucial issue of offshore wind generation is high construction cost because it costs more than three times than a wind generation plant on land. Some offshore wind generation projects use concrete instead of steel for part of the floating body to reduce construction cost. Kyushu University is planning to connect three triangular floating bodies instead of using one hexagon body to reduce construction cost, and install solar batteries to achieve a total output of 3,000 kW.

The purchase price of power by wind generation is fixed at 23.1 yen whether or not it is generated offshore or on land.    

 The floating offshore wind generation system 
developed by Kyushu University