No. 21: On wind generation and offshore wind farming (November 28, 2011)

In wind generation, wind power is proportionate to the area that receives wind and to the cube of wind velocity. That is why location is a critical factor for wind generation. At present, the horizontal-axis propeller windmill is widespread because it can easily be made bigger in size, and the vertical-axis type that can generate electricity regardless of wind direction. Wind generation has been increasing presence both at home and abroad. Wind generation has a combined generation capacity of 194 million kW worldwide as of the end of 2010. The world leader in wind generation is China that has a capacity of 42 million kW, surpassing the U.S.

Japan has a capacity of 2.4 million kW at present. It has several problems with the introduction of wind generation, such as the extra cost to make the facilities resistant to typhoons and thunderstorms and a large amount of cost to acquire land for the facilities. In particular, land acquisition cost needs studies and examinations. Deforestation is necessary to build facilities and expand the roads for transportation of equipment and machinery. At the same time, health damage caused by noise and low-frequency sound if facilities are built in the vicinity of a residential area.

According to the report on potential renewable energy in Japan published by the Ministry of Environment, Japan has a potential capacity of wind generation between 24 million kW and 415 million kW. It is reasonable to estimate that Japan will have a generation capacity of 30 million kW on the condition the current efforts are made in the future. Because Japan is surrounded by the sea, offshore wind farming attracts strong attention. However, In addition to reducing the cost and developing technology, it is necessary to modify relative legal systems to foster the coexistence of offshore wind farming and ocean right including fishery right.

Wind generation is strongly characterized by regionality because of the necessity of wind. It is and will be mainly installed in northern part of Japan, such as Hokkaido and the Tohoku district. Therefore, even if wind generation accounts for only 10% of Japan’s total power demand, it will almost accounts for 100% of the power demand in northern districts. It is urgent to develop technology for the coordination of wide-range power distribution grips and the stability of power systems.