Operators of wind turbines are already under pressure to improve the structures' quake-resistance strength. Now, they face another problem with nature: endangered birds flying into the turbines' blades.

The bird strike problem has become so serious that measures to protect the fowl are slowing the spread of wind power as a source of electricity generation.

While wind power has strong support from the government, plans to build wind farms have been suspended, delayed or scaled down in at least 10 locations over the past three years.

Endangered raptorial birds, including golden eagles, were confirmed to be living around the planned wind farm sites.

A total of 14 birds designated by the government as national treasures, including white-tailed sea eagles, have died at different sites by flying into completed wind turbines.

To prevent further delays, the Environment Ministry plans to compile guidelines next fiscal year on the selection of appropriate sites for wind farms.

The Asahi Shimbun recently surveyed planned wind farm sites throughout the country in cooperation with the Wild Bird Society of Japan.

It found that endangered raptorial birds were confirmed around 13 proposed sites during the past three years in the prefectures of Hokkaido, Nagano, Shizuoka, Mie, Fukui, Shiga, Tottori, Okayama and Shimane.

Plans to build wind turbines have been suspended in five of the 13 sites. At another five sites, plans have been delayed or changed. Environmental groups are demanding plans be reconsidered at the three remaining sites.

One of the 13 sites, which is located in Iwami, Tottori Prefecture, was expected to become one of Japan's largest wind farms, with 32 wind turbines generating a total of about 80,000 kilowatts.

However, the number of turbines is now likely to be drastically cut.

In its environmental assessment, the company planning to build the wind farm found that five pairs of Hodgson's hawk eagles could have built their nests in areas within 3 kilometers of the turbines, according to documents obtained by The Asahi Shimbun.

It is unknown how many wind farms are planned in Japan. The number of applications to the government for subsidies related to those facilities stands at about 40 a year.

In 2007, stricter earthquake-resistance standards for wind turbines were introduced, slowing the construction of turbines. Moves to protect endangered birds have furthered the stagnation.

Next fiscal year, the Environment Ministry will consult experts as it draws the new guidelines, which are expected to reduce the threat to endangered birds.

Those measures will include the following:

・Showing geographical features that put birds at risk of crashing into wind turbines; and

・Giving consideration to the routes of migratory birds.(IHT/Asahi: January 7,2009)