Tokyo Electric Power Co., Japan's biggest generator, and nine other regional utilities plan to increase their solar-power output as the country turns to renewable energy to reduce greenhouse-gas emissions.

The utilities target annual solar-power output of 140 megawatts by the year ending March 2021, compared with 4.25 megawatts in the year ended March 2008, the Federation of Power Companies said in a statement today. The targeted output can power 40,000 households in Japan.

Prime Minister Yasuo Fukuda has pledged to cut the country's emission of greenhouse gases blamed for global warming by as much as 80 percent by 2050. The government will provide subsidies and tax breaks to households and companies that make use of solar energy.

``The costs are significant, especially when securing vast amount of lands to install panels,'' Shosuke Mori, the federation's chairman, told reporters today. ``We will consider setting panels at power substations or on idle plots of land around our existing facilities.''

Mori, who is also president of Kansai Electric Power Co., Japan's second-biggest power utility, said construction on 40 megawatts of solar-power capacity will begin by March 2010.

Kansai Electric said in June it is partnering with Sharp Corp. and the western city of Sakai to build a 10-megawatt solar-power plant by the year ending March 2012. Kyushu Electric Power Co. is also planning to build its first solar-power facility by 2010.

Japan, the signatory to the 1997 Kyoto Protocol, emitted 6.2 percent more greenhouse gases in the year ended March 2007 than in 1990. Under the climate-change pact, the country has pledged to cut emissions by 6 percent from the 1990 level by the end of 2012.