BEIJING, April 12 (Xinhua) -- The number of Chinese households with their own methane supply will double by 2010 under a government scheme to build methane gas tanks in the countryside.

    The government is to fund the building of 4,000 large-and medium-sized tanks in livestock farms, the Ministry of Agriculture announced.

    Under the National Rural Methane Project, the number of households with a methane supply will increase by 23 million in 2010 from 22.6 million at the end of last year.

    The number of large-and medium-sized methane tanks in farms will reach 4,700.

    An eight-cubic-meter rank can provide 80 percent of the energy used by a family of four annually.

    The methane used annually by 40 million households, or 15.4 billion cubic meters, is equivalent to 24.2 million tons of coal and would save 140 million mu, or 9.3 million hectares, of forest, said Vice Agriculture Minister Wei Chao'an.

    The government spent 5.5 billion yuan on building 5.73 million household methane tanks from 2003 to 2006.

    Since the 1970s, China has been promoting the use of methane pits to process rural organic waste and provide clean energy.