"...the world’s largest cow-dung methane power plant started operation on January 21 in China’s Inner Mongolia region. With an investment of 45 million RMB (roughly $US5.7 million) from the country’s largest milk producer, Mengniu Dairy, the plant is able to supply 10 million kilowatt-hours of electricity to the national power grid."
The article goes on to say that methane from cows is actually a significant contributor to greenhouse gas emissions, and:
"The practice of methane capture has caught the attention of international carbon traders. Under the Kyoto Protocol, the international agreement to reduce greenhouse gas emissions, companies can trade so-called “carbon credits” to help them meet their allowances of greenhouse gas emissions. China has become a major destination for European carbon buyers due to its low prices for the credits. The country also benefits from the financial resources and technologies transferred as a result of those trades."