Three hydrogen-powered buses appeared in streets of Beijing on Tuesday, bringing emission-free public transport to China for the first time.

"This marks the first public operation of fuel-cell buses in Beijing, it is the first ever in China, and one of the first in a developing country," said Renaud Meyer, Deputy Resident Representative of the United Nations Development Program in China. "The hydrogen refueling station will be fully operational this summer."

The buses will run 18.2 kilometers from the North Gate of the Summer Palace to the university district at Wudaokou.

Thirty-three fuel-cell buses have been released onto the streets in eight European countries including Britain, Germany and Spain.

"It is our hope that through this project, we can build the foundation towards full-scale commercialization of hydrogen fuel-cell buses to promote sustainable transport, the use of renewable energy, and cleaner air," Meyer said.

In Beijing and Shanghai, public buses are among one of the major contributors to air pollution. Later this year, three more fuel-cell buses will be launched in Shanghai and a hydrogen refueling station will be built.

Beijing will expand the hydrogen refueling station, and use data from the operation of the three buses to support efforts to commercialize fuel-cell technology.

Despite considerable efforts and significant achievements in China to combat air pollution and greenhouse gas emissions, China continues to rank second among the world's largest oil consuming countries.

The transport sector, which relies almost entirely on oil, is projected to account for most of China's new demand for oil over the next 20 years. It is predicted that by 2010, the amount of emissions from big cities will represent 64 percent of total emissions from all cities in China.