Storyline: Non-fossil fuel used in China for winter heating [Voice_over] As northern China slips into a winter chill, renewables and waste are becoming new sources of energy to heat homes. In Lanzhou city, the capital of northwest China's Gansu Province, sewage is being used for heating for the first time. Heat pumps extract heat from the treated wastewater as it leaves the sewage treatment plant. Compared to fossil fuels, heat pump-wastewater systems can reduce carbon emissions by 47,000 tons annually. In another district of the city, geothermal water, which is pumped from 2,300 meters below ground, is the main heat source. The temperature of the water can reach 74 degrees Celsius. Thermal water heating can reduce coal use by 7,000 tons annually and thus reduce carbon emissions by 19,000 tons. [Sound_bite] Shi Yonghua, local resident: "This year the temperature is higher than last year." [Voice_over] Data shows that as of last year, there were 41 million people using renewable energy for heating in the country's northern region. [Restrictions: No access Chinese mainland]