Baoding, China
CHINESE state-run energy giant Sinopec has drilled hundreds of wells across the country without finding a single drop of oil. But that was precisely the point: instead of black gold, the almost mile deep holes are providing clean heat for local homes.
While two-thirds of China's electricity is generated by coal, almost all of the homes in northern Hebei province's Xiong district - home to 400,000 people - are heated by wells as deep as 1,500 metres.
In a new apartment in the district, a 60-year-old retiree watched his granddaughters hop about in bare feet, impervious to the frost outside.
"This floor heating works like a dream," said Li Fuzeng. "And they say it's clean energy." The...