A solar panel installation in Ruicheng County in central China's Shanxi province, which is known as "the sea of coal".

In recent years, the Chinese county has vigorously developed and utilised solar energy by building photovoltaic power plants on barren mountains.

As world leaders gather in Madrid for the United Nations climate summit, the spotlight is falling on China, the top emitter of greenhouse gases.

China burns about half the coal used globally each year. Yet it is also the leading market for solar panels, wind turbines and electric vehicles.

It has more solar energy capacity than any other country, at a gargantuan 130 gigawatts. If the country were generating electricity at once, it could power the whole of Britain several times over.