Hula Girls, a well-known recent Japanese film, tells the story of how coal-miners’ daughters in northern Japan retrained as Hawaiian dancers when the city’s famous Joban pit faced closure. Their attempt to start a new business – a Hawaiian-themed hot spring resort – initially scandalised the conservative town, now part of Nakaso city, but eventually came to be regarded as a heroic attempt to adapt to a post coal-powered era.

Yet if one goes to Nakaso these days, one of the first things you are likely to spot is a coal-fired power station running at full pelt. Championed by Japan’s trade ministry and run by a consortium of nine power companies, the experimental plant is one of the most advanced examples of clean-coal technology. Japan is hoping it will prove the technology’s commercial feasibility, designed to reduce CO2 emissions to that of an oil-fired plant.