Guardian: Rising more than 200 metres above the vast, deserted plains of the Atacama desert, the second tallest building in Chile sits in such a remote location that it looks, from a distance, like the sanctuary of a reclusive prophet, a temple to ancient gods or the giant folly of a wealthy eccentric. Instead, this extraordinary structure is a solar power tower that is being built to harvest the energy of the sun via a growing field of giant mirrors that radiate out for more than a kilometre across the ground...