The Gemasolar solar power station near Seville has an incredible 2,650 panels. The mirrors - known as heliostats - focus 95 per cent of the sun's radiation onto a giant receiver at the centre of the plant. Heat of up to 900C is used to warm molten salt tanks, which create steam to power the £260million station's turbines. But, unlike all other solar power stations, the heat stored in these tanks can be released for up to 15 hours overnight, or during periods without sunlight. Therefore it can operate through most nights, guaranteeing electrical production for a minimum of 270 days per year, up to three times more than other renewable energies. It is expected to produce 110 GWh/year - enough to power 25,000 homes in the Andalucia region.