IT is usually claimed, and in addition true, that sufficient daylight falls on Earth in the middle of an hour to fulfill a 12 months’s price of world energy wants. A few of that daylight is presently transformed into electrical energy by arrays of solar panels: by the top of 2023, these panels coated virtually 10,000 sq. kilometres of Earth’s floor, producing some 1,600 terawatt-hours of electrical energy, about 6% of that generated worldwide.