"Solar cells will in all likelihood be the single biggest source of electrical power on the planet by the mid 2030s. By the 2040s they may be the largest source not just of electricity but of all energy. On current trends, the all-in cost of the electricity they produce promises to be less than half as expensive as the cheapest available today. This will not stop climate change, but could slow it a lot faster. . . . The benefits [of cheaper energy] start with a boost to productivity. Anything that people use energy for today will cost less - and that includes pretty much everything. . . . Cheap energy can purify water, and even desalinate it. It can drive the hungry machinery of artificial intelligence. It can make billions of homes and offices more bearable in summers . . . . But [the] most consequential [result will be that] cheaper energy will free the imagination, setting [the] wheels of the mind spinning with excitement and new possibilities."