A solar panel system covering a desert area the size of France could provide enough energy to supply the entire world. As global warming continues and fossil fuels near their imminent end, this proposition appears less and less the stuff of a science fiction novel. Germany and Jordan are showing how solar energy is becoming an increasingly economically viable energy source for domestic needs. In a changing world, one solution to many of today's problems could be installing photovoltaic panels on everyone's housetop.