Here's a conundrum: If solar power is still prohibitively expensive even in the richest nations on the planet, how will it ever spread to the parts of the world that need cheap, clean, and reliable energy the most? Inspired by the belief that clean energy is a fundamental human right, the Solar Electric Light Fund is delivering solar power and wireless communications to villages in more than 15 developing nations. With funding coming from private- and public-sector partnerships, SELF uses these technologies to help alleviate local problems, powering water purification and pumping, lighting up households, and providing energy to schools and medical facilities.