Oil and GDP are closely linked together, with the more oil consumed by a country generally meaning the higher the GDP of that country. With that said, energy costs of solar, wind and other technologies have come down substantially in recent decades meaning that "clean" solar power is actually one of the cheapest ways to generate electricity over its lifespan. So why haven't we switched completely over to solar? Well, it's not that easy. Learn more about your ad choices. Visit megaphone.fm/adchoices