In the 1980's and 90's, the solar car was deemed the future of transportation. Yet, just as quickly as it arrived, the solar car disappeared. But today, as the problems caused by our reliance on fossil fuels have grown, so has a demand for alternative sources of energy for our vehicles. While electric cars are rapidly gaining a larger share of the automotive market, this technology still relies on electricity from a grid often fueled by petroleum or coal. And this is why some companies today are again trying to harness the most powerful energy source we know: the sun.