Exelon (EXC 0.55%), one of the largest power companies in the U.S. and the largest provider of nuclear power, faces some short-term headwinds because of shrinking margins operating its enormous nuclear capacity in the face of low natural gas prices, which are forcing the company to keep its rates low. However, the future looks bright in the long term. Nuclear is one of the most powerful and reliable sources of energy, so with much of the company's diverse energy portfolio coming from nuclear, a zero-emissions power source, the company can stay insulated from EPA regulations. And as more cash starts accruing on the books, Exelon has its eye on several innovative renewable-energy projects over the next few years. See more in the following video.