We are just beginning to scratch the surface of the potential for solar energy, both in the U.S. and around the world. And a recent presentation on the industry's outlook by Shayle Kann of GTM Research described a path to $2.8 trillion in solar power investments globally between now and 2035. Even with that enormous amount of investment, Kann is estimating that solar would provide just 17% of the world's energy, up from around 2% right now.