Making glass invisible: A nanoscience-based disappearing act. By texturing glass surfaces with nanosized features, scientists almost completely eliminated surface reflections -- an achievement that could enhance solar cell efficiency, improve consumers' experience with electronic displays, and support high-power laser applications. Source 3u.
I have to say that well made clean glass can be transparent and invisible until you walk into it and bounce off. Then you look around to make sure no one just saw you do that. If they can make glass even less reflective and more transparent I can see it helping make solar power much more efficient.