Here's a technology to watch...

Here's a technology to watch...  Optical rectennas.  “Huh?”, you say?  These are devices built with nano-materials that convert light directly to electricity, and they work in a way that's different from the silicon photovoltaic cells that make up all solar panels built today.  The optical rectennas have one advantage that gives them huge potential: the teensy rectennas can be “tuned” for various wavelengths (colors) of light – so they can convert (theoretically, anyway) all light to electricity.  Today's solar cells can't come close to that.  This means that solar cells built with optical rectennas have the potential to be much more efficient than today's solar cells.  They also have the potential to be easier and cheaper to build, because the materials involved are not crystalline.

It's very early days for this technology, but it's one I'm going to watch closely...