Would it be possible to use a lens or a mirror to focus light onto a solar panel in order to make in more efficient? And is something like this already being used? It was just a thought and I haven't spent much time on it, but I figured I'd ask.
yes it is being done. i've seen adds for such a system. on the other hand, if you had a 5 sq in Lens focused on a small cell, and a 5 sq in cell, they'd be about the same. in fact, the cell might be a bit better because (A) there wouldn't be any loss in the Lens, and (B) it might be that the solar cell would use some frequencies to which the Lens was opaque. in addition, the cost of solar cells is dropping, making the cost of the mirrors or lenses uneconomical by comparison.
