Two MIT researchers have developed a simple method to use "organic solar concentrators" — colored glass — to create windows framed by solar cells that can "increase the electrical power obtained from each solar cell 'by a factor of over 40'". The concentrators not only make it possible to create windows (albeit colored ones) that let in some light while also harvesting solar power, but are also much less expensive than intricate mechanical systems used to rotate existing solar panels.
The MIT solar concentrator involves a mixture of two or more dyes that is essentially painted onto a pane of glass or plastic. The dyes work together to absorb light across a range of wavelengths, which is then re-emitted at a different wavelength and transported across the pane to waiting solar cells at the edges. In the 1970s, similar solar concentrators were developed by impregnating dyes in plastic. But the idea was abandoned because, among other things, not enough of the collected light could reach the edges of the concentrator. Much of it was lost en route.As "sixswitch" said in the MeFi thread: "I just can't believe it took this long for someone to go from 'Hey, this Space Lego piece is bright along the edge' to building this." Dye-coated glass to channel energy into solar cells [ScienceCentric.com]