Jonathan Mapel at MIT Energy Conference

How do you get more electricity from a solar cell? Fancy plastics. So says Jonathan Mapel, shown here at the third MIT Energy Conference held in Cambridge, Mass., over the weekend. Mapel is a Ph.D. student at MIT's Research Laboratory of Electronics, which is starting a company called Covalent Solar to commercialize technology developed at his lab.

Rather than make solar cells more efficient at converting light to electricity, Covalent Solar plans to make solar power less expensive by using less silicon through concentration. When light hits a plastic sheet, it moves to the edges through dyes and waveguides (along the edge, where the thin strips of silicon solar cells are, rather than full-size cells).

It may sound simple, but it's actually hard, says Mapel.

Covalent isn't the only company using optics and plastics to use less silicon. Start-up Solaria is building panels around a plastic encasing that concentrates light on thin strips of silicon.