Jun 08 2009
Back in the 80's Edmund Scientific used to sell an amorphous solar cell educational kit: a small lozenge of flexible plastic that contained a pinkish purple solar panel, a couple of lengths of wire, a small light, and a tiny electric fan. The nifty thing about that little solar cell was that it really was flexible; unlike the rigid crystalline solar panels we've all seen you could curl that little sucker around your finger and it would still work if you set it in the sun. While they don't appear to sell that exact kit anymore (and if I'm wrong please tell me, I only took a quick spin through the results of their search engine) they do sell a similiar solar cell that has a glass panel glued to the front.
Jump forward twenty years (and no jokes about my navigational abilities, please): a startup company in Ohio called Xunlight has perfected a process by which they can manufacture thin-film amorphous solar cells meters on a side. Amorphous cells are cheaper to manufacture than the crystalline silicon kind due to the fact that much less material goes into their construction - they're much thinner than standard solar cells (one millionth of a meter). To make up for the lack of efficiency three different materials instead of one are used in the manufacturing process, each of which is sensitive to a different portion of the visible spectrum. All things considered, these panels are about 8% efficient, a far cry from the 20% efficiency of standard cells. Still, these solar panels have hit the contractor market for clients that are interested in covering the roofs of their houses with it to offset the amount of electricity they pull from the grid. I did some research to see how much they go for per square meter but the outfit selling them doesn't have prices posted; instead you have to contact their sales reps to get a price quote. Interestingly, a few other companies are competing in the same market but are using different semiconductors with different degrees of success. Xunlight is aiming to hit the commercial market by next year.