you're not as smart as you think

I'm often reminded that if I've thought or wondered about something, many other people have as well, and at least one or two of them have actually developed some sort of product/answer/blog about it. Sometimes I really enjoy this, as when it's about some interesting political or intellectual point, sometimes not so much, as when it's an idea for a business that I thought would be fun, new, and profitable (not that I have a bevy of investors and lawyers waiting in the wings to make that happen anyway).

Today's reminder, though it could be turned into a product, is one that just makes me happy to see that yes indeedy, someone's working on this. Being from Michigan and interested in green technologies I've been wondering about the flip side of heavily-insulated, or highly-reflective, or even vegetative roofs (all 'cool roofs'); they make great sense during the summer air-conditioning season by keeping the inside of a building cooler in the first place, but in the winter they rob the building of any benefit there may have been in that passive warming. It's the same problem with passive solar heating with windows; in the summer they have to be shaded all the time. But roof systems, unlike windows, aren't easily uncovered or tinted. Unless they're thermochromic. If the roof can change color based on the outside temperature, it can selectively absorb or reflect heat. Cool, in an exceedingly green and nerdy way. Eventually (a viable product is likely a decade away), the roofs of entire neighborhoods in the north could shift imperceptibly from heat-hoarding black to a field of reflective white.