The New York Times took up the idea of white roofs with an article today. It goes into some interesting history on why places like Florida would have buildings with black roofs. The author also notes that “the extra heating costs [of white roofs] may outweigh the air-conditioning savings in cities like Detroit or Minneapolis [or Maine]”. Strangely (to my mind), there isn’t a mention of what seems like the logical next step: finding a simple way to turn black roofs white for the summer, then back to black for the winter.
My experiment in that very idea is working well. I’ve only actually covered half of my roof (out of pure laziness, really– I just haven’t unrolled the other half) but so far it’s been rather comfortable in the house, with none of those stiflingly hot no-sleep nights yet. I suppose they may be coming in August. I’ll get the other half covered soon.