GetOffYourGas wrote:I don't know a single person who has a 2,400+ sq. ft. home on a single floor. Assuming that on average, single family homes are two floors, that's 1,200 of roof space. Assume again that only half is useable, certainly true if you're north-south oriented, less so if east-west. Also, what percentage of those homes are shaded? Certainly in the northeast, at least 20% of homes are too shaded for practical solar.
I sort of whitewashed over this when I said that not every roof would be usable. The point of the exercise was to demonstrate that there is a lot of roof area on the US, and that we would not have to cover nearly a fifth of it to cover our electricity usage.
Also keep in mind that 2,400sq.ft. is the AVERAGE. You have a handful of very large homes offsetting a majority of smaller homes, and smaller homes tend to be single story. I don't feel the estimate is completely out of whack.
GetOffYourGas wrote:I'd love to see the original calculations, though.
There is a link to the other post/topic in the first post of this thread.
Both me and RegGuheert used, effectively, 4 kWh/day for our generation estimates. That number is such that it covers over 95% of the country even per your graphic. That potentially makes it a rather severe underestimate, but to really hash that out you'd need to include population distribution and blah blah blah.... it's just an estimate for discussion's sake, so assume a less-than-ideal case to be conservative.