This was created a few weeks ago for a local hackathon run by a sustainability focused non-profit in Chicago. Placed first out of around 13 teams and thought I'd run it past the HN crowd. Unfortunately we only have data for Chicago at the moment, but the team & I plan on making improvements and adding data.
Some more background is here: http://www.dnainfo.com/chicago/20140707/downtown/how-green-i...