New York’s solar map is very nice: http://nycsolarmap.com/. I especially like the calculator tools, and how things are tied directly into the building outlines. There is a claim that it’s the largest LIDAR based solar map in the world – I would have to disagree since LA County’s solar map (http://solarmap.lacounty.gov) cover 3,000 square miles.
There are a number of solar maps out there now – I think these “competitive” solar maps are good for the whole industry – they constantly push everyone to get better.
I was interested to see that they are using the ESRI community basemap, since NYC in the past has developed it’s own systems (which have always been nice).