Sustainable Design Lab at MIT and MoDe Studio estimated the potential hotspots for electric photovoltaics in Cambridge, Massachusetts and mapped it.

“High PV Potential Area” is the footprint, in square feet, of the portions of a roof that, by considering both the real surface projection to its actual slope and this surface’s annual irradiation, yield a “good” to “excellent” result. These values are based on MIT’s calculations and are shown as orange and yellow dots on the viewer, respectively.

If all the door-to-door salesmen trying to sell me solar panels showed me something like this for where I live, I’d be a lot more receptive.