New England just doesn't have a lot of light. The time to return on investment is commendurately longer. And in the winter it's much worse.
NREL has solar availability maps. Alas the scale sucks; there's great monthly average views, but all done with the same yearly average scale, so during the summer everything is the same full-red potential (>5.75 kWh/m^2/d) and during the winter everything is (mostly) the same low potential (<4kWh/m^2/d). Still, one can kind of read some pattern from fall/spring & see how a lot of NE looks a lot like, say, Seattle (<<4 average).
https://www.nrel.gov/gis/solar-resource-maps.html
NREL has solar availability maps. Alas the scale sucks; there's great monthly average views, but all done with the same yearly average scale, so during the summer everything is the same full-red potential (>5.75 kWh/m^2/d) and during the winter everything is (mostly) the same low potential (<4kWh/m^2/d). Still, one can kind of read some pattern from fall/spring & see how a lot of NE looks a lot like, say, Seattle (<<4 average). https://www.nrel.gov/gis/solar-resource-maps.html