Very hard to give info as state by state laws differ .
But here goes .
NJ has good promos for solar power.
NJ has
Lower power cost in the winter and gear heat has value.
NJ has higher power cost in the summer and gear heat has negative value.
Solar works better in the summer and worse in the winter due to sunlight .
So for NJ solar makes sense . Especially if you do grid tied setup with no battery .
Oregon and Washington have cheap power. I would think a solar setup makes no economic sense.
Maybe in AZ it works ALSO CA.
Not sure about CO.
AZ and southern CA are very good solar areas from the standpoint of lots of sun and few cloudy days.
As I recall the largest commercial solar plants in the US are in AZ or in the Mohave Desert / Imperial Valley parts of CA.
CA also has the oldest and some of the largest commercial Wind Power farms in the US - I think the state overall has slipped to 3'd on total wind generation behind Texas and Iowa though.
The Tehachapi Pass (west from the city of Mohave following California 58) was an impressive wind farm area 35 years ago - I don't want to even think about how crowded it is NOW with windmills.
Oregon has lots of cloudy days pretty much anywhere in the state, not good for solar.
They DO seem to have some fairly strong government support for "renewable" energy, but the northern part of Oregon also gets SOME Columbia River hydropower and probably has lowish electric rates.
The parts of Washington State that have few cloudy days are also where most of the VERY VERY low cost hydropower is at, not much point to trying to go solar here.
CA is also VERY VERY high "on the grid" electrical rates pretty much anywhere in the state (mostly the highest in the US outside of HI), which would make alternative sources like solar and wind a lot more competative than most areas.
I believe most of CA also has some pretty hefty government support for solar and wind, but not sure if that applies to small-scale folks or just to large utility companies.