Certainly, it depends on the states involved....and how they calculate the credit. Living an income-taxing state and working in a non-taxing state, you'd end up with no "other State" credit, so if you have enough taxable state income, the "state" energy credit should be available.
And for the Federal Energy Credits, which state you work in is immaterial to the credit calculation....which could be greater than the state credit for the same installation $$ (not sure about CA though).
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
