Good luck, just signed a contract for solar and for a heat pump. With the solar you can negotiate with the companies, not so much with the heat pump folks as they have that game pretty locked in but you can still get them to shave off a few $100s. From my research, it should be between a $3-$4 ppw for install here in Maine (we are pretty expensive), but very dependent on the panels and inverters and overall size of the system. I think I did okay as I was able to negotiate rec panels with Iq8 enphase inverters for far less than what other companies were quoting me for less superior systems. With that said, I haven't had my installation yet so can't recommend at this point.