@Griffin Malcolm I had solar panels installed on my home a year ago. The loan you get for the solar project is a large loan with the ROI not being evident for many years. It is also a separate loan from your mortgage.
Some things to consider:
1. Yes, your property value MAY increase (there are differing opinions about this) but, when you sell, the loan must be paid off either through the increase in price for the home or a separate agreement where the buyer assumes the loan for the solar.
2. Your property insurance will increase to cover the value of the solar panels.
3. The salesperson is not a tax expert and the government refund is not exactly the way they describe. Not sure what the NY refund situation is, but the federal refund is amortized with carry over credit until used up so that you never receive a refund from the IRS greater than what you paid in for the year. (This frustrated me immensely because I was going to pay off a higher interest debt and take the higher payment after the 18 months.) They told me that VA had incentive tax breaks/refund as well, but my tax guy said "Nope!"
4. Unless you are storing your energy and are completely off the grid, you will always have the fees for being on the grid each month. (Another thing that irritated me about the lack of transparency by the solar company. To be fair, they did say that I would always see a bill from the electric company, but it was not explained.)
5. If you have to replace your roof, you will need to have the panels removed and reinstalled by an authorized solar installer - quite probably the same company who installed them in the first place. If they deem your roof needs work when they evaluate it, you will have to re-roof first.
If I had it to do over again with all the proper facts in front of me, I would probably have made a different decision. I do track the progress of savings/expenditure and hope to someday see a savings someday.