Thank you so much. I keep hearing different things. I'll be curious to see what type of documentation will be needed.
I usually don't have anything specific TO include on my taxes, so I'm new to this. Is there a link the IRS has that might give me idea for what has been required in the past?
Yes. Read the Form 5695 instructions for the Nonbusiness Energy Property Credit for tax year 2017, starting on page 2 - https://www.irs.gov/pub/irs-prior/i5695--2017.pdf