At age 66 that is not that big of a consideration for me. The deal spreads over 25 years. Whoever buys my house will end up with most of the benefits I am just interested in the technology.
If you just want to tinker with the technology set up a shed or a portable batter bank you can take camping, put on a trailer, or run a pump to see if it something you are interested in.
Your panels will need to be paid off before you can sell your house, unless your buyer is willing to pay off the balance. No mortgage company will be willing to fold the pay-off amount into a new loan for the buyer.