First, solar panels physically last 25 years but they are only warranteed for 80% power output at 20 years (90% at 10 years).

Second, in 25 years you are almost guaranteed to need a new roof on your house. You need to account for the cost of someone coming to remove the panels and re-installing them afterward.

Third, you'd be better off financing the $5000 cost of the system on a 0% interest credit card for 18 months than paying double the cost of the panels over a very long contract.

Finally, if you move within that 25 years, which the average American almost assuredly would, you may still have obligations to this company that will may or may not transfer to the new owner.