Time2roll, I’ll try to explain. First of all this is with ratios, not your real numbers. So, at payout in 5 years your Internal Rate of Return is 0%, you just broke even. However, run it out to 10 years and you got about 15.1%. Sounds good, but look at Monte Carlo and consider. Repairs? New inverter/charge controller, my experience says you need at least one. I used solar on about 1000 lease custody units on oil and gas wells. I also saw about 5% loss of power in 10 years. Plus I am in a location with snow, lower angle in the sky, and TREES that I will not cut. Tech and trees rule my installation out.
How about roof repairs (assuming rooftop)? Twenty years is an old roof here, how much more does solar add? It is not a liquid asset, who would buy a used solar array? Attached to the house, will you move, divorce, or have a forced sale? Loss of fees, commission etc., assuming it adds value to the home, so about 10% loss on any added value. Treasuries have a low commission to sell, and in 24 hours the money is yours. Houses not so much, 90 days from your decision to sell is smoking fast. There are books of considerations, rolling it all out; I would look for a 3 to 4 times premium on any active investment over treasuries. Putting you above the limit, until you consider repairs.
Now I think this way by birth and training, and thank goodness my wife has the same type of mind or she would kill me. However, owning a camper “ain’t no thinking thing” and makes no sense, no how, no way. The only reason we did it, is because we wanted to, and we got only 3 states left! However, anytime someone says investment, my ears pick up.