If electricity and natural gas prices go up 3% per year for inflation (natural gas impacts me because I'm converting my gas appliances to electric, thus avoiding my natural gas bill is part of my savings in solar) my solar system will pay for itself in about 13 years. Truth is, that's not the main reason I bought it.
What I'm really shooting for is a hedge against potential spikes in energy costs. For instance, go to https://markets.businessinsider.com/commodities/natural-gas-price and click the 1YR option to see the natural gas price for the past year (in Henry Hub). You'll see that nat gas has gone up 125% from what it was this time last year (currently $5.21, was $2.31, a difference of $2.9 within a year, which makes it more than double what it was a year ago). That impacts not only your natural gas bill, but also your power bill since some of your power is generated from a natural gas plant. If you live in an area that had an Obama shut down coal plant (as I do), your power company is even more dependent on natural gas than before.
How often will that happen? I don't know. But having a huge portion of my energy made from solar makes me lose less sleep over rising energy costs. So when the Occasional Cortex types vow to spike our energy costs to force use to repent from our cow farting sins, it doesn't bother me near as much as it used to. My monthly expenses going into retirement have a fairly smooth expectation in part because energy cost volatility doesn't impact me nearly as much as they used to.
I am glad that you live in an area where solar cells will eventually pay for themselves. It does not work that way where we are at.
How do you figure that your batteries will survive for 19 years? I am not sure that you have a clear understanding of how batteries are used in a functioning solar system. Even if you had them only on a self leveling trickle charger most batteries will not be in useful condition after 19 years even if you never used them.
Perhaps the machinations of the leftists should bother you and that you should do something about it instead of thinking you are a step ahead. Do you honestly think that you will be allowed the “solar allowance” much longer?