Thanks. Good numbers.
I've been toying with the idea of doing some solar for years. But the problem I keep finding with home solar, is that the ROI is never, once you account for inflation. That $26k spent today is paid back at lower future-dollar value, it'll be worth only $14k in 20 years at a very modest 3%. Your actual payback value will hover somewhere in the middle, being spread over time. But I think you know that inflation during our current administration has spiked from ~1.5% up to somewhere close to 7%, depending on how you measure it. If they don't get that under control, your ROI goes strongly negative.
If you ignore inflation, which is a real nasty trick most solar companies employ to calculate ROI, I've seen ROI's of 13 - 25 years. That depends on system size and usage, usually favoring "smaller costs less".
Meanwhile, the same $26k invested in any tax-deferred account (IRA, your 401k, etc.) will grow to roughly $100k at a relatively safe 7% annual, over a similar 20 year period. So, rather than hoping to break even, which will usually never happen, we're actually losing $74k through this investment.
Not criticizing, you must have some non-financial reason for wanting to do it, and that's all good. But I'd be doing it mostly for less noble financial reasons, and would rather have the extra $74k in my retirement account. Each year I get older and closer to downsizing, the opportunity for any ROI diminishes, so we're probably reaching a "no return" point already.
