Fair question — and here's the honest answer. It's not "solar vs. the stock market."
If you invest the cash instead of going solar, your money grows — but you still pay the electric bill every year, and it keeps rising. That's money leaving your pocket that could have been invested.
If you go solar, you spend the cash up front, your power bill basically disappears, and you can invest the money you used to send the utility — every month, in that same market.
So the real choice is:
- Invest, and keep paying a forever-rising power bill, or
- Erase the bill, invest the savings, and own something that adds value to your home.
Both of you can invest. Only one of you also gets to stop paying the utility.
Estimate based on your inputs — not financial advice. Turn on the two "Net worth" lines on the chart to watch it play out.