A year ago I installed solar panels+batteries, and now have a year of electric bills to compare.
2024: $4,133.13
2025: $655.62!
The entire year was less than the previous year's July bill.
Also got an EV last year so that amount ALSO includes my "gas" costs from charging at home. (~$1500/year with my prev gas car.)
Hard to think of a pair of purchases I've been happier with!