This is an awkward question.
So let’s say you buy a solar panel and it costs you 0, and at the current price of electricity (and other factors), it will take x years for the solar panel to SAVE you 0 on your electricity bill, thus paying for itself.
What is this phenomenon or duration of time called?
I guess you could compare it to "breaking even", except you were not investing money for the purpose of making money. You were investing money for the purpose of saving money.
