A 5 year ROI on a system that should last at least 20 years isn't an investment to feel better about yourself. It's a way to save money.

Three years ago, I was paying about $0.12/kWh, now it's about $0.22/kWh and installing a system makes sense.

It's cash up front for a savings later. My roof was due for replacement 'soon' but not immediately, and I didn't model the cost of moving that 3-5 years from the future to the present.

If you can't manage a 5 year planning horizon on a house, I'm not sure that home ownership is a great idea.

I get it if the ROI is 10+ years... too much uncertainty to put a lot of capital in.