Really? ROI in just 3 years. That seems very low to me.

In the US in California setting up a total PV installation with batteries is priced out between 20K to 25K. I don’t know about you, but typical residential power bills are running about $300/Month.

So, for someone who goes completely off-grid with a power bill of around $2500 year isn’t going to hit "break-even" for about 8–10 years. Best case, with zero maintenance costs.

Did you get a subsidized install from the government?