If you spend US$6000 on panels and batteries, your electricity bill is US$300/month, and the outages and power lines cost you nothing, then your payback time for the off-grid solar system would seem to be 20 months, under two years, not 10 years. The outages and power lines would seem to shorten the payback time further, not lengthen it. Without disparaging the feel-good control thing, which I think is reasonable and important, I feel like I must be misunderstanding something about your explanation.