And in 15-20 years when it's replaced, it's likely the replacement will cost a tenth of current prices. Batteries are getting so much cheaper every year that I'm delaying purchasing only because I don't want to lock in today's prices, and I'm hoping for an aggregated demand response solution that can start paying me for battery usage as well. Just being able to island my house and ride out a blackout isn't as much of an incentive at the moment.