It was a first move in a good direction. The first flat screen TV's were outrageous in cost as were the first computers. One Powerwall @ $7,000 might also present a cost. If the cost for such a device described above was down to $500 in the future, it would certainly be a desirable solution for people that lose power. I have a lockout device currently on my circuit panel to shut service from the utility when power fails so I can power my house from a generator without back feeding electricity into utility power lines. Cost of that was $100 for the lockout.