I don't understand where you get your $50,000 figure from. You can get 8 Powerwalls for that price for a total of 108kWh of energy storage. I don't know what Americans are doing all day to consume 4500kWh per capita (residential energy usage) but even with such a high rate of energy consumption that setup has enough storage to keep running for days during a grid outage. I live alone and consume less than that so this system could keep the lights on for slightly more than 2 weeks. Buffering solar power with such a setup feels like a joke.