Comment by tyingq

A Tesla Powerwall 2 weighs 114.0 kg and provides 13.5 kWh.

Average US household electricity consumption is 877 kWh/month, which would be 29kWh/day.

Either they mean a very efficient/small house, or homeowners with unusually frugal habits.

Edit: Average UK household electricity consumption appears to be around 10kWh/day.