Derek White, owner of Northwest Electric and Solar, set the timer on his whole home Tesla Powerwall backup battery to turn on at 3:30 pm and off at 10:30 pm. The the battery runs the whole house during these hours, not just the outdoor lights.
Even though here in Washington we do not have time-of-use pricing on electricity, Powerwall’s “price schedule settings” allow Derek to avoid an increase in his electric bill caused by all those added lights. Thoughtfully, he is also not adding to the strain on the grid during a peak demand time of the year (dark cold winter weekday evenings when people arrive home from work, turn on lights and heat). Unlike a generator, the battery is silent and burns no fossil fuel.
The cell phone screen shots below show the Customize menu that allows for self-powering the whole house and allows the owner to ensure that the battery does not go below a certain percentage. The second image shows the Powerwall is powering the home with no electricity from the grid (electric utility).