There is no requirement to use batteries to back up a grid connected solar house, any of the current generation options work fine.
The question raised was could solar PV supply a majority of residential electric load if it was basically unavailable at night.
In ten years, when the OP expects solar PV to be cheaper than all other forms of generation, how much power will really be needed at night?
I can easily imagine a house with very little night time consumption. Natural gas furnace, gas stove, gas water heater and dryer; nothing exotic. Refrigeration electric load can be shifted to the daytime by simply setting the controller to over-chill the freezer during the day.
That leaves computing devices, lighting, and entertainment for the night time electric load.
Don't forget hair dryers, vacuum cleaners, and microwaves, all devices that (in northern latitudes) are used before sunrise or after dark during the colder 5 months of the year.
Maybe we can totally flip culture on its head by going to work when it's dark and enjoying the few hours of sunlight all to ourselves.
The question raised was could solar PV supply a majority of residential electric load if it was basically unavailable at night.
In ten years, when the OP expects solar PV to be cheaper than all other forms of generation, how much power will really be needed at night?
I can easily imagine a house with very little night time consumption. Natural gas furnace, gas stove, gas water heater and dryer; nothing exotic. Refrigeration electric load can be shifted to the daytime by simply setting the controller to over-chill the freezer during the day.
That leaves computing devices, lighting, and entertainment for the night time electric load.