In warm climates the highest energy use is during the sunniest part of the day. Energy companies actually pump water from lower lakes to higher lakes at night and generate electricity during the day as the water flows back down through the turbines. Electricity consumers can also sign up for programs that charge less at night.
What this means is that photo-voltaic cells on individual homes and businesses would be connected to the power grid and would supplement the power supply during heavy load periods. If enough of them were used, then the coal-fired and natural gas plants could be throttled down.
If a home had enough cells and the occupants were not at home during the day using electricity, their meters would run backwards.
No storage system is needed.
Pumped storage is actually only effective at two or three locations nationally.
Good in theory - doesn’t work in th ereal world mountains and machinery and EPA.