[bluefirebrand]

Not necessarily. A large component for solar+storage is using the storage to offset the time that the energy is available. It's not just storing for overproduction

For instance, most places will have peak energy usage in the evening, when everyone gets home from work, starts the laundry, turns up the thermostat and makes dinner and such, kind of all at the same time

If you can store the solar energy at noon and use it at 6pm when everyone has come home from work and started making dinner, then you can prevent a demand peak from ramping up fossil fuel plant

So you aren't necessarily just aiming to store the overproduction, you're using the stored solar when it's more useful