Solar power is convieniently most availible at midday when AC demand is greatest. If your solar cells produced some excess this couod pump water uphill or compress air or wind springs or spin flywheels or charge capacitors or recharge batterys.
It helps to improve storage, it helps to improve distribution and it helps to improve generation.
I don't think that any single tecnology has the potential for giveing us all the power we want as clean as we want it, we need to develop everything together.
