No no no, you got me wrong.
You're saving a lot more because:
- you redirect your "whenever" power usage (car charging, other high power use like dishwasher, washing machine, dryer, etc.) to that period, thus reducing your expenses, while allowing the battery to still charge (solar generates power at night too, unless it's pitch black, albeit considerably less than you would during the day)
- during the peak time, you use the battery and solar and supply the system back, essentially bringing your peak usage expense to near 0.
At the end of the day you're balancing out your incoming and outgoing power - and with the battery you can be even completely grid-free (albeit still connected as a backup), if needed.