Most California utilities now charge based on when you use power, not just how much. Power is most expensive 4-9pm — when everyone's home — often 2-4x the midday rate. This has literally changed how people live: laundry after midnight, AC off on sweltering evenings, pool pumps running at 2am even though they work better in daylight.
Solar + battery flips this completely. Your panels make power when it's nearly free (daytime), your battery deploys it when the utility charges the most (evening). Instead of arranging your life around rates, the system arranges the rates around your life. That freedom — using power when you actually want to — is one of the most underrated things solar buys you.