Hi Kaby,
If you're heating water with solar energy, you can store the hot water in an insulated tank, like the water heater tank in your home. If you're generating electricity from the sun, you can store the energy in batteries. Or you can send the electricity back to the neighborhood through the power lines and get credit on your electric bill for the extra electricity you produce. That's called net metering, and many states now have net metering laws which require the utility to buy back your extra power.
Solar Mike