During the middle of the day, the solar array achieves its maximum output. Your solar array sends DC power to your inverter which converts the electricity to AC, before deciding where to send it. Given most families are out to work or school, most of your power is sent to the Grid or used to charge your DC home battery for later use.
By sending power to the Grid, you are eligible for a FiT or Feed-In Tariff. You will receive between 8-16c for every kilowatt-hour you export. Alternatively, you can charge your DC battery, which will provide you with cost-efficient power during the evening.