It is important to know that the solar panels function in the presence of light not heat, so whenever the sun shines, even in overcast conditions, the solar panels convert this light and generate DC electricity. This electricity is then fed into a solar inverter, which converts DC electricity to 240V 50Hz AC electricity that is usable by your home and your power grid.
If your solar power system is generating more electricity than you are consuming, the surplus will be fed to your power grid. Generally, electricity retailers monitor how much electricity is provided to the power grid by your solar power system and in return they provide you with a credit for generating surplus electricity. Feed-in tariff policy set by the Australian Government determines how much credit you can get for generating your own electricity and selling the surplus to your electricity retailer.