This is the most common system which connects your solar panel installation to the main electricity grid. It will allow you to feed energy back into the grid via your meter when you are not using your electricity at the time. But in net metering which NSW electricity distributors adopted after NSW solar bonus scheme, you use your energy first before you buy energy from the main grid system if the solar panel yields is less than your consumption. If the solar panel yields more than your consumption, the grid connect system can feed excess power to the grid where it is consumed by other users. In that case, you can yield revenue from the excess power by selling it to the grid. Electricity retailer gives 6 to 8 cents per kW voluntarily. You may check the links for bonus scheme and retailers for more information.