Check out this short video and read on to find out.
The feed-in tariff is surplus energy that you're creating from your solar system each day, that goes back into the grid. The network and retailers then give you a credit for that surplus energy. The surplus energy then goes towards your nighttime usage where the credits during the day offset the nighttime usage where your solar system is not producing.
It also goes towards getting rid of the supply charge which is what the network charges you each day to be connected to the grid. The network then gives you a credit for all your export energy that you’re putting back into the grid and that changes throughout the network with different retailers charging different amounts.