STCs are Small Scale Technology Certificates (formerly known as Renewable Energy Certificates: RECs). STCs are a tradeable commodity that give you an up-front discount on your new renewable energy system. STCs are traded on a market similar to the stock exchange.
The number of STCs that you are eligible for depends on the capacity and location of your solar system. Australia has been divided into four solar zones representing the amount of solar light radiation hours (hours of sunlight). The solar zone in which your system is located determines the number of STCs your system can create.