The Feed-in Tariff (FiT) is a government run scheme designed to promote small scale renewable electricity generation, for example solar panels or wind turbines. You're paid for all the electricity you generate it doesn't matter if you export it to the grid or use it all yourself.
The Feed-in Tariff (FiT) scheme closed to new applicants on 1 April 2019. This doesn’t affect you if you already receive FIT payments.