Following the closure of the Feed-in Tariff (FIT) scheme to new applicants in March 2019, the government recognised the need to pay small-scale renewable energy generators for the electricity they export to the grid. Consequently, the Department for Business, Energy and Industrial Strategy (BEIS) introduced the Smart Export Guarantee (SEG).
Under the scheme, all licenced energy companies with 150,000 or more customers must provide at least one SEG tariff. Smaller suppliers can offer a tariff if they want to on a voluntary basis. All suppliers can also choose to offer other means of making payments for exported electricity, separate to the SEG arrangements (see ‘Alternative finance arrangements’ below).
If you already receive a FIT on your installation, this is unaffected by the introduction of the SEG.
https://energysavingtrust.org.uk/advice/smart-export-guarantee/