The European emissions trading system covers fixed installations exceeding certain capacity or production thresholds in sectors listed in Annex I to the directive: energy production, steelmaking, cement, heavy chemicals, paper and glass. A site under the ETS has an account in the national allowances registry and declares its emissions every year. Any installation outside this scope falls under the Effort Sharing Regulation by default.
Read the source article: SNBC 3: what obligations apply to businesses?