The EU Emissions Trading System (EU ETS) began on 1 January 2005 and its second phase which ran until 2012. Phase III started on 1 January 2013.
EU Member States set emissions caps for all installations covered by the System. The number of allowances allocated to each installation for a phase is set out in National Allocation Plans produced by each Member State.
Further information about the EU ETS is available from the GOV.UK website - click here