Residual mix

Under the Directive of the European Parliament and Council on the Common Electricity Market (2009/72/EC), there is an obligation on electricity suppliers to provide invoices and marketing materials for end consumers that indicate the share of every energy source in the supplier’s total fuel mix for the previous year in a comprehensive, clear and nationally comparable manner.

On the basis of §582 of the Electricity Market Act, the transmission system operator is obliged to develop a method for the calculation of residual mix and, by 30 June, to publish the calculated quantities of residual mix for the previous calendar year. Residual mix refers to a set of electricity for which the origin is not verified with a certificate of origin.

In Estonia, in order to prove consumption of electricity generated from renewable sources, certificates of origin issued under §581 paragraph 3 of the Electricity Market Act that are registered (issued in or imported to Estonia) and thereafter cancelled in the electronic database managed by the transmission system operator, are deemed certificates of origin. Only electricity covered by a corresponding certificate of origin is considered electricity with proven origin.

National residual mix allows calculation of the origin of electricity supplied by electricity retailers but not covered by certificates of origin, and makes the data comparable.

Residual mix 2014-2018