The Association of Issuing Bodies - the AIB[1] - promotes the use of a standardised system, based on harmonized environment, structures and procedures in order to ensure the reliable operation of international energy certificate systems. This standardized system is known as EECS - the European Energy Certificate System - and is set out in "The EECS Rules"[2] and its supporting documents.
Of the 27 countries of the European Union, 15 are now active members, along with Norway and Switzerland. Since 2001, more one billion (1,068 million) 1MWh certificates have been issued, of which 817 million have already been used (cancelled)to guarantee to consumers the origin of the renewable energy they have purchased. In 2010, more than 232 million certificates were issued, and 211 million of these were cancelled.