Next to energy efficiency, in the context of GHG reductions, additional policy mechanisms to the incumbent EU Emissions Trading scheme (EU ETS) are discussed. Such is the case of Non-ETS Domestic Offset (DO) schemes, which can reduce CO2-eq.emissions in the non-ETS sectors and trade these as CO2 credits on the ETS market. Taking into account that the EU’s “Linking Directive” (EC 2004) creates the conditions to use credits generated by emission reduction projects certified by the UN Framework Convention on Climate Change Kyoto Protocol (KP) within the EU ETS market, in this paper we employ the institutional analysis method of interactions in order to provide insight of a combined White Certificates (WhC) and DOs cheme. Special attention is paid to the parameters that seem to hamper harmonization of WhC and DO. Aim of this paper is to discuss whether smart market- based instruments, such as WhC, can be complementary to the effectiveness of mechanisms fostering energy efficiency such as DOs projects and vice versa. In this respect, the potential combined scheme is assessed (ex-ante) with the help of standard criteria that refer to the triptych energy, environment & society. Given the outcome of the study made, it is fair to say that such a DO/WhC combined scheme could be selected if the additionality concern is to minimize short term social costs of reaching a certain goal. However recent information and research conducted so far cannot yet uphold an ambition that a WhC/DO scheme of this kind could also drive technical change, keep consumer costs down and be equitable.
