Analysing the interaction between emission trading and renewable electricity support in TIMES

As the number of instruments applied in the area of energy and climate policy is rising, the issue of policy interaction needs to be explored further. This article analyses the interdependencies between the EU Emissions Trading Scheme (EU ETS) and the German feed-in tariffs (FITs) for renewable electricity in a quantitative manner using a bottom-up energy system model. Flexible modelling approaches are presented for both instruments, with which all impacts on the energy system can be evaluated endogenously. It is shown that national climate policy measures can have an effect on the supranational emissions trading system by increasing emission reduction in the German electricity sector by up to 79 MtCO 2 in 2030. As a result, emission certificate prices decline by between 1.9 €/tCO 2 and 6.1 €/tCO 2 and the burden sharing between participating countries changes, but no additional emission reduction is achieved at the European level. This also implies, however, that the cost efficiency of such a cap-and-trade system is distorted, with additional costs of the FIT system of up to €320 billion compared with lower costs for ETS emission certificates of between €44 billion and €57 billion (cumulated over the period 2013-2020). Policy relevance In order to fulfil ambitious emission reduction targets a large variety of climate policy instruments are being implemented in Europe. While some, like the EU ETS, directly address CO 2 emissions, others aim to promote specific low-carbon technologies. The quantitative analysis of the interactions between the EU ETS and the German FIT scheme for renewable sources in electricity generation presented in this article helps to understand the importance of such interaction effects. Even though justifications can be found for the implementation of both types of instrument, the impact of the widespread use of support mechanisms for renewable electricity in Europe needs to be taken into account when fixing the reduction targets for the EU ETS in order to ensure a credible long-term investment signal.