Coal phase out, energy efficiency, and electricity imports: Key elements to realize the energy transformation

The energy transformation requires a shift in the energy sector from fossil fuels and their related technologies to carbon free technologies which are mainly renewable energy technologies. In addition to them, three key elements foster the realization of smooth and stringent transformation paths: coal phase out, energy efficiency, and electricity exchange. By applying the techno-economic energy system model REMod-D, the German case is analyzed in this paper with a focus on effects created by emphasizing these three elements in an energy transformation strategy. The analysis covers their impact on the power sector, heating sector, and transport sector which are influenced by the actual shaping of these elements. Overall, the model results show a shift in the German energy system towards a system using more electricity. This electricity is generated up to 85% from photovoltaics, wind power, and other renewable energy sources. Each of the three elements, if employed, leads by itself to a reduction of efforts on the level of developments such as the deployment of renewable energy and renovations, as well as the electrification of vehicles. In the case of combining the three elements, complementary effects can even be summed up. In the Active scenario with a joint use and implementation of the three key elements, this combination is analyzed as part of a cross-sectoral energy strategy for the transformation. Each element can reduce the total system cost by around 16 billion EUR per year. This paper concludes to prioritize these three key elements in the energy strategy in addition to the strong expansion of renewables and the change of heating systems and vehicle concepts.