Interdisciplinary assessment of renewable, nuclear and fossil power generation with and without carbon capture and storage in view of the new Swiss energy policy

Abstract Swiss electricity generation is based on hydro and nuclear power, but current energy policy includes the nuclear phase-out by about 2035. This may lead to higher CO 2 emissions of the Swiss power supply due to domestic fossil power generation or electricity imports. For compliance with the Swiss CO 2 law, low carbon technologies such as renewable energies and Carbon Capture and Storage (CCS) gain importance. In order to support rational decision-making in this context, we compare various domestic and foreign renewable and non-renewable power supply options for Switzerland in 2035 based on environmental, economic, social and security of supply related indicators using multi-criteria decision analysis (MCDA). Our evaluation puts a focus on CCS technologies and uses (a) a novel approach that allows calculating the distribution of the MCDA results of all possible unique weighting profiles, and (b) two specific weighting profiles. The results show that domestic potentials for hydro and biogas power should be primarily exploited. Among the fossil and import options, natural gas plants with or without CCS and solar-thermal electricity imports are viable. Plants with CCS face a key trade-off: they may trigger social conflicts which must be weighed against the desired CO 2 emission reductions.