Applications of SOECs in different types of energy systems:German and Danish case studies

Different aspects of electrolyser integration in energy systems was investigated in order to determine the potential of using this technology in the future. The first analysis examined the influence of the use of co-electrolysis for the fuel production process in comparison with using steam electrolysis as a source of hydrogen that afterwards is combined with carbon dioxide. The second investigation looked into whether the fuel production chain should include distribution of the intermediate product syngas or distribution of the final product in the form of liquid fuels. Thirdly, the potential for using combined capacities of SOEC and SOFC was investigated as this can potentially improve the profitability of the investment, but also improve the stability of the energy system by offering grid-balancing capacity when intermittent resources cannot meet the demand for electricity. Finally, five different energy systems were analysed in order to determine the operation of electrolysers: Danish 100% renewable scenario for 2050, smart energy system Germany 2050 and three nuclear scenarios for Germany with different shares of nuclear energy (15%, 30% and 45%) of the electricity production. The analysis shows that different system designs influence the feasible utilisation capacity of electrolysers differently and this is mainly connected with the system flexibility