Long-term scenarios for the transformation of the energy system in Germany 3. Short report: 3 main scenarios

The project "Long-term scenarios for the transformation of the energy system in Germany" examines the techno-economic impacts of alternative paths for decarbonising the energy system and how Germany can achieve the goal of greenhouse gas neutrality. Specifically, this report summarises three scenarios. Decarbonisation requires climate-neutral energy sources. Essentially, these are electricity, hydrogen and/or synthetic hydrocarbons. For this first report, we have modelled one scenario with very heavy use of each energy carrier (TN-Electricity, TN-H${}_2$-G, TN-PtG/PtL). Further scenarios will follow. The following basic insights can be gained from the comparison of the present scenarios. The industrial sector is facing a profound transformation in many industries and value chains. Without large quantities of CO${}_2$-neutral energy sources (electricity, H${}_2$, PtG/PtL), the transformation is not possible. Energy-intensive primary industries in particular are facing a comprehensive conversion of their plant stock. In addition, the capture and possibly the use of CO${}_2$ from process emissions, e.g. in the cement industry, with the corresponding transport infrastructures, is an issue that becomes relevant in all scenarios. Based on current knowledge, an increase in direct electricity use in the areas of providing heat in heat grids, a significant number of buildings (heat pumps) and as an energy source in significant parts of car & transport transport is a robust strategy. According to current knowledge, air and maritime transport is also dependent on hydrocarbons in the long term, which can be provided from biogenic sources or possibly in the form of synthetic hydrocarbons (PtG/PtL). For long-distance transport, process heat, poorly insulated buildings and industrial processes, various technical solutions are conceivable, but with different consequences. For the poorly insulated buildings, the following options exist: Use of expensive synthetic hydrocarbons or, to a very limited extent, biomass; use of hydrogen with corresponding effort in converting appliances and supply infrastructure, and direct use of electricity with re-insulation, if possible. In all scenarios, a high expansion of renewable energies in Germany and Europe is central. The central challenge lies in the provision of land and securing the necessary acceptance for this. The electricity grids - both at transmission and distribution grid level - must still be significantly expanded in all scenarios, even after 2030. Efficient sector coupling and a transformation of the heating grids are central elements for the integration of renewable energies. Germany will continue to import energy in the long term. However, the imported energy sources will change. The land requirement abroad for German energy supply is considerable, especially for PtG/PtL imports. Energy efficiency is an important component of the energy transition to reduce the land pressure from electricity generation from renewables at home and abroad. The development of a European hydrogen network is part of a robust strategy for many possible scenarios. In this context, adapting the gas grid to declining methane demand and the transport of hydrogen is an important task. Speculating on a large-scale use of synthetic hydrocarbons would be a risky strategy, as this scenario is only conceivable under very specific conditions in terms of its economic impact mechanisms. Furthermore, our analyses show that, according to current knowledge, greenhouse gas emissions in Germany cannot be completely reduced to zero. For this reason, the research and development of technologies for negative emissions should be accelerated.