System comparison of storable energy carriers from renewable energies

Abstract

In the course of the transformation to a greenhouse gas-neutral society in the second half of the 21st century, the use of synthetic energy carriers based on renewable electricity or biomass is under discussion. This project evaluates the environmental impacts of technical and logistical options for the generation of such energy carriers on the basis of environmental impact categories such as global warming potential, acidification or land use. The production of five products (Fischer-Tropsch fuels, methanol, synthetic natural gas, biomethane and hydrogen) was examined based on various process steps/procedures and their current and future technical data. By using regional factors for Germany, Europe, and the Mediterranean region - like the availability of renewable energy carriers such as wind or PV and of raw materials such as carbon or water as well as transport routes to Germany - these processes were combined to form supply paths for these energy carriers. Using the method of life cycle assessment, the environmental effects were analysed for today and 2050. In addition, the costs for plant construction and operation were estimated. The results show that synthetic energy carriers generally have a significantly lower global warming potential than today's fossil reference products due to the use of renewable energies. However, the production of electricity generation plants and associated economic processes - such as steel and cement production - can still make a relevant contribution to the global warming potential if they are not also greenhouse neutral. At the same time, it is this production of the necessary plants that leads to (sometimes significantly) increased burdens compared with the fossil reference in almost all other impact categories, most notably in terms of water and land use. This study therefore also provides indications of which environmental impacts must be further reduced in the future. Quelle: Froschungsbericht

An essential prerequisite for a sustainable energy supply and greenhouse gas neutrality in Germany and worldwide is the complete conversion of the energy supply to renewable energies. Wind and sun are the sources with the greatest supply potential. However, these energy sources have a low energy density and are not uniformly available everywhere to the same extent. Therefore, a system is needed for the temporal and spatial connection between energy provision and use, which manages the provision of primary energy from the sun and wind, its conversion into storable energy carriers and their transport to the place of use. In addition to the transition to climate and environmentally compatible energy sources and their efficient use, this connecting system must also have the lowest possible environmental effects. This research project examines such supply paths with the method of life cycle assessments and thus provides indications of which measures must be advanced in order to reduce the environmental effects of the supply, storage and transport of storable energy sources. It remains essential to use energy as sparingly and efficiently as possible in order to reduce the required amount of storable energy sources from renewable energies and thus their environmental effects as much as possible. In addition to the final report as a summary of essential methods and results and the appendix with a detailed presentation of the work carried out, the data tables with the input data for the life cycle assessment calculation, its results and the results of the cost estimates are also provided below for further work in this topic area.Final report „System comparison of storable energy carriers from renewable energies“ (2 MB)Annex to the final report „Detailed analyses of the system comparison of storable energy carriers from renewable energies“ (87 MB)Data tables:Input data for life cycle assessments (Excel file, 1 MB)Results of life cycle assessments (zip-file with Excel files, 4 MB)Results of cost estimates (zip-file with Excel files, 400 KB)