System comparison of storable energy carriers from renewable energies : Section V 1.3 Renewable energies, Werner Niederle : Final report by Axel Liebich, Thomas Fröhlich, Daniel Münter, Horst Fehrenbach, Jürgen Giegrich, Susanne Köppen, Frank Dünnebeil, Wolfram Knörr, Kirsten Biemann (ifeu – Institut für Energie- und Umweltforschung, Heidelberg); Sonja Simon, Simon Maier, Friedeman Albrecht, Thomas Pregger, Christoph Schillings, Massimo Moser, Regine Reißner, Schwan Hosseiny (Deutsches Zentrum für Luft- und Raumfahrt, Stuttgart); Gerfried Jungmeier, Martin Beermann, Dorian Frieden, Neil Bird (Joanneum Research Forschungsgesellschaft mbH, LIFE - Zentrum für Klima, Energie und Gesellschaft, Graz) ; commissioned by German Environment Agency ; publisher: Federal Environment Agency (Umweltbundesamt) ; study performed by: ifeu - Institut für Energie- und Umweltforschung gGmbh; Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR) Institut für Technische Thermodynamik; Joanneum Research Forschungsgesellschaft mbH ; edited by: Section V 1.3 Renewable energies, Werner Niederle

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.