Utilisation of excess electricity in different Power-to-Transport chains and their environmental assessment

Future energy systems with dominating shares of non-dispatchable renewable energy sources will be confronted with excess electricity generation. Power-to-Transport applications for passenger cars are a promising flexible consumer for utilisation of excess electricity instead of its curtailment. Goal of this article is to design and assess future Power-to-Transport chains with regard to their substitution potential of conventional passenger cars and accompanying environmental impacts. This analysis focuses on Germany in the year 2050 as one example for a future renewable dominated energy system. As technologies battery and fuel cell electric vehicles as well as synthetic natural gas vehicles with internal combustion engines are analysed. To guarantee fuel supply, energy storage options are taken into account. Results show that excess electricity input enables highest travelling distances for the battery electric vehicle. This trend continues in the results of the environmental performance of the Power-to-Transport chains. With the lowest environmental impacts in eleven out of 13 categories battery electric vehicles show the best environmental performance. Furthermore, a detailed assessment of contributions from individual stages of the Power-to-Transport chains to entire results revealed that the vehicle construction dominates the majority of impact categories.