Large scale renewable power integration with electric vehicles : long term analysis for Germany with a renewable based power supply

Abstract

The use of electricity from renewable energy sources (RES) in the transport sector has many advantages compared to the internal combustion engine (ICE). A transition from a fossil fuel based mobility to one based on electricity from renewable sources can allow for significant greenhouse gas reductions (GHG) as well as of air pollutants and noise in urban areas. In addition, greater independence from imported oil in the transport sector can be achieved. The aim of this work is to study the feasibility and system impact of electric mobility in the German power system with a high share of fluctuating renewable energy. One major advantage of electric vehicles (EV) is the high flexibility in charging times, which can be used to integrate renewable power generation and to make the operation of the system more efficient. This work will focus on the period comprised between 2030 and 2050, since at that time it can be assumed that electric vehicles under favourable conditions can reach a significant magnitude for the power system. The REMix model developed at the DLR couples the in the energy economics well established approach of linear optimisation with a geographic information system (GIS) that provides spatial and temporal information of the renewable energy potentials. The GIS-based dataset is a key element of the model and is calculated based on satellite measurements, weather service and land cover data for the whole of Europe with a high spatial (10 x 10 km) and temporal (hourly) resolution. In contrast to other planning models, in which only typical load situations are represented, REMix considers real weather conditions and thus allows representing the particularities of fluctuating renewable energy sources in an optimization model. The results prove the feasibility of a power system with a RES share of over 85% assuming an ambitious network expansion based on underground HVDC lines. The analysis points out that controlling the charging times of plug-in electric vehicles (PEV) and with a flexible hydrogen production for fuel cell vehicles (FCV) not only the additional demand of EVs but also the renewable power generation required to power these vehicles can be integrated in the system. These actions allow completely avoiding increases of the residual peak demand, of surpluses from RES, as well as of the required transmission network expansion.