Research in focus

Accelerate mobility

Making a short trip downtown with the small electric car to do some last-minute shopping before dashing off on vacation to Italy in the hybrid station wagon in an ˈon-the-flyˈ changeover. Using the car as a versatile variable, which protects resources and the environment and can be changed depending on the mobility requirements – is this the future of the automobile? At present, we are still far away from living in exhaust-free and silent cities, on the contrary: almost every day, the media report alarming levels of fine particles in the air of Germany‘s major cities, along with the request to use public transport – not to mention the smog levels in the international megacities, which regularly hit new highs. Are all the great speeches about the forthcoming end of the oil age just pious hopes or will we be able - to our own benefit - to achieve the agreed climate protection targets for the traffic sector and to ban harmful emissions such as car exhausts and noise from our cities by 2050 at the latest?

Politics and society have high hopes in electric mobility. The purchase grant for electric cars that was recently adopted by the federal government is aimed to significantly increase the number of electric vehicles on Germany’s roads. In the scope of the project »Modellregionen Elektromobilität« [Electric mobility "pilot regions"] the German Federal Ministry of Transport and Digital Infrastructure (BMVI) has been funding the expansion and the market preparation of this technology since 2009. Stakeholders from science, industry and municipalities are working hand in hand in order to establish the required infrastructure to advance electric mobility. Fraunhofer IBP’s department Life Cycle Engineering is also involved in this process. In the scope of the major project of environmental accompanying research, Roberta Graf, a scientist at Fraunhofer IBP, leads the working group on passenger cars and commercial vehicles. Within this conglomerate of experts she accompanies project partners with regard to key issues of contents and methods and carries out scientific assessments of the collected data and project findings. In this context, her focus is on the environmental impact of the vehicles. In addition, her working group also assesses the road capability and environmental performance of battery electric vehicles (BEV) and plug-in hybrids in daily use. These studies are conducted in close cooperation with the project partner thinkstep AG, using specific software systems and GaBi data bases. »Right from the beginning, cooperation between the partners was distinguished by great mutual trust. We received extensive data material from various areas. On this basis, we were able to conduct detailed analyses and evaluations in order to establish basic methods for the research and development of new approaches. The results are reflected in our differentiated final report«, the scientist explains. Life cycle assessments are based on a comprehensive data collection relating to the real use of vehicles. In the pilot regions (including the cities of Stuttgart and Hamburg, the Rhine-Main area and the Rhine-Ruhr district) the scientists collected consumption and mileage data along with several other important parameters including road distances, charging efficiency of usage profiles and temperature dependency and processed this data. The main task is to derive recommendations from the experience gained in the pilot regions and to provide a broad range of stakeholders with appropriate guidelines how to accelerate the market development of electric mobility in Germany.

But how environmentally friendly are these innovative drive systems and vehicles? Regarding life cycle assessments of electrically driven vehicles it takes more than just avoiding exhaust gases. »A fundamental result of the study was that electric cars are only more eco-friendly than conventional cars if appropriate conditions of use are ensured«, Roberta Graf declares. »It also became clear that users can exert a much stronger influence on the environmental profile of the hybrid vehicles«. Graf is convinced that »the plug-in hybrid car, which is powered by at least one electric motor and an additional energy converter, drawing the required energy from a storage device and from a fuel tank, will not disappear from our roads in the near future, mainly because its large cruising range is of great importance. The study however showed that the cruising ranges of battery electric vehicles (BEV) can still be significantly extended«. Depending on the specific use and the driving style, cars with low battery capacities mainly score in urban delivery and distribution traffic situations. Individual mobility and integrated transport chains still hold large potentials for increasing efficiency.

»By conducting LCA analyses, which include the provision of raw materials up to the recycling of the materials that were applied in the electric vehicle, we were able to identify the ecological backpack and to precisely assess both the use of resources and the environmental efficiency«. To analyse the environmental impact, IBP researchers not only take account of the vehicle use proper, they also consider the associated supply of energy and the production along with the maintenance and the disposal of the vehicles.

At the beginning of its life, the environmental LCA of an electric car is not a pretty picture. In its manufacturing phase the environmental impacts significantly exceed those of a conventional vehicle. This effect can be attributed to the battery systems, i.e. mostly to the procurement, the processing and the production of the high-tech materials used in the battery cells. Compared to the other materials deployed in the vehicle (mainly steel, plastics, light and non-ferrous metals) these materials imply considerably greater environmental impacts. This is why up to 60 percent more carbon dioxide may be emitted during manufacturing, depending on the design of the battery system and the vehicle. The long-term demand for critical raw materials such as rare earths, for instance, demonstrates the difficulties concerning the supply of resources. In view of this situation, efficient recycling of disused electric cars is indispensable to address the raw materials problem in the long run. At the same time battery technologies need further development in order to minimize the use of materials from the outset.  

If the electric car is appropriately used, its ecological benefits are manifold. Besides selecting a usage profile which is suitable for the particular vehicle, two other factors are essential: the distances users drive and which kind of electric power they use for electrical refuelling. Based on today's electricity mix, i.e. the present percentage composition of the energy sources used for generating electricity, an electric car must be driven for about 60 000 km before achieving an ecological advantage over a petrol-fuelled vehicle. This corresponds more or less to their current mileage. More than 50 percent of the electricity volume used in Germany is still supplied by fossil fuels like brown coal, black coal and natural gas. Things are different, however, if green electricity is used. If an electric car is powered by wind energy, its environmental performance will be balanced already after 25 000 kilometres. »To really relieve the environment, this green electricity would of course have to be supplied in addition«, project leader Roberta Graf remarks. »If we succeed in implementing the energy transition by expanding renewable energy, electric mobility (as a climate-friendly solution) will also play an important role for the traffic of the future. During operation, the electric engine neither releases CO2 nor any pollutants, but the electricity needs to be supplied from renewable sources to minimize the level of emissions, also regarding power generation«.

But also with regard to vehicle charging there is still a lot of room for improvement. Whenever users of electric cars have found one of the few charging poles, which are still quite rare in Germany, they still cannot be sure whether they will actually be able to recharge their car. Providers and payment systems must match in order to be able to settle the costs. Harmonizing the electricity supply in conjunction with providing a full nationwide network of filling stations for electric vehicles are necessary actions to promote electric mobility in this country. »In this context, energy companies might increasingly draw on the benefits of electric vehicles«, says Graf. For instance, if connected to the grid, parked electric cars could compensate for fluctuating infeed volumes of wind and solar power and thus increase grid stability.

Expectations are high, whether the politically initiated measures will be successful and really put one million of electric vehicles on German roads by 2020. That the transition to electric mobility can be a success has been proven in Norway. Already today, the market share of electric cars in the market for sale of new vehicles is almost 25 percent. This is a world record. In Norway, privileges like free parking lots, free electricity, exemption from the payment of tolls for tunnels and ferries, and the use of the bus lane during rush hours are incentives for switching to electric cars. For German users, however, special provisions are not quite so abundant.  

» According to the current state of technology, a car that is 100 percent 'clean' is still utopia today«, Graf declares. »However, the more we invest into research and development, the better are the chances that the environmental performance of our means of transport will be continually improved. Already now, contemporary concepts of mobility, carefully choosing vehicles according to needs and driving in an environmentally friendly way can contribute to substantially reduce the current level of air pollution«, Graf underlines, calling upon all environmentally conscious users to assume responsibility and become more flexible with regard to their individual mobility.