Research in focus

Mobile and eco-friendly – when are electric cars a sensible option?

When we’re about to buy a new car, the impact this has on climate change is not generally top of our list of considerations. Instead, we tend to focus on what the car has to offer. One key feature is that it gives us individual mobility, which in turn increases our flexibility in terms of time. According to statistics from Germany’s Federal Motor Transport Authority, in 2012 there were 30,452,019 gasoline-powered and 11,891,375 diesel-powered cars on the country’s roads, compared with just 4,541 electric cars. So the majority of all registered vehicles are cars with a combustion engine – cars powered by an energy source that is ultimately finite; cars that generate exhaust emissions; cars that, taken together, make lots of noise. So is the electric car the more sensible option as a matter of course? Research has long since focused on the question of alternatives to conventionally powered vehicles, and switching to electric cars constitutes one of the options that has attracted the most attention. Yet scientists, along with the car industry and ultimately end customers, face many different questions when weighing up this option. Just how sensible is the electric car to the environmental balance? To what extent is an electric driven vehicle greener than a gasoline or diesel fueled one? Can electric cars really meet an individual’s need for limitless mobility? Michael Held, head of the "Energy and Mobility" Working Group at the Fraunhofer Institute for Building Physics IBP, is one of the people looking at these and many other questions on a daily basis. His specialist area is Life Cycle Engineering, or to be more precise Life Cycle Engineering for energy and mobility systems.

“We live in an age where we have to think about how we can conserve resources for the long term and manage them economically. This basic notion of sustainability underpins the work we do in the Life Cycle Engineering department,” is how Held explains his daily research work. He goes on to say that for the automotive sector, however, the debate surrounding alternative power trains is not just about their environmental impact. “Of course the transportation sector has a major impact on the climate change (global warming). But the dependency on fossil fuels also throws up other questions,” Held explains. For instance, the question of crude-oil supplies has become much more acute over the past few years. Germany has no reserves of its own to guarantee long-term supplies without costly imports. Meanwhile, the general public’s mobility requirements continue to increase sharply. There are already around one billion vehicles on the world’s roads. By 2030, experts expect that figure to double. Emerging economies such as China or India in particular are seeing enormous growth in vehicle registrations. The German government has therefore decided to take a different approach to reducing dependency on fuels based on crude oil, by promoting solutions such as electromobility. The advantage of electromobility is that it employs a wider variety of energy sources and power-generation technologies. If electric vehicles are charged using power sourced from additional renewable energies, they will also be playing a major role in helping to reduce the impact that transportation (private transport) has on the climate.

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Yet it is not enough simply to fit a car with an electric drive. An electric car needs to present a real alternative to a conventionally powered vehicle – and do so from both an environmental and an economic standpoint. Here is where the Life Cycle Assessment and, based on it, Life Cycle Engineering come into play. The Life Cycle Assessment is a systematic analysis of the full environmental impact of a product, process, or service throughout its entire life cycle. “This assessment is not meant to mask – and in no way supplants – economic or engineering considerations,” Held explains. Rather, the point is always to examine how sensible it is. In this case, scientific research needs to determine to what extent the vehicle life cycle analysis is altered when alternative drive components are employed. What energy mix is the most effective when charging electric cars, and does it make sense to charge them with electricity generated from conventional power stations (fossil energy sources)? Research is focusing on these issues as well as on the environmental added value of using electric vehicles. At the same time, however, it is important never to ignore potential users and their needs. Held explains that the diversity of his research area “means my work is always very case-specific,” before adding that it is still possible to determine trends, and hence to come to conclusions about the potential bandwidths of environmental profiles and key requirements. “A car has lots of components that we analyze as part of the Life Cycle Assessment. We look at vehicle construction, the materials used, as well as utilization profiles, right through to disposal of the car – in other words, from the cradle to the grave," Held says. One of the components of interest to him is the battery system, since this is currently a key technology for electric vehicle concepts. The production of necessary high-tech materials of batteries requires expensive and energy intensive mining of scarce raw materials and processing. These factors are, in turn, reflected in the Life Cycle Assessment for electric vehicles. To promote sustainability, automakers and their suppliers have to take into account factors such as the availability of resources or compliance with environmental regulations in the countries where the materials are mined. These contributory environmental aspects can in fact have a major impact on the vehicle life cycle. The recycling of the battery and the remaining auto components also feeds into the Life Cycle Assessment. “Tailor-made solutions ultimately help to ensure that a product has long-term environmental added value,” Held explains.
While the battery may figure heavily in the production phase of a vehicle’s Life Cycle Assessment, this may balance out in another life cycle phase. Depending on how the battery system is dimensioned, the climate impact of manufacturing an electric car may be twice that of a conventional car. But drivers can offset this and bring their cars back into line with conventional vehicles by, among other things, filling up their cars with a clean mix of electricity obtained from renewable energy sources and clocking up relatively high mileages. “The earlier the break-even is achieved, the greater the environmental added value,” Held says. So buying an electric car is only worthwhile if you are sure you will be able to clock up the necessary mileage. When it comes to the battery, another problem that is a current headache is range. In this respect, conventional cars still put today’s electric vehicles in the shade. Moreover, charging a battery still tends to take far longer than normal refueling. “Drivers want their car to have a long range, even if it’s actually just a psychological factor.” Held points out that most people’s average daily mileage is less than 50 km – well within the capability of an electric car. That is why electric cars are best suited to city and urban traffic, where they can help greatly to reduce local emissions and noise. “Many people believe that electromobility will replace conventional mobility in the long run. I’m not one of them,” Held states. “What we really need is greater integration of the various modes of transport, with electromobility and conventional mobility complementing each other wherever it makes sense.” And that is why the Life Cycle Assessment is such an important factor in sustainability analysis. “Based on what we’ve learned so far, we now need to look at how we can make electric cars more acceptable for private use or in public transportation in cities. And ultimately we need to find ways and means of extending these concepts from the urban setting into rural areas.”
(ate/taf/jae)
Further information:
Statistics from the Federal Motor Transport Authority
 

RESEARCH IN FOCUS

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