Holger Haas is responsible for location development at the Economic Development Department in Stuttgart. He coordinates activities for the electric mobility model region, one of eight in Germany. When Haas drives to a business appointment he generally takes the company car. It’s a diminutive smart that occupies a space in the underground car park beneath the office building where he works. “We naturally have to set a good example to other motorists, so we purchased two electric cars,” he explains on the way to the garage.
When he reaches the car he pulls out the charging cable that supplies the vehicle with electricity. He rolls up the cable and gets into the car. When he turns the key in the ignition there is almost no sound at all. No engine noise, no vibrations. The vehicle is almost silent as it rolls out of the car park. The electric motor hums gently as Haas pulls into the traffic. The car shows what individual mobility could look like in the future: environmentally friendly and quiet.
He and his colleagues in other parts of the company are working on ways of enabling electric cars to cover longer distances without needing to recharge. The further you want to drive with a single battery charge, the bigger that battery has to be. A bigger battery makes the car heavier, and this in turn impacts negatively on its range. Bayer MaterialScience aims to compensate for this by developing innovative lightweight construction solutions.
“Composite materials made of polyurethane and carbon fibers are lighter than steel and aluminum and have already demonstrated their strength in several crash tests,” explains Jörg Palmersheim, an expert in polyurethane applications in automobiles at Bayer MaterialScience.
Its driver, Holger Haas, is satisfied, although he does feel there are a lot of things about the car that could be improved. He generally leaves the climate-control system switched off, for example. “Air-conditioning and heating drain the battery perceptibly – and that cuts down the vehicle’s range,” he explains. A completely new temperature-management system will have to be developed for vehicle interiors to prevent electric cars from turning into a sauna on wheels in the summer and a refrigerator in the winter. Better insulation, for example, could keep the temperature stable inside the car.
The weak spot here is the glazing. A car’s interior heats up through the glass in the summer and loses heat through it in the winter. Glazing made of the polycarbonate Makrolon could be the answer. It slows the exchange of heat between the interior of the car and its surroundings, keeping the temperature inside at a pleasant level. An occupant cell insulated with polyurethane can intensify this effect considerably. Haas parks the electric car in the cool underground car park at work and connects the battery to the charging station. When there are more electric cars on the road in the future, not everyone will have the luxury of his or her own charging post in the garage. “We need public charging stations,” says Dr. Berit Krauter, a plastics expert at Bayer MaterialScience. Most of the charging stations in use today are made of metal, an expensive option. “Stations made of the polycarbonate blend Bayblend would be a low-cost, stable and durable alternative,” the expert explains.
Bayer is pursuing innovative developments of this kind in the interests of sustainable mobility, so that in the future more people can drive electric cars like Holger Haas. Despite many people’s reservations about the limited range of electric vehicles, the cars available today would be sufficient for many drivers’ needs. The electric smart that Holger Haas drives can go about 135 kilometers on a single charge.