My first and at the same time penultimate visit to the IAA happened in 1991. Even then, I was mainly interested in two things: firstly, how fast the car could drive? Secondly, how else can the auber be powered by diesel or gasoline?? For the latter, the trade show at that time already presented some technically advanced ideas. Both Mercedes and BMW showed prototypes of hydrogen engines, because the idea of a hydrogen economy already had this attraction at that time, which helps it to this day to always new life despite all adversities. The prototypes burned hydrogen gas directly in modified reciprocating engines instead of fuel cell stacks, but the basic infrastructure problems were little different. At the same time BMW showed the compact car E1, a surprisingly finished looking electric car.
"They’ll want that …"
The E1 looked so close to series production because BMW had actually designed the show car with series production in mind. In the nineties, there were briefly serious efforts to make individual transport more efficient. These resulted, for example, in Audi’s large A2, which the E1 not coincidentally looks very similar to: as small as possible (it was only 3.46 meters long), at the same time as much space as possible inside, as light as possible built on an aluminum chassis and, despite all safety requirements, with a lot of glass for active safety from a good view.
The Munich engineers also did their homework prudently from a technical point of view. In the floor of the E1 was a sodium-sulfur battery, an experimental use of this storage technology in the 1990s, which is now used in storage power plants. Since this type of battery operates at temperatures above 300°C, it is no longer used in electric cars. BMW put at least 20 kWh into the little car. This amount of energy should be sufficient for driving distances of "up to 200 km".
To make this possible, the engine on the rear axle remained reasonably dimensioned at 32 kW. From a standstill to 50 km. At 120 km. The E1 charged by Schuko plug. That took 6 to 8 hours with deeper discharges, but BMW integrated in the nose charger a small cable drum, so you always had some range to the socket with you. Even from today’s perspective, there is little to be said against these key data, but much to be said for it.