BMW's new eco-exhaust

News

2 mins read

4 March 2009

A thermo-electric heat-collector originally designed to power space satellites is one of the futuristic technologies that BMW will add to its cars to save fuel and cut carbon emissions, BMW's head of development, Klaus Draeger, has said.

The ‘thermo-electric generator’ is being tested now, attached to the exhaust, where it captures waste heat transferred down the exhaust.

“We will be ready for production in about five years,” said Draeger.

The centrepiece of a thermo-electric generator is a group of thermocouples that generate electricity when heated. This means that the waste heat from the car engine can be used to generate electricity.

Fuel savings of five per cent are already being predicted by BMW.

Up to 30 per cent of the energy wasted by an internal combustion engine flows down the exhaust. Recouping even part of this energy would make a dramatic saving in overall vehicle efficiency.

BMW’s predicted five per cent saving in the thermoelectric generator is bigger than the savings of three per cent achieved by the two current key Efficient Dynamics technologies - stop-start and brake energy regeneration.

BMW’s future electric car programme, project i, is also on track to produce its first vehicle in the “first half of the next decade”.

Under consideration are two, three and four-wheeled vehicles. A three-wheeled BMW would mark a return to BMW’s roots when it built three-wheeled cars to mobilise post-war Germany.

BMW has labelled the project Megacity Vehicles and is exploring urban mobility in a variety of cities – all with populations of at least five million – ranging from the freeway-dominated, like Los Angeles, to ancient and crowded European cities like Barcelona.