Thermoelectric generators can use any available heat source – in this case waste heat emanating from an internal combustion engine's exhaust – to create electricity that can reduce the load on a car's alternator. BMW hopes its system can power things like the climate control without putting a drag on the petroleum-powered engine.
BMW's engineers believe they can reduce a given vehicle's fuel consumption by about five percent with their TEG, which they say is a bigger reduction than can be achieved with such technologies as stop/start and brake regeneration. We say every little bit helps.
[Source: Car Magazine]