Thermoelectric generator in the test car. Various shotsThermoelectric generator in the exhaust pipeGraphic: Function of the thermoeletctric generatorDriving scenes test car with thermolelectric generator. Various shots. TripodOnboard: DriverDetail: Speedometer. Cars is acceleratingDisplay shows function of the thermoelectric generator3 D-Animation. Showing the next generation of NASA-Mars-Rover with thermoelectric generator. Various scenes (Courtesy: NASA. See footnote)

Q: How ist the thermoelectric generator (TEG) working? A: The thermoelectric generator is based on a physical effect which was discovered by Thomas Seebeck in 1821. This effect describes the conversion of heat into electricity. If a temperature difference is applied to the ends of a thermoelectric material, which usually consist of semiconductors, a voltage is generated. The higher the temperature difference, the more voltage is generated. In a vehicle it is possible to integrate a thermoelectric generator into the exhaust system. Q: What is the benefit for the customer? A: This is, in particular, very attractive as, even in a highly efficient combustion engine, only 1/3 of the energy contained in the fuel is converted into mechanical power. The remaining 2/3 are wasted heat. A thermoelectric generator in an automobile uses the temperature difference between the hot exhaust and the significantly colder coolant for electric power generation. The goal is to use as much heat as possible in order to generate electricity without limiting the performance of the engine. Q: Where has these technology been applied before? A: Thermoelectric generators have been applied in aerospace for several decades. For deep-space missions such as the well known NASA Voyager mission, it is not possible to generate electricity by means of solar power. NASA engineers have therefore used thermoelectric power generators to supply these space probes with electricity. Furthermore, the new NASA Marsrover will presumably be driven by a thermoelectric generator. Together with the BMW Technology Office in Palo Alto, California, we established the first contacts to NASA/JPL 4 years ago and started the development of first laboratory samples to proof the feasibility for the automotive application with high tech companies in California This was the starting point for BMW to possibly introduce this technology to future BMW vehicles. The goal is to further increase the efficiency of our powertrains in order to reduce CO2 emissions. Q: Which are the benefits for the customers? A: Our customers have the benefit of further reducing CO2 emissions and fuel consumption without limiting driving pleasure with a thermoelectric generator. In customer driving, an improvement in fuel consumption of up to 5% is achievable. Furthermore, this energy recuperation system has additional benefits: after a cold start, the engine or the heater is supplied with additional heat and the vehicle reaches sooner its operating temperature. The most fascinating fact is that energy is being regenerated while driving, e.g. on a highway or while accelerating. This technology is an ideal means in combination with the BMW EfficientDynamics braking energy recuperation system. Q: What are the further technical developments, when is start of production? A: We are currently in the development phase – however it is not determined yet as to when we can start with the production since we still have a long journey in the thermoelectric material development.

Monitor shows different Efficient Dynamics measures in function: No energy use by the electric steering system Airconditioning compressor connected Airconditioning compressor disconnected High engine load. Airwalves open.Increasing of the electric waterpump power. For optimal dynamics. Low engine load. Closing airwalves. Lowering of the electric waterpump power. For optimal efficiency.Monitor while driving: High engine load. Airwalves open.Increasing of the electric waterpump power. For optimal dynamics No fuel injection Internal combustion engine in efficient stratification operation Low engine load. Closing airwalves. Lowering of the electric waterpump power. For optimal efficiency. Braking energy recovered.Unloading generator. Converter lockup clutch open. Internal combustion engine stopped. Supplying the vehicles electric system with recuperation energy. Unloading generator. Homogenuous engine operation. Converter lockup clutch closed.

Driving scenes test car with predictive energy management. Various scenes. Tripod. Monitor shows load-prediction and overtaking-possibility Calm driving detected. Diminishing distance to vehicle ahead. High acceleration probable. Charging electric storage. New target value for cooling fluid temperature: 80 degrees. Opening air walves. Increasing of the water pump power. For optimal dynamics. Calm driving detected. New target value for cooling fluid temperature: 110 degrees. Closing air walves. Lowering of the electric water pump power. Leaving the urban streets in less then 500 m. High engine load. Sufficient energy raise available. New target value for cooling fluid temperature: 80 degrees. For optimal dynamics. Motorway entry detected. Full throttle accceleration porobable. Charging electric storage. New target value for cooling fluid temperature: 80 degrees. Preparing temporary disconnection of the aircondition compressor. Drving scenes with both cars. Car with energy prediction overtakes car with TEG.Driving scenes BMW 530 i with predictive energy management. Various shots. Tripod.

Question: What is predictive energy management? Answer: Today we manage energy in BMW cars based on information about the actual situation of the vehicle condition and the actual driver behaviour. The predictive energy management can do a short predictive look in the future with the help of sensors. For this purpose, We use systems that are already available in the car, for example the distance radar or the navigation system. With this information We can predict the propability of an overtaking manoever, we can predict, whether the driver will be in a traffic jam situation or will drive into a traffic-calmed zone. Then we can optimize the car already before a forthcoming even to then be able to react with a maximum of dynamics and efficiency. This is the consistent further development of BMW efficient dynamics for us. Question: What are the decisive advantages for the customer? Answer: With BMW predictive energy management the customer experiences a vehicle that is optimized adaptively for less consumption and better driving performance. The driver will, for example, have less fuel consumption in traffic jams, he can overtake with a better driving performance. Further fuel consumption reductions are possible through an intelligent, traffic related customization of the vehicle's operating strategy. It is known that one can save much fuel with a foresighted way of driving. We want to enable the vehicle to use a part of this potential. The new functionalities bring about more customer benefit and more driving pleasure. Question: How much the driver is affected by it in the practice? Answer: The systems work essentially in the background. However, the customer experiences a vehicle, that intelligently supports him without disturbing his attention. The customer notices the benefits when filling up the car at the gas station although he drives more dynamically. Question: Which further developments have to be done, when does it come to the Start of Production? Answer: We are still in the developmental stage With BMW predictive energy management. We have already shown the potential of the prediction in test vehicles. Today, the base technology for this already is available in present BMW vehicles. So, there should be nothing in the way of bringing these functions to production on a medium-term.