BMW is pushing ahead with its second-generation Efficient Dynamics green car technology – with help from space scientists at NASA.

Employing a thermoelectric generator similar in principle to those developed to power satellites will, according to BMW’s head of development Klaus Draeger, boost economy by some 5% on the combined cycle. Expect to see the new Efficient Dynamics tech in showrooms by 2014.

Explain how satellites are going to help future BMWs travel further on less fuel please…

Thermoelectric generators – or TEGs – convert heat differences between radioactive metals to generate electricity. With car engines expending a high percentage of their energy in the form of heat, BMW has hooked up a TEG to a prototype’s exhaust system to generate around 200W of power. ‘Some of the heat generated by combustion is converted to electric energy which is then fed back into the car’s power supply to feed high-demand systems such as climate controls,’ Draeger told CAR Online.

Sounds like something that crazy Doc Brown hooked up to his DeLorean in Back To The Future…

Well, a thermoelectric generator sure sounds cooler than common-rail injection, but we’ll have to wait some time according to Draeger. ‘Already at the prototype test stage now, these generators will be in series production on our cars within the next five years,’ he added, saying that the anticipated 5% economy boost was bigger than the combined efforts of stop-start and brake energy regeneration – cornerstone features of the company’s current Dynamic Efficiency technology that already allows BMW to meet upcoming 2012 and 2015 EU regulations.

What else has BMW got up its efficiency sleeve?

While it recently announced that it would be introducing an eight-speed automatic transmission for its volume models in preference to double-clutch units – promising significantly reduced internal friction levels and a wider spread of gears for enhanced economy – BMW told CAR that it has now developed the means to hook up this transmission to its stop-start system.

Previously only manual boxes could work with the stop-start technology, restricting the system to a minority of BMW models. Expect the new 7-series, X6 and next year’s 5-series to be the first models to benefit from these lightweight and quick-shifting boxes.

