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A radioactive 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 ‘thermoelectric 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 thermoelectric gene...Read the full article

Autocar:

BMW's radioactive eco-exhaust

Are you sure about the 'radioactive' bit Mr Rendell? On satellites and the like a radioactive isotope is the heat source whereas the whole point here is the heat is available, from the exhaust gases, in a car.

With a decent heat source close to where cool air (flowing underneath the car), a stirling engine might be possible to get a bit more rotary movement to convert into electricity.

I guess BMW are only talking about low levels of radioactivity, but isn't this is only going to create another environmental crisis in twenty years time when these cars come to be scrapped?

Teg, the radioactive bit is nonsense. I was trying with my first comment to gently move the journo to review what he'd wriiten. He's got his wires crossed, perhaps in search of an eyecatching headline, read here:

http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

http://en.wikipedia.org/wiki/Automotive_Thermoelectric_Generators

Mr Rendell's confused the former with the latter.

Dr Draeger, BMW's Development boss, received an award for BMW's work on this technology last year:

http://www.autobloggreen.com/2008/09/25/bmw-wins-koglobe-2008-award-for-thermoelectric-generator/

I used to be a chemist in a Dept of Energy lab in the US (weapons). I used to have to analyze RTG powder. It was a silicon/germanium mixture with small amounts of other elements such as boron. Eventually this was used to convert heat from some plutonium into electricity. Of course I never saw that part, just the RTG powder. Horseandcart is correct, the RTG in this case uses the heat from the tailpipe to generate electricity in place of the chunk of radioactive material. There is nothing even slightly radioactive about this application.