I read not too long ago about a new experimental technology that allows conversion of heat directly into electricity.
It would be interesting, I think, if they were to apply that to the automobile. You could do away with the alternator, reduce the drag on the engine, and reduce the weight at the same time. Might also be able to reduce the size of the cooling system.
Unfortunately, the research is only in the “pure research” phase at this point. Probably by the time they get it ready for market, the gasoline powered engine will be extinct anyway.
It is not so much turning heat into energy, but turning the energy that creates the heat in the first place into another form of energy.
Example; applying brakes creates friction which creates heat. instead of allowing the process of slowing a car to create heat, you have the slowing process create electricity via a generator activated when you apply the brakes. Just think energy containment because there is no free ride on energy. You cannot just put a fan out the window of a moving car and create energy to run the car, eh?
Not very new, either. It's called thermo-electricity and has been around for quite a while. It works both ways -- you can also apply electricity and cool something (heard of thermoelectric coolers?)
What you read recently was probably some hyped up 'improvement'.