Here's an unusual approach for generating electricty in a car: Imagine burning fuel to generate an extremely bright light so that the light can strike photodiodes to generate electricity for the various subsystems in cars that need electricity.
MIT researchers are trying to unleash the promise of an old idea by converting light into electricity more efficiently than ever before.
The research is applying new materials, new technologies and new ideas to radically improve an old concept -- thermophotovoltaic (TPV) conversion of light into electricity. Rather than using the engine to turn a generator or alternator in a car, for example, the new TPV system would burn a little fuel to create super-bright light. Efficient photo diodes (which are similar to solar cells) would then harvest the energy and send the electricity off to run the various lighting, electrical and electronic systems in the car.
Such a light-based system would not replace the car's engine. Instead it would supply enough electricity to run subsystems, consuming far less fuel than is needed to keep a heavy, multi-cylinder engine running, even at low speed. Also, the TPV system would have no moving parts; no cams, no bearings, no spinning shafts, so no energy would be spent just to keep an engine turning over, even at idle.
"What's new here is the opportunity for a much more effective energy system to be created using new semiconductor materials and the science of photonics," said Professor John Kassakian, director of the Laboratory for Electromagnetic and Electronic Systems (LEES), where the work was conducted. The idea is to create intense light, let it shine on new types of photo diodes to make electricity, and bounce any excess light back to the light source to help keep it glowing-hot. In theory, Kassakian said, efficiency could be as high as 40 percent or 50 percent.
Of course the "In theory" part means they haven't yet achieved such a high level of efficiency. But I'm surprised that burning fuels could be made to emit such a high percentage of their energy as photons to even make possible such a high efficiency for electric generation. If such a high level of efficiency could be achieved then it would have a lot of other practical uses. How about burning fuel to generate electricity for houses or commercial buildings? Or why not use the electricity to power the car rather than use an internal combustion engine?
|Share |||Randall Parker, 2006 May 19 04:32 PM Energy Transportation|