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Creating Power From Wasted Heat

Posted by Zonk on from the that's-borg-technology dept.

Roland Piquepaille writes "Today, about 90 percent of the world's electricity is created through an indirect and inefficient conversion of heat. It is estimated that two thirds of the heat used by thermoelectric converters are wasted and released. But now, researchers from the University of California at Berkeley have found a new way to convert this wasted heat into electricity by trapping organic molecules between metal nanoparticles. So far, this method of creating electricity creation is in its very early stage, but if it can scale up to mass production it may lead to a new and inexpensive source of energy."

4 of 186 comments (clear)

  1. New source of power ? by Anonymous Coward · · Score: 5, Insightful

    How is this "a new source of power" ? it's just improving efficiency by reducing loss.

  2. Re:Not by trapping molecules actually... by drerwk · · Score: 5, Informative

    Why do you have to use the radiator?
    I inferred from the article that one might add these devices to the radiator to recapture lost heat, and that it would be done for cars already in use. But your question is quite valid. The actual reason for a radiator in a car engine that has one, is to keep the temperature of the engine low enough so that the moving parts continue to move, that the oil lubricates, and that parts don't actually melt. If one had materials that could take the heat, say piston liners that were excellent insulators and still allowed the piston to move, and all of the excess heat simple exited the cylinder you would not need a radiator. Or if you owned a Beetle, a 2CV, or some other vehicle with an air cooled engine you would not need a radiator.
    But fundamental to thermodynamics is that you can not have a cycle more efficient than the Carnot Cycle http://en.wikipedia.org/wiki/Thermodynamic_cycle. This give a max efficiency = 1-(TEMPlow/TEMPhigh), so you always want that low temp to be as low as possible - for a car engine that would be the ambient air. If you have your device, then the hot side is on the engine, and the low side is in the air. But the device itself will get hot, an you will have to blow a lot of air on the cold side to keep it cold. It you let the whole device rise to the same temperature you get no conversion.
  3. Re:generation vs consumption by Doppler00 · · Score: 5, Insightful

    LED light bulbs are overrated. Compact florescent bulbs are much more efficient, but they aren't a sexy as LED's. Here's some ways to conserve, but no one will do this:

    1. No more incandescent bulbs.
    2. Live 10 minutes away from work in a condo/apartment instead of the suburbs in a giant house
    3. Stop leaving your computer on all day

    Actually, #2 is about the only one that really saves the most money. Smaller places cost less to heat/cool, and not driving as much saves a huge amount of energy.

    But, oh environmentalists are more concerned about prohibiting housing developments or zoning that actually makes sense.

  4. "Wasted" heat is not available for this device. by jolathe · · Score: 5, Informative

    The "wasted" heat that thermal power plants reject to the surroundings is rejected at a temperature only slightly above ambient. A steam turbine generator has an exhaust steam condenser which operates at a vacuum, where the steam condenses at only a few degrees Fahrenheit above the ambient temperature. There is no significant temperature difference available for the new device to operate with. While thermal power plants do reject over half the fuel energy consumed to the surroundings, it is a myth that this rejected heat can be effectively used. The rejected heat is available at a low temperature, only slightly above ambient, therefore little effective use can be made of it. This is the penalty that the laws of thermodynamics impose on the conversion of heat into work.