Michael Giberson
I don’t understand the physics here – it’s some combination of quantum mechanics and carbon nanostructures – but according to this news release from the University of Arizona, it can turn waste heat into electric power. So far the interesting properties have been simulated in a computer model, but not demonstrated in a physical device.
Turning Waste Heat Into Power
UA physicists have discovered a new way of harvesting waste heat and turning it into electrical power. Taking advantage of quantum effects, the technology holds great promise for making cars, power plants, factories and solar panels more efficient.
Follow the link for more. The underlying research is forthcoming in ACS Nano: Justin P. Bergfield, Michelle A. Solis and Charles A. Stafford, “Giant Thermoelectric Effect from Transmission Supernode.”
No indication that they have repealed the laws of thermodynamics. Under those laws, there has to be a temperature difference between the heat source and the cold sink for energy to be captured, and the efficiency of the system is proportional to the difference in temperatures measured from absolute zero.
Fat Man: “No indication that they have repealed the laws of thermodynamics.”
Right. We’re just wrapping this up in my Physics 2 class today. Thermocouples have been known for a long time. You have two junctions of different conductors kept at a difference in temperature and you’ll get some electric power, though not much. This appears to be a fancier version of the same thing. It takes advantage of the fact that waste heat from an engine or power plant comes out at rather higher than the temperature of the environment, and the remaining temperature difference can be exploited to generate a little more power. But you can turn only a small fraction of the waste heat into useful work, and that fraction goes toward zero with the temperature difference. The effect is to increase slightly the efficiency in the overall use of energy, at the cost of whatever it takes to build, install, and maintain this gagetry.