Creating Power From Wasted Heat 186
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."
Re:New source of power ? (Score:5, Interesting)
I mean, hell. If this works well, it could be used as a component in hybrid vehicles; they only have 25% efficiency on the gasoline engine, and if they're parallel types, the heat generated by the gasoline engine could be used to keep the electrical engine in juice.
It might even be possible to recapture a bit of energy off the moderate heat generated in the electrical motor.
Of course, there will be the thermodynamical morons in here, trying to say that this little device is next in the step towards the latest self-powering promise, drawing energy from the zero point or whatever other perpetual motion bollocks is being flouted these days.
Here's a hint guys: you can't win and you can't break even. You can only take your income (solar energy) and savings (batteries, fuels, and nuclear fuels) and spend it (burning fuel or running electrical equipment). If you can boost your output per unit input, great stuff - but please don't assume it means you've hit a lotto (perpetual motion) that doesn't exist.
2nd Law (Score:2, Interesting)
TEC? (Score:1, Interesting)
Its an organic peltier... nifty. Wonder if it works as well as a heat pump.
Re:What? (Score:4, Interesting)
Anyway, my point, after reading TFA, it became pretty obvious that this stuff would work like a thermocouple, but you could fit many of them over a large area. It's isn't so much "nano-magic", as it would be a miniaturization of an idea that sees daily application. It sure would be cool if they get it functional.
And yet... (Score:3, Interesting)
the Carnot efficiency of 86% for a combustion temperature of 2000 centigrade.
And even the reamining "waste" heat could be used if better planning happened:
district steam, drying and other industrial uses.
Re:Not by trapping molecules actually... (Score:3, Interesting)
How about sticking this thermocouple directly on the engine block/exhaust pipe/other and just add another radiator somewhere else? You know, like what they do for turbochargers or transmissions.
It'd be nice if it helped your main radiator, but is doesn't have to. If you don't assume that, then you don't have to worry about a fan or insulation & the rest of your objections vanish.
But in the end, I'm not sure what you'd do with the extra electricity in a car, unless we're talking electric motors.
Re:What? (Score:3, Interesting)
Re:New source of power ? (Score:2, Interesting)
The people who always bring up the impossibility of perpetual motion lose the argument before it even begins, since they fail to realize that it is not a closed system (and therefore not a claim of perpetual motion). But they yell louder than anyone else, so the general populace goes on believing that the Earth is the center of the solar system.
Environmentalists? (Score:4, Interesting)
Re:"Wasted" heat is not available for this device. (Score:4, Interesting)
In a hydroelectric dam, you can convert a portion of the potential energy of water flowing downhill into work. You can only convert the energy when the water is flowing downhill and you cannot convert all of the energy because that would stop the water from flowing. The maximum efficiency is the head difference (high and low water points). Unless the low point of the dam is at sea level, you are not getting all of the potential energy out of the water.
The 2nd Law of Thermodynamics and Carnot Efficiency have the same major points. You can only convert some of the heat to other work while it is moving from hot to cold and the maximum efficiency is the difference in the high and low temperatures relative to absolute zero.
As the parent post pointed out, power stations attempt to exhaust condensation heat as close as possible to ambient temperatures and there isn't much "waste" heat to recover. If there was an efficient thermocouple device like the article, its use would be in all the industrial waste heat from sources that are currently too small to justify existing heat recovery systems.