Scientists create inexpensive new thermoelectric material
A test of the new material, being conducted at Michigan State University's Center for Revolutionary Materials for Solid State Energy Conversion
Wherever there’s enough of a temperature gradient between two surfaces, thermoelectric materials can be used to generate an electric current. If a coat were made with thermoelectric felt, for instance, a current could be generated by exploiting the difference between the wearer’s body heat and the cold outdoor air. Now, scientists have developed an inexpensive new type of thermoelectric material, that could make the technology more commercially viable.
The material was developed by a team from Michigan State University, led by Prof. Donald Morelli. Although synthetic, its composition is based on that of a family of naturally-occurring and vastly-abundant minerals known as tetrahedrites. That composition has been tweaked just slightly, to make the finished product thermoelectric.
The production process involves grinding “very common materials” into a powder, then using a combination of heat and pressure to compress them into the sizes needed.
Although some other materials are more efficient at converting temperature gradients into electricity, Morelli maintains that many of those are unfit for practical use because their components are rare or toxic, or they’re too expensive to synthesize.
“Typically you’d mine minerals, purify them into individual elements, and then recombine those elements into new compounds that you anticipate will have good thermoelectric properties,” he said. “But that process costs a lot of money and takes a lot of time. Our method bypasses much of that.”
It is hoped that the new material could be used to cost-effectively harvest electricity from sources such as vehicle exhaust pipes, industrial power plants, and home furnaces.
A paper on the research was recently published in the journal Advanced Energy Materials.
Source: Michigan State University
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
You would be better off using liquid cooling on the solar panels and run the waste heat through a Stirling engine.
Great for applications where you want to slow down the transfer of heat-energy (such as the supplied coat example).
Don't start thinking about using these in places where there is an excess of energy that needs to be disposed of... putting these on processors to make use of the heat differential there, would likely destroy the processor since the removal of the excessive heat-energy needs to be accelerated, not slowed (to do work creating electrical energy).
So they want to make a coat that sucks heat from the body? Isn't that what a coat is trying to prevent?
If used in the forcing mode then the material would take heat away quicker.
re; Two Replies
Places where there is an excess of energy that needs to be disposed of is where we should be thinking of placing them. Granted it would take adding a larger radiating surface but in exchange for capital cost you get fuel cost free electricity.
So this opens up the possibility of recovering low grade heat from sources such as internal combustion exhausts and even power station stacks, producing electrical energy directly?
If that can be done economically, that will be a seriously valuable breakthrough.
Of course, reversed, it will be usable for the construction of refrigeration plants with no moving parts on a much larger scale than is commonly available for the TEC-operated drinks coolers for use in cars and campers, and if the temperature can be lowered sufficiently, perhaps even superconducting power transmission lines.
I'm drooling over this....if it's really cheap, the USB charging peltier junction camp stoves might just come down in my price range....and yeah, it would be cute to charge my phone simply by WEARING my jacket.
Of course, the patent royalties will probably keep the price up to the point where I still can't justify it.....but 20 years from now, watch out! :)
would that work with giant solar collectors to focus heat and make KWh?
NASA had a peltier / thermocouple energy recovery car they built in the 1970's. There are PDFs of the article out there.
IBM had a new fab created peltier in the works a while ago I heard about on NPR. No word since, any one got anything on that? I vaguely remember in the high teens for efficiency.
If they could adapt it to salvage waste heat from power plant condensers, that would be a major breakthrough. The condenser in a typical steam cycle squanders almost half of the input energy. That's why big plants are usually located near large bodies of water or have huge cooling towers with cloudy plumes coming out of them. Combined-cycle plants boost efficiency over that of steam-only plants, but there's still an enormous amount of low-level heat just going to waste.
I always wondered why they didn't centrifuge out the cold steam and reprocess the hot part. Anyway, maybe some good cheep TEM's will make this viable.
re; Charles Bosse
Expansion cooling affects the entire gas mass equally and injecting liquid water into the boiler is much easier than recompressing steam and reinjecting it into the boiler once you add maintenance costs the efficiency is just not there.
Heat build up has always been a problem with solar panels. If that waste heat can produce power, while heat sinking the panels for greater efficiency, that is a double win.
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