51–60 of 96 posts
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The history of moving parts in space missions (RTGs) is why Kepler's mission is degraded: keeping reaction wheels and other spinning things lubricated and moving when you can't get in there and service them is hard.
Why wouldn't airgapped bearings be used for this? Is it too heavy?
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So write the paper after that's all done.
You don't understand the difference btw a research paper and a product launch. A paper is to provide inspiration. In this case, a high ZT p-type crystal may indicate a new mechanism that can be applied to searching / designing new thermoelectric materials. It's not for selling you a working device that can be put in your shopping cart. (I did research in nano thermoelectrics and published a few papers in this field)
> The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges. This is literally inventing half a solution. Shockley didn't go to the press when he'd built half a diode. (OK, this is snarky, but I think this is another case where…
Isn't graphene a high quality p type material as well? What makes a material p or n?
Graphene can be modified by changing its topology to be p or n, but GO is n by default. Do electron and hole features have to match in these constructions?
So I can use electricity to mine cryptocurrency and convert the excess heat back to electricity? I wonder how efficient such a thing would be.
I wonder why you don't have a miner-hot-water heater? Use energy to mine and the waste heat to keep your tank warm.
Are you telling me this sort of thing already exists today?
I wonder if you could get it small enough to use with CPUs. Could extend the battery of a laptop for example. I’m also thinking of AC units, where it could lower the power consumption at the same time as lowering the heat we diffuse into nature, especially in big cities where the most rooftops feel like saunas.
I once read in some article that CPUs have the same power consumption as equivalent output of a nuclear reactor, based on size, of course. So the 1 inch of a CPU takes as much energy as 1 inch of a nuclear fusion output from a nuclear reactor. Again, I don't know if this is true, but if it is, that's a lot of heat energy, given the number of computers in the world.
But maybe I remember wrong, this was probably 15 or 20 years ago that I read this.
> Those could be installed everywhere from .. water heaters .. to scavenge some of the 65% of fossil fuel energy that winds up as waste heat. Modern condensing gas boilers for domestic use are better than 90% efficient, the exhaust gas is very cool so I don't think that thermoelectric devices have much to offer there.
That is because the 90% is heat efficiency, this is for extracting electricity, which is much harder.
That kind of efficiency would be a big breakthrough if it where affordable, imagine the applications.
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> I’m also thinking of AC units, where it could lower the power consumption Nope, if you use this on hot side, AC will have to work more to get rid of heat, but this device will still provide less power than ac must now use. Design criterium for AC's is that hot side should be as cool as possible (so it has a big fan to cool it down), but thermoelectrics require hot side to be as hot as possible. AFAIK compressor uni…
I don’t think that’s right. The solid state methods can sustain a temperature differential with a given power/heat flow. If the hot side is cooler, the cold side can be cooler, or less power is required.
In summer, the sun (rudely) gives me excess unwanted heat in my house. I need to expend even more energy to get that heat from inside to outside my house. (We call this process "Air Conditioning".)
What would be ideal is if the heat energy could be converted into some other form of energy that I could dispose of. Maybe if I could turn it into electricity I'd put a lightbulb in my window and shine the converted heat energy away.
I don't really care if that process is inefficient because that heat was completely free and unasked-for. I don't need to do anything useful with the converted heat energy, I just want it gone. If the process of converting heat to a disposable form of energy can be done for less energy than air conditioning needs, then its worth doing.
Heat is energy. In summer, the sun (rudely) gives me excess unwanted heat in my house. I need to expend even more energy to get that heat from inside to outside my house. (We call this process "Air Conditioning".) What would be ideal is if the heat energy could be converted into some other form of energy that I could dispose of. Maybe if I could turn it into electricity I'd put a lightbulb in my window and shine the…