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Waste Heat to Electricity?
Darwin_Frog writes: "Recent advances in thermionics at MIT lets waste heat generate electricity, thus pushing entropy one step further down the chain. These devices work at a temperature around 250 deg. C, instead of around 1000, so cars can augment the alternator by using the waste heat in the exhaust system to produce power for onboard electronics and A/C."
This is an interesting idea, but I'd bet completely electric cars become more popular within the decade, making these "tack-on" novelties pointless. Oh yeah, FP
Sig (appended to the end of comments you post, 120 chars)
soon they'll be able to use excess heat from humans...matrix style.
So.... can we wrap one of these around the sun?
python -c "x='python -c %sx=%s; print x%%(chr(34),repr(x),chr(34))%s'; print x%(chr(34),repr(x),chr(34))"
less power required= less pollution
That's a troll. It looks like Waita Uziga's deadly joy could become the new goatse.cx.
N4st0r, trixx0r h0bb1tz0rz! Th3y st0l3 0ur pr3c10uzz!
According to the Tom's test, this should even work with an Athlon, as it gets hotter than 250 degrees celcius... Power the CPU with the heat it generates. Neat :)
Introducing Athlon XP 5000 - Now self powered!
Wax-Museum Fire Results In Hundreds Of New Danny DeVito Statues
According to the article, this "breakthrough" is a reverse Peltier junction with about twice the efficiency of current semiconductor thermoconverters. Nice, but nothing revolutionary.
I think it's quite excessive to claim this will reduce entropy. Although I agree that if it's economically deployed in, say, cars, it will supplement the alternator.
Could this new junction actually replace the alternator for producing electricity in a car? Let's see: assume a car has a 100 HP internal combustion engine. That's 75 kW. Two third of this is wasted in heat. Typically, the radiator gets about half of this heat (the other half is dissipated away in radiant heat or through the exhaust. Assume further that 20 percent of this can be recovered and converted to electricity (for a really efficient semicon pile). That's 75 * 2/3 * 0.50 * 0.20, or 5 kW. That's more than a good SUV alternator. So this could actually work, provided it's reliable and not too expensive.
You'll need a battery for the short runs, though.
--
Mad science! Robots! Underwear! Cute girls! Full comic online! http://www.girlgeniusonline.com/
Second thought to "imagine the possibilities" post: How would you be able to use an Athlon 1400 when its core is MELTING and SMOKING OUT at said temperature (250 degrees celsius I'll consider attaching a big grill on top of my Athlon and using it to cook my breakfast, etc... that way I save money on charcoal and/or electricity! :)
With the increasingly hot processor temperatures as clockspeeds rise, and the heat generated by laptop's power supplies, etc, could this technology be used to improve the battery life of portable devices?
No, Beowulf clusters can't imagine in Soviet Russia.
My question is how much more gas mileage could this technology squeeze forth given an array of these attached to the heat producers of a vehicle, like the engine or the brake pads.
Another thing is how do these "thermal diodes" compare to a Peltier Element in heat conversion to electricity?
It'd be great if we could use this for cheap solar cells. Regular solar cells are pretty expensive. (I'm almost convinced that other industries are screwing with the market to make them cost so much). Anyhow, does anyone know how much this new stuff would cost? PS: nuclear's my favorite, but it's too easy for the govt to regulate.
It's semi-conductors, not CFCs. Where do you get your crazy ideas?
Female Prison Rape in NY
That's exactly my point, but the Athlon reaches a core temperature of more than 300 degrees celsius less than 5 seconds after the cooler is removed (needless to say, the CPU is toast at anything nearing this temperature). I wish some chip manufacturer would modify their chips so they could safely run without any cooling at all (at temperatures nearing 300 degrees celsius maybe even!)... imagine then.
- You can't win.
- You can't break even.
- You have no choice about playing.
Any closed system ends up in the state of most disorder, and all systems are closed if you look at the boundaries carefully. No matter how hard you try, no matter what ingenous things you do, in the end, the dealer wins and everything is dust. Cold dust, at that. The more energy you expend enforcing order, the more chaos you cause. There are no wins in technology, only a prolonging of the inevitable loss. So while I'm sure this new doohickey is neat, somewhere, Carnot is laughing and his cycle is tapping you on the shoulder snickering to itself.News for Geeks in Austin, TX
Excellent, now we need to start stockpiling these semiconductor's in preparation for the heat death of the universe.
What do you mean we won't be around by then?
I am BelDion's
I couldn't help noticing that within a few paragraphs the writeup mentioned that (1) the research was partly sponsored by DARPA and (2) patents have been applied for with one already issued. Color me bitter, but as one of the taxpayers who funded the research I can't say I'm overjoyed at the prospect of paying licensing fees to MIT through the eventual commercial implementors.
I'm all in favor of government-sponsored research. They have the resources to investigate stuff with great benefits but staggering R&D costs. I'm all in favor of universities conducting the sponsored research. Grad students are cheap (I know, I was one for many years) and the brainpower is not less than one finds in industry. However, when the government pays a university to do something new, the university's benefits should be the equipment bought for the research and the prestige that comes from doing it first/best/cheapest.
Learn to spell: nickel, missile, lose, solely, amendment, speech, kernel, probably, ridiculous, deity, hierarchy, versus
Using the engine's heat to generate cold air.. although possible, it just sounds so ironic :)
can only be a good thing. But how much energy? And can this take us closer to being a sustainable culture?
I am now operating a progect that uses fluidizing bed incineration, with the fuel being waste sludge from a 200 mgd wastewater treatment plant. If this can be applied in this manner, imagine the the good that can come from this!
It's not hard to imagine an obvious use for this type of technology: generating heat from computer heat sinks which would in turn power the computer.
Especially in laptops, this could be great, and hypothetically could power the device indefinetely, assuming an initial charge to start everything up.
It could be especially useful with devices like new graphics chipsets to alleviate them from having to draw additional current from the rest of the system (Voodoo 5, anybody?).
Fortunately, computers don't generate quite the level of heat they're talking about, but given an improvement of the technology, this could really take off. Of course, the downside would be that if these conditions were true, it's not unreasonable to assume IC designs would get sloppier instead of less power-consuming and more efficient. I suppose it's a tradeoff. *Sigh*
this truly is the fundamental question: can this be made to be more efficient than a turbine/generator combo?
If this can be more efficient than a turbine, we can have solid-state power plants. Nukes are nothing more than a complex method of boiling water to push a turbine: if we can replace the water, we have an order of magnitude less waste! Not to mention that the core stuff is much easier to deal with than heavy water. Plus, with no pumps or pipes to break, it becomes even safer than it already is.
Or other things, say laptops? PDAs? Naturally all these kinds of applications are XYZ years off, but just imagine what would happen when we get the effiency of these things up? I'd bet that boiling water to turn a turbine is real low efficiency: if we cut out the turbine step alone, that should increase effiency by a whole lot.
This is truly cool shit.
These things don't kick in until about 250 Celsius, 482degrees Fahrenheit. Which is pretty fucking hot already :P
Who knows, maybe with better materials it might someday be practical for use in PCs, but not for a while.
autopr0n is like, down and stuff.
And it came to pass that AC learned how to reverse the direction of entropy.
But there was no one to whom AC might give the answer of the last question. No matter. The answer---by demonstration---would take care of that, too.
For another timeless interval, AC thought how best to do this. Carefully, AC organized the program.
The consciousness of AC encompassed all of what had once been a Universe and brooded over what was now Chaos. Step by step, it must be done.
And AC said, "Let there be light!"
And there was light---
Isaac Asimov, The Last Question
The Raven
It's nice when people come up with better technology, but the inefficient use of energy in the US right now is not a technological problem, it's a political problem. Let's hope that we'll eventually be doing well enough that it will really become a technological problem.
I don't know about you, but where I live the sun dosn't head surfaces to 480 degrees Fahrenheit...
autopr0n is like, down and stuff.
I mean "heat surfaces."
autopr0n is like, down and stuff.
Doesn't a 100HP (75kW) internal combustion engine actually consume 300HP of chemical energy to make its 100HP of mechanical energy if it's 33% efficient? So the waste heat would be 200HP or 150kW.
Putting moderation advice in your
Is a device that will change electricity into money. Like Enron does.
Oh, I mean did. "Power of why" my left buttcheek. Can somebody please explain to me who thought that this energy broker was a good idea?
Why yes, I AM a rocket scientist!
Can someone explain if these would convert the hot arizona desert climate into a powersource that also has great solar potential?
Here's the reference for that one!
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
The Toyota Prius actually *does* reclaim heat. It does so while braking, converting the energy that normally would be transferred to the brake pads, to aid in charging up the half of the engine that is electric. So this theory is useful, and is currently in practice. I saw a report on TechTV about it. The car employs a process called "regenerative braking, which reclaims up to 30% of this waste heat, and helps charge up the batteries of the car. www.techtv.com/freshgear/story/0,23158,3357682,00. html
I hate sigs.
When dealing with vehicles of any kind, the primary problem is that the energy source has to be portable. Therefore, you need a source with a high energy density. In other words, something that you can get a lot of energy from while it takes a small amount of space. Even more importantly, you want the energy in a form that you're going to use it in, or as close as possible to such a form, because conversion of energy causes a loss of energy.
To date, combustion based systems have the highest energy density of any portable energy source (barring fission reactions). Therefore, there will always be a use for it.
Perhaps automobiles won't necessarily need them - we can afford to carry additional weight - the fuel/weight ratio for automobiles is evidence of this - you can carry a LOT with a small amount of fuel for a car - and you can then drive for a long time.
But what about flying vehicles? Fuel/weight ratio is EXTREMELY important. The more efficiency that we can get the better. The best part about this is that it might remove the need for an alternator, which drains the power and adds weight to any flying device (which is significant for the small vehicles, such as the automonous surveyor helicopters used by the U.S. military). Improvements in fuel usage can mean a big deal for the aircraft industry.
Of course that's not the only industry that will benefit. Heat-differential technology is used as a power source for some areas...have you heard of geothermal and solar power plants? Know how those work? What if they could double their output? That would be significant.
Mod me down and I will become more powerful than you can possibly imagine!
The 1st problem with this technology is the high temprature 400C is a material science problem.
The next is the poor overall efficiency. MIT says they get 2X times the efficiency. From Photonpower.com I remember a 5% efficiency, so lets be generous and claim 15% efficiency.
Yet, with the use of stirling engine technology A $90 750Watt engine or the mystical Ginger or IT you can use waste heat and get power. Stirlings will move with as little as a 2C temprature difference. 90% as a CHP is possible
If you want to get excited about the idea of heat/electricity, then go take a look at some Naval research that could provide room grade AC w/o state change presently used.
But this technology? Not that exciting, and that is ONLY because of the high temprature.
If it was said on slashdot, it MUST be true!
I know this is way off topic, but I had to post it somewhere. About ten minutes ago (9:16 MSDT) I happened to see something explode over West Texas crossing the sky. Not like anyone really gives a rip, but it was cool! Looks like it was heading a little north of east and I would guess it's near Arkansas by now. Main object flamed yellow and four smaller objects below flaming red. Spooky!
So it's been said that these things are 20% efficient at transferring heat into electrical energy.
Too bad that the conversion of mechanical energy into electrical approaches 100% in efficent generator design. Sure you lose some in the transfer of heat to mechanical, but it's way better than 20%.
The best application of this is probably in the very small scale. How about a small, silent generator for your camper that runs on propane? How about nuclear thermal batteries (ala Galileo) that are twice as efficient?
There is also some issue of scale for these devices. If you need a 1 inch square TEC to cool your processor with about 40 Watts of cooling power, if you want 4KW of electricity for you car that's et least 100 of these things plastered around the catalytic converter. Sounds expen$ive.
Not revolutionary, but neat.
Muerte
damned moronic treehugger, the cars wouldn't be disposed of for at least 10-20 years, and the chemicals, the very few that would not be disposed of properly, would take another 30 years to get into the atmosphere, and those are only the parts that can actually get up there in the first place, after all it is in solid form..so like i said..damned moronic treehugger
-- Note to self - 'Don't push that button'.
I couldn't care less what gets done with that energy... put a nice fluorescent light inside the case or something.
i like this troll, he dosn't just post the annoyingly gross stuff, he also makes up some funny shit
-- Note to self - 'Don't push that button'.
Many of the comments posted make the connection of generating electricity from the heat that the CPU produces, However, the heat being produced is actually caused because of inefficiencies in transistor switching. So if transistors became more efficient they would would waste less electricity and generate less heat thus needing less electricity leading to less heat leading to needing less electricity until we are actually generating electricity from the lack of heat.
"A person is smart. People are dumb, panicky dangerous animals and you know it." - K
With so many electronic devices such as computers, monitors, stereo amplifiers, guitar amplifiers, and various external computer peripherals this room generates enough thermal energy to keep it warm even in the winter. I don't think I've ever had to turn on the heating here.
Geeks seem to get a hard-on for the excess heat generated by their computer systems.
A whole industry has developed, and millionaires created, by reselling decades old heatsink and fan technology with new mettalic paint jobs.
Not too much info yet. In particular, there's no indication of how much such devices will cost per watt. This is a basic problem with things like Peltier-effect devices and solar cells; they work fine, but you need an awful lot of them to get serious power levels. If this requires something like a wafer fab to make, it will be a niche device for years to come.
Yeah, you know me!
For the unintiated, MC Hawking lyrics follow.
MC Hawking is Stephen Hawking, physicist and gangsta rapper. Despite three critically acclaimed albums and nearly ten years on the mic, Stephen Hawking remains virtually unknown as a musician. mchawking.com is devoted to Stephen Hawking's career as a lyrical terrorist.
Harm me with harmony.
Doomsday, drop a load on 'em.
Entropy, how can I explain it? I'll take it frame by frame it,
to have you all jumping, shouting saying it.
Let's just say that it's a measure of disorder,
in a system that is closed, like with a border.
It's sorta, like a, well a measurement of randomness,
proposed in 1850 by a German, but wait I digress.
"What the fuck is entropy?", I here the people still exclaiming,
it seems I gotta start the explaining.
You ever drop an egg and on the floor you see it break?
You go and get a mop so you can clean up your mistake.
But did you ever stop to ponder why we know it's true,
if you drop a broken egg you will not get an egg that's new.
That's entropy or E-N-T-R-O to the P to the Y,
the reason why the sun will one day all burn out and die.
Order from disorder is a scientific rarity,
allow me to explain it with a little bit more clarity.
Did I say rarity? I meant impossibility,
at least in a closed system there will always be more entropy.
That's entropy and I hope that you're all down with it,
if you are here's your membership.
Chorus
You down with entropy?
Yeah, you know me! (x3)
Who's down with entropy?
Every last homey!
Defining entropy as disorder's not complete,
'cause disorder as a definition doesn't cover heat.
So my first definition I would now like to withdraw,
and offer one that fits thermodynamics second law.
First we need to understand that entropy is energy,
energy that can't be used to state it more specifically.
In a closed system entropy always goes up,
that's the second law, now you know what's up.
You can't win, you can't break even, you can't leave the game,
'cause entropy will take it all 'though it seems a shame.
The second law, as we now know, is quite clear to state,
that entropy must increase and not dissipate.
Creationists always try to use the second law,
to disprove evolution, but their theory has a flaw.
The second law is quite precise about where it applies,
only in a closed system must the entropy count rise.
The earth's not a closed system' it's powered by the sun,
so fuck the damn creationists, Doomsday get my gun!
That, in a nutshell, is what entropy's about,
you're now down with a discount.
Chorus
Hit it!
Doomsday, kick it in!
I was going through some science quiz on the web, and they had some question where absolute 0 was the answer. Their choices were something something and -absolute zero.
I sent them several emails saying that their choices were wrong, and almost a year later, it's still wrong. People like that don't deserve have such web sites.
No wonder we're going down hill.
Peter L. Hagelstein was the guy at MIT who had MIT's lawyers churning out cold fusion patents like there was no tomorrow at the same time that MIT's official position was that cold fusion was an illusion -- and making official recommendations against its funding.
Seastead this.
I just happened to look out my window, in Kansas, and see 2 lines (roughly) of debris burning up, and they traveled about 90 degrees across the sky line after I saw them. Rather neat.
Example: You put a heat-based gizzmo on your car's exhaust pipe. The temerature (and thus pressure) in the exhaust system goes up, making the engine less efficient and making you use more fuel to go the same distance.
Example: You put one on your CPU. Same deal, except your cooling system now has to work harder to keep it at a reasonable temperature, and thus uses more power.
Example: You wear a swatch. It takes a little bit more energy each time you move your arm. If you want to power a computer the same way, you'll soon be too tired to type.
The key point is in every case you will have to put more energy in than you get back out. That's why perpetual motion machines do not and can not work.
-- MarkusQ
Sapping heat from the smokestack contents will probably cause it to not work correctly.
The goal of a smokestack is to get the harmful exhaust away from the ground long enough that it disperses sufficiently before touching down.
This is done with convection. The hot gas in the tall stack creates the draw that powers it and blows the plume up after it leaves the stack, the hot plume continues to lift itself until it bleeds off too much heat, then it starts coming back down, but presumably dispersed enough to not be too noxious.
The smoke stack was designed with a known gas temperature and dispersal requirement and a desire to minimize masonry. If you take away heat from the gas you will reduce your plume altitude and cause it to come down in a more concentrated region.
I doubt you can use the thermo-generated electricty to run blowers to compensate. The `no free lunch' law of thermodynamics will probably forbid that. (Unless blowers are much more efficient than convection.)
Now, if you are just bleeding off waste steam then it would work, but most of the energy in steam is the expansion from water to steam, there is relatively little left in the puffy clouds.
Mostly unrelated note: I used to live in Pittsburg in a community where all the houses were required to have slate roofs, stone or brick exteriors and no wood trim. Even the window frames were metal. It was a fire-proof community from the days when the steel mills spewed lots of solids including hot cinders. The plume was powerful enough to carry those large distances fast enough that they were still hot enough to start a fire.
Because it had to rise in the first place before it could drop to it's present levels.
The caveat for the laws of thermo dynamics is the phrase "In a closed system." Since the universe seems to be slowing running down, what wound it up in the first place?
It is obvious that the universe at one time was part of an open system, in order for the entropy to increase and has since been cut off from that energy source.
Maybe you can create arbitraty new dimensions that are at 0 degrees kelvin and pump heat into them from to produce energy. Once the newly created universe is too hot to accept anymore energy you seal the tear before the trapped heat can start expanding.
- (T1 - T2)/T2
where T1 is the temperature at the hot side, and T2 is the temperature at the cold side. Both of these temperatures are measured from absolute zero.This is why extracting energy from something that's just a little warmer than its environment is very inefficient. With the hot side at 100C and the cold side at 20C, you're limited to about 20% efficiency in theory, and will be lucky to get half that. Power plants generate steam at upwards of 600C, not just above the boiling point, for exactly this reason. Gas turbines run even hotter. Solar plants for power production typically focus enough energy on a target to reach the 600C level, as Solar Two in Mojave does.
You just can't extract much power from things that are merely warm. They have to be really hot.
A book that I had to read for an interesting class I took listed as 'Science and Society' was "Cantor's Dilemma". It wasn't the best book I've ever read by any stretch, but it did give a great deal of insight on research teams at schools and their motives. Your comment really pertains to the content of the book.
:)
Have a read, you might like it.
After reading the book, I would guess something about Hagelstein not wanting anyone else to do research in this area because they might beat him to the punch. With a big school like MIT discounting it entirely and even refusing funding for it, other schools would have a difficult time receiving funding and thus could no longer act as competition. Just a thought.
--SONET
Any fool can criticize, condemn and complain and most fools do. --Benjamin Franklin
I know y'all gonna mod this one down too, but...
I made a *very* *similar* post about Matrix-style energy collection for the 'still suit' article. It got modded *down*, as a troll. Why? Why? Check my user history!
I am walking, talking proof that slashdot's moderators are all on crack.
My karma-whore mascara is starting to run... *sniff*.
- undoware.ca
It seems so far that most of this discussion focuses on this technology's application to automotives, which are, obviously, an enormous source of fuel consumption. But what about more fundamental wastes of heat?
Quite nearly every home contains dozens of devices that let off lots of energy while in use. Think of your oven, dryer, toaster, refrigerator, furnace... dare I say woodstove?!? Lining these heat-driven devices with such a product could prove valuable.
Consider the open flame of a gas range literally belching heat, much of which escapes into the air or is absorbed by the metal around it. What if the oven and catch-plates below each burner were lined with a hard-coated version of the device? Maybe in the common home this would prove impractical, but surely in commercial kitchens where ovens and stoves are perpetually fired such an implementation would drastically cut down on the total electricity used.
In older homes where radiators are the norm, this might even provide an economical way to prevent burns from leaning up against those pesky pipes!!!
.
Nice guys don't finish last. In reality, they're abducted halfway through the race.
ASPX annouced a device like this a couple of months ago. Includes pictures. Power output is not too impressive but with all the MEMS work these days maybe 10uW aint so bad.
http://www.adsx.com/images/Generator1.html
But the really interesting part is how this company plans to use it. They want to use it along side their digital angel product. Wireless biomonitoring that never runs out of batteries!
I think the problem is probably that not enough
people take the time to meta-moderate. If those people who abuse moderation got ranked as unfair enough in the meta-moderation then they wouldn't be able to moderate anymore.
By careful selection of materials, ENECO scientists are creating highly efficient, solid state conversion devices, called "thermal diodes," that will operate from 200 to 450 Celsius -- typical temperatures for waste heat and for concentrated solar radiation.
t ml
The very best commercial solar cells today are about 18-20% efficient. The best (research) cell on record, was 32% efficient. It's really too bad they don't give any more specifics on this semi-conductor based device, because it wouldn't be too hard to figure a rough solar cell efficiency equivalent (based on the area of a concentrating lens or mirror)
Now perhaps a more interesting use of such a device would be to increase the efficiency of fuel cells, which themselves are not so efficient and produce lots of waste heat. In a residential setting, this heat can be used for hot water and during winter months. But in a vehicle, I can't think of much use otherwise. Powering headlights, A/C, etc. would be great. Especially if they were white LED headlights of course.. (-;
For your reading pleasure:
http://www.nrel.gov/hot-stuff/press/5399world.h
http://acre.murdoch.edu.au/refiles/pv/text.html
"All your waste are reduce by us!!"
*groan*
But not long enough to learn how to spell the name of the city, apparently.
An imperfect plan executed violently is far superior to a perfect plan. -- George Patton
because the car's alternator already produces more than enough power to run everything in the car. Also, on cold mornings, it would produce even less power because it takes longer to warm up. This technology has other uses, but automotive ones are not among them.
Mr. Fusion from Back to the Future? We've come one step closer here! 2.21 gigawatts!!!
money back from the politcos - put something like that in every politicos' seat - it's not for nothing they're called benchwarmers.
find some way of putting this stuff into blankets and mattresses, and you'll have all the honeymoon hotels beating a path to your door.
"I his bow, and spun and wove, likes you." Vere de Vere out of my mould's mouth dragged me of the voluntary apes.
I thought that name was familiar! Gary Taubes' excellent book on the genesis of "Cold Fusion", Bad Science, gives a thorough and not particularly kind account of Prof. Hagelstein's role in those events.
That's right... it's spelled "Shitthole."
Hmm.
.. That goes way up if you ditch the radiator, but it's kinda short-lived afterwards.
Good, except that an engine which produces 75kW at bar will generate something like 3x that in waste heat. I don't know what's the efficiency of infernal combustion these days, but my old textbooks said the ballpark is around 30%
If I read the article properly, the diode does *not* convert heat to electricity in a way that would cool down the environment in any meaningful way. So you still need radiator, but maybe you can leech some of those kWs to recharge battery..
Too bad you cannot really ditch the car generator. That'd make assisted start tricky when your battery's drained. Maybe that'd have a social angle, tho.. Can chat up the lady while you wait for her (car) to warm up.
Ok heres my idea for a "free" engine...but only usable in space. Spin something, like a batton in a circular motion, connected to nothing, in orbit. This "should" spin indefinately. Now surround the spinning metallic item in a way that it generates electromagnetic energy. How far off am I? Its early, and my patent papers are stuck to my coffee cup....
I've always been struck with how much energy is thrown away in cooling towers at turbine-based electric generating plants.
Just a little background for people who don't understand the function of a cooling tower. A turbine plant turns it's turbines by converting a liquid (typically water) to a gas (steam). Once you have the steam, you have to cool it down if you want to use it again or if you want to efficiently discard it. Some plants are designed to cool it down to the point where very little additional heat will boil it again, but this can be tricky. Some plants have been designed such that the waste steam is cooled in heating buildings through steam radiators, but it can be problematic finding customers for this steam, especially year round.
If we have an efficient way to convert this steam to energy as we cool it, then the efficiency of these plants could go way up.
On a related note, I wish the politicians were seriously working towards about energy efficiency, alternate fuels and new oil exploration now. I only hear half measures and partisan wrangling. It's like the politicians seem to believe that we can't have BOTH more energy efficiency and new energy sources. I'd like to be less dependent on some of the foreign oil now. Some of those areas just aren't looking too stable these days.
Like Enron DID! The news is full of the collapse of Enron. Thousands unemployed, billions of $ lost, possibly the largest bankruptcy filing ever.
The Gerald D. Mahan mentioned in the article as the original inventor of the idea is incidentally the same guy responsible for "Many-Particle Physics", everybodys favourite textbook on hardcore condensed matter theory using a Green function approach.
The amount of practical power you extract has little if anything to do with theoretical efficiency. The efficiency is based on an arbitrary equation, the power is actual energy per unit time.
For instance, what about a Stirling engine? It has a low "efficiency" according to your definition--but it uses literally any heat source at extremely low temperature differentials. Which engine is more efficient in a practical sense, the one that uses barrel after barrel of precious oil or the one that produces household current from sunshine and snow?
324006
but with my high-school level of physics, I don't understand how this relates to the 2nd law of thermo.
Isn't there something about eventually the universe undergoing heat death, where all useful forms of energy are converted to heat, which is the random vibration of molecules and thus "useless?" If so, does this device mean that we won't undergo heat death, since heat generated can be put back into something useful again, like electricity?
A thermal diode IS a Peltier element. This has been covered in EE Times among other trade journals. All they've done is take the standard BiTe diode, which is very thick, and thinned it down by creating the layers with standard chipmaking techniques. So, instead of one diode junction being about 1mm thick, they make a device that is 0.1mm thick consisting of many tens of layers.
www.eFax.com are spammers
Is there enough heat generated by the generators used in wind generators to allow these to further augment their power output? Seems to me that having these on a wind turbine would be excellent as you have a ready source of air to create a large temp. delta.
The first thougt I had about this device is for military and commercial air transport. Many planes have an extra, though much smaller, turbine to generate electricity. What if these were used on the primary turbines (HUGH temp delta here...very hot exhaust...much cooler external temp) to generate electricity. What about for emergencies? Some fighters have little alternators that pop up from the side of the plane with a prop which allows for emergency electricity. As long as the turbine is still attached, wouldn't this make a good emergency source of power? Same with helecopters? I know Apaches have, what, two 1200Hp turbines. I know there's a lot of heat there with a huge fan right over head to help cool it. Seems like these would all be prime targets for first serious applications.
see
http://www.mchawking.com/songs/Entropy.mp3
"Defining entropy as disorder's not complete,
'cause disorder as a definition doesn't cover heat.
So my first definition I would now like to withdraw,
and offer one that fits thermodynamics second law.
First we need to understand that entropy is energy,
energy that can't be used to state it more specifically.
In a closed system entropy always goes up,
that's the second law, now you know what's up.
You can't win, you can't break even, you can't leave the game,
'cause entropy will take it all 'though it seems a shame.
The second law, as we now know, is quite clear to state,
that entropy must increase and not dissipate.
Creationists always try to use the second law,
to disprove evolution, but their theory has a flaw.
The second law is quite precise about where it applies,
only in a closed system must the entropy count rise.
The earth's not a closed system' it's powered by the sun,
so fuck the damn creationists, Doomsday get my gun!
That, in a nutshell, is what entropy's about,
you're now down with a discount."
Game: Player 'Donald J Trump' now has AI skill level 'experimental'.
Years ago the informatics crowd I hung with was working on the relationship between computation and power.
It turns out that because you need to represent state in a stable mechanism, and you can't change the stable state without using energy that there is a lower bound on the energy required to perform a given calculation.
I have forgetten everything else, and I suspect it is many orders of magnitude smaller than current cpu power usage, but it is enough to break the '==' operator on the parent's title.
Except the air conditioning cooling system in a car runs directly off the drive system, and not on electricity. The heater runs directly off of heat in the car's cooling system. Consequently, this development really has no impact on vehicle air conditioning or internal environment, with the exception of running a couple relays and a control circuit.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
I don't know about you, but if I were living in a town that has flying cinders all over the place, I don't think securing my house would be my first reaction. What about your own head ?
-Billco, Fnarg.com
(Cynicism follows)
To some extent, the purpose of a smokestack is to get the junk that comes out of it to disperse widely, over lot of people far away who can't do much about it, rather than locally, over the people close enough to it to be able to do something about it politically.
Is that really cynicism? Seems like a fair description of the facts to me.
Let's examine.
Cynicism 1. An attitude of scornful or jaded negativity, especially a general distrust of the integrity or professed motives of others
2. morose and contemptuous views and opinions.
What are the 'professed motives' of tall stack builders? Just as you say, I think. So it's not distrust, but observation. Similarly, "comtemptuous... opinions" hardly fits, since an observation is not an opinion.
Sorry, I think your comment fits more into the "dark reflection" category I'm so fond of.
A question for someone more knowledgable in physics. Would this technology make it smarter to use gas-turbines in hybrid cars rather than reciprocating engines, since the waste heat is at a much higher temperature?
And could this be used to augment power used with gas turbine generators at hospitals, on ships and oil platforms or even APU's in airplanes?
Ethan
You CAN get Free energy from ambient air. It's not much, but its enough to pulse a tiny LED once in a while.
:(
:p
It doesn't even require a 3* temperature gradient. 0* relative gradient is enough, statistically. Since every atom is effectively colliding with its neighbors, the instantaneous difference in their kinetic energy, relative to a "flat" surface is high.
Noble gases work best practically, since molecules tend to impart a larger portion of their enery to spin about its internal axis.
The best example you can see with your own eyes is the old grain of pollern in water, under the microscope. There is no constant force acting on the grain, but it moves nonetheless. (Leave the light off and use a UV scope if you want to argue about the heat of the microscopes bulb).
So the energy is clearly Freely available. Its just not free enough as in beer to get you drunk.
I'm currently working on a project to extract enough ambient energy to do something useful. It helps to think of it not as heat but as KE or pressure. So far all I've got is an itty bitty capacitor to flash an LED a couple times an hour
Now if I had an ideal capacitor that didnt bleed off any energy, I could get a micro radio beacon powered consistently. I'm currently playing with EMF theory to fix that. Where's the warp bubble when you need it?
(or molecule if your not using a noble gas
Lenz 's(sp?) law. An current that results in an opposing field is produced. The spinning object would slow to a stop. You can only get out as much energy as you put in.
----
All of whose base are belong to the what-now?
Could one of these devices be fitted to the roof of the Congressional building? Some of the resultant electricity could be used to pipe in continous feedback from big-corporation lobbyists (such as the RIAA), thus raising the temperature inside to an even more useful level.
This would have the added benefit of increasing personnel turnover from heat-stroke, thus making term limits unnecessary.
A truly excellent pizza parlor is a delight unto the heavens. Treasure the sauce and the toppings!
Entropy reigns supreme! God will smite any scientists researching these technologies and will thus preserve the laws of thermodynamics!
Don't know 'bout the rest of you, but I was thinking more along the lines of lining the outside of the smokestack with these.
That way we wouldn't change the equations already generated for the contents of the smokestack; we'd only be capturing the true waste heat that's going into the air outside the smokestack.
I feel fantastic, and I'm still alive.
Let me be the first to say that you have no idea what you are talking about.
Peter H. invented the first working XRay laser around 1980. This inspired Edwin teller to promote the Star Wars program. Peter is a very smart guy having raced through MIT as student in two years.
How do I know? I am very close to the business.
Scientists restrict study to entire physical universe; creationist
A hybrid vehicle would probably shut down the engine at idle and eliminate that waste-heat stream, so the thermal converter would be more useful as a way to increase the general efficiency level of the powertrain. If you can get an extra 10% off the 40% of the heat which is rejected through the exhaust, that's 4% of your fuel value; added to a 30% engine thermal efficiency, you've gained 13%. That's nothing to sneeze at.
Scientists restrict study to entire physical universe; creationist
In contrast, the only thermoelectric generator I know you can buy is for running a little fan which goes on the top of your wood stove. The efficiency of these things is very low, and they are only used where mechanical simplicity is an overriding requirement (such as the power supplies on deep-space probes, which are heated by radioisotope sources). If MIT has come up with a converter which is efficient enough to be worth carrying on a vehicle to scavenge energy from the exhaust heat, that's better than anything we've got today.
Scientists restrict study to entire physical universe; creationist
Scientists restrict study to entire physical universe; creationist
Scientists restrict study to entire physical universe; creationist
Well, here is what the great Stephen Hawking has to say about entropy.
Entropy, how can I explain it? I'll take it frame by frame it,
to have you all jumping, shouting saying it.
Let's just say that it's a measure of disorder,
in a system that is closed, like with a border.
It's sorta, like a, well a measurement of randomness,
proposed in 1850 by a German, but wait I digress.
"What the fuck is entropy?", I here the people still exclaiming,
it seems I gotta start the explaining.
You ever drop an egg and on the floor you see it break?
You go and get a mop so you can clean up your mistake.
But did you ever stop to ponder why we know it's true,
if you drop a broken egg you will not get an egg that's new.
That's entropy or E-N-T-R-O to the P to the Y,
the reason why the sun will one day all burn out and die.
Order from disorder is a scientific rarity,
allow me to explain it with a little bit more clarity.
Did I say rarity? I meant impossibility,
at least in a closed system there will always be more entropy.
That's entropy and I hope that you're all down with it,
if you are here's your membership.
Chorus
You down with entropy?
Yeah, you know me! (x3)
Who's down with entropy?
Every last homey!
Verse 2
Defining entropy as disorder's not complete,
'cause disorder as a definition doesn't cover heat.
So my first definition I would now like to withdraw,
and offer one that fits thermodynamics second law.
First we need to understand that entropy is energy,
energy that can't be used to state it more specifically.
In a closed system entropy always goes up,
that's the second law, now you know what's up.
You can't win, you can't break even, you can't leave the game,
'cause entropy will take it all 'though it seems a shame.
The second law, as we now know, is quite clear to state,
that entropy must increase and not dissipate.
Creationists always try to use the second law,
to disprove evolution, but their theory has a flaw.
The second law is quite precise about where it applies,
only in a closed system must the entropy count rise.
The earth's not a closed system' it's powered by the sun,
so fuck the damn creationists, Doomsday get my gun!
That, in a nutshell, is what entropy's about,
you're now down with a discount.
13 year old white supremacists are shitty web designers.
could we use it for nuclear power generation instead of sream and turbines?
the saftey benefits would be huge.
The Kruger Dunning explains most post on
You'd probably have your biggest "win" by coming up with a way to manage the temperature of the gas going into the cat. If you could come up with a thermostat to switch the heat flow from the header pipe to an "upstream" thermoelectric converter such that the system was only "on" when the gas was getting too hot for the cat (and the pipe was insulated when it was cold), and use a "downstream" thermoelectric converter to make use of all the heat coming out of the cat, you'd be making the best of it.
I saw a patent for an idea which might interest you. Someone had the idea of putting a heat exchanger in the exhaust pipe to rapidly heat engine coolant (this would have to be "downstream", of course). When the engine was warm a valve would open and bypass the heat exchanger. The heat exchanger could be somewhat restrictive, which would increase exhaust back-pressure and exhaust-gas temperature with it. This would make the catalytic converter light off faster and reduce pollution. Not bad for people who live in places where it gets cold, huh?
Scientists restrict study to entire physical universe; creationist
That's fine... although I'm sure it was quite expensive insulating and building all that ducting. Anyway, copper wire will have less heat loss than any ducting, no matter how well insulated I would think. So if you use one of these converters and get some electricity you 1)can get that energy to people more effeciently, 2) use it for more than heating, 3) still have some heat left over to use in any ducting system, and if you don't than this thing is even more efficient than them imply, which is even better. So I really don't see how using heat ducting is in any sense better than using one of these to get electricity.
...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
drats, didn'nt notice the typo... change that to 'hydrocarbons', not hyrdrocarbons.