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Waste Heat to Electricity?

michael posted more than 12 years ago | from the negative-entropy dept.

Science 330

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."

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Waste heat. (-1, Flamebait)

Anonymous Coward | more than 12 years ago | (#2642708)


Should work well in Pentium and Athlon systems then.

shouldn't this be +5 funny? (-1)

dead_puppy (532541) | more than 12 years ago | (#2642832)

or do all you faggots lack a sense of humor?

ep (-1)

bitchslapboy (193543) | more than 12 years ago | (#2642709)

This early post for Ida!

I claim this first logged in post in my name! (-1)

Pr0n K1ng (160688) | more than 12 years ago | (#2642710)

Get it in ya!

I claim this follow up post ... (-1)

egg troll (515396) | more than 12 years ago | (#2642751)

...for the Queen of Spain!!

Neat Idea, but not terribly useful... (0, Troll)

PoiBoy (525770) | more than 12 years ago | (#2642711)

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

Re:Neat Idea, but not terribly useful... (-1)

bitchslapboy (193543) | more than 12 years ago | (#2642717)

The major problem with electric cars right now is battery technology. We need batteries that can work for about 200-300 miles before recharging just to get the technology at a minimum acceptable level. Because recharging takes so long you can't just refuel it in 10 minutes like a gasoline powered car. Thus a fully charged battery needs to last for at least a full day while under heavy driving conditions, like road trips, to be completely accepted.

Re:Neat Idea, but not terribly useful... (2, Interesting)

djberg96 (133496) | more than 12 years ago | (#2642763)

Well, hybrid technology is already here. I drive a Toyota Prius (and love it!) and there's also the Honda Insight. Neither reclaim heat, however, so this may be one more may to charge the battery while the engine is running.

Chrysler has a diesel hybrid in development, a prototype called the ESX3, that currently is getting around 72 mpg. The main problem for them is *cost*. As time passes, this will go down. I don't know if they reclaim engine heat, but I doubt it.

Ford *does* have an all electric prototype but it, and any early all-electric cars would be primarily designed for the folks who want a strictly "in-town" car. This notion is already catching on in the form of NEV's (Neighborhood Electric Vehicles).

But, yes, this sort of technology will be probably be pointless within 20 years, at least for automobiles. May have some other uses, however.

More info (3, Informative)

Raven42rac (448205) | more than 12 years ago | (#2642891)

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

Re:Neat Idea, but not terribly useful... (2, Insightful)

archen (447353) | more than 12 years ago | (#2642737)

When an electric car can keep me warm in -40 degrees below zero, while driving against the wind for a 300 mile drive I'll be impressed.

Personally I'd put more stock in a vehicle powered by hydrogen.

Re:Neat Idea, but not terribly useful... (1)

HerrNewton (39310) | more than 12 years ago | (#2642747)

You've driven across North Dakota in the winter, haven't you?

Re:Neat Idea, but not terribly useful... (2, Informative)

archen (447353) | more than 12 years ago | (#2642780)

Actually yeah, that's what I was talking about :)

Granted that people talk about how combustion engines waste heat, but no one ever seems to adress how that very heat is neccesary for many parts of the world. I suppose with vehicles, electic cars are a good idea for those in cities that mainly would just need to drive across town, but lets face it; many people use vehicles like an SUV just to drive across town.

Re:Neat Idea, but not terribly useful... (2)

Legion303 (97901) | more than 12 years ago | (#2642896)

-40 degrees below zero

Wouldn't it have been easier to say "40 degrees"?

-Legion

Re:Neat Idea, but not terribly useful... (3, Interesting)

cascino (454769) | more than 12 years ago | (#2642740)

It's true, the applications for automobiles seem rather limited, but thermionics could stand to revolutionize the nature of power plants.
IANAS, but I believe that today's newest and most efficient coal, oil, and even nuclear power plants can at some point be looked at as a simple heat -> steam -> turbine system, the same concept that's powered locomotives for over one-hundred years! As you'd imagine, such a system is terribly inefficient.
Thermionics, as I understand it, eliminates the "middleman" of the equation by translating heat directly to electricity. It certainly will be interesting to see how this develops on a commerical and thus much larger scale.

Re:Neat Idea, but not terribly useful... (0)

HBD (450014) | more than 12 years ago | (#2642805)

i read some of these replys, no1 is addressing the obvious issue that these could replace heat-sinks, and not be wasted in cars..lol

Probably not (2)

autopr0n (534291) | more than 12 years ago | (#2642839)

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.

EXTREMELY Useful (3, Informative)

fireboy1919 (257783) | more than 12 years ago | (#2642895)

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.

Quit talking outcher ass! (-1)

Flarners (458839) | more than 12 years ago | (#2642713)

* g o a t s e x * g o a t s e x * g o a t s e x *
g g
o / \ \ / \ o
a \ a
t `. : t
s` \ s
e \ / / \\\ -- \\ : e
x \ \/ --~~ ~-- \ x
* \ \-~ ~-\ *
g \ \ .--------.___\ g
o \ \// ((> \ o
a \ . C ) ((> / a
t /\ C )/ \ (> / t
s / /\ C) (> / \ s
e ( C__)\___/ // _/ / \ e
x \ \\// (/ x
* \ \) `---- --' *
g \ \ / / g
o / \ o
a / \ \ a
t / / \ t
s / / \/\/ s
e / e
x x
* g o a t s e x * g o a t s e x * g o a t e x *

finally! (-1)

ArchieBunker (132337) | more than 12 years ago | (#2642767)

The goatsex man returns!

Just wondering (-1)

egg troll (515396) | more than 12 years ago | (#2642782)

Hey how is Meathead doing these days?

Hello, slashdot goons! (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2642715)

Please check out my new website!!
It is here! [cyborg.ne.jp]

Thank you, and I hope you like it!

Re:Hello, slashdot goons! (-1)

Anonymous Coward | more than 12 years ago | (#2642721)

You're a fucking sick goon, you riceball.

Re:Hello, slashdot goons! (0, Troll)

BitwizeGHC (145393) | more than 12 years ago | (#2642731)

That's a troll. It looks like Waita Uziga's deadly joy could become the new goatse.cx.

Hmm... (-1)

egg troll (515396) | more than 12 years ago | (#2642734)

What the hell is wrong with the Japanese? They're almost as fucked up as the Germans. I guarentee you that if you see some woman getting raped with a cactus while her tits are being punched, its gonna be by a Nip or a Kraut.

Re:Hmm... (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2642799)

Ugh... It's disgusting.

It's actually all legal, as long as they blur or hide the genital area.*

So, your ordinary playboy magazine is illegal in Japan.

Japanese law enforcers: "Look here! A mutilated anime girl with blurred vagina! A porn video that depicts rape, but blurrs the vagina! It complies with the law! Nothing wrong here..."

Not.

Dare you serve a centerfold on your server, and you'll be arrested.

* exception applys to preteen kids, in which case it is OK to show full nudity, even on TV.

Re:Hmm... (0, Funny)

egg troll (515396) | more than 12 years ago | (#2642807)

You have to love a country that lets you buy used panties from a vending machine. Here in America we have to get them from ebay and wait a few days :(

Re:Hello, slashdot goons! (-1)

I.T.R.A.R.K. (533627) | more than 12 years ago | (#2642770)

Oh, man. The bottled fruit [cyborg.ne.jp] story kicks ass!

Hey I was wondering (-1)

egg troll (515396) | more than 12 years ago | (#2642796)

What do your initials stand for?

Re:Hey I was wondering (-1)

I.T.R.A.R.K. (533627) | more than 12 years ago | (#2642902)

I Throw Rocks At Retarded Kids

Matrix style (4, Funny)

King of Caffiene (517266) | more than 12 years ago | (#2642719)

soon they'll be able to use excess heat from humans...matrix style.

Re:Matrix style (0)

Anonymous Coward | more than 12 years ago | (#2642759)

But first, we would need to raise the human operating temperature to 200-450 degrees celcius. That wouldn't be cool, as it could cause brain damage.

Re:Matrix style (0)

HBD (450014) | more than 12 years ago | (#2642809)

well like you said it wouldn't be cool, but not just damage to the brain, it also wouldn't be cool:)

Imagine the possibilities. (-1, Redundant)

Syrcam (540030) | more than 12 years ago | (#2642725)

Imagine everything that you would be able to do with this technology. I definitely look forward to improvement on this technology, and, despite the fact that it works at such high temperatures, it made me wonder: What if you could toss your fan / heatsink out the window and use your own CPU as a means to produce just enough electricity to power that cool set of neon lamps you got at thinkgeek.com? I think you would only be able to do it with an Athlon though, as they build amazing quantities of heat (just as many saw on the first Tom's Hardware video).

Anyway, have a good night,y'all...

Hmm... (0)

dimator (71399) | more than 12 years ago | (#2642727)

So.... can we wrap one of these around the sun?

Hmmm... (4, Interesting)

caseydk (203763) | more than 12 years ago | (#2642728)

I think it might make the EPA happy if companies had these in their smokestacks... maybe reduce their power draw a bit...

less power required= less pollution

Re:Hmmm... (-1, Flamebait)

HBD (450014) | more than 12 years ago | (#2642815)

evr think that the heat would not be at 200+ degrees C at the top of a smokestake treehugger?

Re:Hmmm... (0)

Anonymous Coward | more than 12 years ago | (#2642844)

Not just companies putting it in their smokestacks -- think about the extra wattage power companies can squeeze out of the waste heat left over in nuclear and fossil-fuel plants... Every extra megawatt helps.

This good for Athlon-systems? (0)

Anonymous Coward | more than 12 years ago | (#2642732)

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 :)

True! (0)

Syrcam (540030) | more than 12 years ago | (#2642773)

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.

Re:True! (0)

HBD (450014) | more than 12 years ago | (#2642822)

they have had those for awhile now, just replace all your transistors with vacum tubes and you are set..lol

Introducing... (5, Funny)

Iamthefallen (523816) | more than 12 years ago | (#2642736)

Introducing Athlon XP 5000 - Now self powered!

Re:Introducing... (5, Funny)

mother_superius (227373) | more than 12 years ago | (#2642757)

In this universe, we obey the laws of thermodynamics!

Re:Introducing... (1)

Iamthefallen (523816) | more than 12 years ago | (#2642761)

Really? Well someone's gotta start the rebellion...

Warning - Blatant Karma Whoring follows (2)

sconeu (64226) | more than 12 years ago | (#2642890)

Here's [accesstoledo.com] the reference for that one!

Nice but not the end of entropy (5, Interesting)

SysKoll (48967) | more than 12 years ago | (#2642739)

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.

--SysKoll

Re:Nice but not the end of entropy (0)

Anonymous Coward | more than 12 years ago | (#2642797)

Agreed. The article says nothing about reducing entropy. And in fact, entropy is really not the enemy here. In some sense, entropy is the only thing that makes engines go in the right direction in the first place!

Re:Nice but not the end of entropy (0)

Anonymous Coward | more than 12 years ago | (#2642840)

You have some good back-of-the-envelope calculations going on there...but...

There is a little problem with a concept called a 'heat-exchanger'...the mechanism of how heat gets moved/transferred from either the radiator water or the exhaust gases...will involve extra gizmos (cost) and won't likely be very efficient.

There there is the concept that heat actually flows 'through' these chips...one side gets heat applied to it and the other side of the chip is mounted on a heat sink... this whole thing only works if the heat sink side is COOLED! More gizmos/complexity/total system cost! etc..

Then there is the concept of the general magnitude of your resulting calculation...caught me off guard...5k watts...I forget now, how many watts does a Pentium use these days (before it destroys itself)? 50? not 5000! Yes, there are special (expensive) super-power transistors that handle killo-watts...or the system could scale up with 100 chips...but again...cost/complexity etc.

I seem to recall this technology being used on some of the deep space probes...radio-active material generating some heat...put through some material similiar to this...heat sink is a black radiator into space. Expensive...only a dozen watts or so...very reliable and last a long as the 'fuel' is radio-active (many years). This stuff flew in space in the 60's/70's???

One last thing...I like the fact that the alternator in my car works at full power when I start up my car on a really cold morning...when the thermostat is sending NO water to the radiator and the exhaust gas is just an icy fog. ;-)

Re:Nice but not the end of entropy (2)

autopr0n (534291) | more than 12 years ago | (#2642850)

I think it's quite excessive to claim this will reduce entropy.

I think they meant reduce the delta of entropy.

Re:Nice but not the end of entropy (5, Insightful)

GMwrench (211439) | more than 12 years ago | (#2642854)

I don't think so. First your 100 HP engine will only produce 25-35 HP most of the time. Peak power is only produced during hard accerlation during cruse it's much lower and at iddle almost nonexistant. This is 99% of the time. Also an alternator only produses 1-1.5 KW. And the battery cannot be replaced it's needed to start the engine and supply power at low speed when your charging device is insufficent.

Re:Nice but not the end of entropy (1)

iotaborg (167569) | more than 12 years ago | (#2642866)

Actually it would increase the entropy, because every energy transformation increases the entropy in the universe... here we have a heat -> electricity conversion.

Is that right? (2, Insightful)

name_already_taken (540581) | more than 12 years ago | (#2642873)

Engine manufacturers don't rate their engines based on BTU input (like a water heater or furnace), but on mechanical output (regardless of waste heat output).

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.

Hehehe and the Athlon gets sizzling... (0)

Syrcam (540030) | more than 12 years ago | (#2642741)

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! :)

Portable devices (2, Interesting)

elixx (242653) | more than 12 years ago | (#2642743)

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?

Re:Portable devices (0)

HBD (450014) | more than 12 years ago | (#2642828)

even though that ancient laptop i have burns my lap when i use it as the name implys(and i am sure newer ones are more effcient), i don't think it passws maybee 150 degrees ferinheit, let alone 200 degrees C

Use on Hybrid cars? (5, Interesting)

BlueJay465 (216717) | more than 12 years ago | (#2642746)

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?

Re:Use on Hybrid cars? (2)

MxTxL (307166) | more than 12 years ago | (#2642837)

Yeah, when i saw this, i immediately thought of the honda insight. It does just about everything to conserve what gas energy it does burn, it would be consistant with their design (not to mention really neat) to encorporate something like this in. I do wonder how much more mpg they could squeeze out of it.

Thermionics? Environmentally friendly?! (-1, Troll)

Astral Traveller (540334) | more than 12 years ago | (#2642753)

This article must be a joke. Anyone with the slightest degree of environmental science would know this is bullshit. The story says this technology uses thermionics, chemicals similar to chlorofluorocarbons which have been long known to deteriorate our planet's fragile ozone layer. Putting one of these thermionics devices into every automobile and factory in the country would dissolve the ozone above America in the span of a few years. I, for one, don't want to wear SPF 300 sunblock every time I go outside.

Of course, there is no way the EPA would allow any project involving thermionics to even get to the planning stage. This story is obviously yet another hoax. I wish the editors would bother to do some research before letting hoax links onto the front page.

Re:Thermionics? Environmentally friendly?! (0)

Anonymous Coward | more than 12 years ago | (#2642760)

It's semi-conductors, not CFCs. Where do you get your crazy ideas?

Re:Thermionics? Environmentally friendly?! (2, Informative)

greenrd (47933) | more than 12 years ago | (#2642772)

Thermionics are not chemicals, [utk.edu] you moronic troll.

Anyonw know how much they cost. (5, Insightful)

argoff (142580) | more than 12 years ago | (#2642755)

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.

Huh? (2)

autopr0n (534291) | more than 12 years ago | (#2642856)

I don't know about you, but where I live the sun dosn't head surfaces to 480 degrees Fahrenheit...

oops (2)

autopr0n (534291) | more than 12 years ago | (#2642859)

I mean "heat surfaces."

Re:Huh? (2)

Moofie (22272) | more than 12 years ago | (#2642863)

Then you don't have a good enough reflector set up.

Honestly, didn't you ever burn your name into leaves with a magnifying glass? Concentrating solar energy is pretty easy...just use a curved mirror or a lens. 480 degrees would be no problem at all.

Re:Huh? (1)

kgutwin (243912) | more than 12 years ago | (#2642864)

Well, then you're probably not too familiar with solar ovens, the small ones which can heat to several hundred degrees and the large ones which can reach several thousand degrees... it's a simple process of using reflectors to collect and focus the light.

-Karl

----------

First Anti-Jon Katz Post! (-1)

egg troll (515396) | more than 12 years ago | (#2642758)

If only we could harness the hot air that billows out of Jon Katz' mouth, we could power the whole Eastern Seaboard!!

Goatse.cx guy, dude with a loose anus, dead at 31 (-1)

WeatherTroll (529760) | more than 12 years ago | (#2642765)

I just heard some sad news on talk radio - the goatse.cx guy was found dead in his home this morning. There weren't any more details. I'm sure everyone in the Slashdot community will miss him - even if you didn't enjoy his work and/or aren't a troll, there's no denying his contributions to Slashdot culture. Truly a Slashdot icon.

thermodynamics, and entropy, and all that (5, Funny)

StandardDeviant (122674) | more than 12 years ago | (#2642775)

here's the layman's formulation of the things that give chemistry students the cold sweats, the rules of the game as it were:
  1. You can't win.
  2. You can't break even.
  3. 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.

Re:thermodynamics, and entropy, and all that (3, Insightful)

Phanatic1a (413374) | more than 12 years ago | (#2642783)

While that's all very true, it's not tremendously *relevant* here. While you can't break even, you *can* get arbitrarily close to breaking even. Nobody's claiming that thermionics allows you to build an over-unity device, or violate the 2nd law.

What this does do is allow us to design more efficient processes than before. That's a cost savings, a resources savings, and quite allowed by Carnot.

Re:thermodynamics, and entropy, and all that (1)

Deflatamouse! (132424) | more than 12 years ago | (#2642794)

Yep. The amount of energy involved in developing this technology, and the energy used to manufacture the devices will, in the end, most likely use up more energy than the amount it saves. Very pointless in fighting entropy.

Re:thermodynamics, and entropy, and all that (1)

zenyu (248067) | more than 12 years ago | (#2642826)

Very pointless in fighting entropy.

Grrr. If this gives my laptop an extra hour of use it is certainly not pointless. This is like saying that getting those solar cells from 30% effeciency to 60% is pointless. But that would change energy policy.
(Conventional (cheaper) solar cells are only at 10-15%, which is less efficient than plants at converting energy.)

But from what I read this is twice as efficient as the old technology, while computers have been doubling in power every year most of the world isn't like that and most people would be happy if their income doubled. This is still not as efficient as a turbine, but this can be added at the end of the cycle just before the steam is shipped off to office buildings, especially in summer.

Re:thermodynamics, and entropy, and all that (0)

seanadams.com (463190) | more than 12 years ago | (#2642878)


1.You can't win.
2.You can't break even.
3.You have no choice about playing.


That's a weak, if not utterly wrong, argument for entropy. I haven't studied thermodynamics, but entropy is something I've heard of, looked up in the dictionary, dug around for on google, etc, and frankly I have never seen a acceptable explanation of this "basic" law which so many take for granted. Why is it that it's always presented as some magical "incresing order of things"?

Heat *is* energy. We have ways of turning it into other forms of energy, they're just inefficient, and generally require temperatures above boiling.

Nobody is proposing that your laptop could power itself off the heat it generates. However, lots of systems are designed to recover some of their "wasted" energy. Electric cars have regenerative brakes, for example. This doesn't make them perpetual motion machines, it just gets them a little closer.

Will the experts please explain the following: why can't I extract heat from the atmosphere, and turn it into electricity/motion/whatever? We have no problem doing this if there's lots of heat (geothermal power plants), but why can't I have a sort of "reverse air conditioner" that works at room temperate?

Re:thermodynamics, and entropy, and all that (0)

EricBoyd (532608) | more than 12 years ago | (#2642884)

True, but they still arn't actually limited by Carnot: max efficiency = 1 - Tlow / Thigh where T is temp. in Kelvins. so for 250 deg C, we've got max eff. = 1 - (25+273)/(250+273) = 43% compared to their cited 20%. Leaves lots of room for improvement. Anyway, the real way to gain efficency is never to convert the fuel to heat in the first place, i.e. use a fuel cell, and get ~100% efficiency.

IMPORTANT WARNING: Avoid CmdrTaco's "special taco" (-1)

WeatherTroll (529760) | more than 12 years ago | (#2642776)

This is an important warning to all slashdotters. CmdrTaco has been luring people (mainly underage males) into the slashdot compound to eat his "special taco".

You may be wondering what CmdrTaco's "special taco" is. You will be wishing that you hadn't been wondering after you finish reading his post. To make his "special taco", CmdrTaco takes a taco shell and shits on it. He then adds lettuce, jacks off on the taco, and adds a compound to make the person who eats the taco unconcious. Of course, the compound does not make the person unconcous until the taco is fully eaten. Thus CmdrTaco force feeds the taco to the unsuspecting victim.

After the victim is unconcous, he is held against his will and used for CmdrTaco's nefarious sexual purposes. This includes shoving taco shells up the victim's ass, taco snotting, and getting JonKatz involved. Trust me, you do not want JonKatz anywhere near your unconcious body. Also, rumor has it CmdrTaco is looking for a new goatse.cx guy. Don't let it be you!!!!!

Please, if CmdrTaco offers you his "special taco", RUN LIKE HELL!!!!!!!!

Re:IMPORTANT WARNING: Avoid CmdrTaco's "special ta (-1, Troll)

Syrcam (540030) | more than 12 years ago | (#2642778)

You have some basis (just look at his creative writing post as a reply to the Debian article earlier in the day)!!!!!!

Slashdot fags caught spanking chode (-1)

goatman.cx (536700) | more than 12 years ago | (#2642779)

Yes, it was reported by the Boston Globe yesterday that Rob "CommandWhore Taco" Malda, Homos, and Cowboi Kneel were stopped by Boston police after having accausted a street bum by playing "swords" with their respective erect phallii, and "poking" the helpless street person in the chode.

Good good.. (1)

BelDion (109503) | more than 12 years ago | (#2642781)

Excellent, now we need to start stockpiling these semiconductor's in preparation for the heat death of the universe [everything2.net] .

What do you mean we won't be around by then?

Re:Good good.. (0)

HBD (450014) | more than 12 years ago | (#2642851)

ummm..no offence, but you are a moron, these generate electricity from heat, the heat death of the universe is when it expands so far there is little energy left, these would be pretty damned usless...

First Steve Albini Post!! (-1)

egg troll (515396) | more than 12 years ago | (#2642787)

COPPER by Shellac

Copper, let us take you to a furnace where we'll break you
Fire's so big and pretty, you could cry
As a buckle, you could ask me what was wrong with me before - did I need the silver to be suitable?
Copper, I have a use for you, it's easy work and it suits you
Dazzled dirty beauty, you must know
Copper is a conductor and makes for decent cooking
Dazzled by your beauty still, you know
Plated or anodized, you even fool a layman's eyes
Presentable though you might be, it's unwise to try to fight me.
Copper - you'll never be gold.

L337! (-1, Troll)

Syrcam (540030) | more than 12 years ago | (#2642792)

M3 th1n|s d4t S|-|3ll@c r0ck5!!

Second Steve Albini Post! (-1)

egg troll (515396) | more than 12 years ago | (#2642803)

Dead Billy by Big Black

Hey little girl in U.S. dress
Come and give daddy kiss
To Dead Billy, U.S. soldier in green
Little lady, napalm butt
Come and give head to, to
Dead Billy make you boom boom boom
Dead Billy
Dead Billy make you happy
Dead Billy make you crawl
Dead Billy put your hand in his hole
Dead Billy show you what it's like to die
This is not a love song
And this is not a kiss
For Dead Billy
Dead Billy make you happy
Dead Billy make you crawl
Dead Billy put your hand in his hole
Dead Billy show you what it's like to die
This is not a love song
And this is not a kiss
For Dead Billy
No Viet??

Hmmm... (4, Offtopic)

jimhill (7277) | more than 12 years ago | (#2642791)

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.

Irony (1)

GiMP (10923) | more than 12 years ago | (#2642795)

Using the engine's heat to generate cold air.. although possible, it just sounds so ironic :)

Re:Irony (-1)

goatman.cx (536700) | more than 12 years ago | (#2642825)

you suck!

Re:Irony (-1, Flamebait)

HBD (450014) | more than 12 years ago | (#2642855)

only a -1 for this retard, send him back to the promate testing room and it would be better(the special ed room)

Re:Irony (-1)

The WIPO Troll (267426) | more than 12 years ago | (#2642869)

Homos and Cowboy Kneel? Thou hast stolen my jokes!! (BTW: That's Rob "Taco-snotter" Malda.)

beautiful (1)

TheM0cktor (536124) | more than 12 years ago | (#2642811)

can only be a good thing. But how much energy? And can this take us closer to being a sustainable culture?

waste heat (0)

Anonymous Coward | more than 12 years ago | (#2642817)

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!

Re:waste heat (-1, Flamebait)

HBD (450014) | more than 12 years ago | (#2642857)

and just how old are you...8?

Heatsinks for Power (1, Interesting)

EchoMirage (29419) | more than 12 years ago | (#2642824)

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*

Re:Heatsinks for Power (0)

HBD (450014) | more than 12 years ago | (#2642862)

umm..you meen excluding the power to send and receive data from input and output devices such as the minitor, speakers, keyboard, mouse, printer, etc; or do you just plan on defing the conservation of energy without creating a new big-bang?

Re:Heatsinks for Power (3, Informative)

Legion303 (97901) | more than 12 years ago | (#2642874)

Especially in laptops, this could be great, and hypothetically could power the device indefinetely, assuming an initial charge to start everything up.

You *might* extend battery life for a small length of time (measured in tens of minutes at the most) by recycling some of the waste heat, but entropy still rules. You cannot recycle all of the waste heat, so you will be unable to run your device for anything close to indefinitely.

-Legion

Re:Heatsinks for Power (0)

Anonymous Coward | more than 12 years ago | (#2642879)

I don't think this generates quite that much power. Enough to maybe cut the power usage a little, but definitely not power itself.

Those damn thermodynamics laws keep getting in the way of the really cool ideas. :)

is it more efficient than turbines? (5, Interesting)

Pyromage (19360) | more than 12 years ago | (#2642827)

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.

Reversing entropy (2, Funny)

vlad_petric (94134) | more than 12 years ago | (#2642843)


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

use waste heat as -- heat (3, Insightful)

vscjoe (537452) | more than 12 years ago | (#2642846)

That's nice, but it seems like a lot of effort for something that, in many cases, has a much simpler solution: use waste heat for heating. A lot of waste heat could be used for heating homes and water for domestic use, and this is largely untapped in the US. (A lot of low-level waste heat could also be avoided entirely if people gave up on their inefficient water heaters and insulated their pipes.)

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.

Re:use waste heat as -- heat (0)

HBD (450014) | more than 12 years ago | (#2642882)

what if you don't want the extra heat and it would be better served as electricity, in the summer my 2 pcs heat my room up to the point that i have to go into the basement during the day to avoid the heat upstairs, and what about server farms, imagine the savings not having to pay for a/c...

Now what I want....(OFFTOPIC) (1, Offtopic)

Moofie (22272) | more than 12 years ago | (#2642875)

Is a device that will change electricity into money. Like Enron does [enron.com] .

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?

Desert? (1)

astrotek (132325) | more than 12 years ago | (#2642883)

Can someone explain if these would convert the hot arizona desert climate into a powersource that also has great solar potential?

There are other ways to use waste heat. (2, Interesting)

mr (88570) | more than 12 years ago | (#2642904)

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 [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 [omachron.com] or the mystical Ginger [dekaresearch.com] or IT [jedstar.com] 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 [whipsergen.com]

If you want to get excited about the idea of heat/electricity, then go take a look at some Naval research [sciencedaily.com] 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.

Meteor? (2, Offtopic)

0000 0111 (141160) | more than 12 years ago | (#2642910)

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!
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