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124 comments

first post, you dumb faggot (-1, Troll)

Anonymous Coward | about 6 years ago | (#24361251)

go back to sucking on those dicks. get the aids and die. it's your only purpose faggot.

foad, nazi scumbag (-1, Troll)

Anonymous Coward | about 6 years ago | (#24361573)

i have a better idea: drown in shit, you fascist pig. as far as I can tell, that's the only thing your type is good at doing.

Re:foad, nazi scumbag (1)

VillageDolt (1223292) | about 6 years ago | (#24362273)

Take your Zyprexa, please!

Re:foad, nazi scumbag (-1, Troll)

Anonymous Coward | about 6 years ago | (#24363653)

whatever you say faggot. did you get your panties in a bunch because someone called you out over this? homosexuals are a burden on society, just like suvs are. wasteful and useless shitballs.

Re:foad, nazi scumbag (0)

Anonymous Coward | about 6 years ago | (#24364743)

I love Slashdot!

Yeah, frying ants with a parabolic is cool and all (5, Interesting)

iminplaya (723125) | about 6 years ago | (#24361263)

But I like this [enviromission.com.au] better.

Re:Yeah, frying ants with a parabolic is cool and (1)

Sandbags (964742) | about 6 years ago | (#24367867)

Who about this: www.dotyenergy.com

Finally! (5, Funny)

Anonymous Coward | about 6 years ago | (#24361299)

Finally, we have a truly renewable source of energy - we can just harness all the hot air coming from our politicians.

Re:Finally! (-1, Flamebait)

Anonymous Coward | about 6 years ago | (#24361337)

That's a good ol' knee slapper right there. Hey, I got one: women can't drive!

Re:Finally! (-1, Troll)

Anonymous Coward | about 6 years ago | (#24361471)

CmdrTaco could use it for lube when all the tops at the gay bar run train on his ass. One saturday night could provide electricity for the rest of the month.

Technical point (5, Insightful)

Bruce Perens (3872) | about 6 years ago | (#24361323)

It's not possible to make electricity directly from heat. It is possible to make it from a difference in heat between two points.

Re:Technical point (5, Funny)

ettlz (639203) | about 6 years ago | (#24361369)

Yes, on this site we obey the Laws of Thermodynamics!

Re:Technical point (4, Funny)

Anonymous Coward | about 6 years ago | (#24361581)

The other campaign may call it pandering, but I think the American people deserve a temporary holiday from the Laws of Thermodynamics.

Re:Technical point (1)

pushing-robot (1037830) | about 6 years ago | (#24361687)

I also propose a 90-day gravity holiday, during which time I will get rich selling flying cars.

Re:Technical point (1)

DrMrLordX (559371) | about 6 years ago | (#24363749)

It wouldn't take 90 days for us all to die if gravity took a holiday. In fact, I'm sure it'd be a matter of seconds.

Re:Technical point (0)

Anonymous Coward | about 6 years ago | (#24364139)

*WOOSH!* (stupid lameness filter)

Re:Technical point (1)

pushing-robot (1037830) | about 6 years ago | (#24364237)

True, but I can't say a holiday from thermodynamics would be any more enjoyable.

Re:Technical point (1)

dna_(c)(tm)(r) (618003) | about 6 years ago | (#24365127)

The other campaign may call it pandering, but I think the American people deserve a temporary holiday from the Laws of Thermodynamics.

Meanwhile, in Cobb County, those would be referred to as the Theories of Thermodynamics, after all energy is^H^H could be inteligently designed...

Re:Technical point (1)

I cant believe its n (1103137) | about 6 years ago | (#24365913)

Have you been smoking moon rocks? Dont you know thats loco?

Somebody think of the children!

Re:Technical point (4, Informative)

cnettel (836611) | about 6 years ago | (#24361389)

You make electricity directly from heat. You can't make electricity directly from temperature (or stored heat) though.

Re:Technical point (0)

Anonymous Coward | about 6 years ago | (#24362097)

You make electricity directly from heat.

That depends on what you mean by directly.

Imagine that heat is "water" (the low quality energy) and electricity is "wine" (the high quality energy). You can turn "wine" directly into "water" but you can only make water into wine if you have two containers with different amounts of water and you let the water flow from the container with more water to the container with less water. Even then, not all the water that flows between the containers can be converted into wine.

You can also reverse the process and use the process of turning "wine" into "water" to cause some of the water in the container with less water to flow back into the container with more water.

So how much water flows between containers compared to how much is converted to/from wine? Well, it depends. If the difference in the amount of "water" in the two containers is small relative to the total amount of "water" in the containers then lots of "water" flows between the containers and only a small amount of "water" is converted to/from "wine".

If the difference in amount of "water" is large relative to the total amounts of "water" then the amount of "water" flow is small and the amount of conversion to/from "wine" is large. In fact, if the one container didn't have any "water" at all (corresponding to absolute zero) then there would be only conversion and no flow at all.

It's worth noting in our analogy that we can always convert "wine" completely into "water" and we can always let "water" flow between the containers to reduce the difference in the amount of water between the two containers. What's hard is converting the "water" into "wine" and increasing the difference in the amount of "water" in the containers. In fact, according to the Second Law of Thermodynamics eventually all the "wine" in the universe will turn into "water" and all the "containers" in the universe will have the same amount of "water" in them.

A subtle point is this. Imagine that we have have our containers with different amounts of "water" in them. Imagine that we have two processes. For these same containers, one process (that we can run either in forward or reverse) has a lot of flow between containers and only a little conversion to/from "wine" and the other process (that we can also run in either forward or reverse) has only a little flow between containers but lots of conversion to/from "wine".

Well, here's what we do: use the small-flow/high-conversion process to make "wine" and then we use the large-flow/low-conversion process to create a bigger difference in the amount of "water" in our two containers. At the end of the day we have a bigger difference between our containers and we can even have a bit of "wine" left over.

Re:Technical point (3, Funny)

BrotherBeal (1100283) | about 6 years ago | (#24368971)

What's hard is converting the "water" into "wine"...

So what you're saying is that Jesus can create electricity directly from heat? I'm confused...

Re:Technical point (5, Informative)

Anonymous Coward | about 6 years ago | (#24361403)

It's not possible to make electricity directly from heat. It is possible to make it from a difference in heat between two points

heat != temperature

But you are right that you have to have a cold reservoir to get any work from the system. But heat in thermodynamics is not the same as temperature, and it generally denotes the amount of transfered thermal energy between two systems of differing temperature.

I'm assuming that the cold reservoir is the cooler temperature air surrounding the device.

Re:Technical point (2, Informative)

cool_arrow (881921) | about 6 years ago | (#24361411)

Yes that is true and I believe that the most efficient thermoelectric devices are somewhere in the range of about 5% efficiency in practical applications.

Re:Technical point (2, Insightful)

Bruce Perens (3872) | about 6 years ago | (#24361453)

Oops, I'm getting whipped for "heat in a thermodynamic sense is not the same thing as temperature". But yes, the point here is that they've invented better thermocouple wire and thus possibly an improvement in thermoelectric generation and maybe the Peltier effect. Doubling the efficiency of those things would not necessarily make them competitive with other processes for heating and cooling.

Re:Technical point (0)

Anonymous Coward | about 6 years ago | (#24361529)

It's impossible for you to admit that you are wrong, isn't it.

Re:Technical point (4, Informative)

Doc Ruby (173196) | about 6 years ago | (#24361837)

But quadrupling them would. The old max zT these researchers were improving was about 0.87. They've now got it to about 1.5. And are targeting about 3.0 in their current research.

Freon refrigerators have a zT of about 3.0. Which makes these new materials look directly competitive with them for cooling when they reach that efficiency. Since zT 1 materials are about 10% efficient, zT 3 will be able to reclaim about 30% of waste heat. That would be about 20 points of the ~60% of gasoline energy wasted as heat in car engines. Since car engines are about 20% efficient now, that would mean doubling their fuel efficiency.

If these materials can be made, deployed, and recycled with close to (or less than) the energy inputs required now to make the car radiators/manifolds/exhaust systems they'd probably mostly replace, the benefits would be revolutionary.

Re:Technical point (1)

Orange Crush (934731) | about 6 years ago | (#24362469)

^Even if improved thermoelectrics can't directly compete in a refrigerator-type application, any improvement in their efficiency will be useful in other applications (computer cooling, portable thermoelectric cooler/wamers, etc.)

Re:Technical point (4, Interesting)

Doc Ruby (173196) | about 6 years ago | (#24363563)

The Technology Review [technologyreview.com] article about the tech is more specific about the material's heat/electricity conversion efficiency. Evidently the current zT:0.87 material is about 6% efficient; the zT:1.5 material already achieved therefore is about 10% (about 10.3448276%) efficient. A zT:3.0 device is about 21% (about 20.6896552%) efficient.

10% of the 60% of gasoline's energy content wasted as heat is 6% of the gasoline's energy. If the car got the average 20% fuel efficiency, that extra 6 points would be 30% more than the original 20%. A zT:3.0/21% would be 12.6 points extra, or 63% more than 20% to 32.6%.

A 30MPG car today would get 39MPG tomorrow with the current version material. It would get 48.9MPG with the forecast zT:3 material.

What I'm really interested in seeing is how embedding the higher zT materials inside fuelcells boost their efficiency. Because fuelcells aren't heat engines, they're not limited to the Carnot Cycle's 40% max efficiency. They already get 50% efficiency or greater at "native" voltages (like 1.48V), where their max theoretical efficiency is 83%. But still, much of their 17%+ inefficiency is generating heat. So they can be even more efficient with heat reclamation, perhaps in practice actually approaching that 83% efficiency.

Re:Technical point (2, Informative)

Lisandro (799651) | about 6 years ago | (#24364365)

RTGs (radioisotope thermoelectric generators) would benefit greatly from this aswell. They tend to have long life spans (in the order of the half-life of the radioactive material used), but radiation decay and thermocouple wear reduce their power output much before that.

Re:Technical point (1)

Sandbags (964742) | about 6 years ago | (#24368419)

Well, first, when we get these materials to 30%, not their "we'll be a 3% soon" level, you let me know.

Until then capturing 3% of 60%, but adding weight, complexity, and cost to the vehicle, I doubt will have any real benefit. Even at 10%, we're still looking at better improvement simply by switching to electric drive with gas backups.

If we follow the ideas presented by www.dotyenergy.com, then we don't need to worry about it anyway. If we replace oil with man made liquid fuel, produced using free energy from wind combined with byproducts from coal energy, then we don;t really have a CO2 issue, and since free energy is not a market limited comodity, the price of WindFuels should only rise with inflation, not other market factors, allowing us to at least get past the next few hundred years until another technology that costs less and has lower environmental impact comes along.

Re:Technical point (1)

Doc Ruby (173196) | about 6 years ago | (#24368661)

Current zT:0.87 can get about 6% efficiency; these new materials at zT:1.5 get about 10%; their forecast zT:3 materials will get about 21%, in engines like in our cars. I don't know where you're getting that 3% efficient heat recovery figure from.

Every mechanical process could benefit from recovering significant amounts of heat. Most heat engines, especially gasoline/diesel types, include extra machinery for exhausting heat which could be replaced with probably simpler devices that are like "catalytic converters" capturing the heat instead of exhausting it. Even the windmills and other turbines you prefer would benefit from the increased efficiency: everything would.

The question with a device like a heat reclaimer is whether the energy it captures during its lifetime is greater than the energy it costs to make, deploy and recycle it. Since these devices are said to last a long time, decades perhaps, they probably can pay for their supper. And in constant-duty machines like windmills, they're probably a faster payback than in cars that run for only about 5% of their calendar lifetimes.

We need to use everything we've got to get past the energy/Greenhouse crisis already upon us. We're never going to not care about efficiency, especially as we power ever smaller devices, more mobile and independent of a wired infrastructure.

Re:Technical point (1)

Sandbags (964742) | about 6 years ago | (#24369185)

The exhaust process is a function of vapor expansion,not so much heat dissipation. If we impede that process, we reduce the efficiency of the engine itself. Can we collect enough heat as it flies through the exhaust pipes to recoup more than the combined engine impact, additional weight, and cost?

If our fuels come from green sources, and if CO2 emission of the engine is a non-issue, than only distance per gallon is of concern. If we use WindFuels (www.dotyenergy.com), at least until something better comes along in 30-75 more years, then heat reclamation will only be perused if it is both more effective and/or lower cost than other methods to improve efficiency that we already have and don't use.

We can simply mandate better headers and larger, smooth bend exhaust pipes and improve engine efficiency by nearly 5%. By running an engine only a peak torque (4000-5500 RPM depending on the engine) and use it only to make electricity to poewr electric motors, we can get nearly 40% out of the engine. Replace the ICE with a recombinant turbine, and the heat generated is less of an issue still, and we can approach 50%. All of these methods are available today, and can be implemented without radical vehicle redesign or the use of exotic metals.

I agree, in large installations, factories, power generation systems, and more, heat exchanger technology has clear advantages and uses, but in small scale engine systems, we have a lot of things we can do before we get to using this technology.

You're right, we'll constantly improve and demand more efficiency, but when we're talking about cars that will already be getting 150MPG (GM Tesla) on average commuter drives, the heat available to collect will not dramatically improve the efficiency. Further, how will such a system effect available vehicle space? Fuel cells are a great idea, if you like having a Dodge Durango as a 2 seat model....

Re:Technical point (1)

MillionthMonkey (240664) | about 6 years ago | (#24361477)

Yes but if we were driving our cars around on Pluto, even a tiny temperature gradient could be made to do far more useful work than the same difference in temperature on Earth. This planet is a little too warm for these gizmos and so you see signs of desperation such as thallium.

We need to build a giant ring in space that orbits the sun and keeps the Earth in perpetual shadow. That would allow a wider selection of designs for engineers trying to use exhaust heat to turn wheels. Of course, that's only if you think that the American people deserve a break with these high gas prices.

Re:Technical point (0, Redundant)

oldhack (1037484) | about 6 years ago | (#24361829)

NERD!!

(and the autistic filter)

Re:Technical point (1)

BlackPignouf (1017012) | about 6 years ago | (#24369145)

Please mod this guy down!

Would you mind explaining us what the "difference in heat between two points" is? Heck, what is the heat of a point? (hint: it's undefined)
Make yourself a treat : buy yourself a good thermodynamics book and come back when you're finished.

Thank you.

For those who didn't RTFA: (0)

magus_melchior (262681) | about 6 years ago | (#24361333)

The new material contains thallium [slashdot.org] . Greenpeace will have a field day with this one.

Re:For those who didn't RTFA: (5, Informative)

magus_melchior (262681) | about 6 years ago | (#24361355)

And since I can't make hyperlinks correctly on slashdot, I'll try again: thallium [wikipedia.org] .

Nasty stuff, as its compounds are very easily absorbed through potassium uptake pathways in your body, but behave very, very differently from potassium. I seem to remember a chemist friend telling me that if you deal with thallium, you practically need an entirely separate lab for it.

Thallium (2, Interesting)

MillionthMonkey (240664) | about 6 years ago | (#24361423)

Thallium accumulates in your testicles. I remember hearing stories about labs handling thallium where only women were allowed.

Re:Thallium (2, Funny)

moderatorrater (1095745) | about 6 years ago | (#24361467)

Great, now I'm going to start getting spam about using thallium to enhance my testicles.

Re:Thallium (4, Funny)

value_added (719364) | about 6 years ago | (#24361481)

Thallium accumulates in your testicles. I remember hearing stories about labs handling thallium where only women were allowed.

Well, the article does explicitly state that "The material does all the work."

Re:Thallium (2, Interesting)

Mspangler (770054) | about 6 years ago | (#24363657)

"I remember hearing stories about labs handling thallium where only women were allowed."

True. While I was at the U of I my chemistry professor was trying to stick thallium atoms to a cyclopentadiene molecules for some odd reason. The students working on it were all girls.

Re:Thallium (2, Informative)

MillionthMonkey (240664) | about 6 years ago | (#24363881)

my chemistry professor was trying to stick thallium atoms to a cyclopentadiene molecules for some odd reason.

Usually when they stick goofy metals on organic compounds they intend for the metal to be replaced with some organic moiety. The metal guides the reaction so that the organic replacement attaches to the right carbon atom. Thallium cyclopentadiene is a starting material for prostaglandin synthesis. You add methoxymethyl chloride to it, and the methoxymethyl group replaces the thallium and you get methoxymethylcyclopentadiene plus thallium chloride.

Benzoxymethylchloride works too if you want to start with benzoxymethylcyclopentadiene.

Re:For those who didn't RTFA: (0)

gormanw (1321203) | about 6 years ago | (#24364283)

A friend of mine was studying using solar to heat salts, as the salts were very poor thermal conductors. I am reminded of the principle that when changing energy from one form to another, there is always loss. It is in this loss where we find costs. There is a blog http://www.economicefficiency.blogspot.com/ [blogspot.com] that talks about the cost of "green" technologies. I would like to see more discussion on those topics.

I used to work with thallium (1)

wurp (51446) | about 6 years ago | (#24369451)

I was a lab grunt for Dr. Shams (not sure of spelling, Pakistani guy) and Dr. Sheng at the University of Arkansas on the superconductivity lab. Dr. Sheng actually held the world record on high temperature superconductors for about 5-8 years, for Tl2Ca2Cu3Ox (a thallium based ceramic superconductor).

Our only precautions were to put on a mask and latex gloves before opening the thallium bottle and to clean up any spills. I had been told that about 4 grams was enough to kill me, and it accumulates as it's a heavy metal.

I'm fine and apparently quite fertile, since I have three kids and we only meant to have two :-) All are perfectly healthy.

This is *not* intended as an anecdote to convince you that handling thallium is safe. I just thought it was interesting that we didn't have more safety features in place. I hope they do now!

Re:For those who didn't RTFA: (0)

Anonymous Coward | about 6 years ago | (#24361489)

Greenpeace should pick their poison already, so to speak.

Re:For those who didn't RTFA: (1)

maeka (518272) | about 6 years ago | (#24361669)

Greenpeace should pick their poison already, so to speak.

I'll take the continuation of gradual environmental change with its multiple solutions over widespread exposure to fast-acting poison, thank you very much.

Re:For those who didn't RTFA: (2, Interesting)

mosb1000 (710161) | about 6 years ago | (#24362333)

It's doped with thallium, that means that the thallium is imbedded in the metal alloy. I don't think it's going anywhere.

Re:For those who didn't RTFA: (1)

maeka (518272) | about 6 years ago | (#24362385)

If there's no issue, then there's no issue.

Re:For those who didn't RTFA: (1)

Doc Ruby (173196) | about 6 years ago | (#24363437)

Not if they recycle it. The scientists point out that the heat reclaimer component, with no moving parts, will last the lifetimes of several cars. So it should be reused rather than disposed.

Besides, cars already contain lots of highly toxic materials, especially if you consider the toxic products when cars burn, which many do.

Put that in a power plant? (3, Insightful)

4D6963 (933028) | about 6 years ago | (#24361351)

Could it be used to get more power out of a nuclear power plant?

So, this is a reverse peltier? (1)

metalcup (897029) | about 6 years ago | (#24361373)

Peltier elements are used to rapidly cool small surfaces (such as PCR racks, etc), and they use electricity and some trick of semiconductors to do it (http://en.wikipedia.org/wiki/Thermoelectric_effect). So this is a reverse peltier effect then? cool...

Re:So, this is a reverse peltier? (3, Informative)

cnettel (836611) | about 6 years ago | (#24361407)

Any Peltier element can give you power as well. The point is that even the theoretically optimal difference is totally lousy if your heat difference is somewhere like the one between water freezing and water boiling. You need a colder cold sink, or a much hotter heat source, to get some serious efficiency. RTGs tend to be quite hot in the hot end.

This allows better RTGs, but they would only be marginally efficient for, say, reclaiming computer case waste heat. This is especially so as you can't put them on the CPU directly, where the differential is great, because they are insulating as well. You will need to put it at the radiating end, over a large surface.

Peltier devices work both ways (2, Informative)

EmbeddedJanitor (597831) | about 6 years ago | (#24362063)

Use power to shift heat or generate power from heat flow.

Re:So, this is a reverse peltier? (1)

famebait (450028) | about 6 years ago | (#24366695)

You can run peltier elements backwards.

The problem is that efficiency is utterly lousy to begin with, and then degrades, so it is only used in very niche applications. If the new material improves even just the lifetime issue, it expands usefulness quite dramatically.

Hot technology (2, Interesting)

gmuslera (3436) | about 6 years ago | (#24361399)

That material reach its peak at 950F (~500C). Not sure if MIT approach will worth combining with this as maybe the area needed could make electricity by other means.

But there are a lot of areas where heat is produced, and some of this could be used to get extra electricity.

Maybe the most important point, at what cost? how rare/expensive is that new material? If is very, maybe the main use would be not for our normal lifes, but maybe for i.e. space probes.

Re:Hot technology (1)

jonadab (583620) | about 6 years ago | (#24361613)

> That material reach its peak at 950F (~500C).

I think my attic gets nearly that hot in the summertime...

Re:Hot technology (2, Informative)

sokoban (142301) | about 6 years ago | (#24361623)

Maybe the most important point, at what cost? how rare/expensive is that new material? If is very, maybe the main use would be not for our normal lifes, but maybe for i.e. space probes.

Lead is very cheap, Tellurium is about 20 some odd dollars per pound, but Thallium is damn expensive. In the late 90's Thallium was running about $600 per pound. That said, I'm not sure how much Thallium will be needed for this application.

Re:Hot technology (3, Insightful)

im_thatoneguy (819432) | about 6 years ago | (#24364797)

Well we are using Platinum in extremely warm car parts as it is. So placing rare earth metals in our exhaust system isn't a far out idea in the automotive industry. ;)

Geothermal plug in (3, Interesting)

SubComdTaco (1199449) | about 6 years ago | (#24361401)

From the article: "the material is most effective between 450 and 950 Fahrenheit" So simply plug this into a geothermal source, instant energy solution until Earth's core freezes.

Re:Geothermal plug in (1)

CDMA_Demo (841347) | about 6 years ago | (#24361653)

From the article: "the material is most effective between 450 and 950 Fahrenheit" So simply plug this into a geothermal source, instant energy solution until Earth's core freezes.

How about those floating colonies on venus?

patent pending & ah, (insert MIT randomly) aga (1)

CDMA_Demo (841347) | about 6 years ago | (#24361427)

This research was funded by the BSST Corporation; the State of Ohio Department of Development's Center for Photovoltaic Innovation and Commercialization at Ohio State University; the Beckman Institute; the Swedish Bengt Lundqvist Minne Foundation; and NASA's Jet Propulsion Laboratory.

Heremans' team is continuing to work on this patent-pending technology.

Detailed Scientific Analysis Here (4, Informative)

Doc Ruby (173196) | about 6 years ago | (#24361473)

The article at the Green Car Congress site titled New Approach to Developing Thermoelectric Materials Doubles Efficiency" [greencarcongress.com] has a lot more scientific details than that article linked from the summary, especially on the actual formula that determines "zT", which is the thermoelectric conversion efficiency coefficient:

The dimensionless zT for thermoelectric materials is calculated by the formula zT= T*(S2)/), where S is the thermoelectric power or Seebeck coefficient of the TE material, and are the electrical and thermal conductivities, respectively, and T is the absolute temperature.

And also detailed nanomaterials engineering analysis of the quantum structure of the quantum chemistry's thermoelectric effects.

How much does it cost? (1)

eccenthink (1312043) | about 6 years ago | (#24361483)

No mention of actual cost as far as I can tell. It's twice as efficient but does it cost 100 times more or twice as much? The former probably makes it far less useful, the latter would be great.

Re:How much does it cost? (1, Funny)

Anonymous Coward | about 6 years ago | (#24362491)

does it cost 100 times more or twice as much? The former probably makes it far less useful, the latter would be great.

A very good point! But let me make sure I understand it. You're saying that it would be better if it cost less? Man that's some good thinking. How do you do it?

Re:How much does it cost? (1)

Doc Ruby (173196) | about 6 years ago | (#24363587)

Cost compared to what?

Gasoline and other petrofuel prices are going nowhere but up, up, up, until there isn't enough to use for fuel anymore (oil and natural gas, anyway). And the actual costs of pumping all that CO2 into the Greenhouse are hard to calculate: how much does Greenland melting the seas 20 feet higher cost?

The comments attached to the fine article... (4, Informative)

Horar (521864) | about 6 years ago | (#24361503)

... contain a link to a possibly more useful article with some more comprehensible numbers:

http://www.technologyreview.com/Energy/21125/ [technologyreview.com]

e.g. The device could increase fuel efficiency of vehicles by approximately 10 percent.

2. ??? (1)

pr0nbot (313417) | about 6 years ago | (#24361567)

Merge this with the new MIT solar dish and you're in business!'

Ah cool, now we know:

  1. xyz
  2. ???^H^H^H Invent thermoelectric material
  3. Profit!

Themoelectrics Already Pretty Good (5, Interesting)

Doc Ruby (173196) | about 6 years ago | (#24361571)

Even though that article linked from the summary says that typical engines in cars get about 25% of the gasoline's energy content into car motion, it's actually about 20% [wikipedia.org] . That's a lot of wasted energy: about 4:1 waste:use.

But lots of combined cycle plants [wikipedia.org] (like CCGT gas turbines) reclaim a lot of their waste heat into more power. Taking a maximum mechanical power extraction of 60% of the gas' energy up to 85% by heating steam, which is an additional 25% of the original mechanical power.

CCGT reclamation tech is probably not practical for vehicles, so this new material is a welcome advance. Especially if the researchers get the zT from its new 1.5 high to its predicted 3.0 or so. But in fact DARPA has funded Trinh Vo at Lawrence Livermore National Labs to grow nanowires that already have a zT at 3 [llnl.gov] .

More of that kind of material research is very welcome, because at zT 3, these materials can replace freon refrigerators with the same electrical efficiency. Since freon refrigerators require lots of energy to build, and then to recycle, replacing them with a simple material that can scale to any size (including very small, as in microelectronics), means a vast sector of modern industry, including transportation, could switch. If making the material is less energy intensive, and less reliant on a limited critical resource than the freon refrigerators or the CCGT reclamation systems, global energy efficiency could take a giant leap.

A leap that could be just around the corner, in Ohio.

Re:Themoelectrics Already Pretty Good (1)

Ancient_Hacker (751168) | about 6 years ago | (#24361881)

>at zT 3, these materials can replace freon refrigerators.

Uh, how? The Freon cycle can give EERs of 15.
An average Peltier device has an EER of under 0.4.

The numbers don't seem to work out.

Re:Themoelectrics Already Pretty Good (3, Informative)

Doc Ruby (173196) | about 6 years ago | (#24362175)

"A thermoelectric material designed to replace a conventional Freon-gas refrigerator [llnl.gov] must have a ZT of at least 3."

Re:Themoelectrics Already Pretty Good (1)

Ancient_Hacker (751168) | about 6 years ago | (#24370447)

Well yes, a Zt of 3 would be nice, but it's not sufficent.

In general devices that take in random energy (heat) and output very structured energy (DC) have very low efficiencies, like single digits. It's hard to corral random molecular motion into coordinated electron motion. Your typical thermocouple puts out millivolts.

Re:Themoelectrics Already Pretty Good (1)

sapphire wyvern (1153271) | about 6 years ago | (#24362357)

It would also likely have dramatic health & nutrition impacts in developing countries, as refrigeration becomes economically accessible to people who would not previously have been able to afford it.

That might partially offset the energy savings, but since it would have direct benefits in reducing food wastage, it's still a very good thing.

Re:Themoelectrics Already Pretty Good (1)

MobyDisk (75490) | about 6 years ago | (#24362887)

They aren't saying that this material would make a more efficient refrigerator, only that it would be a simpler/cheaper one. I am guessing that places that don't have refrigeration are that way due to a lack of a power source. I'm not sure this will help.

They have decided to name it... (1)

HitByASquirrel (710289) | about 6 years ago | (#24361585)

unobtainium.

The Counter: Stats, Browser Stats, OS (-1, Offtopic)

Anonymous Coward | about 6 years ago | (#24361587)

OS Stats
Fri Feb 1 00:01:02 2008 - Sun Jul 27 17:58:00 2008   177.7 Days

1. Windows XP    24505649 (75%)
2. Win NT    3942033 (12%)
3. Mac    1489133 (4%)
4. Win 2000    1213843 (3%)
5. Unknown    435445 (1%)
6. Win 98    346220 (1%)
7. Linux    290942 (0%)   Oooo!!
8. Win 3.x    33071 (0%)
9. Unix    7492 (0%)
10. Win 95    6442 (0%)
11. WebTV    4478 (0%)
12. OS/2    1435 (0%)
13. Windows ME    833 (0%)
14. Amiga    58 (0%)
15. Windows Vista    4 (0%)

Browser Stats
Fri Feb 1 00:01:02 2008 - Sun Jul 27 17:58:00 2008   177.7 Days

1. MSIE 7.x    13245541 (41%)
2. MSIE 6.x    11799793 (37%)
3. FireFox    5327487 (17%)
4. Safari    1097345 (3%)
5. Opera x.x    264601 (1%)
6. Unknown    243968 (1%)
7. MSIE 5.x    107408 (0%)
8. Netscape comp.    89349 (0%)
9. Netscape 7.x    28882 (0%)
10. Netscape 5.x    27243 (0%)
11. Netscape 4.x    19417 (0%)
12. MSIE 4.x    13853 (0%)
13. Konqueror    11351 (0%)
14. Netscape 6.x    570 (0%)
15. MSIE 3.x    146 (0%)
16. Netscape 3.x    93 (0%)
17. Netscape 2.x    32 (0%)

Re:The Counter: Stats, Browser Stats, OS (0)

Anonymous Coward | about 6 years ago | (#24361609)

15. Windows Vista 4 (0%)

Something is especially rotten in Denmark, and that #15 score can't be correct, either. Or caaaan it?

Straight from The Core (1)

Deltaspectre (796409) | about 6 years ago | (#24361597)

Unobtanium anyone?

Power Efficiency Rating? (2, Insightful)

mux2000 (832684) | about 6 years ago | (#24361603)

What's this power efficiency rating? How much is 1.5 in God's honest Watts per Kelvin, or a simple percentage of power in/power out?

Old news (1)

jdb2 (800046) | about 6 years ago | (#24361629)

A while back there was an article on /. about a "quantum afterburner" : a device that could directly extract energy from a heat source, say, car exhaust, in the form of a laser beam.

Here's a link to the cached Nature article : http://209.85.141.104/search?q=cache:RV6U7lxRqFUJ:www.nature.com/nsu%255C/nsu_pf/020128/020128-3.html+quantum+laser+heat+car+exhaust&hl=en&ct=clnk&cd=1&gl=us [209.85.141.104]

jdb2

I have a cheaper way (2, Funny)

redcaboodle (622288) | about 6 years ago | (#24361651)

Just attach a generator to the lower jaws to my husband and his mother. The energy they produce by moaning about the heat should cool the whole of Cologne for the summer.

What is the %Efficiency of a 1.5 zT? (1)

Doc Ruby (173196) | about 6 years ago | (#24361661)

This advance's benefits are all described in terms of an increased zT [wikipedia.org] now up to 1.5, predicted to go up to 3 or so in the really perfected version of the material. But what does "zT" mean in actual efficiency?

In real terms, let's say that a car engine today consumes about 300KW total contained in its gasoline flow, converting about 20% of that into 60KW for forward motion, and about 60% of that into about 180KW of heat (out the exhaust, and heating the engine/radiator, car and road). If the zT 1.5 material were used at maximum effectiveness in capturing some of that 60%/180KW waste heat as electricity, how many KW of electricity would it put out, into, say, a battery?

Re:What is the %Efficiency of a 1.5 zT? (2, Interesting)

florescent_beige (608235) | about 6 years ago | (#24362435)

z is related to the Seebeck coeff (which tells you how much voltage a given delta-temp gives you in a material), the resistivity and thermal conductivity. It is multiplied by T (the average temp at which the performance is measured) to give a non-dimensional number.

zT doesn't tell you the efficiency because that would depend on the delta T (next para), but it is roughly proportional to it for given operating conditions. zT = 1 materials have efficiency maybe around 5% under best conditions, for zt = 3 you might be around 20%. Notice that if you know S and delta T you know the voltage: you can do some simple circuit calcs with a matched impedance and get the power it will generate. Compare that to the heat energy you get from the delta T and the thermal conductivity and you can get an efficiency, but instead of that lets just throw out some round numbers.

Remember efficiency depends on the delta T due to the 2nd law of thermodyamics. The smaller delta T is the lower the max theoretical efficiency is. If the engine exhaust is at lets say 500F the max efficiency any device could get would be 1 - (492 + 72)/(492 + 500) = 43%. So that would be 78kW of your 180kW for a thermodynamically perfect device.

So if you can get maybe 20% out of thermoelectrics under the best conditions, the low-temp engine exhaust scenario would probably mean you could get at best 10%. So 20kW or so I'd guess. Once you design an actual system it would probably be more like 5 or 10kW.

Use the paint (1)

TheCastro (1329551) | about 6 years ago | (#24361679)

Remember a few days ago there was an article about paint being able to help absorb sunlight for use on solar panels, well combining the two could actually work with absorbing light and heat energy from the sun.

Nuclear Reactors (1)

Sibko (1036168) | about 6 years ago | (#24361693)

I wonder what this kind of technology, once sufficiently advanced enough to absorb the high levels of heat, could do to change nuclear reactor designs.

Imagine a Geothermal Cluster of This Stuff (1)

Doc Ruby (173196) | about 6 years ago | (#24361729)

If this stuff can efficiently convert heat to electricity with very little energy input to manufacture it (compared to, say, steam engines), and can withstand high temperatures without being destroyed, what would it do to geothermal electric production?

Would it not only increase the efficiency of the plants, but perhaps also make accessible lots of geothermal that is expensive to reach with today's bulky mechanical probes? Could we just drill to hot depths, then snake cables down it, and "plug into the ground"?

Re:Imagine a Geothermal Cluster of This Stuff (1)

famebait (450028) | about 6 years ago | (#24366793)

I think there is still a loong way to go to compete with modern land-based thermal plants. Even modern ships stretch their diesel impressively far.

But for applications where you can't lug around industrial-scale heavy machinery, all improvements in heat reclamation are welcome, even though it's all in a different ballpark for the foreseeable future.

Re:Imagine a Geothermal Cluster of This Stuff (1)

Doc Ruby (173196) | about 6 years ago | (#24367797)

I think increasing the efficiency of thermoelectric materials will be welcome in all thermal plants, whether stationary on land or otherwise. There is no need for competition in these technologies, they're complementary. I'd love to see geothermal efficiency jump by 20%.

But there's also probably lots of places that can't support a full geothermal plant. But which could support some dinky infrastructure about as heavy as an old-West windmill. If it were made of this stuff, that could mean quite a lot of power. Especially in remote locations, a combination of wind/solar/geothermal with storage could add a geothermal "trickle charge" to the statistical average wind/solar recharge blasts, and guarantee full power at constant duty.

Pity it sounds pretty poisonous (4, Insightful)

D4C5CE (578304) | about 6 years ago | (#24362057)

thallium-doped lead telluride

An achievement made up of toxic elements, the first being rat poison, the last being the rarest there is. Chances are this won't be cheap to make nor to dispose of, and I wonder what hazards it would pose to the environment if released (vehicles do crash or get abandoned from time to time).

Re:Pity it sounds pretty poisonous (1)

ceoyoyo (59147) | about 6 years ago | (#24363467)

Not even close to the rarest there is. Tellurium is a little more common than gold or platinum. We already use platinum in catalytic converters. As you say, thallium is something that can be found in the average garage or basement already.

Correction (0)

Anonymous Coward | about 6 years ago | (#24362307)

That should be THE Ohio State University in the original posting. They get PO'ed without the definite article.

Sweet, sweet, sweet (1)

Runaway1956 (1322357) | about 6 years ago | (#24362505)

Sweet. Without actually researching further than a couple links, it looks as if this doo-hickey thing-a-ma-bob will be able to replace alternators (or in some few cases, generators) on vehicles. Sweet. It wonÂt wear out, since there are no moving parts. ItÂll last the lifetime of most vehicles, reducing upkeep expenses, it should weigh considerably less than an alternator, which will help fuel efficiency. I like it. Heck, you canÂt HELP liking it!! Hope it makes itÂs way to market soon!

But how does it compare to the JTEC? (2, Informative)

WindBourne (631190) | about 6 years ago | (#24363789)

Johnson Thermoelectric Energy Conversion System [johnsonems.com] ? Seriously, this one is being developed to operate at lower temps. I wonder if this new one will work better or not? But it sure would be useful to add one (or both) of these to say power plants to absorb some of the heat and continue generating more electricity.

cars? (1)

Pictish Prince (988570) | about 6 years ago | (#24363929)

Where's my thermoelectric flying car, goddam it!

Don't get too excited (1)

Kupfernigk (1190345) | about 6 years ago | (#24367873)

Most boat owners could really do with a cheap generator that produces not more than around 25-50 watts (which will drive your central heating system in colder climates and your refrigerator in hot ones - you don't really want a big Diesel running for hours a day and big batteries for when it is not running.)

A few years ago I investigated thermoelectric generators and contacted the suppliers. The unit is basically a thermoelectric generator, air-cooled, with a propane heater providing the hot side. Which at first sight looks very simple. The conversation went something like this.

"You don't want this, it's not economic."
"Nor is spending $10000 on a new generator just to produce an average 50 watts."
"It still isn't economic."
"Perhaps I'm an eccentric millionaire?"
"Still not worth it."

In fact, they flatly refused even to quote. Which suggests that current thermoelectric technology, with all the peripherals, is hugely expensive. So how is it suddenly going to be easy and cheap to stick this in a car exhaust?

2x Efficiency of SECOND best? (1)

owslystnly (873793) | about 6 years ago | (#24368083)

"The invention, thallium-doped lead telluride, is twice as efficient as the second most efficient material used in thermoelectric power." Erm, how much more efficient is it than the FIRST most efficient material?

Nothing new about it (0)

Anonymous Coward | about 6 years ago | (#24368801)

The damn peace & freedom loving French ( I hate them ;-) )did it up in the Pyrenees back in the 70's
http://www.time.com/time/magazine/article/0,9171,909204,00.html

This is where it is http://en.wikipedia.org/wiki/Odeillo

Typo (0)

Anonymous Coward | about 6 years ago | (#24369105)

Excuse me, shouldn't it be THE Ohio State University?

Gradient (1)

vainov (107102) | about 6 years ago | (#24369595)

Meny have pointed out that such a device is useless w/o a temperature gradient. However, when such a gradient exists, there is a solution that is much more potent, commercially available and suitable for use in most environments that I can think of right now. I'm of course talking about the Stirling engine!
During extremely favourable conditions such a device, combined with a generator, can turn as much as 30% of the energy in the gradient into electrical power!!! That, my friends, is a lot!
A more polite and probable outcome, like 10%, is still excellent when there is a source of heat that would otherwise go to waste. This new device may fill some nische, but once enegry prices have risen enough the Sterling enginge will be king!

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