Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

MIT Unveils Sun-Free Photovoltaics

Soulskill posted more than 3 years ago | from the channeling-dark-power dept.

Power 103

An anonymous reader writes "Researchers at MIT just unveiled a new solar power generator that doesn't need sunlight to function. The button-sized power generator can tap energy from heat, the sun's rays, a hydrocarbon fuel, or a decaying radioisotope, and it can run three times longer than a lithium-ion battery of the same weight. It is hoped that the technology may one day be used to generate power for spacecraft on long-term missions where sunlight may not be available."

cancel ×

103 comments

Sorry! There are no comments related to the filter you selected.

I've got an even better idea (4, Funny)

elrous0 (869638) | more than 3 years ago | (#36925580)

We use this thing to run a space heater, which in turn heats up the generator and provides even more energy. Bingo, we've got an endless energy supply. String a bunch of these puppies together and goodbye fossil fuels!

You're welcome, world.

Re:I've got an even better idea (3, Funny)

Thelasko (1196535) | more than 3 years ago | (#36925760)

Please read my signature.

That is all.

Re:I've got an even better idea (1)

elrous0 (869638) | more than 3 years ago | (#36925802)

Innovators don't answer to laws, man. We break them.

Re:I've got an even better idea (1)

blair1q (305137) | more than 3 years ago | (#36925836)

In this case, you don't, any more than a turbocharger "runs" the engine it makes more efficient.

This thing can, however, help your space heater by scavenging heat that would otherwise be wasted by going through the walls instead of into you. But you can get almost the same effect by adding styrofoam insulation to the walls, which would be much cheaper and more reliable.

Re:I've got an even better idea (1)

Bert64 (520050) | more than 3 years ago | (#36931374)

But how about in a data center, where the heat is generated but not wanted...

Re:I've got an even better idea (1)

HeckRuler (1369601) | more than 3 years ago | (#36925920)

Please then, throw yourself at the ground.
And miss.

Re:I've got an even better idea (1)

Lifyre (960576) | more than 3 years ago | (#36926162)

I've tried that a few times. Every time I succeed the Earth gets upset and comes rushing at my head like an angry hippo.

Re:I've got an even better idea (0)

Anonymous Coward | more than 3 years ago | (#36926670)

I seem to recall a similar scenario with a whale and a bowl of petunias.

Re:I've got an even better idea (1)

garaged (579941) | more than 3 years ago | (#36930302)

you gotta be a computer simulation scientist

Re:I've got an even better idea (0)

Anonymous Coward | more than 3 years ago | (#36925960)

damn beat me to it.

Re:I've got an even better idea (1)

guybrush3pwood (1579937) | more than 3 years ago | (#36926018)

Think bigger: We build millions of these things, place them next to a volcano, and use them to power a supercomputer with a neural interface. We run Minecraft on it. We attach legions of rats to said interface. Then we harvest the electricity generated by the rats' bodies. We use this electricity to power a concentrated beam of light, and use it to push a solar sail attached to a spacacraft. Then we go to Mercury, repeat, and go to Alpha Centauri. Repeat enough times, and rule the Metaverse.

Re:I've got an even better idea (1)

darrad (216734) | more than 3 years ago | (#36926270)

Or we could just ask the SuperComputer to use the rats to determine the meaning of life, the universe and everything...

Re:I've got an even better idea (1)

sabt-pestnu (967671) | more than 3 years ago | (#36926660)

Sorry, you lost me at Minecraft. /em is busy creating pixelated mice and a supercomputer using Minecraft blocks.

Re:I've got an even better idea (1)

Arancaytar (966377) | more than 3 years ago | (#36927724)

mice and a supercomputer

So, what is the ultimate question?

Wrong law (1)

elsurexiste (1758620) | more than 3 years ago | (#36926274)

This machine transforms heat into work. It could be used to reverse entrophy! Take that, thermodynamics!

Re:I've got an even better idea (1)

ISoldat53 (977164) | more than 3 years ago | (#36926282)

Put it where the sun shineth not.

Re:I've got an even better idea (1)

Sulphur (1548251) | more than 3 years ago | (#36931174)

Put it where the sun shineth not.

Two words: fiber optics.

Re:I've got an even better idea (-1)

Anonymous Coward | more than 3 years ago | (#36926602)

Moot (Christopher Poole) here,
On behalf of myself and all the moderators on 4chan, we'd like to apologize for elrous0. Here at 4chan, we take every foreseeable security precaution to prevent the escape of those in our charge, both for the safety of the inmates, as well as the safety of the public. Due to circumstances we are still investigating, elrous0 managed to escape containment at /sci/, which is the name of the unit where we house the physics trolls. We here at 4chan offer our most sincere apologies for this incident. Elrous0 has been returned to our care now, and will temporarily be housed in our highest-security wing (known as /b/) until such time as we can ascertain how he was able to circumvent our security arrangements.

Again, please accept our apologies for the inconvenience, and our assurances that this will not happen again.

Re:I've got an even better idea (1)

bberens (965711) | more than 3 years ago | (#36926958)

Umm, big problem with your theory there bud. By creating an infinite loop of heat creation you'll dramatically increase the rate of global warming.

Re:I've got an even better idea (1)

NatasRevol (731260) | more than 3 years ago | (#36927014)

But somebody just put out a paper saying that wasn't happening!

Re:I've got an even better idea (0)

Anonymous Coward | more than 3 years ago | (#36931228)

All that extra energy will be used for powering a *giant* AC.. problem solved..

Re:I've got an even better idea (1)

turing_m (1030530) | more than 3 years ago | (#36928278)

I think it needs a little more oil.

Laptops (1)

amiga3D (567632) | more than 3 years ago | (#36925666)

I want one for my laptop. At last I'll be able to surf continuously.

Re:Laptops (1)

CastrTroy (595695) | more than 3 years ago | (#36925946)

I've wondered about this. Laptops create quite a bit of heat. Wouldn't it be possible to capture some of that heat and charge the battery with it. Obviously you couldn't do this continuously, as per the laws of thermodynamics, but wouldn't it be possible to get some benefit from this? Also, you could probably save on running fans as well if you converted the waste heat back into electricity.

Re:Laptops (1)

pixelpusher220 (529617) | more than 3 years ago | (#36926326)

This would be the laptop equivalent of hybrid cars so yes technically it's possible.

By capturing energy from the 'waste' heat, the heat produced by operating the computer would give it slightly longer battery life. Just like regenerative braking of hybrids charges a battery which then allows them to use the full weight of the vehicle for power generation while only carrying a small percentage of increased weight.

Re:Laptops (1)

wagnerrp (1305589) | more than 3 years ago | (#36927008)

This acts like an insulator. Given a sufficiently large heatsink, you could potentially do this. Within the confines of a laptop, it will simply cause a CPU to run hotter. A hotter CPU requires a higher voltage to maintain stability, which in turn consumes more power and produces even more heat.

Air Conditioner (1)

georgenh16 (1531259) | more than 3 years ago | (#36925698)

Can I put this on my walls in the summer and actually get energy from cooling my house down?

Re:Air Conditioner (1)

Anonymous Coward | more than 3 years ago | (#36925756)

Not as much as it takes to cool it, down but it might reduce the bill at least.

Re:Air Conditioner (0)

Anonymous Coward | more than 3 years ago | (#36926304)

Not as much as it takes to cool it, down but it might reduce the bill at least.

Why not? It's not a peltier element that works on the temperature difference between to surfaces. The energy comes from temperature compared to absolute zero. Walls, floor and inner roof covered with this will convert heat to electricity in a manner that is not related to outside temperature.
Sure, it will convert less energy the colder it gets but as far as I can see there is nothing that says that it can't convert more energy than the amount that is needed to cool the house to a nice temperature.

Re:Air Conditioner (1)

trum4n (982031) | more than 3 years ago | (#36925766)

In theory, yes.

From heat? (2)

Baloroth (2370816) | more than 3 years ago | (#36925726)

The button-sized power generator can tap energy from heat, the sun's rays, a hydrocarbon fuel, or a decaying radioisotope.

Looking at TFA, it looks like it takes heat, converts it to light in very specific frequencies, and then uses that to generate electricity. So, any source of heat whatsoever should theoretically be able to power these. We already possess thermoelectric generators, but they tend to be effective only at very specific and fairly low temperatures. Potentially, this kind of technology could replace conventional turbines in most power plants (nuclear, coal, et al. Basically, any that directly generate heat). Anyone know what kind of efficiencies these could operate at vs. steam turbines? I know turbines are fairly efficient (but large, hence this new tech), but it seems like these could (maybe) exceed those.

Also, if these things could be designed to require fairly low heat, then I imagine they could be used in basically any everyday device, generating low power from room-temperature heat. They don't seem to require the heat-differential of thermo-electric generators, so I wonder if they could supplement/ replace batteries in many daily electronic devices (pacemakers and hearing-aids come to mind, cell phones likely require way to much power). Anyone know if that kind of thing is at all practical?

Re:From heat? (1)

Rising Ape (1620461) | more than 3 years ago | (#36925830)

They don't seem to require the heat-differential of thermo-electric generators

In this house we obey the laws of thermodynamics! (sorry).

Steam turbines are pretty good efficiency-wise (as a fraction of the theoretically optimum Carnot efficiency), given the constraints on operating temperature that they operate under due to corrosion considerations and so forth. If something could work with a higher temperature heat source, it could get higher efficiency.

Re:From heat? (1)

WindBourne (631190) | more than 3 years ago | (#36928678)

Yes, in certain places, they are efficient. However, if you do not have a good enough cooling source(say a river on a very hot day, space, etc), then it does not work so well. This is to steam turbine electric generation what LEDs are to Incandescents. What is really interesting is that it could be possible to replace these every 10 years and gain more efficiency.

Re:From heat? (1)

thynk (653762) | more than 3 years ago | (#36925940)

I think it's neat tech alright, but I'm not sure converting the heat energy to light energy to electricity is going to be more efficient than converting heat energy to electricity. Since TFA doesn't seem to give us any efficiency stats, it's hard to tell.

Re:From heat? (0)

Anonymous Coward | more than 3 years ago | (#36926612)

But we don't convert heat energy into electrical energy. We convert heat energy into mechanical energy into electricity. The mechanical step is where the bulk of our efficiency problems come from.

Re:From heat? (1)

Rising Ape (1620461) | more than 3 years ago | (#36926844)

The mechanical step is where the bulk of our efficiency problems come from

Not really, in fact the mechanics are pretty efficient. The problem is mostly thermodynamics. Heat is a poor place to start if you want to get usable energy - you can't do better than the Carnot efficiency by any means, as that would imply the universe spontaneously lowering its entropy.

Re:From heat? (1)

Exceptica (2022320) | more than 3 years ago | (#36931504)

> as that would imply the universe spontaneously lowering its entropy

The universe spontaneously lowers its entropy all the time. Cases in point: you, your parents, their parents, etc, etc.

Re:From heat? (1)

White Flame (1074973) | more than 3 years ago | (#36927434)

We don't ever convert from heat energy to electricity in standard power production. It's always heat to mechanical energy to electrical energy.

Thermocouples do directly convert heat to electricity, but they're typically not for power generation (except in specialty scenarios like satellites), they're mostly for sensors.

Phase Change dictates Mechanical stage (0)

Anonymous Coward | more than 3 years ago | (#36928758)

The reason we use steam turbines as the mechanical step, no matter what the originating heat (fossil fuel, nuclear decay, solar, etc.) is because the phase change from liquid to vapor for water is such a huge volumetric difference that it is extraordinarily efficient for energy conversion. Photovoltaics, even these new ones, will never be as efficient in energy conversion if it tries to skip the mechanical step.

There's a reason that many energy storage systems employ molten salt or making ice during off peak hours. It make sense to use phase transitions of materials as the energy conversion step.

Re:From heat? (0)

Anonymous Coward | more than 3 years ago | (#36926000)

They don't seem to require the heat-differential of thermo-electric generators

No - Thermal Emitters work on the basis of heat differentials. Just that due to lack of moving parts etc, conceptually it can be quite efficient, while in practice it is not so. Reg: the story, Thermophotovoltaics [wikipedia.org] is a widely studied field. The major innovation here is that while previously the emitters emitted photons in a range of wavelengths (depends on the emitting temperature - higher it is, the shorter the wavelength and better captured by the PV), these emitters can finetune and send wavelengths in specific frequencies - which means that the associated PV has comparitively losses while capturing the photons.

Re:From heat? (1)

elsurexiste (1758620) | more than 3 years ago | (#36926228)

Problem, thermodynamics?

Re:From heat? (1)

Nyrath the nearly wi (517243) | more than 3 years ago | (#36926744)

All devices like this do not convert heat into electricity. They convert a heat gradient into electricity. The original heat is still there.

Re:From heat? (0)

Anonymous Coward | more than 3 years ago | (#36927420)

This thing uses heat to make infra red and then runs solar of it, how does it actually require a gradient, I am probably missing something but should this not work even without one? If not why not?

I am not a physics student but it would be good to know either way, also do you know of any hypothetically possible situations or systems ,eg extremes of gravity, in which the assumptions on which the laws of thermodynamics are based would be broken enough to cause action against the second law.

Re:From heat? (1)

lyuden (2009390) | more than 3 years ago | (#36930602)

Because if something could absorb light of particular wavelength it can radiate light of particular wavelength. So hotter body radiates more energy than it absorbs from colder body and energy flow from hotter body to colder one. Second law of thermodynamics yeah. There is quantum magic during absorption and conversion of photons to electric current but it did n't violate energy conserving.

Re:From heat? (0)

Anonymous Coward | more than 3 years ago | (#36926942)

What about body heat? The power demands of a pacemaker are actually microscopic.

Wrong units (2)

bar-agent (698856) | more than 3 years ago | (#36927122)

The power demands of a pacemaker are actually microscopic.

How low are the power demands of a pacemaker in terms of the Library of Congress?

a friendly warning, friend... (1)

Thud457 (234763) | more than 3 years ago | (#36928286)

You know, once all units are freely convertible into standard federal LOCs, google is going to divide by zero and trigger the singularity.

Re:From heat? (1)

timeOday (582209) | more than 3 years ago | (#36927120)

Also, if these things could be designed to require fairly low heat, then I imagine they could be used in basically any everyday device, generating low power from room-temperature heat.

According to the article:

a slab of tungsten, engineering billions of tiny pits on its surface. When the slab heats up, it generates bright light with an altered emission spectrum because each pit acts as a resonator, capable of giving off radiation at only certain wavelengths.

Is that black body radiation?

Radiating visible light requires a high temperature (a hunk of tungsten doesn't glow at room temp), but maybe you can emit other frequencies at lower temperatures?

Re:From heat? (1)

Baloroth (2370816) | more than 3 years ago | (#36927748)

That was my though exactly. TFA and the summary both say this works in sunlight, so I assume it has a fairly low threshold of heat to start "glowing". It seems like it might be possible to make them "glow" at room temperature. The law of thermodynamics wouldn't be violated AFAIK (the device would get colder, requiring new heat to be added... but there is plenty of that in our environment). The efficiency would be probably be... well, very, very low. Like I said, it'd be for low power devices. Essentially a regenerating battery, like a solar-powered calculator but working off heat rather than light.

Re:From heat? (1)

adolf (21054) | more than 3 years ago | (#36929890)

Why not just skip the energy conversion from heat to light that makes this new widget special, and just use the correct mix of fuel/air/catalyst/whatever to make coal/oil/gas burn -bright- (instead of merely hot), and use a photovoltaic without any new wizardry?

Of course, it'd be blindingly inefficient compared to running a steam turbine with the same fuel. But then, so is this other gadget...

I think there's a lot of new applications which open up with a contained method for converting heat into electricity without moving parts: If it's small enough, it can help my phone recharge (or at least discharge more slowly) if I leave it in a hot car, for instance.

But replacing large steam turbines seems a little far-fetched. You'd still need substantial cooling if you want substantial power output, which generally means using water, which -- gosh -- generally means that it's easy to just drive a turbine instead.

(That said, it might be fun to capture some of the waste energy from existing steam turbine plants...)

Re:From heat? (0)

Anonymous Coward | more than 3 years ago | (#36930062)

The real product is vibration free power for a nuclear submarine

Perpetual? (2)

Marble68 (746305) | more than 3 years ago | (#36925742)

So, Can I combine it with a battery and then use it as a heat sink for the CPU in my phone?

I only need juice until it gets hot, right?

Re:Perpetual? (2)

Arlet (29997) | more than 3 years ago | (#36925840)

In order for the device to extract energy from heat, it needs to be cold itself.

Re:Perpetual? (1)

bar-agent (698856) | more than 3 years ago | (#36927046)

In order for the device to extract energy from heat, it needs to be cold itself.

Couldn't it work the other way? The device is hot and the surroundings are cold?

Re:Perpetual? (1)

Crudely_Indecent (739699) | more than 3 years ago | (#36929090)

TFA indicates that the heat from any source is converted to specific light frequencies, then to electricity.

As far as I understand the process (from TFA), heat is required but not cold.

Both linked articles are short, you should read them.

Re:Perpetual? (0)

Anonymous Coward | more than 3 years ago | (#36929778)

Couldn't it work the other way and use electricity to move heat from one location to another?

Battery Comparison (1)

Thelasko (1196535) | more than 3 years ago | (#36925744)

Comparing this device to a battery is like comparing a gas tank to a an electric motor. A battery stores energy, while this converts it to another form.
How much more power does it produce than a solar panel of the same weight?

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36925826)

100% more - this works in darkness, solar panels do not.

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36926454)

100%... I don't think that word means what you think it means...

Re:Battery Comparison (1)

NatasRevol (731260) | more than 3 years ago | (#36927136)

Fine, 1000%. Happy???

Re:Battery Comparison (1)

wagnerrp (1305589) | more than 3 years ago | (#36927076)

Correction. This works in the absence of visible light. Just because something is not emitting light in the visible spectrum does not mean it is dark in the infrared spectrum.

Re:Battery Comparison (4, Informative)

dhj (110274) | more than 3 years ago | (#36925962)

Good point... The summary left off an important bit of information from TFA:

"Based on that technology, MIT researchers have made a button-sized power generator fueled by butane that can run three times longer than a lithium-ion battery of the same weight; the device can then be recharged instantly, just by snapping in a tiny cartridge of fresh fuel"

So... using this to convert butane to electrical energy it lasts three times longer than a lithium-ion battery of the same weight.

But if you look at energy density of the two fuel sources: http://en.wikipedia.org/wiki/Energy_density [wikipedia.org]

You find that butane/propane/gas/diesel is about 45 megajoules / kg and Li-ion batteries store about 0.75 megajoule / kg. Converted energy 2.25 megajoules (3x Li-Ion) out of stored energy 45 megajoules = 5% efficiency rate converting butane heat to electrical energy using this device.

--David

Re:Battery Comparison (1)

Thelasko (1196535) | more than 3 years ago | (#36926190)

You find that butane/propane/gas/diesel is about 45 megajoules / kg and Li-ion batteries store about 0.75 megajoule / kg. Converted energy 2.25 megajoules (3x Li-Ion) out of stored energy 45 megajoules = 5% efficiency rate converting butane heat to electrical energy using this device.

You neglected to include the mass of the oxygen consumed in that butane reaction. Don't worry, everyone does. At 13 oxygen atoms per butane molecule, and ~16 grams per mole that's 208 grams of oxygen per 58 grams of butane for a stoichiometric reaction.

Forgive me, my thermochemistry is rusty.

Re:Battery Comparison (1)

Thelasko (1196535) | more than 3 years ago | (#36926276)

You neglected to include the mass of the oxygen consumed in that butane reaction. Don't worry, everyone does. At 13 oxygen atoms per butane molecule, and ~16 grams per mole that's 208 grams of oxygen per 58 grams of butane for a stoichiometric reaction.

Sorry, my point is that the lithium ion battery is heavier, in part, due to its need to carry both reactants with it. Butane can react with the oxygen in the atmosphere. However, if you didn't have the convenience of abundant oxygen, like in space, you would have to carry the oxygen with you making the whole thing 4.5 times heavier.

Re:Battery Comparison (1)

Overzeetop (214511) | more than 3 years ago | (#36926334)

No, I'm pretty sure he got it right. The 45MJ number is based on a stoichiometric reaction of 1kg of butane with the necessary additional mass of oxygen for complete combustion. You should be getting about 60x the life of a Li-Ion cell, but you're only getting 3x, so you're operating at 5% "efficiency". The battery doesn't store the O2, nor in the O2 included in the 45MJ/kg, so it's straight algebra.

Re:Battery Comparison (2)

gstrickler (920733) | more than 3 years ago | (#36926464)

And you've neglected to account for the actual mass of the butane/Li-Ion reactants vs the mass of the reaction chamber and TPV. The Li-ion battery needs only a casing, all the other mass is the anode and cathode. The TPV needs a container for the butane, a reaction chamber, ducting for air to enter the reaction chamber, and the separate TPV cell.

Then, we need to look at volumetric energy density comparisons too, as devising a container strong enough to hold a mass of butane with comparable energy in a similar volume to a Li-ion cell might be too heavy for a portable device. Both volumetric and gravimetric energy density are important in portable devices.

When we see actual efficiency ratings for these TPV devices, then we can evaluate their usefulness.

Re:Battery Comparison (1)

adolf (21054) | more than 3 years ago | (#36929984)

Stated like that, it sounds almost as useless as the fluff about small-scale butane-powered fuel cells and tiny little gas turbines that I saw on these very pages a decade or so ago, none of which seem to have actually materialized.

Re:Battery Comparison (1)

wagnerrp (1305589) | more than 3 years ago | (#36927114)

Unless you're talking about going into space, you don't have to carry your own oxygen.

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36928846)

water

Re:Battery Comparison (1)

charlieo88 (658362) | more than 3 years ago | (#36930158)

Does it consume enough oxygen that an enclosed, non-space environment is a problem, such as an office building or airplane?

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36931184)

unless you breath oxygen and the window is closed.

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36929384)

But what if you surrounded a butane flame with these!

This raises the efficiency of butane...? Right?

Re:Battery Comparison (0)

Anonymous Coward | more than 3 years ago | (#36941440)

How much of the weight is the power generator and how much is the butane. If only 5% of the weight is accounted for by the actual butane, then it could be 100% efficient. In other words, there is an important component missing from your calculations.

BODY HEAT! (1)

_0rm_ (1638559) | more than 3 years ago | (#36925804)

I am simply stunned that nobody has mentioned body heat. Think about it, all you would need to do to charge your cell-phone is put it in your pocket! Spelunking? Attach a patch to your arm and your light lasts even if you (idiotically) run out of batteries. The applications for this tech are endless, and quite frankly, the article criminally neglects this fact.

Re:BODY HEAT! (0)

Anonymous Coward | more than 3 years ago | (#36926128)

Feels like somewhere between skynet and the matrix.

Re:BODY HEAT! (1)

ThorGod (456163) | more than 3 years ago | (#36926524)

The problem there is biological organisms are very efficient. Off the top of my head, 500 calories will get a biker 5+ miles down the road, whereas 500 calories might get a car ~300 feet down the road. (Obviously wrong statistic, but you get the idea.)

Re:BODY HEAT! (1)

_0rm_ (1638559) | more than 3 years ago | (#36936502)

But we still generate heat regardless.

Generator not equal battery (0)

Anonymous Coward | more than 3 years ago | (#36925856)

What does "runs three times longer than a battery of same weight" even mean?
The generator runs as long as there is radiation around it, no?

Re:Generator not equal battery (1)

shadowrat (1069614) | more than 3 years ago | (#36925986)

yeah, and i can make a battery run longer than a battery of the same weight by not drawing as many amps from it. can this thing provide 1.2v at 20ma 3 times longer than than a AA battery? sounds awesome. does it only provide .2 micro milliamps ? um then i'm not impressed.

Re:Generator not equal battery (1)

SleazyRidr (1563649) | more than 3 years ago | (#36927722)

I thought it might be that the generator itself burned out once it had produced 3 times as much energy as the lithium battery could hold.

Anyone see any numbers? (1)

blair1q (305137) | more than 3 years ago | (#36925858)

I've clicked on everything I can see, and I don't see the actual efficiency rating they keep alluding to.

Re:Anyone see any numbers? (4, Funny)

sweatyboatman (457800) | more than 3 years ago | (#36926398)

did you punch the monkey? I think you need to punch the monkey to see the specs.

Re:Anyone see any numbers? (0)

Anonymous Coward | more than 3 years ago | (#36928602)

I actually LOL'd. I rarely do that.

already done (1)

fche (36607) | more than 3 years ago | (#36925938)

Those clever Germans have already mastered solar power without the sun.
http://bishophill.squarespace.com/blog/2010/4/13/its-true.html [squarespace.com]

Re:already done (1)

rbrausse (1319883) | more than 3 years ago | (#36926294)

Those clever Spaniards have already mastered solar power without the sun.

ftfy, the German mentioned in the blog was the language of the Swiss news report about an article in the Spanish paper El Mundo.

If you are unhappy about all the nations mentioned just read this [theecologist.org]

Re:already done (1)

fche (36607) | more than 3 years ago | (#36926408)

That's hilarious, thanks for the correction.

You mean its a peltier plate (0)

Anonymous Coward | more than 3 years ago | (#36925974)

Hoopty Fucking Doo

How many buttons (1)

Iamthecheese (1264298) | more than 3 years ago | (#36926068)

are in a square foot?

Carnot cycle (0)

Anonymous Coward | more than 3 years ago | (#36926120)

I suspect the Carnot cycle is a valid predictor for the potential efficiency of this type of device. Even though that may be the case, this is an interesting device. It appears to be a possible way to fulfill the role of a fuel cell without the fuel cell's sensitivity to fuel quality.

ROADS! (0)

Anonymous Coward | more than 3 years ago | (#36926140)

Implement this into the road system and you'll solve the energy crisis! You could probably power half the US with the amount of heat being generated on Texas roads today! /dnrtfa

Oh, whatever, (1)

ThorGod (456163) | more than 3 years ago | (#36926584)

I had this idea like 5 years ago. But, being a mathematician, I merely discovered the existence of the idea. These engineers have only supplied an example implementation of the idea.

Trivial, trivial.

(sarcasm)

Electricity from heat is trivial and old (2)

140Mandak262Jamuna (970587) | more than 3 years ago | (#36926984)

How old are thermocouples? Seriously folks, that someone took heat energy and created a current flow is no reason to go ga ga. Look at efficiency. Carnot heat engine is quite abstract and no matter what, there is an absolute maximum efficiency given the temperature of the source and the sink. Unless you have a bottomless pit of of sink at absolute zero degree kelvin, this sucker too would look very much like a thermocouple. Curious, interesting, might find some application in some weird situations. But in general, if ain't gonna replace either the IC engine or the battery any time soon.

Re:Electricity from heat is trivial and old (1)

NewWorldDan (899800) | more than 3 years ago | (#36927222)

I think the point of this thing is that it's a major improvement in conversion efficiency over thermocouples. One of the target applications is RTGs on spacecraft. So maybe you can get 3x the electricity out of the same chunk of plutonium. That's a major improvement. However, using it as a replacement for laptop batteries probably isn't going to fly.

Re:Electricity from heat is trivial and old (0)

Anonymous Coward | more than 3 years ago | (#36928634)

Thermocouples don't generate "current" they will modulate a current flow by altering the circuit impedance.
This device can create an electrical potential difference from a thermal potential difference. But at these efficiencies it's just a nifty way to convert butane into c02.

Global Warming = Global Electricity Generation! (0)

Anonymous Coward | more than 3 years ago | (#36927448)

We will need Tesla Towers with giant electrodes. And transformers, many transformers, to step the voltage down from lightning to household...

Di3k (-1)

Anonymous Coward | more than 3 years ago | (#36928220)

by BSDI who seel BSD managed to make Contaminated while driven ouct by the

Sigh (1)

pdfsmail (2423750) | more than 3 years ago | (#36928268)

Nice little gizmo I admit. Hope it turns out to actually be useful (or lead to something that is) For those who want to make a free energy device: You know people, science concluded a long time ago that you can not make more energy from nothing. If it was that simple it would have been done a long time ago. You imply that if I had lightbulb 1 and solar panel 1 in a room, then there was a wire running to another room running lightbulb 2 which shined on panel 2.. which in turn had a wire back to 1 that the energy created would be able to sustain enough power to keep each light running indefinately...... please dont say yes. It will not happen, Wires have resistance and lose energy, and solar panels are not 100% efficient at converting light to energy (nothing has a pure 100% conversion rate, light, heat, electrical, wind, etc..). If it is not 100% efficient then it will lose energy and eventually die, on top of that if it were 100% efficient you couldn't bebefit from it because all the energy involved would then be dedicated to keeping the system going, hence you would need a system that creates energy from nothing to even be slightly beneficial - impossible. I find that most people that seriously believe that it is possble are first semester college students or hippies that read one basic physics book and somehow missed the part above (or couldnt comprehend it).... and get wild impossible idea that thousands of scientits have already disproved. could we drop this idea and try something else less annoying? Maybe wait until a scientist (not you) discovers how to harness something like dark enery / dark matter - if it exists - and use it for energy.

Supplemental technology (1)

LongearedBat (1665481) | more than 3 years ago | (#36930522)

It's unlikely to replace current electricity generators but it could be a good supplement. Something that converts ambient heat to electricity could be used to...

- extract that bit more electricity from the exhaust of steam turbines and engines (ex. electric hybrid cars).

- extend battery life of devices that get hot (ex. laptops (though good laptops run fairly cool anyway)).

- be used to cool things down for "free" (if we can make them efficient enough). Uses: fridge walls, aircons, solar panel coolers, etc.

This sort of thing could be a very useful supplemental technology. I couldn't find in the articles how efficient they are. Anyone know?

Spacecraft? (1)

yarnosh (2055818) | more than 3 years ago | (#36930704)

Seems to me that if you're on a spacecraft and you don't have some sort of nuclear power plant, you're in trouble. Or should I be thinking "probes" here?
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?