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How to Charge Your Cellphone Using Wasted Heat
Ilya writes "Companies such as BMW are investing in Thermoelectric Generators to make their cars more efficient by replacing the alternator. Thermoelectric Generators convert wasted heat from the engine into electrical power. This green instructable shows how you can use the same technology right now at home to harvest expelled heat from home appliances to charge your cellphone and other gadgets. Also features a lego racer powered by the roaring flames of a tea candle."
Bill Winston Ministries?
BWM makes awesome cars
I like to work out in my rec. room with various exercise equipment. My favorite? The Carnot cycle (http://en.wikipedia.org/wiki/Carnot_heat_engine)
I just hop on and convert all the waste heat in the room to useful energy
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I could probably power a small village :-)
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Authority questions you. Return the favor.
Should really have been called "Cannot" cycle.
If I had an Ass, I'd call it Fanny Bottom, then I could slap my Ass; Fanny Bottom, on the Arse.
Given that the average American consumes 13,500KWh per year, getting a couple of Watt-hours into your phone from wasted heat instead of the grid isn't going to make a damn bit of difference.
"I bless every day that I continue to live, for every day is pure profit."
finally someone invents a use for the formerly useless lego mindstorms thermal sensor. Use it to let your mindstorms bot find a recharging stations
Some drink at the fountain of knowledge. Others just gargle.
I read the article in Car & Driver the O.P. is referring to a while ago (if it's not already obvious the automotive company he is referring to is BMW). At least in automotive applications, it begs the question, is it worth the effort? The extra parts, weight, and cost you'd have to add to a vehicle would probably cause you to break even in terms of MPG or dollars per gallon. The situation is similar with diesel engine options, the extra initial cost of the diesel optioned vehicle is often times just not worth it, despite the MPG advantage.
laptop heat? can that be used to charge it self?
Great! Something to finally help the terrible battery life on my 3G.
Yes, but your battery will still go dead.
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This is something I never quite grasped from physical chemistry class. Obviously you can reclaim some energy from heat, but you can't reclaim it all, as that would break the 3rd law of thermodynamics. How much energy can you actually reclaim from a given amount of heat? Is it a constant fraction, if so where does that number come from? Is it variable? If so, what does that number depend on?
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No. See the laws of thermodynamics.
If the geiger counter does not click, the coffee, she is not thick.
That would be the second law, that would be broken if you could recover all the heat. The third law is a bit more obscure and basically means that the first two laws apply to everything.
The amount you can recover varies according to the efficiency of the device you use to recover it, and depends completely on the details of your setup. Obviously no device is 100% efficient (that's the second law again), so you will never be able to recover all of the lost heat. It is possible to get remarkably high efficiency in some setups.
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While my own knowledge of thermodynamics is minimal to say the least (never really studied physics at university, got stuck deep in comp sci instead), I seem to remember something about heat tapping generators reducing the thermodynamic efficiency of an internal combustion engine. If an additional load is introduced on an internal combustion engine, whether that be a direct load such as an extra belt on the output shaft to run the alternator or an indirect one such as a "waste" heat conversion alternator, then wouldn't that also reduce the output power of the engine (necessary in the case of the alternator since gasoline engines will not run without one)? Perhaps I am missing something that a physics geek could easily explain or is there really a "free lunch" here with regard to waste heat?
That heat is traditionally used for roasting nuts
AT&ROFLMAO
but you will get longer life out of it then?
Some of the energy can be recovered, but not enough to charge the battery.
Troll, n. - Someone who disagrees with me
Surely the primary objective of a combustion engine is to provide a means of propulsion, not heat generation?
Perhaps I'm missing something?
I totally made a joke about this a few days ago... http://slashdot.org/comments.pl?sid=1201373&cid=27599775
The musings of just another geek and his junk.
If only we could come up with some sort of mineral oil solution to absorb my body heat, i could power my computer from the heat my body generates! I could even get my neighbors to join in and we could pool our bodyheat to power a super computer. And maybe to relieve boredom we could all play in a "virtual world" so that we don't waste our energy on non-supercomputer related activities. Maybe the Matrix Online would be a good choice.
How much energy is produced? I'd imagine not a lot. How much does it weigh? Does it cost more in fuel to lug these around than they can produce? You'd need one at the exhaust, one at the engine, one at the brakes..
Is this another deal where I spend $1000 and get 5w/hour?
I just hop on and convert all the waste heat in the room to useful energy
If you're doing exercise, it'd be a Carnot heat pump, n'est-ce pas? One end would get cold, and the other hot...
Only if you run your computations in reverse some of the time.
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Regenerative breaking?
Does that mean hitting it with a sledgehammer recharges the battery?
"City hall" in German is "Rathaus" Kinda explains a few things......
I guess farts are funny anymore.
Having to work for a living is the root of all evil.
Heat can be used to do work.
News at 11.
Yes, you will get longer battery life if you turn some of the "heat" into electricity. There are some problems to look out for, though. The thermocouples don't really convert heat into electricity. It's the temperature difference between the hot and the cold side which creates the electricity, so you have to have a heat source and a heat-sink capable of sinking the heat without warming up too much. Since the cool side has to stay cool, the temperature difference between the air and the heat-sink is low, which means you need a much bigger heat-sink than normally. (The instructable shows a thermocouple with heat sink mounted on the side of a bike exhaust: the additional drag probably costs more energy than the device can extract from the heat difference...)
JTEC. Use this, drop the alternator as well as the serpentine belt and move towards an all electric system. This would allow them to move a GAS car to an electric powered steering (or perhaps a motor driving hydraulic pump), a heatpump that would also go into an electric car. This would allow a car company to more easily move towards electric cars.
I prefer the "u" in honour as it seems to be missing these days.
"It was the G1-1.4-219-1.14 $75 from tellurex."
Using "waste" sure is expensive...
I was visiting Illinois State University's physics department because I am planning on attending this fall. They were working on a material along these lines with a fairly high efficiency rate but they were just starting actually trying to make small amounts of the material.
Their intended use of the material would be in steel foundries, etc. where millions of dollars are spent on power and even something not very efficient could save a ton of money.
From what I gathered talking to the professor there the same efficiency increasing techniques could be used even with smaller temperature differentials as long as you had different materials used.
Sorry but they don't have too much information on their website. They had a few posters with information in the building but not much online.
http://www.phy.ilstu.edu/programs/research.html
A link to the professors bio:
http://www.phy.ilstu.edu/facandstaff/marx.html
I THINK they said the calculated efficiencies would be along the lines of 15-25% depending on materials, temperature differentials, and the actual temperatures. It may have been higher than that though.
Cooking on your car's engine.
Have gnu, will travel.
It's also worth noting that these heat-to-electricity units impede the flow of heat. Just like putting a dam with a turbine in it makes the water levels upstream go up, a peltier style generator would increase your laptop's temperature.
Hopefully, the generator will provide the extra energy needed to power all the extra fans you'll need.
Keep the hot side hot and the cool side cool... don't tell me McDonalds had the secret to providing a minuscule increase in energy efficiency and only used it to make a crappy burger!
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I wanna use my huge bank of toasty little wall warts to charge my cell phone. If I can do that the lazy little power-sucking tribbles might finally justify their existence.
Peltier Junctions are really old news, they're not very efficient at all, they don't last forever, and they're not particularly cheap. TFA doesn't have anything new to say or any links that have anything new to say. Mod the entire post down to -1, Useless post and move on.
Are YOU using the TOOL, or is the TOOL using YOU? Think about it!
So your cars Catalytic converter could become a replacement for the Alternator? That might even boost millage as not having the alternator would reduce drag on the engine.
How %efficient are these thermoelectric devices in outputting electric power W from the power W extracted by cooling the wastefully hot devices? And how much power does it take to manufacture one of these thermoelectric devices?
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If you're living in a cold climate, the exhaust from the dryer ought to go to a heat exchanger to help heat up your house.
If you're living in a hot climate, it's a waste of energy to use anything other than clotheslines and drying racks.
Any sufficiently unpopular but cohesive argument is indistinguishable from trolling.
What's with all the McDLT references as of late? Is this a new internet meme?
That was a fucking delicious burger though.
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I have a secret plan to run ipods off of the Cosmic microwave background radiation.
Can I use the waste heat from an electric motor to charge the battery that run the motor?
I've abandoned my search for truth; now I'm just looking for some useful delusions.
You can use this or some similar gadget to turn anything into a timed device. About twenty bucks.
Weaselmancer
rediculous.
You don't get much from thermoelectric conversion - in my business of wireless sensor networks you see a lot of offerings. The best stuff in the past couple years generates about 50uW/sq cm for a 5C difference. That's good enough for a wireless sensor hugging a tree, perhaps. Available power goes up for more thermal difference, but it's unlikely that anytime soon either BWM, Adui, or even Fnord, for that matter, will be replacing the inexpensive, reliable and robust automotive alternator with a pricey power-producing muffler. Well, maybe Fnord.
The way this works is that the hotter your CPU (or whatever is generating the heat) gets, the more electricity it generates. So if your CPU is already at the limit of its heat tolerance (e.g. if your laptop's heat management system has told the fan to turn on), then adding this would only make it worse because you'd use all the power -- and more* -- to run the fan faster. If, on the other hand, your laptop runs cool enough (without a fan) that it has room to get hotter without breaking, then you could benefit from adding one of these. Basically, it has the same effect on the laptop as increasing the ambient temperature would.
(* see Second Law of Thermodynamics)
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If you were using fans to begin with, this would always cause a net loss in efficiency. The only way to gain would be if the surroundings could absorb the extra heat fast enough without spending extra energy on cooling.
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
I don't understand that people expect me to first watch a video and then click ten links just to read an article. Yes, yes, ad revenue, I know, but I guess the majority of people that are directed to a site like that won't bother to read the text.
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But your ice cream melts faster!
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
Apparently they actually patented various things to do with that burger: http://v3.espacenet.com/publicationDetails/biblio?CC=US&NR=4653685&KC=&FT=E
Just thought I'd point out that, while most of the ideas are sound-- if not net energy loses when you consider the energy cost of producing everything required to charge your iPod-- the idea of using the fireplace as "waste" heat just shows how out of touch the writer is with the laws of thermodynamics and the relative efficiency of these kinds of power generators.
This is effectively a heat engine, and so we can produce no more energy than the maximum permitted by a Carnot engine. Thus, there is very little exergy (layman's definition: useful energy that can extracted.) in such a process. To use your fireplace, or any other source of heat in the home that is designed to heat your home, to generate electrical power is absurd. You wind up losing far more than you gain, as you will now have to run your fireplace that much more to make up for all the "cold" you're bringing into the house.
Bleh, are people really that desperate to get energy for nothing? Have they not yet learned that just using less of the stuff is by far the best way?
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We have a problem the size of a swimming pool and think it would be a great idea if we spent our R&D budget investigating thimble efficiency with respect to making it smaller.
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I used to have neighbors who would leave their air conditioners running all day, then, when they came home, they'd let the doors hang open for a while to let some warm in. Less stupid people could help, too.
I was curious, where do your stupid neighbors live? A "friend" of mine has this extra 0-gauge cable and some splicing gear lying around...
I'm not an electrical engineer, so this may be a stupid question/idea: Are these things any more efficient than current solar cell technology? Would an array of these mounted on or under a sheet of metal and painted flat-black generate more electricity than a similar-sized solar panel? Would it be cheaper to produce?
(Sorry if it was already brought up. I can only get through 3-4 slides at instructables.com before I get too annoyed at all the ads to continue.)
...40 years ago when I was a teenager.
I figured you could wrap the exhaust pipe with thermocouples, and put some more in the engine-to-radiator stream, and maybe generate enough electricity to take some load off of the alternator.
I also had an idea for hand-cranked generators for the back-seat passengers (i.e., my younger siblings) to turn, keeping them busy on long trips!
It's tough being so far ahead of one's time like this... nobody recognizes my genius... they LAUGHED at me in Budapest! They laughed at me in Moscow! But when I complete my next invention.... BUWAHAHAHAHAHAHA!!!!
In times of universal deceit, telling the truth gets you modded -1 Troll
a vehicle functions the way it was designed, meaning if it generates heat, components will function properly based on the fact that heat is dissipated around them. Once heat is harvested and turned into energy, components don't function as expected. I wonder just how many modifications these vehicles will have to take.
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I have thought on this a little myself. The major question that I have been unable to answer is this. The peltier device must also provide some resistance to the transfer of heat while in the process of generating energy. Assuming that the radiator of the engine is engineered for the smallest possible weight (dubious I'm sure, but for the sake of argument...) then is the amount of added weight necessary to compensate for the peltier device and its additional cooling requirements made up by the energy harvested? There is an equation in there which I have never been smart enough to build appropriately. The equation simply asks the question is the energy required to move the extra required weight greater than or less than the energy harvested by the device? If it is greater than, then it is a worthwhile improvement, if it is less than, then it is not. Anyone with a more physics oriented mind care to drum up the variables? Anyone with some math background care to put those variables together?
You're just another crazy "libertarian".
I asked how efficient it is, and how much energy it costs to make, because I want the facts to show whether it is indeed energy economical to use it. Because I'm interested in it, and want to see whether it's realistic.
You, on the other hand, see a question about its actual utility as an attack on it.
Because you're just another crazy "libertarian". You hate facts. You'll defend any fantasy by attacking anyone asking for facts about it.
The "free market" isn't some kind of magic. This geek website is full of stories about devices and projects that cannot be profitable, but which geeks indulge because they have time and money to waste. People making an using something are no proof that it's economical.
My questions were in fact exactly what a "free market" (which exists only in the juvenile minds of "libertarians") needs to know in order to decide whether to buy and sell something. The fact that they repel you shows that you're just another crazy libertarian who doesn't know anything about free markets, economics or even science, but has such a strong libertarian faith that you think chanting "free market" will make it happen, will win your jihad against thinking people going about normal business.
Put down the Ayn Rand, stop dreaming you're John Galt, and get a job.
--
make install -not war
1. The heat of the sun is wasted.
2. Mankind converts the waste energy from the sun into ueful energy.
3. Plug your cell phone into the socket.
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