Instructables

Charge Your Cellphone Using Wasted Heat (and Build a Steampunk Wall-E)

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We updated the instructable with a new implementation you can build without spending all that money on those expensive seebeck generators. This one uses Peltiers in reverse to generate rather than cool. They aren't as efficient but they are much more affordable. Plus most of the parts required are made from scrap.

Quick Jump
'''How to build a Steampunk WALL E'''

First Intro Video


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. In this instructable we show how you can use the same technology right now at home to collect heat energy from car exhausts, waste oil burners and even our hands. We can power electronics, joule thiefs, super caps, Lego Car and anything else you can imagine.

This is our Epilog Laser Contest Entry. If you like it please vote for us.

Index

Step 11 '''How to build a Steampunk WALL E'''

Step 6 Fire Powered Lego Car (Video)

Step 10 Thermoelectric Joule Thief (LED that lights up from oven heat)

Step 1 Whats a Seebeck? Is it different from a Peltier?

Step 2 How much power does a Seebeck generate

Step 3 Building an inefficient 5V regulator

Step 5 Thermoelectric Implementations

Step 7 More Efficient Switching Boost circuit / Info for designers

Step 8 FAQs

Just interesting Thermoelectricity from Tellurex

Stick around and learn about the the difference between peltier and seebeck units, and what electrical circuits you could use to make a green impact on our environment by utilizing wasted heat.

Keep on reading and enjoy our videos :).
- SplitReaction

 
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this is great.it is what we call innovation.www.unn.edu.ng
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please sir,detail me more on this stuff.www.unn.edu.ng
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criggie1 year ago
Please consider designing something to scavenge heat from a car exhaust and do something useful with it.... top up the starting battery, power the accessory circuit, etc.
hai,
i want to ask, i have try the project, but my thermogenerator have produce only 0.5v , could u give some advice how to make thermogenerator produce 3v and how about temperature and temperature ambiance?
Bold Rhino1 year ago
What kind of motor did you use? How did you build it?
J-Ri1 year ago
I think a cheaper and easier way would be to weld a flat plate to the exhaust manifold rather than use flexible TE strips. Not possible for the amateur on cast iron manifolds (which most are), but pretty easy on that steel pipe on your Mazda.

Additionally, your first thought of using the catalytic converter would be more effective (aside from possible water/dirt intrusion, but you will get some under the hood too), while not affecting the operation of it. TE modules don't cool their heat source significantly, especially when we're talking about taking a few watts out of the exhaust of something that generates kilowatts of waste heat. Heating of the cat prior to "lightoff" is the only concern. Once it reaches that temp, it gets considerably hotter. Driving down the road in a downpour doesn't cool the cat enough to lower its efficiency, even if the case is cooled to below 212ºF. Many cats have a fiber glass-like (dunno what it is) layer around the honeycomb to insulate it.
molusco4 years ago
I have a router at home wich produces loads of heat (enough to run a Stirling engine i bought). I've always wanted to do something to refrigerate it. Maybe this is a good solution to get "free" energy and cool it down. Do you think it will work?
splitreaction (author)  molusco4 years ago
Well ya won't get free energy. if you hook one of these up. Hot side to the router, cool side to a heat sink, you could generate some electricity, probably only enough to charge a small battery. Probably not enough to power another peltier cool. However if you build the joule thief from step 10 perhaps you can make it power a LED. I mean hey, it would help cool your router and perhaps add light. But man that must be a hot router.
I think he means free in the sense that he is already paying to generate the unwanted heat.

Unfortunately, you cannot cool the router and generate heat from it at the same time. If you use the power generated by the heat coming from the router to cool the router, you no longer have heat coming from the router to generate the electricity to cool the router.

For a TE module to produce voltage, there must be a temperature difference from one side to the other. This means you have two options; lower the ambient temperature or accept the increase in temperature inside the router.

Additionally, I would be EXTREMELY hesitant to use such a device to salvage energy from any electronic, and some electrical, devices. Doing so will keep more heat inside the device than what was intended, ultimately shortening the life of the device and negating any small gains.
spartans4 years ago
 hey this project is really good and i want to try it once.
hey why are these capacitors used for?
J-Ri spartans1 year ago
They are used to smooth the voltage on both sides of the regulator, and aren't really "optional-ish", you WILL get spikes over the rated voltage without them. How much over depends on a few factors, but they are cheap and you can find them anywhere, so use them.
can u please give more information about the thermal unit..
youwho1 year ago
I am wondering which peltier chip was used in this experiment. The output of the ones I have tried are very weak.

I am trying generate about 5v 3000 mA to charge a cell phone. Any suggestions on a specific peltier chip & heat sink?

Thanks
what is the liquid used under the peltier?
hi i'm currently working on a project designing a portable heating lunch box that i plan to make it work on waste heat but i don't know how. any suggestions on how to power up the lunch box using waste heat?
avanner773 years ago
In her Mintyboost, Ladyada uses the LT1302 to power any USB device. After looking at the efficiency graphs, it appears to be almost 85% efficiency at 500ma. Hope this helps.
Hi,

Have you thought about using it to generate hydrogen and oxygen and use in hybrid vehicle?
robcull3 years ago
say you had some warm water that you wanted to cool.
couldn't you set up a seebeck to generate electricity from the thermal energy in the water, effectively cooling the water?
I mean, I'd like be able to convert some excess heat energy into electrical energy, just to get rid of it.
likewho3 years ago
I’ve tried standard peltier modules for power generation with limited success and very short service life. They cannot hold up to the higher temperatures necessary for good power generation performance. I found a terrific supplier with both standard temperature and high temperature TEG modules designed specifically for power generation. They sell a lot of devices on eBay and you can also buy from them direct. The company is Thermal Enterprises and here is are links to a couple of their eBay items.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310148993913&ssPageName=STRK:MESELX:IT


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310209561834&ssPageName=STRK:MESELX:IT
 we just need to get really efficient with these and attach a heat sink to the engine block and exhaust system so that we do not have a need for the alternator and we can just run the electrics in our car from that
geekchic4 years ago
Could I use a thermogenerator that's out of a propane mosquito magnet?
kdunner5 years ago
So not to rain on any parades, but this idea has been utilized for the better part of a decade. Do a google search for "heat powered fans" and see just how common this idea is. Plus, waste heat to charge your cellphones is one thing, but I hardly consider high temperature differences (eg blowtorch) 'waste' heat. Nice production, just I find it hard to believe slashdot thought it warrent of our attention.
splitreaction (author)  kdunner5 years ago
Sorry kdunner. Beserk87 was right. Just give us a chance and read the instructable you will find its not as bad as you think. I'm removing my comment in apology.
I would like to extend an olive branch, in the heat of the competition I disregarded your instructable; I felt jaded that slashdot decided to post your entry on practically the day of the voting. I hate it when people post negative things, and so I would like to apologize for not seeing the potential in your design. I would like to tell you of the potential I do see. I can see a potential marriage of our two concepts resulting in a very cool invention. My entry into the challenge is the wind power composter. The internal temperature of compost gets to 100-160 degrees F. I can imagine that if the base structure had ground penetrating prongs or just heat sinks, then a thermal momentum could be established between the composter and the ground temperature, resulting in the production of a low power source using peltier junctions. This power could turn the composter on its own. My composter uses a gear motor with a ratio of 1255:1 so a tape deck motor could potentially power the composter. I have a few peltier junctions lying around but won't have time to test the output voltage until finals are over (I really don't have time to make this post). What voltage and amperage do you think a 100-160F to 70F condition would create? If it is produces enough power, then the composter could be turned by bacteria alone, and the wind would not be needed at all. That would be a cool idea to try, after finals that is.... Again, sorry for being a troll, I want instructables to be a place of invention, creation and open ideas, and I will not let competition and self interest get in the way.
splitreaction (author)  kdunner4 years ago
My team and I were angry but not anymore. We got a lot of good comments and idea from people. A lot of members even gave us ideas. Like Kyrptonite who wanted us to try a Joule thief. We did it and it was fun. It sounds like you have a temperature delta of around 70F. This technology isn't efficient if you are burning fuel to generate the heat, but collecting waste heat is great. Even at 1% eff you are still collecting energy you otherwise would not have. I doubt the peltier junctions will be enough to generate enough power from a 70F delta. Most of the ones we see other people using don't generate that much power. They really vary depending on who makes them cause peltiers and seebecks use different metals. The peltiers we bought from PC coolers produced maybe a volt at best perhaps 6 mA(50F delta 32F (ice water) 88F human hand). That is why we purchased high end seebeck units. They are much smaller and you can tell because they are usually not sealed in ceramic. Ours generates about 5V open circuit at the same temperature where the peltier generates a weak 2V open circuit. Seebecks we bought cost around 35-80 dollars. I wonder if you could build a solar collector for your setup instead. Imagine building a parabolic mirror to reflect sunlight into a solar oven. Then placing your peltiers against the oven with some decent metal to passively cool it. you could probably even combine it with some photovoltaic cells if you have them too . You can use that to trickle charge a SLA (sealed lead acid battery). Perhaps then the stored up energy could rotate the barrel a couple of times a day. Just not the entire day. 1255:1 is an amazing gear ratio btw.
Hey guys, please send something that tells me how to assemble the microcontroller and how to connect it. Please is everything I need, I know about programming, but no how to connect the pic to the motors and peltier units. Please is for my science fair project. I would be very thankful.
no , they used a blow torch as a source of heat, for experimentation purpurses.
splitreaction (author)  kdunner5 years ago
(removed by author or community request)
he clearly didn't read any of your guide - at all. but the grammar correction is just a kick in the balls, especially since there's a spell check not 2 milimeters under the text field :P
Arshad1154 years ago
 this is one big instructable!...brilliant!..
Insidio4 years ago
Hi friends, I think I need some help. There's gonna be some cience fair in my school and I'm going to make this Wall-E for the fair. But the problem is that I don't have any legos and those wheels and lego motors. I bought some 9 volt motors, the Peltier units, and almost everything except for the pic.
So my questions are: Can I make a Wall-E with those motors or maybe using some wheels from a remote control car?Actually I have some old Tyco RC Air Rebound, I know I have to change some things in the design, there's no problem with that. And can I use a PIC16F84 instead of the Pic Kit2?
If I can use the electric car wheels and the PIC16F84 please give me some idea of how can I do it. If I can't I think I'll have to buy the Pic Kit2.
Thanks for your attention: Hugo
100_0184.JPG
nachos4 years ago
 if someone one could tell me if this item would work i'd really appreciate it because i need to order it soon.

tinyurl.vom/yffb987
nachos nachos4 years ago
 Would The $75 dollar one on the site you recommended work as well as the one you used? the one you said you used is not there anymore.

I'd really appreciate a reply asap because I  need to order it soon.

Thanx 
Nice, I built on too, you can see it here. It's difficult to keep the cool side cool though!  sites.google.com/site/reukpower/teg-gnerator-2
nachos4 years ago
 will this one work?  tinyurl.com/yffb978    
its a peltier

Thanx in advance


i would like to get my hands on a few of each of these for future experiments etc. Does anyone know where i can find them? Awesome but incase my question is wrong are seebeck and peltier units different products or the same product used differently if so i apologise and this question should be correct. Does anyone know where i can get my hands on some thermoelectric units like the ones in the video?
ebay
Foaly74 years ago
So, say you have an electric motorcycle, and the battery heats up from prolonged use. Could you use this to charge the battery, recycling the heat coming from the battery?
Please give any suggestion to the "Instructables the Movie" at http://www.instructables.com/community/Instructables-the-movie/
ellislake4 years ago
the wall-e is great but instead of using a candle why dont u use a solar colleter and focus that on the peltier unit to produce heat,then u can mount a light sensor in the middle of the solar collectar,then then the little robot will seek out the birghtest light which will pick up the most heat and this will move him around all day long,this will ra\lly only work if its outside though or in a conservatory where you get direct sunshine.. what you think
splitreaction (author)  ellislake4 years ago
I had a friend who suggested that, I gotta say it would be fun, but you guys have too many ideas for us to try out. :-P Btw sad sad day, our wallE lost an arm today :-(
Aww, a Wall-E without an arm just isn't right.
lol at the arm loosing.hve you got any other ideas that you havnt yet made i could possibly make some for you and do an instructable
robot7974 years ago
give me a kit of it
splitreaction (author)  robot7974 years ago
which wall E or the 100ma boost? We would love to make kits, but we would need to make sure enough people are interested
Hey how much would you sell a pelter kit with a motor for?
splitreaction (author)  dombeef4 years ago
Well the cost of the components we used the kit would have to be at least $40
Oh ok
what i would do for the heatsource is get some boiling water in a cup And use a old cup as a makeshift double boiler and melt some wax (could do it in a old coke can with a lighter under) once its melted put whtie spirit or Methalted spirits (isopropyl etc) in with it not alot Then put it into ice moulds or very small chocolate moulds and leave it to Dry at room temp Then knock them out and they will burn for quite long and A big flame (add a wick if you want a more candle like thing)
splitreaction (author)  stephenniall4 years ago
I use those for camping. They are awesome to start a fire in the rain. Be careful, even the small candle is hot enough to melt the thermoelectric unit into nothing. Ours is at the bare minimum of violating the spec the way we set it up. :-P
Great project! They also sell cheap USB extenders at the dollar store.
splitreaction (author)  alkaline95004 years ago
I bought one of those once and got really disappointed. Good USB 2.0 cables have two layers of shielding, a foil and a braid for better signal quality, I cut the usb cable from the dollar store apart and found only 4 wires and no shielding. It may be sufficient for small stuff, but high data rate transmissions will get glitched with those dollar store cables. I sometimes use them for the connector when I'm building a charger since mine don't transmit data
sourcer4 years ago
whats the difference between thermoelectric unit and thermo coupling? because when I google it, the latter one kept on jumping out. can they be used the same way? if so, how?
splitreaction (author)  sourcer4 years ago
They are the same. Imagine a thermoelectric unit being an entire grid of thermocouples stacked in series and parallel.
what is the voltage you used in the instant ice video
splitreaction (author)  Robinson ruiz4 years ago
instant ice is using the device in peltier mode, 12Vs hooked up to a car battery. Otherwise it would take too long for a video. I've seen better photos where the ice is not water but ice from condensation
I know this may be a long shot but I suppose there's no harm in asking!

Ok let's say I wanted to use waste body heat to power this thing and for the cooling side I used one of these http://www.coolshirt.net

What are the chances of this working?
splitreaction (author)  richandcreamy4 years ago
Well I can get a Lego motor to turn from body heat alone. But it feels very very cold. Odds are you aren't going to generate more than you it cost you to cool the otherside. Still fun to say you did it
Jakoul4 years ago
What's to stop you from using a alcohol stove as the heat source? Sorry if it's a dumb question!
splitreaction (author)  Jakoul4 years ago
Its not a dumb question. Its an great suggestion! Thanks! It could be a heat source as long as it fits. We just threw it together with what we had on hand. We're not big fans of the candle method but this idea was easier to do. One suggestion we even looked into was using left over charcoals from a BBQ. Unfortunately its not BBQ season yet so we don't have a chance to try it. We would probably have to design the thermoelectric generator to be more of an oven shape.
Another thing could be camping magnesium tablets. I use this all the time for experiments in place of a candle. It produces more heat than a candle, doesn't go out as easily and burns clean. Btw great instructable, can't wait to try some of these out!
You are the man! I love that idea. I work 24/7 so I'm sorry it took so long to reply.
DualPhase4 years ago
Will this step up from any voltage, say 1v? Do you know the efficiency percentage?
splitreaction (author)  DualPhase4 years ago
Which part of the instructable are you referring to?

The boost circuit will step up from 0.8V, but its efficiency depends on the load current.

At 1V the spec sheet doesn't specify an efficiency at that 1 volt. At 2.5V with an optomized design and a current load of 100ma it would be 85% eff from Vin to Vout. Realistically at 1v I would predict less than 65% efficiency. Boost don't tend to be very efficient especially at low voltages.

I seriously doubt the peltier will be able to supply that much current to maintain that regulation with 100mA at 1V

datasheet
http://www.instructables.com/files/orig/FA8/3QVR/FT7PRXIN/FA83QVRFT7PRXIN.pdf
Perfect. I ordered a few of them. Thanks
Wall-E is pretty steam punk looking if you ask me.
Nice i'able Great detail, I would love to see the seebeck used to power the Shocker circuit thereby converting its small voltage upto 240DC pulse which could then drive a transformer. Just a thought.. great work !!
GriffN4 years ago
I had to laugh when I read that WALL-E went Steampunk, just because that's not very Steampunk. Correct me if I'm wrong, but Steampunk is more of an aesthetic than a propulsion type (even then, it's not steam powered). Really just nit-picking. I like the rendition of WALL-E. The head is pretty nice.
splitreaction (author)  GriffN4 years ago
I was aiming to make him look Steampunk rather than steam powered. I guess the painted metal didn't come out too brass or copper like. A different paint would probably help, but I admit I am no artist and that paint was reused. But hey its a WALL E that's powered off a candle!
Candlepower WALL E is definitely something I can get behind ;)
Kryptonite4 years ago
I have a real welder. I know what I want for Christmas!
Kryptonite5 years ago
Any one tried to hook this up to a joule thief? I really want to try this, thanks for the instructable!
splitreaction (author)  Kryptonite5 years ago
Update, We builta joule thief and it works with it. We have it powering a High power 1 watt Cree X Lamp LED. We chose the Cree X Lamp for its efficiency. It didn't perform any better than the MAXIM boost circuit we have on step 7 but it sure was more fun and cheaper. It will light up a white LED if you placed ice on one side and your hand on the other. Our switching frequency is 240kHz with a 8 turn winding on the inductors aorund the torroid. Photos and video to follow.
I've been looking for one for a while but where did you find the terroid?
splitreaction (author)  Kryptonite4 years ago
I raided my job, they have a collection of old pcbs to be recycled from various test equipment lying around. I ripped the torroid from that and I use some cat 5 wire they had lying around. The 2n3904 and the led were the only parts i couldn't easily find (but i had them from other projects). It was a cool recommendation. we appreciate it. (Btw check back after 7pm tonight. Someone gave us an amazing idea and we are going to do a major overhaul to show it. probably an additional ten steps)
Oh wow, looking forward to it!
splitreaction (author)  Kryptonite4 years ago
Its UP! Thermoelectric Steampunk WALL E but i forgot to add the joule thief for his eyes... doh!
A slight bit of tweeking required?
Wow I'm glad my idea turned out alright, thanks for the Instructable.
You could make a light that lit up when one sensor was against your skin and the other was exposed to cold weather, like on the outside of your clothes on a cold day.
splitreaction (author)  Kryptonite5 years ago
I'm going to build a "joule theif" tonight if I can find a torroid. I realize a "joule theif " seems to be the instructables standard DIY boost circuit. But I don't think it will beat the efficiency of the new boost circuit we are working on. Since the Joule theif is almost free when the parts are salvaged its worth a shot. I owe you a cookie if it beats the MAXIM856 integrated circuit I designed in Step 7. By the way if $75 is out fo your range, go for a peltier. The peltier will probably be enough for a couple LEDs. Our Maxim856 boost circuit lights an entire 10 LED array from very little heat.
Eric_T4 years ago
Go Wall-E Go..... I've seen this in person and its very impressive. Awesome job!
Kryptonite5 years ago
I went to tellurex.com but you didn't say which model of seebeck unit we should use.
splitreaction (author)  Kryptonite5 years ago
The model number is: G1-1.4-219-1.14. When you get to the site, click on "Thermoelectric Power Generation Modules", it should be the last one on the list that comes up. I thought we listed it in step two, but I may be wrong. Thanks.
Cool, thank you! I really want to do this but right now I don't have enough money, so when I start it I'll inform you.
Kryptonite5 years ago
Wow I didn't think it would be that much of a success with my idea of a joule thief, but I'm happy to be a help! ~K
Chops2115 years ago
It's not an invention; it is applying a device that most people have never heard of, to conserve energy. How you do not see how this is a green application is beyond me. The greatest thing to come from this instructable is that it gives engineers such as myself a new toy to play around with and see if we can use it efficiently to power electronics where there are temperature differences (e.g. trains, power plants, inside computers, etc.). Kudos to splitreaction for looking beyond the the box...
fwjs285 years ago
congrats, your featured on slahdot :P
splitreaction (author)  fwjs285 years ago
Oh wow! Slashdot crashed www.splitreaction.com Awesome!
Heh, first time I've heard of a DDoS as awesome. ; )
Dzwiedziu hcold5 years ago
It's not an DDoS. It's the The Slashdot effect... :] Oh, and about the idea: my brain broke. My (future to be) hybrid car engines should be covered with seebecks to help recharge the batteries. The non-hybrids (preferably diesel) will have their alternators ripped out ;]
hrmm...sounds interesting...
ohbot325 years ago
nice but to get the output you and portraying youneed a large amount of waste heat. how will you charge your cell phone at the airport? you going to start a fire? there is not enough heat from body heat to generate the power required to charge a cell phone not tomention a laptop. nice try dont see the application just yet. needs more work. thANKS keep up the good work hope to see a feasible prototype soon.
FeedTheGrid5 years ago
Very well-done. I'd like to do some experimenting with these materials. Thanks for sharing. This is good thermoelectric knowledge to have! FTG
leemck5 years ago
Really heat. I tried using a pettier cooler from Halted Electronics Surplus and stopped after seeing less than a volt generated. These seebeck type generators appear to have the specs and ruggedness to make thermo electric generation practical.
Berserk875 years ago
awesome instructable. lots of open ideas in there, plus that tricking the ipod tip should help me out with something.
Notbob5 years ago
If you wanted to use multiple peltier units to feed power into an LED, would they be wired in parallel, or in series? Also, how much volts/joules/watts were coming off of the unit you heated up with your hand (to power the motor)?
splitreaction (author)  Notbob5 years ago
To power an LED you can use both series or parallel. Series will increase the voltage and parallel will increase the current. The actual power will be the same in both scenarios. The temperature of your hand is around 88F and the cold reference on the heat sink was 32F. So its a 50ish temperature delta. I didn't measure it but it would need to be at minimal 20mA at 3.4V so that's 0.068 Watts. Since a joule thief is effectively switching at 200kHz at 50% a very fast rate you are only talking around 0.034W min. You can convert that to joules or volts manually. You have to remember that your hand will start to cool the second you touch the seebeck unit. That will reduce the amount of power you generate. So using human heat as power source like the movie The Matrix would be impractical, unless you like the feeling of cold metal against your skin. It will work for a while but your skin will get cold and then it won't generate anything. I'm probably ranting at this point, so sorry for boring you but remember you asked. :-)
Plasmana5 years ago
I never heard a Seebeck unit before... Great instructable! Also, what is the maximum temperature can a regular peltier withstand?
isn't melting the peltier junction an issue? As far as I know, they usually don't like getting above 170 C... I'd be careful, they're not that cheap...
splitreaction (author)  thecheatscalc5 years ago
You are certainly right. We're worried about destroying our $75 seebeck unit but for the $7 peltier unit from ebay we won't cry as much. We bought cheap Ebay peltier units ($7) and pretended they were seebecks and heated them to 426C. They worked but eventually after the tenth time we melted the wire off and had to resolder it. The seebeck units we bought for $75 afterwards were able to sustain the higher temperature and generated more at lower temperature. I wouldn't recommend high temperatures beyond the spec sheet. But in the spirit of learning we've tried to push ours to the limit of our blow torch :-). After 200C we saw diminished returns. Ours went to 1000F and it still works today. We shield the wires so they wouldn't melt off.
Sandisk1duo5 years ago
Too bad those units are expensive...
thepaul935 years ago
here's an idea... on top of the heat sink put a fan powered by the heat, then you would get more power to power other things. Im not sure if this works but maybe you could give it a try.
splitreaction (author)  thepaul935 years ago
That would be regular power generation. It works to a degree but the heat we are using is not enough to create a steady flow to make the fan generator more efficient than the seebeck unit.
SWV17875 years ago
Sorry this may be a bit off topic but what kind of motorcycle is that in your photo? It greatly resembles my KZ650CSR's front fender and shocks.
splitreaction (author)  SWV17875 years ago
The motorcycle in the video is a 1981 KZ440 LTD. The KZ650 is pretty much the same bike except a higher displacement engine. All of the old KZ's look the same. I recently purchased a KZ750, which is almost identical to my KZ440, just has 4 cylinders instead of 2.
KT Gadget5 years ago
What about a more focused ray of heat instead of just facing the heating part of the surface to the sun? Like a satellite-style structure where the "receiver" (the panel in this case) is facing away from the sun and have the "dish" of mirrors focus on the panel. Add a fan to the heat sink that blows the outside air across the fins since the mirrors are focusing more light (in this case heat) into a smaller area. Would this work efficiently?
splitreaction (author)  KT Gadget5 years ago
I like your thinking. I'm not sure if a seebeck unit would be more efficient than a solar panel this application. I haven't had much experience with solar panels. Maybe someone who has could chime in with more info?
splitreaction (author)  splitreaction5 years ago
I had spoke with an optical engineer about solar panels that use parabolic mirrors to angle the sun's rays into a much small solar cell to boost output. So your idea is very sound. I'm still concerned you would probably get more energy if you used a solar cell. Now nothing prevents us from using both. If you had a solar cell and a themoelectric generator mounted behind it may work out. 1. The thermal generator would be a big slab of metal to reduce the heat on the solar cell. 2. The parabolic collector would serve a dual purpose, "thermal" and "photo reflector"
bowmaster5 years ago
If you live in a desert or other hot/sunny place you could cover you house with these and have "free" power.
splitreaction (author)  bowmaster5 years ago
Not exactly. You pump power through the thermoelectric element by having a temperature difference across the surface. If you don't have a temperature difference you can't have any power flow through the element. So the house in the desert would need to be cold inside to get this to work.
klee27x5 years ago
Instead of recharging an iPod or a super capacitor, which is a just and noble cause, what about charging the CAR's battery? This should reduce the load of the alternator belt just a hair, esp. when a lot of things are running... like air con and stereo. It would be pretty neat if someone could demonstrate a significant increase in mpg with an affordable DIY setup.
splitreaction (author)  klee27x5 years ago
We have done some research towards the horsepower gain on a motorcycle. In fact, one of us won a competition with this idea. However, he concentrated on the power increase from this, and not so much on the MPG part. Check out step 1 for a link to the competition and more info on his research. Thanks for the idea. I think it would be a very nice thing to implement.
splitreaction (author)  splitreaction5 years ago
When I did the calculations on this I figured about a 2hp gain on my 40hp motorcycle. This information was gathered from dynamometer runs of the kz440 bikes that were converted for racing. It was standard to disconnect the alternator when your using the bike for racing purposes. If you scale those numbers up, on a small car of 100hp you should get a 4.5hp increase in power. Almost 5% not bad.
DAND5 years ago
BMW has been investing in this idea, and has made it really efficient. Someone willing to find the right link, it had thermal imaging in it :D
RansomXvi5 years ago
What's the song playing in the instant ice video? BTW Love this idea. My cousin works at a plant where they use a lot of peltiers. I'm planning to get my hands on a few :)
splitreaction (author)  RansomXvi5 years ago
Glad you enjoyed our instructable. The song is "Seventeen Years" by Ratatat. Here's the whole song on youtube http://www.youtube.com/watch?v=PYCKGG4VOZY
PS1185 years ago
Hold on... so is a Peltier unit physically different than a Seebeck unit (like an LED is to a solar cell), or is the distinction based on application (like a motor is to a generator)?
splitreaction (author)  PS1185 years ago
They work both ways, but vary in temperature range and metal composition. So I would relate it more like a motor is to a generator. Peltier operate at room temp and are usually Bismuth Telluride Seebeck are usually rated to higher temp and use PbTe or SiGe
C_Maconroe5 years ago
How would a laser support for some power?
splitreaction (author)  C_Maconroe5 years ago
The laser is just the contest prize. We just want to win it.
Great instructable. I've always loved these things. Thermoelectric effects are awesome. One thing, though: when using the heatsink on the motorcycle, wouldn't it be more effective if the heatsink fins were horizontal? Obviously when stationary the vertical fins will be better due to heat rising, but when you're riding the bike, you want as much airflow across the surface area of the heatsink as possible. One note for readers: If you're looking for peltiers and don't want to pay $75 for one, check out everyone's favorite auction site where there are always auctions offering them individually and in lots for decent prices. Since the Peltier and Seebeck effects are effectively inverses of eachother (okay, this is dumbed down a bit, but for the average inventor, you can think of it this way), any old peltier device will generate a current if a difference in temperature is applied, and likewise, if a current is applied, the device will induce a change in temperature. So search the auctions by searching for 'peltier' (no I'm not a seller or associated with one, but nobody should pay $75 for a single one of these devices).
splitreaction (author)  inventorjack5 years ago
Yes, you are correct. It would be much more efficient if the heatsink fins were mounted horizontally. The reason we mounted it vertically is because of the configuration of the heatsink. It allowed us to easier clamp it on to the exhaust pipe, and since the motorcycle wasn't moving, it worked out well as proof of concept. We plan to get a better heatsink and mount it with the fins horizontally. Thanks for the advice. :)
I have to also stress the need for effective waste heat transfer, particularly in a closed environment.

Once tried a clever (I thought) idea with a peltier on a wood stove. I added a small fan to the heat-sink. Worked until the ambient got too warm, and, since the peltier only worked on the difference in temperature, the thing stopped generating power. Fan stopped and it ultimately self-destructed.
splitreaction (author)  frenetic5 years ago
Yup. Thats the second hardest part, finding a free cooling source! We were very happy with the seebeck units. Even the heat from our hand and ambient cooling we could power a small motor.
splitreaction (author)  inventorjack5 years ago
You're right, but I want to be careful with the wording. Lets not call the $75 units peltiers. They are optomized for the seebeck effect. We used both auctioned Peltiers and the scientific grade Seebecks. One of those $75 units easily matched 3 or more ebay'd Peltier units in total output power for a given heat delta. We noted more details in in the FAQs page 8. Good point!
I don't disagree with you on efficiency. I just figure the average experimenter might want to start out with something less costly. One device designed with the Seebeck effect in mind may outperform 3 standard peltiers, but you can buy 15 peltiers for the price of one seebeck. Then again, you'd need a lot more heatsink in that case, so that might make a difference.
Agree, the seebeck and peltier effect are one and the same and involve electrons having excess energy and a requirement for energy as they pass through equivelant N and P junctions of the bismuth telluride pillars in the devices, however the pillar configuration and solders used can be specialised for TEC (cooling) or TEG (generation) operation. What is the running temperature of the heatsink on the cold side of the TEG (thermoelectric generator)? Since the effective output of the TEG is directly related to the delta temperature between the hot and cold side of the TEG the heatsink needs to be as big as possible. The other thing to watch out for is the temperature of the TEG when no air is being passed over the heatsink. High temperatures will damage the TEG through copper migration into the bismuth telluride pillars and may lead to the TEG delaminating if the solder temperature is exceeded. (Some manufacturers use solder temperatures as low as 160-180 degrees C). Unfortunately the flexible and non flat substrate peltiers are a long way off as populating a non flat substrate with bismuth telluride pillars is exceedingly difficult and leads to the pillars being stress snapped due to the different expansion of the hot and cold faces. Nice instructable, clear, nice pictures and videos. Keep up the good work,You'll get my vote for the epilogue.
frollard5 years ago
Thats really cool, literally Using the exhaust to heat one side, and the engine air intake to cool the other (free airflow!!!) would be advantageous, if you can duct it right.
SinAmos5 years ago
You guys have my vote.
I'm sold. I love this idea and it has my support in the contest.
SYMMETRY5 years ago
Excellent Tut. I'm going to try some of this stuff on my electric mountain board. I could hook it directly to the motor and create a turbine fan out of the motor. should provide a good amount of cooling.
kelseymh5 years ago
That is a excellent level of detail! The use of all of photos, drawings, specifications, and video really gets the information across to anyone who wants it.
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