From the looks of it, not great. He says the theoretical maximum he could get get is about 2.3 watts, but never says if he actually gets there. He just says he got a peak voltage of 2.7.

It is about the same as PV in terms of dollar-per-watt output, but this is much more difficult to maintain so it isn’t much competition in it’s current form. But like he said, this was a quick experiment. With refinement it could be put to useful work.

Yeah it would be nice to see some real recorded data on the power output.

It would be interesting to see an old satellite dish painted silver with the peliter element in the focal point, as much more energy could be captured this way.

Somehow thermally connecting the ‘cool’ side of the peltier to the ground could give a better temperature differential.

No point me trying it, I live in the UK :)

Wow, cool hack!

What’s next? Magnetohydrodynamics? :D

I did a study on these devices in an engineering design class. We found that to offset costs in ~5 years, these would need to be placed in a temperature differential of about 2-300*C. These cells are usually ~.25″ thick, so maintaining that kind of temperature differential proved cumbersome and limited the potential applications. Still have a couple, they cool “soda” pretty quick and work great as cooling coasters.

There is a fan that runs off of your stove that uses this technology: EcoFan 800

Not trying to be a shameless plug but there are a lot of things you can do with that kind of tech.
http://www.perpetuapower.com/powerpuck_150.htm
I for one hope to see this kind of technology taking over more battery powered objects. I hate when a battery fails. If I could even have a trickle charger to charge stuff it would be nice.

Same kinda idea here, except using a some pans and a campfire.

Thermoelectics are an area of quite a bit of interest at the moment, I’ve a few side projects dealing with them but they are currently horrifically inefficient (2-4%), but new materials are in the pipeline which should up it a lot. They’re worse in generation than power use and require fairly complex load balancing to work well – draw too much current from them and their voltage drops, their apparent thermal conductivity rises and they start to reduce their own temp difference and produce less power. Likewise too low a load and you generate plenty of voltage but at low current so low power again. Ideally you need to monitor and control the load and temperatures for peak power throughput at any given temp difference.

Various car manufacturers like BMW are already working on fitting them as a replacement for an alternator in vehicles, reducing crank losses and recovering waste heat.

Man, I was working on this stuff 15 years ago, this brings back memories. My wife still laughs about my experiments on the kitchen counter when we were dating. I guess if she didn’t run away when I was geekin’ on that she was good to keep!

I remember looking into automotive cooling (needed way too many Peltier’s and current to get enough BTUs), automotive electric production, even had a few can coolers in the works way before I saw them on the market. Shoulda done it myself…

Oh it’s been used already in another hack to power a PC fan using the heat from a small burner cut into a food can. The fan blew on the cold side to extract the heat faster, increasing a bit the efficiency.

Here’s a way to build a motor powered entirely using the Seebeck effect : cut a dozen 10cm strips of copper and brass wire, and twist them together at their end so as to make loops of wire, one half copper, the other half brass. Make the loops elongated, with the twists far apart. Cut a disc out of cardboard and glue the wire loops all around it, one twist towards the center, the other twist sticking out of the disc. Always keep the copper/brass wires oriented the same way. The loops must have as much area as possible without touching each other. You should get something star-shaped, with 12 wire twists sticking out. Now take a pin and balance the rotor on top of it, so that it can rotate freely. Put a magnet under the cardboard disc, with its magnetic axis perpendicular to the disc. Lastly, bring a small candle so that the flame touches the wire twist sticking out just next to the magnet. After a while the rotor should start turning.

Here’s how it works : the copper/brass twists form a thermocouple. When a temperature difference develops between the two twists, a voltage potential is created. The voltage is very small but since the two wires are basically in short circuit a relatively high current will be generated. This current will interact with the magnetic field and generate a Lorenz’s force, perpendicular to both the wires and the field, making the wheel turn. The next loops comes in contact with the flame and the cycle repeats.

To make a better contact between the wires you can solder them. The nature of the solder is not important. A copper-solder-brass junction is equivalent from a thermoelectric point of view to a copper-brass junction.

I hope this was intelligible. I’ll probably put some plans for this on my website one day when I feel less lazy than usual.

It could make a nice aluminum foil hat to power a one LED heads-up-display.

This isn’t thermoelectric per say, more like thermomechanic. I see a few commenters here have mentioned cars and reclaiming heat from the engine.

The easiest and to date far most efficient way of doing this? Add another step to the combustion cycle where water is sprayed into the chamber!

Fuel and air is sucked in, compressed and explodes. The piston comes back up pushing out the exhaust (at which point the engine will be at ~1600 degrees Celsius). Insert a spray of water and some of the waste heat is spent flash-boiling it pushing the piston down again.

The only problem is lubrication. Oil and water isn’t exactly known to work well together.

we all hate mechanical parts because they wear, but there is nothing as efficient as heat pump, it strange that there isn’t much project about it, heat pumps perfect for camping it can work off solar or camp fire

@Plastbox – The material and lubrication problems are vast, and the engine itself isnt anywhere near that sort of temperature, only the gas within it – the metal surfaces are kept surprisingly low.

BMW are, if you read the tech papers on it, indeed working on exhaust manifold mounting the peltiers. The problem then is cooling the cold side – as with all heat engines you still need to get the cold side as cold as possible for energy generation.

This isn’t a very old one but I saw another similar hack using a TEC a couple of years back.

This isn’t a new idea and it’s terribly inneficient.

Next time you link to anything on instructables, could you host a copy of the CC licensed content here rather than link to it behind their pay wall.

pretty cool. it’s a future million dollar technology…that can be made in a basement.

Harold:
Considering the fact that all energy on earth is indirectly some form of solar energy, I wonder how inefficient solar cells actually are.

Consider fossil fuel.. Prehistoric plants and algae use photosynthesis to get energy from the sun. They in turn are eaten by animals of ever higher standing on the food chain. A very small number of these are actually fossilized in a way that yields raw oil and gas which we can use.

Compared to a consumer-level 14% efficient solar panel I’d say they are doing a quite marvelous job at converting solar energy to working power.

And of course, thermoelectric plants using molten salt etc. are far, far more efficient than regular solar panels, and are capable of producing power through the night from all the heat stored in the melted salt.

Well, this is not new, I have some thermo-electric coolers, which are these silicon and ceramic sheets, they are very good at cooling or generating heat, but backwards… Not that good, for instance, if a Peltier effect cooler is used to generate energy, from a 100W heater/cooler you will only get around 10W (at max. and if lucky)…
In the energy generation field they are good not for dedicated generation but for energy recycling. They are being used in some cars, around the engine to get all the unused energy (heat) emitted by the engine. This can make the engine run a lot better because like this the exceeding heat can be absorbed by the TEC and converted to electricity. But they are no match for solar panels and less for wind turbines/generators. They can also be used to absorb the heat behind a solar panel too, for instance :) Solar panel life improved and energy generated :)