Thermoelectric Generators?

[Nojoke Matt]

I've been looking for solutions to producing a little power for a yurt. Basically just to run a laptop and maybe some lights. Now I bumped into a site that looks a bit too good to be true:
http://www.tegpower.com/products.html

I haven't found anywhere that I could buy one of these things. Does anyone have anything like this running? Do they work? Is it something I could cobble together myself (having a mental block on how electrical things work wont help)?

Or are there any other alternatives. The yurt will be in a dense woodland so solar and wind power might not work, plus setup cost would be an issue.

Oh and I have no connection with the website.

Any help would be great from electrical expert types or folks that use this kind of power gen. Thanks in advance!

[Green Aura]

No idea, honey, although I find the idea very interesting.

I found this - http://www.bioenergylists.org/stovesdoc ... S_2005.pdf - too technical for me, but if you can get your head round it then you can explain it to me

[KathyLauren]

The principle is genuine. Stovetop fans powered by thermoelectric generators are popular here, and can be purchased at mainstream stores.

However, I seriously doubt if you could power a laptop off the generator you linked to. Chances are the device does work, and you probably would be able to run a small fan or a few LEDs off it. You would need a lot of them to run a laptop.

[Nojoke Matt]

I saw that document Green Aura....it made my brain bleed!

Yeah KeithBC. I wasn't sure about the website. It kind of suggest that you could charge a battery such as a 12v leisure battery from a woodstove, but if that's the case why aren't these things on the market? Would be damn convenient. I've seen the fans and even a radio built into a parafin lamp. I was just wondering if there was a ready made stove unit that worked. If there's one thing in the world that I just don't understand is electrical stuff.

[Ellendra]

I've been looking for solutions to producing a little power for a yurt. Basically just to run a laptop and maybe some lights. Now I bumped into a site that looks a bit too good to be true:
http://www.tegpower.com/products.html

I haven't found anywhere that I could buy one of these things. Does anyone have anything like this running? Do they work? Is it something I could cobble together myself (having a mental block on how electrical things work wont help)?

The one at the top of the page said "no longer available", but the ones below it had "add to cart" buttons, implying that they could be ordered right then and there. The one with the cooking pot says it can be used to charge 12v batteries, which means you can then use the 12v battery charger that most laptops come with (essentially use the 12v battery as a go-between).

Once again, I dawdled too much on an invention, and someone else beat me to it! I've been mentally designing something exactly like these for years, but I have no workshop space and was unable to build any prototypes. It's basically thermocouples combined with voltage and current regulators. Simple enough, but getting it so it provides the right amount of power without melting components can be tricky.

[KathyLauren]

The one with the cooking pot says it can be used to charge 12v batteries, which means you can then use the 12v battery charger that most laptops come with (essentially use the 12v battery as a go-between).

You need to have some idea of the quantity of electricity needed and the rates at which it is produced and consumed to know what you can and can't run off the device. The fact that it can charge a 12 volt battery doesn't tell you enough. It might take 3 days to fully charge the battery. If the battery is good for one hour of laptop use, you will have a problem.

You need to know the watts available and required, because the rate of electrical production and consumption is measured in watts. The information on the device says it will produce 4 watts under ideal circumstances: lots of heat available and good cooling of the radiator fins. To get that good cooling, considering that the device is mounted on the stove, you are probably going to have to use a couple of watts of that power running a fan. That leaves 2 watts to do useful work like charging your battery. How long will it take to charge the battery with 2 watts? It could be a long time. Will the charger even work on only 2 watts? If it wants 20 watts, for example, it will draw down the voltage below 12 volts until it no longer charges at all.

What if you want to charge the batteries in the summer? You will have to run the stove to produce heat. Since cooling the device will be more difficult in summer, the electrical output will be less, and it will take longer to charge the battery, so you will have to burn the stove longer.

I'm not saying it's a bad idea. Anything that captures waste heat and puts it to use is a good thing. But you would not want to rely on this as your primary source of electrical energy. At best it can be a minor supplement to solar, wind or micro-hydro power.

[Nojoke Matt]

Hmmmm......if there was a full on commercial website product and loads of folks using them I might be tempted but it is a good idea. Thanks for looking folks!

Next idea the bicycle generator?

[Odsox]

I've seen this in it's opposite incarnation, as with a lot of things in physics it works backwards too.

I forget what it's called when used in electronics, but it's used to cool components as an active heatsink.
If you apply a voltage to the wires then one side on the plate gets cold and the other side gets hot.
Never used one though.

[Nojoke Matt]

Yeah there are travel fridges on the market too.

Well here's the lantern.....quite interesting and they are only £17 on the manufacturers web site. It's not clear whether you can plug stuff into it to charge......maybe a web enabled mobile phone might be a solution for me charged from one of these?

http://www.eetimes.com/design/power-man ... wers-radio

[dave45]

Odsox - its called the Peltier effect - try wikipedia - and is supposed to work both ways.. not very efficient though. Readily available on ebay (but mainly for supercooling overclocked CPUs) if you want to play with one.

[dave45]

Hey the ebay ones look just the same as the tegpower pics ! hmmm - better check the max temps though !