Electricity from Coal Stove--No Moving Parts

Thermoelectric generation (TEG) utilizes heat flow through a device, composed of semiconductor materials, to generate an electric current. It has no moving parts, and relies on heat differential on one surface of the device compared to the other. Most commercially available devices have a heat limit on the "hot" side of the device of 300°C, or 572°F, and a maximum "cold" side heat of 180°C, or 356°F. The greater the difference between a hot site and cold side, the greater the electric energy produced.
Most devices are one or a few inches square, and a fraction of an inch thick. They have very long functional lives and are maintenance free. Although peak power output is not especially high, utilizing a few of them at once may produce meaningful output. Certainly, enough to recharge a cell phone or other battery recharging device, or even operate a 12 V light bulb.

For example, a single 2.2 in.² device that is 572°F on the "hot" side and 86°F on the "cold" side produces nearly 15 W of power. These temperatures suggest that this technology may be ideal for coal stoves. The difficulty may involve adequate cooling of the "cold" side. Most manufacturers recommend applying a heat sink to the cold side, and I'm guessing that a heat sink repurposed from a PC may be a reasonable choice. In my hand fired stove, a great deal of cold air rushes back of the stove to enter the ash pan vents, and I'm trying to figure out a way to direct some of this flow over the heatsink fins.

The 2.2 in.² device costs about $80 purchased singly, or $60 each when purchasing 10 devices. Manufacturers claim that their devices are much cheaper than solar technologies considering power output.

I came across some interesting links today and thought I would post them here:

http://www.customthermoelectric.com/powergen.html
http://www.tegpower.com/
http://www.tegpower.com/pro3.htm
http://www.customthermoelectric.com/pow ... ec_sht.pdf
http://www.customthermoelectric.com/app ... aphite.pdf

Ashcat, very useful information. The Tegpower links you provided show two products that are developed for immediate use. While I have no experience with them and want to learn more, the 12 volt battery charger unit (http://www.tegpower.com/pro8.htm) is ready to roll simply by sitting on top of a coal or wood stove with surface temp of 350 degrees F minimum--I think most stoves would do this. Might make a fine trickle charger during heating season and also could recharge a depleted 12V battery during outages. Similarly, the camping lantern generator (http://www.tegpower.com/pro9.htm) literally has a 5VDC output through a standard USB port, though it would have to be mechancally set up to attach to a stove. Keeps your electronics humming. Would like to know what others think.

Thanks for the follow-up, Beeman. It seems as though it would be fairly easy to modify the lantern unit to attach to, or rest near, a coal stove. The USB output device is attractive for charging cell phones, laptops, etc., as is the "trickle" charger.

I first heard about this technology from reading a news story about the use of BioLite stoves in NYC recently, after hurricane Sandy. These use scrap wood/kindling to supply the heat:
http://biolitestove.com/campstove/camp- ... sandy.html

Ashcat wrote:Thanks for the follow-up, Beeman. It seems as though it would be fairly easy to modify the lantern unit to attach to, or rest near, a coal stove. The USB output device is attractive for charging cell phones, laptops, etc., as is the "trickle" charger.

I first heard about this technology from reading a news story about the use of BioLite stoves in NYC recently, after hurricane Sandy. These use scrap wood/kindling to supply the heat:
http://biolitestove.com/campstove/camp- ... sandy.html

OMG, Just what every 3rd world Yuppie needs. Charge your cell phone while "Roughing it".

The Home stove is a very expensive version of the "Rocket Stove" which is promoted as a fuel saver in third world countries. The main purpose of the rocket stove concept is to have a cheap stove that would heat food with little wood for people that can't afford firewood. Side benefit is less pollution.

I'll plug this device into the same grid as my solar panel and wind turbine.

The Peltier Effect has been known for some time. I actually bought a few of the modules to test with. The raw modules are readily available on Ebay or other electronic warehouses, and the price isn't bad.
Heres one: http://www.ebay.com/itm/TEC1-12710-TEC- ... 3f1be34a12
Interesting play toy. You can build your own "Charger" for $10 or $20. Not much amperage though, unless you gang them together.

What you really want is a long lived heat source. That's the principle of the radioisotope thermoelectric generators. The heat come from a decaying radioisotope and if used in a spacecraft the cold of space. See wikipedia for the history:

http://en.wikipedia.org/wiki/Systems_fo ... iary_Power

All the units use the dissimilar metal thermocouple junction principle, just the heat and sink thermal sources are different. I worked at JHU/APL all my professional career. During the early and mid-sixty's the SNAP units powered our satellites until one launch failed and sprayed Plutonium-238 over a wide area. The desired power source then changed to solar panels.

Yanche--APL must be a fascinating place to work! I'm sure you have a few stories you can't talk about.

Continuous heat from a coal stove, for 5-6 months, might be a good enough source to keep a battery charged or have LED light in case of prolonged power outage.

More on the Seebeck/Peltier Effects: http://www.wisegeek.com/what-is-the-seebeck-effect.htm

http://www.youtube.com/watch?v=Ftj1ox5UHAU

video of guy using stove-top generator ... runs a small vacuum ... ~4amp?? @ 120 v = ~500W .... not enough to run a refrigerator but a few lights

Worth the $$ ? Nah....use an inverter instead

Gosh.... $80 for a 15 watt device seems expensive to me, especially when you are supplying the fuel for the heat source.

Here's a 60 watt solar panel for $87:



http://www.solarblvd.com/Solar-Panels-& ... _info.html