Thermopile, let extract some electricity from heat without steam

Discussion in 'General Electronics Chat' started by Jacquesl, Feb 8, 2007.

  1. Jacquesl

    Thread Starter Member

    Dec 9, 2006
    29
    0
    I want to build a Thermopile to generate usable electricity with a heat source, like a small fire or something,
    I can build something like this but, I only get 1 mA and an ant of a volt. And it subjected to 1700C blow torch, it sucks.

    So does anyone have some info about that, would be nice, to light a candle and then your able to watch a DVD
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,145
    1,791
    Only in some alternate reality which you seem determined to inhabit since you are so dissatisfied with this one.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    The Russians did something like that back in the 1920's. It took thousands of thermocouple junctions to generate enough electricity to run a radio. It was a collar on the glass shade on a kerosene lamp.

    You still can't get something for nothing. Modern steam plants are much more efficient than thermopiles. It's really a hobbist-level phenomenon.
     
  4. kender

    Senior Member

    Jan 17, 2007
    263
    0
    A parffin candle puts out about 1W altogether. I don't know if you'll be able to run a DVD off 1W even if do the impossible and convert all of the candle's energy into electricity. However, you might be able to run an MP3 player with small earbuds.

    The Russians did something like that again in the 90s, when they have sent an expedition to the Amazon. They needed the power and the couldn't use solar panels, because they were under the canopy all the time. Their device worked of a campfire. It looked like a descent sized pot. The water would go into the pot to provide a guaranteed 100C at the low side of the temperature gradient.

    It's not an entirely hobby-level phenomenon. Thermopiles are very useful, when you need to make a source of power that will work for dozens of years without service. Essentially that translates into "no moving parts". For example, all spacecraft that go further than Jupiter can't derive enough power from the solar panels. Another example are the drifting buoys used for oceanography research (of at least so they say). They all use nuclear reactors with thermopiles. There’s also an ongoing academic research into the use of the thermopiles to power the implants inside human body. The thermopile would work on the temperature gradient inside the human body.
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    I question whether nuclear reactors (which require human monitoring for safety, large cooling systems, an exhaustively extensive paperwork) are used on drifting buoys.
     
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Do you have references for that statement? I highly doubt any country would let that technology float around the ocean without supervision ... close supervision.
     
  7. kender

    Senior Member

    Jan 17, 2007
    263
    0
    I couldn't find a reference on the web. I heard about such buoys about 10 years ago in Moscow. It could be an urban legend.

    However, I found a mention of a thermopile design with combustion for bouys
    http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0611397

    and an exibition-type page about thermopiles
    http://www.dself.dsl.pipex.com/MUSEUM/POWER/thermoelectric/thermoelectric.htm check out "thermoelectric generators today" section at the bottom of the page

    An article about a spacecraft radioisotope thermoelectric generator (RTG). However, thermopiles are referred to as "thermocouples" in this article.
    http://en.wikipedia.org/wiki/Radioisotope_thermal_generator
     
  8. kender

    Senior Member

    Jan 17, 2007
    263
    0
    Found it! There's only one mention of the buoy in this article, though.
    http://www.bellona.no/bellona.org/e...al/russia/navy/northern_fleet/incidents/37598
    http://www.bellona.org/english_import_area/international/russia/navy/northern_fleet/incidents/31772
    There are also some IEEE articles, but I can't get to them.

    Radioisotope generators. I have confused them with nuclear reactors.
     
  9. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Kender,

    Interesting articles. I would not doubt the vandelism in the former Soviet Union concerning the RTGs at lighthouses.

    I don't know if the US deployed RTGs in the NOAA monster bouys, although that report certainly names bouys as an application. Those monster bouys replaced the Weather Station Patrols that was done by the U.S. Coast Guard.

    Lots of reports will indicate potential applications, but drawing the line from the potential to the actual might not exist.

    Thanks for the links, they certainly were an interesting read.
     
  10. kender

    Senior Member

    Jan 17, 2007
    263
    0
  11. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    A candle only supplies 0.5W at the most. Not enough for a DVD, I'm afraid.
     
  12. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    Me to, since these buoys can be easily intercepted. And a nuclear reactor without maintenance is dangerous no matter how small it is. To end with, nuclear combustible is very expensive to be used like that.
     
Loading...