Thermoelectric power

  • Thermoelectric power

    Posted by BiggKidd on December 15, 2022 at 5:21 pm

    Has anyone here played with thermoelectric power or even seen it in use? I recently bought one of those wood stove fans that’s powered by the heat of the stove. It not only works but it works better than I thought it would. I’m not saying it makes a big difference in the way the stove heats the room because it doesn’t make a big change. But it impresses me in the fact that it takes heat from the stove and using the difference between the stove temp and the air temp it makes electricity to power the fan. Which has me wondering if all of us using woodstoves for heat in the winter aren’t missing some free power. Why couldn’t we be making some useful power from that heat?

    BiggKidd replied 8 months ago 10 Members · 88 Replies
  • 88 Replies
  • TagNBee

    Member
    December 15, 2022 at 7:41 pm

    i have the same type of fans on my stoves. they work great. we also use the stove to heat water through coils. I would love to learn how to harness more of the energy escaping in the form of heat

    • BiggKidd

      Member
      December 15, 2022 at 9:08 pm

      Well here ya go. I think it could be greatly improved upon if it were built in during construction. Not in to the stove but in to the house. Via floor heating using the cold water as coolant to make the TEG’s work better. Everything in a loop water out of the floor to the TEG’s for cooling then heated by the stove through the floor for radiant heat and back to the TEG’s to cool them before being reheated in the stove and looping again. Winter is our shortest solar days and additional power would be great!

      https://www.tegmart.com/thermoelectric-generators/wood-stove-air-cooled-45w-teg

      https://www.youtube.com/watch?v=7O3FlujxXCw

      • This reply was modified 11 months, 4 weeks ago by  BiggKidd.

  • BiggKidd

    Member
    December 15, 2022 at 10:27 pm

    See how much of that stove top in the video is open and he has a 45W generator on there? Well imagine if you had designed a system for the purpose of making power and heat and used all that surface area. I see the potential for a good bit of power production without the loss of any valuable heat. I can see the possibility of making 500+ watts when your heating your home with a purpose built system! Now wouldn’t that be cool? Oh I can not wait to get my hands on some parts to make a prototype!

  • BiggKidd

    Member
    December 15, 2022 at 11:15 pm

    I’ll be danged this is pretty much exactly what I was referring to doing.

    https://www.tegmart.com/thermoelectric-generators/wood-stove-water-cooled-100w-teg

  • MartHale7

    Member
    December 17, 2022 at 1:28 am

    The biggest danger with these is for them to get too hot and the heat destroys the unit. For myself I would rather have solar panels and a lithium battery. I buy used panels at 60$ for 200 watts of power, add a charge controller and a battery for the money you are further ahead than the stove in that you can have the sunshine charge the battery in the background. It is what I am doing to run my home with 4,000 watts of power. Cloudy days I use a generator,

    • BiggKidd

      Member
      December 17, 2022 at 2:40 pm

      After 15 years living off grid in Va I know any power we can make in winter is good power. We are always power short in winter and this might just be the answer.

      • MartHale7

        Member
        December 18, 2022 at 3:31 pm

        Yep power is a good thing and having backups to the backups I am a firm believer.

    • Angespag

      Member
      February 3, 2023 at 9:30 pm

      Where are you getting the $60. 200 watt panels?

      • MartHale7

        Member
        February 3, 2023 at 9:40 pm

        I got them from Santan Solar.

        https://www.santansolar.com/product/used-jinko-265w-solar-panel-pallet-of-15/


        I have testing these and I am getting 222 watts per panel out real power.

        I buy the pallet deal. These are used, but are working great for me.

      • Hippocrates_Garden

        Member
        February 3, 2023 at 9:49 pm

        And the shipping was how much? I’ve ordered from SanTan three times. Prices are great, but don’t forget to factor in the shipping charges. $79 panels with shipping to Northeast Arkansas ended up right at $100/ea. (still good for 255W panels)

      • MartHale7

        Member
        February 3, 2023 at 10:00 pm

        Shipping varies with location, but for me it was 300 for 31 panels. This is my second order with them I split the cost with them so for me I paid 1/2 of the shipping cost. But they have been a good company to me.

  • MartHale7

    Member
    December 17, 2022 at 1:29 am

    That said, they do have their place -> https://www.youtube.com/watch?v=TNbeL-adIqA

  • MartHale7

    Member
    December 18, 2022 at 3:38 pm
  • BiggKidd

    Member
    December 18, 2022 at 4:22 pm

    Pretty neat concept isn’t it?

  • BiggKidd

    Member
    December 19, 2022 at 12:44 am

    I think I’m gonna try modifying one of these for 12 volt power. Everything I need except the pump for a good test run. Same place has a pump that will work for another $8. It’s $49.99 with the cooling sheet AKA TEC12706’s. If I can get 20-25 watts at 12 volts with this setup I’d call that a big win! If that much works I’ll get three more and have a home built system of 100 watts for a fraction of the cost.

    https://usa.banggood.com/TEC1-12706-12V-170W-Semiconductor-Refrigeration-Sheet-Air-Conditioning-Assembly-Cpu-Water-Cooling-Head-Radiator-Refrigerator-p-1968150.html?rmmds=detail-topright-recommendation&cur_warehouse=CN&ID=6320961&trace_id=87921671401182154

  • BiggKidd

    Member
    December 20, 2022 at 5:35 pm

    Well I decided to take a chance and gamble on this to the tune of $300 for a DIY system. If it works out then we should make at least 1kw of power from it every 24 hours and possibly up to 2.4kw every 24 hours during the winter when the heats on. Hopefully it will help with generator run time during the low solar winter months. A big added bonus for us is it will also let us pump some heat to parts of the house that don’t get any now via the cooling system for the modules. I think being able to move some heat around the house probably had as much to do with my decision to spend the money as making power did, maybe even more. The heart of the system will be 2 of these units deconstructed and modified for my purposes.

    https://www.ebay.com/itm/174280115967

    I have a bunch of new old stock heater cores I’ll use to remove the heat from the system and put it where we need it, IE: the bathroom and my daughters room.

  • BiggKidd

    Member
    December 20, 2022 at 9:30 pm

    Just wanted to point out I don’t really expect these modules to last. That’s part of the plan believe it or not. This was the least expensive way I could find to get the hardware. I’ve already found higher temp better quality TEG modules to replace them when they fail. Buying the hardware each piece by piece would have more than doubled the price without the modules. It was those little Aluminum water tanks and the Aluminum heat sinks I needed to make this work.

    If this system does nothing more than move heat around the house I could still call that a win. Wood stove “central” heating for $300. lmao It gets cold in the bathroom and kitchen, my daughters room isn’t as bad but it could use more heat too.

  • BiggKidd

    Member
    December 21, 2022 at 4:05 pm

    Hi guys got a question for you all. I need a decent soldering iron and I am looking for suggestions, hopefully with links. For a good soldering iron that won’t break the bank but will always get the job done, I’ve had it with the junky one I’ve got!

  • BiggKidd

    Member
    December 21, 2022 at 11:57 pm

    Started actively working on this project today. First off I want to start with a good foundation. Which in this case is some inch thick iron or steel scrap I bought for unknown reasons one day when I saw it. It was one of those cases ten or so years ago when I said I’ll need that one day, guess that day was today. lol So I found it and cut it in three nearly equal pieces of roughly 3×21 each to make a nice thermal mass and help temper the ups and downs of the woodstove. We all know thermal mass is effective in slowly distributing heat and in this instance I am hoping it will also keep the stove from overheating the thermoelectric modules and help them maintain a more steady heat without those huge peaks and valleys woodstoves can have. I have a ton of cleaning to do on them and I’m thinking I’ll weld them together in to a single unit roughly 9×21 and maybe put handles on the ends to make handling it easier. Haven’t decided yet but I may weld another 1/4 plate on top to make it nice and flat & even across the surface. Does anyone KNOW if this will also keep the top surface from getting as hot as the top of the stove gets? I sure hope so! lol

    I did get them clean enough for a test run over the next few days to try and get an idea what kind of difference it makes. I won’t honestly be able to tell until I get the IR thermometer, but I should be able to tell if it tempers the heat some. They are on the stove now the little fan finally cut off, wonder how long it’ll take to come back on sitting on top of them?

    • This reply was modified 11 months, 3 weeks ago by  BiggKidd.
  • BiggKidd

    Member
    December 28, 2022 at 3:34 am

    The “test” or 12 volt single unit of 4 came in today. So I got it all taken apart and cleaned the pieces, once I get the thermal paste I can reinstall them in reverse. But that’s about all I can do until the temperature gun gets here and I can see what I need to use for a thermal buffer. Although I do believe the 1 inch thick steel I have on top of the stove now will work for that. I’m not as worried about getting 100% performance I’m more concerned with longevity at 50-75%. I am going to have to figure out how to handle the two outside fins on the aluminum heat sink as they are about 1/4 longer than the rest.

  • BiggKidd

    Member
    January 3, 2023 at 8:10 pm

    I have almost everything to make this work EXCEPT the temp gun and new soldering iron I ordered. Amazon first said 2 days I ordered on 12/22/22 it’s now 1/3/23 and the stuff still hasn’t even shipped. Now it looks like I’ll be lucky to get them by the middle of the month. WTH?

  • BiggKidd

    Member
    January 6, 2023 at 3:35 am

    Alright the IR temp gun came in and testing of the stove’s heat output has begun. Problem is it’s not cold enough to burn it very hard. I have a pretty good base line for now but I need to test it when it’s rolling and that would run us out of the house right now. lol It’s 39 out and 73 f in and the stove top is 84c and the steel plate is 60c. The steel plate seems to change temperature much slower and seems to stay about 20-25c cooler than the stove top. Which is what I was hoping for but I still have to see where the top end temperatures get before I know which way to go setting up.

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