Anybody Using Thermo Electric in their PV System?



  • GreenerPowerGreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    Re: Anybody Using Thermo Electric in their PV System?
    icarus wrote: »
    ...The problem was taking the heat away from the cold side. I think that my problem was that the hot side was too hot.
    Yep, from thermo stand-point, each TEC in my experiment produces ~5W, this means it would pump (@~4% efficiency) ~120W (~350 BTU/hr for 10 of them) of otherwise waste heat back to the room. You would need large enough heat sink for this heat amount for convection heat dissipation (or a low power fan from the power output if you don't use all the power output).
    If you can put the hot side on something other than the top of the stove it would help, something like the top of a hot water bucket, or a stack of bricks or stones. That would temper the hot side a bit, and make getting the heat off the cold side a bit easier.
    I would put "the pan" vertically and thermally coupled to the flue/stove-pipe (or curve it to be part of the pipe before attaching the TECs) and experiment with the placement of its height for not getting it too hot if you are handy in such task and the physical of the flue/stove-pipe permits.

  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: Anybody Using Thermo Electric in their PV System?

    Neat stuff, and had a thought. There is no need to just consider air cooling. They use water to cool computer processors, so there's no reason why water can't be used to cool one of these TEC jobbies. If a TEC will produce power with a 50 degree differential, water can get you there.

    All you'd need to do is build a heat sink that uses water instead of air fins, and pipe that water into a radiator on the outside of the house. You'd also have to use an antifreeze to keep the water from freezing on the outside. Build it so the radiator is higher than the TECs and you can use convection force to circulate the water. If it isn't enough, add a couple more TECs to power a low draw water pump. No need to have a strong pump since all you are doing is circulating the water, not pressurizing the system.

    You'd also have the option of using freon (not necessarily R12, using freon as a generic term) to cool the plates like a heat tube, as used in this refrigerator example. They are able to draw enough heat PASSIVELY to keep a freezer cold inside the house in the winter, it'll surely draw enough heat to draw 50-75 degrees off a TEC without using any power at all.

    EDIT - It also occurs to me that you could set up a hot water and a cold water loop as power generation. You could use solar water heating to heat a set amount of water, then use that hot water to generate electricity 24 hours a day. It looks like the solar shed I planned to build when I finally build a house would be perfect for adding some of these units on, you could heat enough water with solar tubes to heat your household water, provide heat for the house itself, and provide heat for the hot side of these generators, turning the hot water system into a tri-use system instead of a dual-use system, with no real loss of heat depending on the answer to my question below. It may not make tons of power as you guys say, but if it were to, say, make enough to counteract any ghosting loads from the TV set or enough to keep cell phones and laptops charged, might be worth looking into.

    Hope these new thoughts help out on this, if it works for someone I'll be very interested.

    I do have a question though, is there a measurable difference in using a TEC vs not using a TEC? I mean say you have 5 gallons of water in an insulated box and you raise the water temp to 150 degrees, then let it cool down on its own, and measure the time it takes to get to room temperature. Would there be a difference in how long it takes for 5 gallons to cool to room temp with a TEC vs without a TEC, if all else is equal? In other words, is the TEC actively drawing a lot of heat away, or is it just accepting what happens its way and making electricity out of it?
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Re: Anybody Using Thermo Electric in their PV System?

    I was reading on forum about "I get my electricity from wood" and it is just what you are doing! They use a steam engine and it looks pretty cool. They also have a Lister diesel that they run on veggie oil that has a gen head that they can use to charge batteries with. It just has to be built for 12, 24, or 48 volts. Pretty cool stuff! Check it out

    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
Sign In or Register to comment.