[Stoves] TEG Thermoelectric Generator for stoves

Thu Jan 3 19:15:24 CST 2019

Crispin:

Could you please give some idea of daily average and peak electric demand
of some users, and corresponding locations, where TEGs can be viable
substitutes for pico-PV or diesel/kerosene generators?

It would help to know the cost and quality of the requisite amount of
biomass and the split between cooking and non-cooking requirements.

Why not just use the TEG for electric cooking via induction stoves?

Over the years I have found solid or liquid biofuels for small-scale
electricity provision - own use or small grids for greenfield
electrification - to be a waste of money or attention. Past failure is no
guarantee of future failure, and biomass for grid feed-in or cogen is an
established business line but even then for limited range of contexts.

Trees grow on land, need water and labor, and skills and finance.
Renewability is mere puffery; nothing is strictly renewable, not even
research grants.

Nikhil
------------------------

On Thu, Jan 3, 2019 at 2:51 PM Crispin Pemberton-Pigott <
crispinpigott at outlook.com> wrote:

> Dear Tony
>
>
>
> I found in Singapore these units:
>
> https://www.ebay.com/bhp/thermoelectric-generator
>
>
>
> Look at the second item. Notice that it only goes to 150 C. That is a
> problem.  Attached is one example with a 200 C upper temp limit. Watch that
> very carefully. It ha to do with the melting temp of the solder used to
> connect the many modules in each one. Exceed that temperature just once,
> and it is over. Keeping them under 150 is difficult. However it is
> important to remember that the heat flow is dynamic: if you can pull a lot
> of heat away from the TEG, you can put it against a surface that is
> considerably hotter than the rated limit. For example you can have a 350
> degree heat source and a 150 degree rating, as long as the temperature
> inside the TEG is under 150, because you are pulling the heat out at
> perhaps 40 C with water, for example.
>
>
>
> P&N has a unit
> <https://www.alibaba.com/product-detail/Strong-durable-thermoelectric-electric-generator_1926529487.html?spm=a2700.7724857.normalList.6.3cd4229dRJBbf6>
> which claims to be 250 C but the caution at the bottom of the page is 225
> or less. They have models with up to 2 amps output each. These are very
> high performance compared with what was available two years ago.
>
>
>
> But cut off that cooling momentarily and the TEG is fried. Look at the top
> photo here
> <http://www.peltier-thermoelectriccooler.com/supplier-217741-teg-thermoelectric-generator>.
> You can see little ladder-like structures between the plates. Each one is a
> separate TEG soldered to the plates.
>
>
>
> Yes, they are coolers running backwards, but the low cost of the coolers
> makes it worth it., The difference is not much. The ones I used were 40mm
> square and 1 watt and $1.00. I found the identical units for sale over the
> counter in Beijing for the same price so someone is banging them out in
> large numbers.
>
>
>
> I found that the high power density ones are far more expensive per Watt.
> Really not worth it.
>
>
>
> And always add an appropriate sized buck-booster so whatever the input is,
> the output is 5.1 VDC. Be careful of totally misleading wording in the ads.
> This
> <https://www.ebay.com/itm/US-40-40MM-Thermoelectric-Power-Generator-Heatsink-Peltier-Module-TEC1-12V-60W-/163399216228>
> is a cooler, not a generator. This
> <http://www.peltier-thermoelectriccooler.com/sale-9851547-peltier-module-teg-thermoelectric-generator-for-power-peltier-power-generator.html>
> one is rated at 250 C on the hot side, 3 Watts. Plus they give proper
> performance curves.
>
>
>
> Here is a test setup using a hot aluminum plate, three 50mm square 1 Watt
> TEGs, and a buck-booster connected to a single white LED:
>
>
>
>
>
> The light is on the end of a purple wire. The blue thing is the USB
> buck-booster that regulates the voltage to ne constantly at 5.1v with a
> current that varies with power available. It is a 600 ma one so it is 3 W
> at 5.1 v.
>
>
>
> Here is a photo of taken of a TJ4.0 stove with three TEGs sitting under a
> pot on the end of the heat exchanger. That location never heats up enough
> to damage the generator. The power running the LED is 1 Watt (200 ma at 5.1
> v) limited by the buck booster ($1) which was max 200 ma.
>
>
>
>
>
> That is one HE-LED lighting up the CAU stove lab.
>
>
>
> Pretty impressive. When giving that LED 3 Watts, it is too bright to be
> looked at directly. Oh, and you have to properly cool the LED or it
> overheats rapidly.
>
>
>
> Regards
>
> Crispin
>
>
>
>
>
> *From:* Stoves <stoves-bounces at lists.bioenergylists.org> *On Behalf Of *Tony
> Vovers
> *Sent:* Thursday, January 03, 2019 1:55 PM
> *To:* Discussion of biomass cooking stoves <
> stoves at lists.bioenergylists.org>
> *Subject:* [Stoves] TEG Thermoelectric Generator for stoves
>
>
>
> Dear Stover's
>
> We want to buy some TEG to use in  school stove projects to demonstrate
> applications of biomass energy.
>
>
>
> Most of the online ones we have found seem to be TEC run backwards, low
> temp and look fragile.
>
>
>
> Can anyone suggest a model/supplier to use for stove projects??
>
>
>
> We are in Indonesia but have friends in US or Australia who can bring some
> samples.
>
> Any suggestions??
>
>
>
> Our stoves will be typically kitchen sized cook stoves Rocket and TLUD
> designs.
>
>
>
> Many thanks
>
> TonyV
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>
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