Flue pipe warming plate? / what teg items are run off stovepipe heat?

[MR GUS]

Since purchasing a new top plate for our previously  "straight up" Austroflamm, actually less than i'd feared at around £110 (Oct 2010 price delivered direct from Germany) ,..Stovax who have ceased supply of any aspect of Austroflamm & only those with persistence will now get the contact details of the new supplier (stovax simply  can't be fagged unless you push them) ...dampened my enthusiasm for recommending a stovax associated product!
Proble with the G3 is that it was a knock out piece so unless you are mates with an engineering company, not simple to resolve, ..actually whilst in the spares wilderness I did contact a forge with regards to sorting things out..

Since re-installing it gets up to heat dramatically faster, & has left me boiling up kettles by 50% less in favour of a stove top espresso or two.

This made me think, that whilst the flue (shiny schiedel prima+) needs to exhaust gases at a high temp, could a well supported length of flue  have a solid cast (suitably drilled into the wall for support) to draw off some of that heat in order that my coffee or whatever in a small container (no bigger than a cafetierre) could free up what is essentially stove hotplate space &  the same warming / percolating job via the flue either on the join from the stove to flue or further up the pipe?
Anyone tried?
I'd like to run an eco-fan but don't want to clutter the stove top via a balancing act (pre-warming logs etc) & be chopping & changing kit all the time , leading to increased chances of ruining kit via coffee/ dropping fans etc..
Having a penchant for the Vermont Wild Fire Elm 24" wood stove, they have much raised warming shelves (though output I guess is pretty massive)
Love what this chap does with the old stoves & a pyrex dish!
 www.vermontironstove.com
 Vermont Iron Stove Works LLC

Also how big a teg module would you require to run in room entertainment, ie a dab battery radio, as we go digital it hardly seems worth investing in fm anymore, my concern is obviously not to draw off too much heat that would affect flue gases within the chimney

[MR GUS]

Ivan, never did see a teg lantern radio video up did we?

[Ivan]

I thought I did a video, but can't remember what happened to it. The solar thermal - TEG - powered radio was in operation at the Navitron party when you attended, so you may have seen it first-hand.

The only real problem is not overheating the TEGs. Depending on the spec, they don't like getting over 80C, 120C or 230C. So you've got to design your system so that it keeps the temperature at the TEG below it's design limitation.

I don't think it would make much difference to the flue gas temperatures. Imagine the heatflow from the top of the stove into the room like a stream running down a hill. Putting a water turbine into that stream wouldn't make any more water flow down the hill. It's not the world's best analogy, but it fits.

I got around 3Watts out of my TEG power setup, at somewhere around 3volts. If I had put a fan-assisted heatsink, or a better quality heatsink, I think both would have been considerably higher (I was using 6 TEGs). Various others have achieved 10-20W with TEGs on a stove - so you can get some realistic power if you need it.