Anyone know anything about them? How much electricity one would produce with a constant input of about 90 degrees C? I know that this is quite a broad question - just something that has popped into my head today!!
Enough to power a small fan
The [url= http://www.biolitestove.com/campstove/camp-overview/features/ ]Biolite camping stove[/url] produces enough to charge a phone, up to 2A (at 5V) according to the literature, but the flame will be a lot hotter than 90º.
thats where i got the idea from
It's not the temperature of the hot side, it's the temperature difference between the hot and cold side that generates the voltage, so you need to keep the cold side cold.
I wondered if one would produce enough from heat output of engine/exhaust to do away with the mechanical gubbins that is an alternator...
You can get a 'reasonable' amount and it's worth doing (see next years F1 engines), but I don't think it's enough to get rid of the alternator.
constant input of about 90 degrees C
Its not just how hot the thermoelectric generator is its the temperature difference across the cell. So the amount of (usable) energy produced depends on the ambient temperature and how efficient your cooling design is.
It's very possible to generate significant amounts of energy with thermoelectric generation.
Unfortunately, doing so costs a lot more than other more conventional methods. So you don't "save" anything.
ive seen (on the internet) some water cooled/heated ones that seemed to kick out a few hundred watts
there was a company called teg power but their site doesn't seem work anymore
i was playing with the idea of using hot water from the engine block and cold water from a separate radiator to create a cold fog and hydroxy feed to boost fuel economy but it all worked out too expensive and besides in too lazy