thermoelectric generator

There's probably a good reason... efficiency (as opposed to the cost), toxicity, reliability, engineering to other constraints, etc. The effect is pretty well known, so I suppose there's some basic problem with using it to generate power or whatever (my guess is low efficiency).

Wiki has a decent article on thermoelectric which answers all your questions with a lot of symbols and nowhere does it say, "it's useful!" or "it's a waste of time!"

I know of one consumer device, a thermoelectric generator that sits atop a kerosene lamp to run a small radio. That's not a lot of juice from a pretty potent heat source.

However, if you look at the Wiki article, there's some related links that you might find interesting and helpful.

JoeReal said:

One way of utilizing heat is to heat up water and split the hydrogen and oxygen and feed into the range extender engine. Little electricity is needed if water is heated and you'll recover more from the heat energy.

Here's a new concept car recently shown that uses hydrogen on demand via onboard electrolysis of water:

from CNET:
http://news.cnet.com/8301-11128_3-9960833-54.html?tag=cd.blog

Click to expand...

Hendler posted something like that the other day. I'm very doubtful that there's any advantage to the on-board water cracking system. Cutting the water apart takes energy. Some of it gets lost. The H20 tank and cracking equipment weighs something and gets carried around. This is extremely unlikely to create any advantage.

As in, some of the energy comes from waste heat? Mmmmmmaybe. I remain highly skeptical.

However, back to thermoelectrics. Perhaps it's not as far-fetched as I might have thought...

BMW Improves Efficiency with TE

And it links to another article with interesting details...