First, this one:
http://www.tgdaily.com/content/view/32323/113/
For those who have no time to follow the link:
1. Pack some material with a lot of surface in a tube (like strands or plates or something, even steel wool will work)
2. Heat one extreme, cool the other.
3. Sound waves will develop in the material as the hot air moves. It will sound like a flute.
4. Convert the sound into electricity using some quartz or something, by piezoelectricity.
20-25% efficiency, initially.
Not bad, considering that the best solar cells can give you 40% and regular cells give you 20%. Besides, it complements photovoltaic cells, that use the light more than the heat.
Second, looking into some references about it, I found ANOTHER new way to recycle waste heat. This is harder to comprehend: organic molecules trapped between nanoplates of gold.
http://www.livescience.com/technology/0 ... power.html
It works the same way a Seebeck junction works (thermoelectricity), so it's not totally new.
Who knows, they might work.
Weird conclusion:
Yes, yes, I know, I'm always bringing to this forum farfetched ideas by guys with crazy eyes...
The news is dated in April, so if it really worked, we probably had heard about it.However, what caught my eye was this:
"... only 20% of the energy is lost when sound pressure is converted into electricity".
Wow.
Don't laugh too hard, but... has anybody tried to use an internal combustion engine that way?
I mean, to use the gas pressure NOT to move a crankcase, but to use it as a pressure "source" for piezoelectricity to develop in a suitable "receiver".
I imagine (in my naiveté) a "piston head" made of quartz. It cannot move. It simply receives the pressure and converts it directly into electricty. Would this idea work? If the quartz must vibrate, it's easy to imagine some kind of valve or turbine rotor that provides the vibration, between the combustion chamber and the "generator". The understanding we have on how the phonons behave in a crystal lattice has advanced a lot in the last 30 years, btw.
