Jones, are you saying in simple terms that any thermophotovoltaic device
immersed within a constant temperature environment saturated by infrared
radiation will not produce electrical power? Does this imply that there must
be a sink of some sort that is of lower temperature for these to function? It
is understood that the energy remaining within the closed environment will be
reduced by the electrical energy removed.
Just asking for clarification.
Dave
-----Original Message-----
From: Jones Beene <jone...@pacbell.net>
To: vortex-l <vortex-l@eskimo.com>
Sent: Tue, Jan 29, 2013 12:15 pm
Subject: RE: [Vo]:100% conversion of heat to electricity with
thermophotovoltaics
From: David Jonsson
What I mean is that regardless of how efficient the
thermophotovoltaic is there is no other way for heat-energy to escape the
enclosure except as IR-light converted to electricity.
That is naïve. IR light will escape - whether some small fraction of it can
be converted to electricity, or not.
You cannot keep it from leaving - nor can you force more of it to be
converted than a matching band gap will permit. You cannot even reflect very
much of it.
You seem to be pulling the donkey with the cart. As a practical matter, even
in a perfect vacuum - if you are removing electrical current, you must have
conductive wires to do that. But the main problem is that IR will radiate
from any surface - whether or not the means exists to convert part of it to
electricity – which in your example depends on a succession of overlapping
band gaps. You simply cannot “force” heat to be converted when there is an
easier path - and since conversion is anti-entropic - the easy path is
blackbody radiation without conversion.
Whatever heat flux is not converted usually 95% of it - will radiate. Most
of it will be missed - since IR conversion is inefficient.
Having said that – cough, cough … you can follow up on the mysterious
Qu-tube. It is one of those “holy grails” of alternative energy that has
been around for years.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080009660_2008009120.
pdf
… said to be a superconductor of heat. But NASA did not confirm the claim.
If Dr. Qu’s claim were to be true (and let me add that there are people who
I respect who will tell you that they have seen it) - then it would
potentially do most of what you suggest - to the extent that a
superconductor of heat becomes a superconductor of electricity.
But even so, this kind of tube would not qualify as thermophotovoltaic, at
least not as defined in the article. It would simply be a superconductor of
heat – where the “easy path” is a vector that is also anti-entopic.
Jones
