Generating electricity is all
about changing one source of energy into another.
Hmmm...That sounds about right to me, but where can
you take it from there?
To the stars? Researchers from Los Alamos National Laboratory and Northrop Grumman Space Technology have built a compact generator that converts heat to electricity with the relatively high efficiency of 18 percent using thermoacoustics. And that maybe only the starting point.
The heat can come from an onboard mirror -
concentrating solar energy, or from radio-isotopes, or perhaps... sometime in
the near future.... from a new ZPE source ;-)
The generator is simple, making it potentially long-lived and easy to maintain. You can see from the photo that the size-factor is now much more compact than before - which was one of the problems with earlier thermoacoustic converters.
The generator is simple, making it potentially long-lived and easy to maintain. You can see from the photo that the size-factor is now much more compact than before - which was one of the problems with earlier thermoacoustic converters.
For space use, this is not as efficient as the
latest 3-layer nano-GAs- cells, but it is not and either/or situation, is
it?
A typical commercial solar cell for use on Earth
has an efficiency of about 15% for the first few years, and it goes down from
there - while the first solar cells, built in the 1950s, had efficiencies
of less than 4% - indicating that there is a likely upside to
thermoacoustics, even starting out at a higher level. This (thermoacoustics) is
a field that is as much art as science. But we have always known that about
sound, at least according to audiophiles.
Modern space solar cells, based on gallium arsenide
and composed of 3 sub-cells 'grown' one on top of the other, now allow the
generation of more than 12 kW of electric power on board large telecommunication
satellites. Higher cell efficiency of about 24% allows a more compact solar
array to be employed, but at a cost which is far too high for use on earth - but
giving a reduction in the mass of the satellite and the cost of its launch.
But the thought just occurred - these two
technologies: solar semiconductor cells, and solar thermoacoustic cells, could
possibly be used synergistically on earth (or in space) - i.e. using the heat
rejected from the semiconductor cells to power the thermoacoustics.
Let's see... using cheaper amorphous silicon (15 %
eff) if would not be the full 15% + 18%, when combined with thermoacoustics
- in efficiency, but it might exceed 30% which would make it much more
competitive for earth-bound power.
Jones
