http://cleantechnica.com/2008/10/12/black-silicon-could-revolutionize-
solar-cell-technology/
http://tinyurl.com/3l733w
http://www3.interscience.wiley.com/journal/113445892/abstract?
CRETRY=1&SRETRY=0
http://tinyurl.com/lreufb
and of course google black silicon for much more.
The high efficiency and low reflectivity of black silicon makes it
ideal for a hybrid electric - thermal solar systems with thermal
wells and heat pumps.
I think heat pumps are best implemented as a hybrid thermal well and
solar system. The temperature of thermal wells stays well above
ambient temperature. They are very effective here in alaska. When
combined with a solar hot water collector, thermal solar energy in
the day can be used to heat the thermal well to store energy and
increase overall system efficiency.
I think solar photovoltaic can integrate nicely with this as well.
Solar cells take about 15% of the solar radiation for electrical
energy production, but the left over energy is still available as
heat. Solar cell clad hot water (or other heat collecting fluid)
piping can thus be used to heat a thermal well while simultaneously
producing photovoltaic energy for pumping the water.
None of this is new thinking. The full integration of such a hybrid
system might be though. Integrating solar thermal and electric
capture makes for double duty of each square foot of roof space,
which is critical for the economics of rooftop systems.
As photovoltaic efficiency increases the feasibility of simultaneous
hot/cold thermal storage becomes more feasible. This is accomplished
by compressing gas and using a heat exchanger for hot storage and gas
expansion to freeze water for cold storage. Either hot or cold
storage can be tapped for heating or cooling as needed, and both can
be tapped for generating power via sterling engine/generator.
Some related comments regarding thermal energy storage systems are here:
http://www.mtaonline.net/~hheffner/HotCold.pdf
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
