re: wind and sun resources
16 jan 1998
scott nudds wrote:
>: scott nudds wrote:
>: >produced in volume pv cells could be produced for less than 1/10th the
>: >current cost.
>: do you have any evidence whatsoever for this article of faith?
> yes, i know how they are made. you can run reams and reams of the
>things off in sheets of any desired length.
have you been ovshinskized? dr. pritpal singh also knows how they are made,
although it's been a year since we talked. perhaps things have changed.
> how expensive is tinfoil?
a lot cheaper than steel with a smooth enough morphology and
amorphous silicon with a low enough density of impurities and
defects in 10-12 electrodeposited layers to make good devices
with reasonable yields.
>: at the moment, pv panel prices are increasing with increasing volume.
> do you think this will be the general trend?
for a good while, i suppose, since the process is technically difficult
and performed in very expensive factories owned by oil companies.
date: fri, 29 mar 1996 10:08:16 -0500
to: email@example.com (nick pine)
from: "dr. p. singh"
subject: re: inexpensive pvs...
>i'd gotten the impression somehow that the substrate was
>ordinary cheap mild steel...
ovshinsky's panels used to use a japanese steel because they could
not find an american steel manufacturer that made steel with a smooth enough
morphology to make good devices !! the process is complicated because the
amorphous silicon needs to have a low enough density of impurities and
defects in order to make devices. the amorphous silicon solar panels
actually start off as 8-10% efficiency and drop down to 5% because of
optical generation of defects in the amorphous silicon material. in
research, non-degraded 10% amorphous silicon cells have been demonstrated
but i don't think that they have reached production yet.
it is actually quite difficult to make solar cells that are 10%
efficient - especially over large areas. imagine making square feet of solar
panels that are low in defects and impurities - it's not easy !!
the only company electrodepositing solar panels is bp solar in
england. i'm not sure of the status of their production.
i hope that this information is useful to help you understand a
little more about pv processing. please feel free to disseminate this
information to whomever you wish - but i would like you to mention me as the
source in case others wish to contact me for more information (especially on
my research work).
>>i am working on electroplated solar cells on transparent substrates.
>>the electroplating process is a low
>>temperature process (60 c) and so could potentially be used on plastic
>>substrates with a transparent conducting oxide (such as tin oxide or indium
>>tin oxide) as the transparent contact. this would allow potentially low cost
>>devices to be manufactured since the process and materials costs could both
>>be very low. the transparent substrate would also allow heat to pass through
>>so that the use of these devices in a hybrid electrical/thermal system would
>>be a great idea. it also makes a lot of sense to use these types of pv cells
>>in a hybrid solar collector with a heat exchanger because that would allow
>>the cells to operate a little more efficiently !!
>>i will keep you informed as to how the research is going but don't hold
>>your breath - after all it is research and may take a few years to get to
>>a point before it is commercially viable.
>> in terms of ovshinsky's cells, these are amorphous silicon alloys
>>that are made by a plasma assisted chemical vapor deposition process. those
>>big chambers that you have seen that look like a newpaper press are in fact
>>evacuated chambers in which gases of sih4, geh4, ch4, ph3 (phosphine),
>>ash3(arsine) and b2h6 (diborane) flow. an rf plasma is used to break down
>>these gases and the silicon, germanium, carbon, hydrogen and dopant
>>components are driven to the stainless steel substrate by the capacitive dc
>>self-bias between anode and cathode capacitor plates.
>>the multiple chambers are used to deposit individual layers of a device
>>that may have as many as 10-12 layers !! this is not an inherently cheap
>>process in small scale production (<10mw/yr.) and so the selling price
>>of $4.50 a peak watt is about the production price of these cells.
>>(ussc is very secretive about its books and so the exact production price
>>is generally not known
>>thin film division makes a similar product and they are selling the cells
>>for more than it costs to make them). as far as i am aware only the solarex
>>polycrystalline silicon cell division is making money as a solar cell
>>manufacturer and they are selling at about $3.50 a peak watt for large
>>orders. there is a joint venture between enron corp. and amoco (solarex's
>>parent company) to make a 10 mw/yr. thin film pv manufacturing facility in
>>virginia. until now the amorphous silicon community has said that the cost
>>of amorphous silicon pv will drop dramatically (down to less than $1/wp) if
>>they could take advantage of economies of scale and produce at least
>>enron has called their bluff and so let's see what happens !! keep posted.
>>in the meantime solarex's polycrystalline silicon cell division is
>>ramping up to increase their production capacity three-fold and siemens
>>solar (what used to be arco solar) is also increasing production. so there
>>is a growing market for pv but primarily for remote applications in
hope we see some sun again soon - it's quite dreary outside today.