PV panels

 

Whenever I look at PV panels as an option I get put off by the price- are
they intrinsically expensive or difficult to produce? Or is this just a
volume of production issue? I was thinking of comparing with say processor
chips which contain a LOT of technology in them, but are comparatively cheap
especially when you look at the non-cutting edge versions where the premium
for the state of the art aspect has faded.

Francis

 

Ledz wrote:


They're _not_ comparatively cheap compared to the amount of silicon in a PV
panel compared to a CPU.  It's (partly) a matter of the silicon wafers
being built to chip-maker spec, rather than the much lower standards
required for PV.
--
derek

 

Ledz wrote:

There are a number of issues. About 70% of the manufacturing cost of a
crystalline silicon PV module goes to purchasing raw materials, most
notably silicon. The per-peak-watt cost of a PV module is a function of
both this and solar cell efficiency. Volume production will help bring
down some of the material costs, but it alone will not make PV
economical. Obviously, increasing efficiency is one way to bring the
cost down, but crystalline silicon efficiencies are already close enough
to theoretical efficiency limits the amount of material used in making a
PV module from it has to be reduced. Conversely, folks working on thin
films -- amorphous silicon, CIS, CdTe, organics, microcrystalline
silicon, etc. -- have minimal material costs, but terribly low
efficiencies. *They* are looking to increase efficiency without worrying
too much about material costs.

Thus far, crystalline silicon is still more than 90% of the PV market,
but I suspect that will drop by about half over the next 20-30 years.

Another aspect to your question is the supply/demand issue. Right now,
demand for PV modules far outstrips supply, and PV manufacturers have
not been able to grow the supply fast enough to catch up. As a result,
retail prices are bit inflated and not very indicative of actual
manufacturing costs.


Well, considering that a single silicon wafer full of processor chips
can have a street value well over $200,000, and that a $600 PV module
contains 36 silicon wafers, I'm inclined to say that the technology in
the processor chips is pretty pricey compared to PV. Even for
non-premium processors, you're still looking at thousands of dollars per
wafer. That is because a large number of processors can be made on a
single wafer; when the wafer is finished, the processors are sawed out
of it and individually packaged. Solar cells, on the other hand, are
typically made one cell per wafer because power output is proportional
to the size of the solar cell. The amount of silicon used to make, say,
a Pentium microprocessor would only produce about 100 mW of power if
used as a solar cell.

I'm writing fast, so I hope that's not all too jumbled to understand....

 

R.H. Allen wrote:

Researchers at the Australian National University claim to have
developed a silicon PV cell that uses an order of magnitude less Si.

http://solar.anu.edu.au/pages/publications2003/65micronthinmonosi.pdf

Is this a breakthrough?

(They have some interesting work on PV concentrators and solar thermal
on their site too)

When I did the calculations on the value of a home PV array I found I
could generate considerably more electricity by putting the money in
the bank and using the interest to buy electricity from the local power
station. That was including the government rebate.

cheers,
--mt.

 

Market Theory wrote:

Origin Energy (also in Australia) is attempting to commercialize this
technology right now. From what I understand, assembling the "slivers"
is difficult to automate, but not many details are available. In
principle, it has a lot of potential; in practice, manufacturing issues
might very well offset the savings from reduced silicon consumption.
Until they actually hit the market with a product (or admit failure), it
will be difficult to tell.