pollution

--- In ssi_list@... "victoriatangoman"

> No, that's not the study I was quoting.

If you were just skimming the debate, I was arguing that SPS was
better and that the energy payback of PV cells was only a low
multiple.

You mentioned that silicon semiconductor manufacturing is a cleaner
process than that of gallium arsenide. The article below quotes data
from a Texas Instruments study on silicon, not a small outfit to say
the least and an organization that doesn't have an axe to grind, but
as it acknowledges in the body of the text (which I included) the
pollution situation is now probably more favorable but they couldn't
find more recent data. It does offer a fairly complete look at the
whole process. I leave it to your judgement on how to interpret this
data with respect to PV manufacture, which is less complex than
Integrated Circuits. Nevertheless, there are similarities beyond
just the silicon substrate.

http://www.faultline.org/place/2002/04/toxictech.html

"In 1993, Texas Instruments estimated the resources required and
waste produced in the manufacture of a single six-inch semiconductor
wafer. (In the intervening nine years, production has likely become
more efficient, but more recent industry-wide estimates are
unavailable.) Producing one wafer required 3200 cubic feet of bulk
gases, 22 cubic feet of hazardous gases, and 20 pounds of chemicals,
along with 285 kilowatt-hours of electrical power (enough to power a
refrigerator around the clock for several months) and 2,275 gallons
of water (enough for over 70 bathtubs). Each wafer's production
generated seven pounds of hazardous waste, 25 pounds of sodium
hydroxide, and 2840 gallons of waste water."

TangoMan