Thanks to Rich for a thoughtful post with lots of good context--
including look at all ghg emissions connected with all electronics.
I wonder if the coal industry has been funding this sort of out-of-
context info? (this query is based on knowledge of the sorts of things
big coal has done, not just generalized paranoia).
Margaret
On Aug 5, 2009, at 4:18 PM, Rich Bernstein wrote:
What matters most with the NF3 issue is the amount released per unit
of PV manufactured, compared to the lifetime of the PV. Nobody
writing the stop-buying-PV-because-of-NF3 articles is printing the
important numbers, just the meaningless ones that sound scary.
Actually, they're not meaningless- they mean it is important to
consider NF3 emissions, they just don't provide any useful information
about the environmental impacts of the manufacture of a particular
product. The reason for this is clear: they're all paraphrasing an
article about measurements of atmospheric levels of NF3, and making
assumptions about electronics manufacture with no scientific basis
whatsoever. I believe this is the original article:
http://www.nasa.gov/home/hqnews/2008/oct/HQ_08-268_Greenhouse_gas.html
The closest thing to a useful value I found was a short article about
a manufacturer who removed NF3 from their process, which says it
reduced the GG emissions payback time of their modules by about a
year:
http://www.ecofriendnews.com/environmental_article9150.html
If that's true, the global warming impact of NF3 PV manufacture is on
the same order of magnitude as the other contributions like energy
consumption, i.e. we're talking about a 2-3 year payback instead of
1-2 years. I would tend to guess that they are overestimating the
benefit of their new manufacturing process, meaning that the effect of
NF3 is being overestimated in this case.
So, 1) this is a problem across the electronics industry (of which PV
is a very small part) that means NF3 should be dealt with across the
board, 2) it can be removed from the manufacturing process, and 3) its
GW contribution is probably small compared to the CO2 emissions of the
displaced fossil fuel use. But we need real numbers.
--
Rich
On Wed, Aug 5, 2009 at 10:36 AM, Ryan Hottle<[email protected]>
wrote:
I'm not necessarily against PV solar, but there seems to be a
significant
issue over the manufacture of PV releasing Nitrogen trifluoride,
which is
some 17,000 times more potent a greenhouse gas than CO2 albeit
having a much
shorter lifetime. I am convinced that rainwater catchment with
microhydro,
biomass pyrolyization/gasification, and, in particular areas, wind
are
likely to be the best way for Ithaca and surrounding areas to go.
Article regarding NF3 and PV manufacture:
http://www.foreignpolicy.com/top10-2008/index6.html
Best,
Ryan
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