All Scientists are Sceptics ~Professor Bob Carter

Whenever someone asserts that a scientific question is “settled,” they tell me immediately that they don’t understand the first thing about science. Science is never settled. Dr David Deming

Perhaps the most frustrating aspect of the science of climate change is the lack of any real substance in attempts to justify the hypothesis ~Professor Stewart Franks

A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf

Sunday, 8 July 2012

Photovoltaic cells and Green Illusions

There is a new book in the US written by University of California - Berkeley visiting scholar Ozzie Zehner titled Green Illusions 

The Chapters include inter alia
  • SOLAR CELLS AND OTHER FAIRY TALES  
  • WIND POWER’S FLURRY OF LIMITATIONS
  • BIOFUELS AND THE POLITICS OF BIG CORN
  • CONJURING CLEAN COAL 
And one relevant to Australia's carbon tax debate:

EFFICIENCY CULTURE
Discover why carbon taxes won’t solve our energy challenges
One of our members, a retired scientist,  pointed me to the book, and in particular the chapter on solar cells.

Solar Cells Linked to Greenhouse Gases Over 23,000 Times Worse than Carbon Dioxide
Solar cells do not offset greenhouse gases or curb fossil fuel use in the United States according to the book. 
  
From klfy.com
Green Illusions explains how the solar industry has grown to become one of the leading emitters of hexafluoroethane (C2F6), nitrogen trifluoride (NF3), and sulfur hexafluoride (SF6).

 These three potent greenhouse gases, used by solar cell fabricators, make carbon dioxide (CO2) seem harmless.

Hexafluoroethane has a global warming potential that is 12,000 times higher than CO2, according to the Intergovernmental Panel on Climate Change (IPCC). It is 100 percent manufactured by humans, and survives 10,000 years once released into the atmosphere. Nitrogen trifluoride is 17,000 times more virulent than CO2, and SF6, the most treacherous greenhouse gas, is over 23,000 times more threatening.

The solar photovoltaic industry is one of the fastest-growing emitters of these gases, which are now measurably accumulating within the earth's atmosphere according to the U.S. National Oceanic and Atmospheric Administration (NOAA). A NOAA study shows that atmospheric concentrations of SF6 have been rising exponentially. A paper published in the peer-reviewed journal Geophysical Research Letters documents that atmospheric NF3 levels have been rising 11 percent per year. "
If photovoltaic production grows, so will the associated side effects," claims Zehner. "Even worse, there's no evidence that solar cells offset fossil fuel use in the American context."
Extract from Wikipedia - Sulfur hexafluoride

According to the Intergovernmental Panel on Climate Change, SF6 is the most potent greenhouse gas that it has evaluated, with a global warming potential of 22,800[11] times that of CO2 when compared over a 100-year period. Measurements of SF6 show that its global average mixing ratio has increased by about 0.2 ppt per year to over 7 ppt.[12] Sulfur hexafluoride is also extremely long-lived, is inert in the troposphere and stratosphere and has an estimated atmospheric lifetime of 800–3200 years.[13] SF6 is very stable (for countries reporting their emissions to the UNFCCC, a GWP of 23,900 for SF6 was suggested at the third Conference of the Parties: GWP used in Kyoto protocol).[14] Average global SF6 concentrations increased by about seven percent per year during the 1980s and 1990s,

11.^ Intergovernmental Panel on Climate Change, Working Group 1, Climate Change 2007, Chapter 2.10.2.
12.^ "Mauna Loa and Global SF6". Retrieved 2011-03-06.
13.^ "Atmospheric Lifetimes of Long-Lived Halogenated Species".14.^ "Climate Change 2001: Working Group I: The Scientific Basis". Intergovernmental Panel on Climate Change. 2001. Retrieved 2007-03-31.

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Comment on Nitrogen trifluoride (NF3)
                                                             
http://e360.yale.edu/feature/the_greenhouse_gasthat_nobody_knew/2085/

The Greenhouse Gas That Nobody Knew

When industry began using NF3 in high-tech manufacturing, it was hailed as a way to fight global warming. But new research shows that this gas has 17,000 times the warming potential of carbon dioxide and is rapidly increasing in the atmosphere – and that's turning an environmental success story into a public relations disaster.
by richard conniff

Hypothetical question: You’re heartsick about global warming, so you’ve just paid $25,000 to put a solar system on the roof of your home. How do you respond to news that it was manufactured with a chemical that is 17,000 times stronger than carbon dioxide as a cause of global warming?

It may sound like somebody’s idea of a bad joke. But last month, a study from the Scripps Institution of Oceanography reported that nitrogen trifluoride (NF3), with a global warming potential of 17,000, is now present in the atmosphere at four times the expected level and rapidly rising. Use of NF3 is currently booming, for products from computer chips and flats-screen LCDs to thin-film solar photovoltaics, an economical and increasingly popular solar power format.

Moreover, the Kyoto Protocol, which limits a half-dozen greenhouse gases, does not cover NF3. The United Nations Framework Convention on Climate Change now lists it among five major new greenhouse gases likely to be included in the next phase of global warming regulation, after 2012. And while that may be reassuring, it also suggests the complicated character of the global warming problem.
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Summary
                                               Est. GWP ( x CO2)         Duration in Atmos.(Yrs)

Sulphahexaflouride     (SF6)             22,800                            800 - 3,200

Nitrogen trifluoride      (NF3)           17,200                            est.  740

Hexafluoroethane       (C2F6)            9,200                              c. 10,000



 h/t Bruce.

1 comment:

  1. Can you show the IR absorption spectra for these molecules?

    Also in relation to CO2 is the postulated GH effect power?

    Methane is supposedly 23 times that of CO2 but has a negligible IR absorption capability thus rendering the 23 times warming power claims misleading.

    ReplyDelete





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