Reply #15: Every hear of epitaxy? [View All]

[NNadir]

Here's one solar cell process among many:

http://www.imec.be/wwwinter/energy/advanced_multi_and_epi.shtml

Here's another using SF₆, the persistent and potent greenhouse gas commonly produced industrially today, from the folks at BP Solar:

http://www.imec.be/wwwinter/energy/advanced_multi_and_epi.shtml

The atmospheric lifetime of SF₆ is over 3000 years and its global warming potential is over 20,000 times larger with respect to carbon dioxide (Carbon dioxide = 1):

http://www.cast.crc.org.au/Documents/Media%20Releases/AM-cover%20Award%20Media%20Release.pdf

http://www.climatetechnology.gov/library/2003/currentactivities/othergases.htm

This is only part of the story.

I have previously referenced this website that explores the environmental impact of solar cell production and certainly does not pretend that it is zero, although - even with a battery, it manages to be better than a diesel generator after some period of years (it better be better than a diesel, no?):

http://www.chem.uu.nl/nws/www/publica/e2000-15.pdf

In appendix B2, some scale of the chlorosilanes and tetrachlorosilane lost is given: It has improved from 72% lost to only 18% lost.

It is always possible to make extravagant claims about small scale technologies since they are small in scale. The scale up would have more obvious consequences. However the point is moot. The solar cell industry remains a minor player on the world stage, a game of hype more than practice.

I note that the energy produced by solar PV cells is much less than a single exajoule. As indicated before, it is therefore relatively easy to pretend that environmental impact of this chemistry does not exist. Not so. Were the solar PV industry a significant player on the world stage - and it still isn't - the environmental impact of it would be correspondingly larger. There is no such thing as a free lunch, although certainly there are many people who are comforted by pretending otherwise.