Thanks Rich, This is helpful... Yet, you're right, where's the data? NASA I tend to trust... company publications not so much. Any gas which has risen from 0.02 ppt to 0.454 ppt in the past thirty some years and has a GWP (Global Warming Potential) of 17,000 times that of CO2 (CO2 GWP = 1) is certainly of some concern. I.e. can't simply be written off as a "big coal" conspiracy. We shouldn't let our desire for certain technologies allow to manipulate
Rich could certainly be right that in comparison to coal generation solar still wins out. What percentage of total NF3 is produced by solar? What would happen if existing technologies are scaled up to replace coal generation without consideration of NF3? What is the residence time of NF3 in the atmosphere? If, of course, there is a cost-effective means of manufacturing PV solar in an environmentally sustainable manner, then all the better! Lastly, to respond Karl, pyrolization of biomass which can create biochar to sequester C for centennial to millennial time scales can be sustainably harvested from all sorts of sustainably managed and harvested crops. Short rotation willow coppice, saw dust, saw ends, nut shells, storm debris, urban lawn debris, low-input high diversity energy crops (see the work of David Tilman for this last one). Go talk to Johannes Lehmann at Cornell, he's the world's foremost on biochar and pyrolysis technology. It's been used by ancient Amazonians for millenia prior to conquistadors to create incredibly rich "Terra Preta" in a highly weathered, nutrient poor landscape. I sense a very defense stance on solar....Why is everyone so attached to PV anyway? Solar hot water makes much better economic sense. Concentrated solar look good in desert climate... we might get some of that if HVDC smart grid technologies ever come. Microhydro is wonderful (single moving part, lasts longer than PV, can be manufactured regionally [i.e. in Ithaca], and has minimal impact on stream ecology) particularly if you have the topography which Ithaca has. Energy conservation and efficiency is first of course. And, of course, I think biomass makes a lot of sense--particularly on-farm applications, Karl--where it can be deployed for both heat and power, sequester C, and create a powerful soil amendment. Ok. All the best. Good discussion. Thanks for references Rich, you've obviously been paying attention to this issue... you own a PV installation company? ;) Ryan On Wed, Aug 5, 2009 at 5:23 PM, Margaret McCasland <[email protected]>wrote: > 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 >>> >> _______________________________________________ >> For more information about sustainability in the Tompkins County area, >> please visit: http://www.sustainabletompkins.org/ >> >> RSS, archives, subscription & listserv information for: >> [email protected] >> http://lists.mutualaid.org/mailman/listinfo/sustainabletompkins >> Questions about the list? ask >> [email protected] >> free hosting by http://www.mutualaid.org >> > > _______________________________________________ > For more information about sustainability in the Tompkins County area, > please visit: http://www.sustainabletompkins.org/ > > RSS, archives, subscription & listserv information for: > [email protected] > http://lists.mutualaid.org/mailman/listinfo/sustainabletompkins > Questions about the list? ask > [email protected] > free hosting by http://www.mutualaid.org > -- Ryan Darrell Hottle LEED-AP Environmental Science, PhD Student Carbon Management and Sequestration Center The Ohio State University Rm. 454 Kottman Hall 2021 Coffey Road Columbus, OH 43210 C: (740) 258 8450 NOTE: This e-mail and any attachments may contain confidential and privileged information. If you are not the intended recipient, please notify the sender immediately by return e-mail, delete this e-mail and destroy any copies. Any dissemination or use of this information by a person other than the intended recipient is unauthorized and may be illegal. _______________________________________________ For more information about sustainability in the Tompkins County area, please visit: http://www.sustainabletompkins.org/ RSS, archives, subscription & listserv information for: [email protected] http://lists.mutualaid.org/mailman/listinfo/sustainabletompkins Questions about the list? ask [email protected] free hosting by http://www.mutualaid.org
