Solar Power’s Troubled Horizon

Ξ November 18th, 2008 | → 1 Comments | ∇ A Day at a Time, Technology, Wine News, Wineries |

An enormous number of wineries have gone solar in the United States, the majority here in California. With respect to power requirements, solar often satisfies 100% of operational energy during active periods, the crush, for example. Extra power after crush may then be poured into the grid for a modest return. This summer Jarvis installed 520 solar panels, Far Niente went big two months earlier with over 1300 photovoltaics. Among those wineries already solarized, Grgich, Merryvale, Rodney Strong, Fetzer, Peju, Cline Cellars, St. Francis, Quivira, Shafer. Foster’s will install solar power systems at six of its California wineries, Beringer, Asti, Chateau St. Jean, Etude, Stag’s Leap and Meridian. Of course, the largest winery solar project in the world is Constellation Brands, US branch Gonzales Winery in Monterey County, California to be completed soon.
And these California wineries are just a few of the many world-wide going solar.
But all is not well with the production of solar panels, as well as with that of computers and their chips, cell phones and flat-screen TVs. A recent paper published in Geophysical Research Letters (subscription required) by M. Prather and Juno Hsu, both of UC Irvine, strongly indicts an especially powerful, long-lived green house gas, nitrogen triflouride (NF3), used as a cleaning agent in the production of the products listed above. The paper, titled NF3, the greenhouse gas missing from Kyoto makes the grim argument, through a careful marshaling of the scientific evidence, that NF3, a man-made gas, has 17,000 times the climate warming effect of CO2. From the paper’s abstract:
“Nitrogen trifluoride (NF3) can be called the missing greenhouse gas: It is a synthetic chemical produced in industrial quantities; it is not included in the Kyoto basket of greenhouse gases or in national reporting under the United Nations Framework Convention on Climate Change (UNFCCC); and there are no observations documenting its atmospheric abundance. Current publications report a long lifetime of 740 yr and a global warming potential (GWP), which in the Kyoto basket is second only to SF6. We re-examine the atmospheric chemistry of NF3 and calculate a shorter lifetime of 550 yr, but still far beyond any societal time frames. With 2008 production equivalent to 67 million metric tons of CO2, NF3 has a potential greenhouse impact larger than that of the industrialized nations’ emissions of PFCs or SF6, or even that of the world’s largest coal-fired power plants.”
Indeed, the Kyoto Protocol, popularly known as the Earth Summit, does not list NF3. As Richard Conniff writes in a brilliant summation,
“In fact, NF3 had become popular largely as a way to reduce global warming.[....] The U.S. Environmental Protection Agency began actively encouraging use of NF3 in the 1990s, as the best solution to a widespread problem in making the components for everything from cell phones to laptop computers. [....] So when the semiconductor industry announced a voluntary partnership with the EPA to reduce greenhouse-gas emissions by 10 percent from 1995 levels between 1999 and 2010, NF3 became the replacement technology of choice. [....] In 2002, the EPA gave a Climate Protection Award to the largest NF3 producer, Pennsylvania-based Air Products and Chemicals Inc., for its work in reducing emissions.”
From Air Products and Chemicals Inc.’s web site,
“Air Products continues to advance the technology for replacement of C2F6 cleaning agent for silicon chip production acilities with NF3, nitrogen trifluoride.”
C2F6 or Hexafluoroethane was harder to break down. Some 60% of the gas was released into the atmosphere after use. (And its potency as a green house gas was understood as 12,000 greater than CO2. Hence its inclusion in the Kyoto Protocol.) NF3, by contrast, was said by Air Products to sufficiently degrade during processing to result in less than a 2% escape rate. The dispute is over this number. Is it verifiable? Well, when Ray Weiss and and Jens Muehle of the Scripps Institute of Oceanography researched NF3’s presence in the atmosphere they discovered,
“The amount of the gas in the atmosphere, which could not be detected using previous techniques, had been estimated at less than 1,200 metric tons in 2006. The new research shows the actual amount was 4,200 metric tons. In 2008, about 5,400 metric tons of the gas was in the atmosphere, a quantity that is increasing at about 11 percent per year.”
Richard Conniff again,
“Ray Weiss and his research team at the Scripps Institution of Oceanography reported that NF3 is now present in the atmosphere at four times the expected amount, with atmospheric concentrations rising 11 percent a year. Working from annual production estimates of 4,000 metric tons, Weiss figured that about 16 percent of current production is ending up in the atmosphere.”
Therefore, it is strongly felt Air Products estimate of a 2% release into the atmosphere is woefully low. And here’s why. The figure depends upon state-of-the-art manufacturing technology; many other companies still use inefficient, older technology. Very simple.
So, how does this bear upon the solar panel industry?
“Amorphous silicon thin-film solar photovoltaic cells, manufactured using NF3, are slightly less efficient than crystalline silicon solar cells, the dominant technology. But they are cheaper to produce and expected to supply a rapidly increasing share of the solar market, for both large-scale and domestic applications.
“Because thin-film is a new technology, manufacturers generally use the latest equipment. But a knowledgeable source, who asked to remain unidentified, recently visited thin-film solar researchers in Asia. ‘They were unaware of the NF3 issue. They were using a remote plasma, but they were also using quite a bit of NF3. They weren’t sure they had it set up right for 98 percent destruction. It wasn’t really on their radar.’”
Now, the evolution of solar panel technology may be roughly broken down into three phases or generations: crystalline silicon, thin-film, and nano tech, that slated for mass production soon by companies such as Bloo Solar. Some insight into their protocols may be found here. Which solar panel generation a given winery may have purchased, whether crystalline silicon or thin-film, I was not able to absolutely determine. However, a Mitsubishi rep wrote me the Constellation installation in Gonzales is of the crystalline kind. Good news.
And more good news, well, sort of. Mr. Conniff writes of an already existing alternative to NF3. Flourine.
“According to Paul Stockman of Munich-based Linde Gas, fluorine has zero global warming potential and no atmospheric lifetime. But it’s also highly toxic and reactive. So instead of being shipped in bottles like NF3, it must be generated on site using special equipment. Stockman, whose company manufactures NF3, said fluorine will become essential in thin-film solar manufacturing, because faster cleaning times mean a substantial boost in productivity.”
An industrial accident waiting to happen…
I would encourage readers to read the primary sources linked above. Further, I encourage wineries to do a little extra research. Ask solar panel merchants from where they source their thin-cell panels, ask whether the factory is state-of-the-art, whether a 98% destruction rate of NF3 is guaranteed. It might feel awkward, but for an industry which justifiably prides itself on its environmental responsibility, it just might make a difference. In the long run. Always the hardest.


One Response to ' Solar Power’s Troubled Horizon '

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  1. Morton Leslie said,

    on November 21st, 2008 at 3:02 pm

    I was on a tour of a desert park when the guide mentioned that the parched rock desert we were looking at was a dense rain forest 12,000 years before. It occurred to me then how wonderful it is that mankind has learned that we can keep our climate just the way it is by controlling our greenhouse gas emissions. No more ice ages to worry about, nor melted polar ice and rising seas. Everything stays just the way we like it. Who would have thunk it was so easy.

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