Eco Etiquette: How Green Are Solar Panels?
By Jennifer Grayson
Founding Editor of The Red, White, and Green
April 28, 2010
Send all your eco-inquiries to Jennifer Grayson at
eco.etiquette@gmail.com.
Questions may be edited for length and clarity.
It seems like a good thing that solar is getting popular, but what
about all the materials that go into making the panels, recycling
them, etc.? Is solar really as green as it's made out to be? -
Griffin
Alas, there's a cloud in every green lining. Just when
environmentalists think we've uncovered a win-win solution to some
ecological ill, it turns out there's a downside to be dealt with:
Compact fluorescent bulbs reduce electricity consumption by 75
percent but come with a dash of mercury; a new Prius takes 46,000
miles of driving before paying off the energy cost of manufacturing
(if you make it that far); even tofu, as it turns out, may have a
higher carbon footprint than chicken.
It's not surprising, then, that solar panels also have a dark side;
namely, greenhouse gases and toxic chemicals involved in
manufacturing, and a lack of regulation regarding recycling. First,
though, let's take a look at the big picture.
Solar far outshines electricity produced from fossil fuel sources:
Per kilowatt, it offsets up to 830 pounds of nitrogen oxides, 1,500
pounds of sulfur dioxide, and 217,000 pounds of carbon dioxide per
year. What's more, because photovoltaic (PV) panels generally have a
long lifecycle -- up to 30 years -- the amount of waste generated by
panels past their prime is relatively small, especially when you
consider the three-to-four-year turnover of other electronic waste
like computers, televisions, and cell phones.
But with solar growing in popularity thanks to falling prices and
various tax incentives, we could see a wave of e-waste in the next
20-some-odd years if the industry doesn't take action now: The
Silicon Valley Toxics Coalition (SVTC), which works to promote
eco-friendly practices in the high-tech industry, warned in a 2009
report that "little attention is currently being paid to the
potential risks and consequences of scaling up solar PV cell
production. The solar PV industry must address these issues
immediately, or risk repeating the mistakes made by the
microelectronics industry."
(Mistakes is a nice way to put it; the United States' failure to
regulate e-waste has resulted in our hazardous junk being shipped
off to developing nations, where it piles up in digital dumping
grounds that pollute the air and groundwater and sicken people who
live nearby.)
So what are some of the issues surrounding solar? And how can solar
become greener (ironic though that question may be)? Let's take a
look:
Toxic chemicals. While it's nowhere near the amount produced by,
say, coal-fired power plants, a number of nasty chemicals are used
in solar manufacturing, including arsenic, cadmium telluride,
chromium, and lead. While one immediate risk may be to the workers
who construct these panels, the long-term hazard is where all these
materials will go once the panels are no longer useful.
Companies in the US are working to address these concerns,
implementing take-back programs like the one offered by thin-film
manufacturer First Solar, which recycles over 90 percent of the
materials collected from old panels. Another thin-film company, AQT
Solar, is looking into safer alternatives to cadmium like zinc
sulfide. "Our goal is to definitely reduce our dependence on toxic
materials, and if possible, eliminate them completely," says AQT CEO
Michael Bartholomeusz.
Greenhouse gases. The whole goal of solar-generated electricity may
be to reduce the amount of carbon dioxide going into the atmosphere,
but unfortunately, there are even more potent greenhouse gases
involved before a panel is ever plugged in. The SVTC report states
that sulfur hexafluoride (SF6), which is 22,000 times more powerful
than CO2, is used to clean the reactors used in silicon production.
Nitrogen trifluoride (NF3), another global warming whopper (17,000
times more powerful than CO2), is used in the manufacturing of
thin-film PV panels. This wasn't an urgent issue a few years back,
when thin-film only made up a small percentage of the solar market;
but thanks to cheaper manufacturing costs, thin-film is expected to
double its market share by 2013. Luckily, alternatives exist:
German-based startup Malibu has developed a technology that uses
fluorine, a gas with zero global warming potential.
Manufacturing. It would be great if all solar panel production
facilities were powered by, well, solar power, but this isn't always
the case: The manufacturing side of solar can be very un-green,
since its energy-intensive processes are often powered by
fossil-fuel based electricity. The need to construct brand-new
facilities for production also can add to a solar company's
footprint.
One possible solution? Use existing (but dormant) auto-manufacturing
plants to house production, a la traditional PV manufacturer Skyline
Solar. The company also uses about 90 percent less silicon in its
panels compared with traditional solar installations, to help
minimize the high environmental cost of silicon production.
So, do any of the above disclaimers mean we should say see ya to
solar? Of course not. Even with the energy and waste involved, PV
power in exchange for all our fossil fuels would still reduce air
pollution and greenhouse gas emissions by 90 percent.
Hope this has been enlightening!
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Source:
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