nontoxic materials, practicing safety in
manufacturing and having a take-back policy, which ensures that products are recycled in a responsible manner.
The Emergency Planning and Community Right to Know Act passed by Congress in 1998 established requirements for
reporting toxic chemicals. However, the
requirements are based on the quantity of
the toxic material found in end products
and, therefore, may exempt nanomaterials.
This is of concern because some nanomaterials are extremely toxic, even in tiny
In the EU, the Waste Electrical and
Electronic Equipment (WEEE) and the
Restriction of Hazardous Substances
(RoHS) directives were established in
2003, both of which are intended to minimize electronic waste. In 2006, RoHS was
expanded to cover toxic substances sold
on the EU market. Japan, the leader in PV
manufacturing, has no restrictions either
on materials or on recycling.
Regardless of restrictions, a green and
clean approach would limit or eliminate
use of toxic materials from the start.
Cadmium telluride, a hazardous material used in PV
panels, is handled with care. Photo courtesy of the
US Department of Energy.
SVTC recommends phasing out chemicals
such as lead, cadmium, mercury,
chromium, hydrogen selenide, arsenic and
more. It also suggests developing manufacturing methods that do not result in
waste silicon tetrachloride.
The coalition is working with the EPA
to quantify and define green products, but
there currently are no standards for
“green” solar panels. The group also encourages reuse of silicon from computers
and other electronics as well as explo-
ration of organic and inorganic crystals
that pass a “green chemistry” test.
In the EU, electronics companies must
take back their products at the end of their
life cycle. In the US, it is on a state-by-state basis, but so far 15 states have mandated take-back. Some major electronics
firms also have instituted their own policies, including Dell, Hewlett-Packard and
Sony, and solar firms also are catching on.
The potential for harnessing the sun to
provide the power we need is huge, but it
is not without a cost to the environment if
those involved with every link in the supply chain are not cognizant of the risks involved. SVTC’s Davis sees this as an opportunity for businesses to be responsible
for themselves. “Set up the supply chain
so there’s not any excuse for anyone not
knowing what’s in the product.”
With all eyes on the solar industry right
now, market leaders can serve as a model
not only for how to be profitable while
solving energy problems but also for how
electronics and other manufacturing can
be green from cradle to cradle.
In a word: plastics
Hybrid organic solar cells made
of plastic may help “green” the
solar industry. Although plastics
are generally made of petroleum, one
could debate whether plastic solar is
moving in a cleaner, greener direction.
It is possible that plastics may be the
answer, especially understanding that the
manufacture of each tiny silicon chip
results in 1.7 kg of greenhouse gases,
according to an article published in 2002
in the American Chemical Society’s
Plastic solar cells,
currently under development
at the University of Alberta,
may be an environmentally friendly
alternative to silicon cells. Photo courtesy
of Michael Holly, University of Alberta.
Journal of Environmental Science &
A group at the University of Alberta in
Edmonton, Canada, and at the National
Research Council’s National Institute for
Nanotechnology (NINT), located at the
university, is working on improving the
performance of plastic solar cells. Jillian
M. Buriak, a professor of chemistry at the
university and an NINT principal investigator, describes plastic solar cells as being
like “a clubhouse sandwich.”
Each layer has a function, whether to
absorb light, generate electricity or draw
the electricity out of the device. In traditional plastic designs, the layers don’t
stick well, and the devices are less efficient than they could be.
Buriak said that her group is working
on “the mayonnaise, the mustard, the butter … that bring the sandwich together.”
So far, the researchers have seen improvements in efficiency of about 30 percent.
When asked whether plastic solar cells
would be less toxic than silicon and highly
recyclable, Buriak noted that, “
Considering that many soon-to-be commercial solar
cells on the market are made of CIGS
(cadmium indium telluride sulfide) and
cadmium telluride, our benign plastics are
a heck of a lot less toxic.”
The Canadian research team estimates
that it will be five to seven years before
plastic solar panels are mass-produced. At
that point, Buriak surmised, solar will be
available to everyone because the materials are inexpensive, and panels can be
made in massive quantities using ink-jet