|
In recent years the electronics industry has gained notoriety
for creating an endless stream of disposable products that
make their way at life's end to developing countries, where
poor people without safety gear cut and burn out valuable
materials, spilling contaminants into their water, air and
lungs.
Solar modules contain some of the same potentially dangerous
materials as electronics - including silicon tetrachloride,
cadmium, selenium and sulfur hexafluoride, a potent greenhouse
gas. So, as solar moves from the fringe to the mainstream,
insiders and watchdog groups are beginning to talk about producer
responsibility and recycling in an attempt to sidestep the
pitfalls of electronic waste and retain the industry's green
credibility.
Solar modules have an expected lifespan of at least 20 years,
so most have not yet reached the end of their useful lives.
However, now, before a significant number of dead panels pile
up, is the perfect time to implement a responsible program,
said Sheila Davis, executive director of the Silicon Valley
Toxics Coalition (SVTC).
The nonprofit environmental group has been a leader in recognising
the problems of e-waste, including hazardous disposal sites
in the Bay Area left by the semiconductor industry. Now, it
is focused on the solar boom in Silicon Valley.
Last year, the group published a report
calling for a 'just and sustainable' solar industry
and this year it issued a scorecard of solar companies. The
scorecard
evaluates recycling and extended producer responsibility for
the product's end of life, called takeback - supply chain
and green jobs, chemical use & lifecycle analysis and
disclosure.
Solar energy is the most widely available resource we have.
Every hour, enough solar energy strikes Earth to meet human
energy needs for more than a year, according to NASA. Now
the solar industry is poised for huge growth in the United
States, thanks to policy changes, incentives, technological
improvements and economies of scale.
Solar photovoltaics have recently become less expensive than
nuclear energy on a per-kilowatt-hour basis, according to
a new report from Duke University. Also, solar is widely expected
to reach cost parity with fossil fuels in most markets by
2013.
In 2009, Greentech Media estimated that US solar demand will
continue to increase about 50 percent annually through 2012.
The report said the US capacity installed during 2008 was
about 320 megawatts and it predicted that about 2,000 megawatts
would be installed during 2012. Such growth would put US capacity
ahead of solar leader Spain and, potentially, Germany also.
While most of the new modules will likely have a long, productive
life, factory scrap, transport breakages and field failures
are ready for recycling now. Jennifer Woolwich is collecting
these broken solar modules in a warehouse near Phoenix.
She founded her company PV
Recycling in February 2009 after estimating that she
could harvest 500 panels a week from these sources. She is
not yet collecting at that capacity, nor does she have enough
panels to begin recycling them, but she is talking with solar
manufacturers in an effort to win their recycling business.
"Of those we interviewed, 100 percent want recycling," she
said. "Eighty percent want an independent third-party doing
the recycling."
Woolwich said she has seen a quick evolution in solar manufacturers'
attitudes toward recycling. "Last year, there was kind of
a 'wait and see, we're not sure how this is going to work'
attitude. Over the past 12 months, I've seen a 180 degree
turn - I've seen companies who are hiring consultants to research
their whole value chain to identify waste, including the end
of life of modules. We've received calls from consumers asking
us which companies have takeback programs in place."
Solar companies tend to be secretive about their product
recipes, making some manufacturers cautious about - yet conceptually
open to - third-party recycling.
"We guarantee that intellectual property will not be put
at risk," Woolwich said. "We're not interested in reverse
engineering or selling company secrets. We have certificates
of destruction that we will provide."
For now, though, some companies are doing their own recycling.
SolarWorld,
which received an 88 out of 100 on the toxics coalition's
scorecard, has been recycling its own panels since 2003 at
its main factory in Freiberg, Germany. That factory now receives
broken panels from its US plants in Cabrillo, Calif., Hillsboro,
Ore. and Vancouver, Wash.
"The fact is, there isn't much to recycle," said Ben Santarris,
a spokesman for SolarWorld. "In the future we might expand
recycling to our US plants or contract with a third-party
recycler."
First
Solar earned a rating of 67 on the scorecard. Headquartered
in Tempe, Arizona, it has recycling facilities at its manufacturing
sites in Perrysburg, Ohio, Frankfurt (Oder), Germany and Kulim,
Malaysia. Lisa Krueger, vice president of sustainable development,
said that so far the company is primarily recycling manufacturing
scrap.
"It's our intention that there would be other recycling facilities
worldwide as you get into those volumes," she said.
Solar modules employ a variety of technologies and even models
within the same technology can have different ingredients.
These materials may or may not be classified as toxic, depending
on who is regulating them.
Dustin Mulvaney is a scientist who works on solar issues
at the University of California, Berkeley and serves as a
consultant to the Silicon Valley Toxics Coalition. He has
analysed solar modules currently on the market and has outlined
for each its key ingredients - including potentially toxic
elements and materials that would be valuable to recover in
recycling.
Used in SolarWorld modules, crystalline photovoltaic is the
oldest and most widespread solar technology in the United
States, holding 57 percent market share in 2009, according
to Greentech Media. "As far as hazardous materials go, you're
primarily talking about lead," Mulvaney said.
A thin film technology called cadmium telluride makes up
about 21 percent of the US market. First Solar panels use
this technology.
Cadmium may be carcinogenic. Exposure affects the lungs and
kidneys and can be fatal. "It's gene toxic and a mutagen,
so it has the ability to affect DNA, meaning it could affect
reproduction and future generations' DNA," Mulvaney said.
Cadmium is technically banned by the European Union's Restriction
on Hazardous Substances directive, although the policy currently
allows an exemption for its use in solar modules.
Still, there's not a lot of data about whether cadmium is
toxic in the alloy form in which it's used in thin film -
and cadmium isn't likely to go away anytime soon, as it is
uniquely efficient at absorbing light.
Another thin film material - copper indium gallium selenide
(CIGS) - also has a cadmium layer. Indium is a potentially
hazardous substance, also, particularly in the form of indium
tin oxide, Mulvaney said. Studies have linked it to pulmonary
disease in flat-screen TV recycling facilities. In addition,
selenium has been documented to be a hazardous material.
While CIGS currently has a market share of just 6 percent,
amorphous silicon, which also has an indium tin oxide layer,
holds 16 percent.
California's Department of Toxic Substances Control has taken
note of the European Union's concern about cadmium and is
researching the chemical and physical makeup of various types
of modules.
"We think some solar panels, probably the cadmium thin film
type, might be hazardous waste when shredded or disposed of
in a landfill," said Charles Corcoran, a hazardous substances
scientist at the department.
Only panels classified as hazardous would fall under the
jurisdiction of the department. It is considering regulatory
options to try to steer end users toward recycling rather
than disposal.
"That gets a little complicated because California and US
regulations aren't necessarily in sync," Corcoran said. "An
option might be to transport it out of state where disposal
is legal."
Today, California has no solar module recycling facilities.
However, recycling locally is an important tenet of an ethical,
sustainable industry, said the Silicon Valley Toxics Coalition's
Davis. Recycling locally reduces the process' carbon footprint.
"It would also make people more conscious about what goes
into the products," Davis said - "and it would create local
jobs.
Extended producer responsibility, including module recycling,
is currently an expense rather than a source of profit for
companies, including Solar World and First Solar. "As we get
to scale, we hope those costs will come down," Krueger said.
A dedicated recycler like Woolwich is counting on economies
of scale. Her business plan also includes various revenue
streams, including reclaiming and selling materials and providing
a service of managing manufacturers' collection and recycling
systems.
Davis said recycling costs could be reduced if manufacturers
would take the notion of extended producer responsibility
to the next level: the design phase.
"If you don't look at the recycling when you're designing
the product, then it's really, really difficult to recycle,"
Davis said. "But if you know you're going to have to pay for
the recycling at the end of life, you might make the necessary
design changes in your product now to reduce that cost."
Mulvaney said that if the government were to set a price
on carbon emissions, that would also help make solar recycling
more affordable. Because turning sand into crystals takes
70 to 80 percent of the energy used to make crystalline photovoltaics,
he said recycling silicon would "save so much energy in production,
it could become a money saver."
Still, most companies that are beginning recycling programs
today are proceeding under the assumption that recycling will
be a cost. They are preparing for that expense by creating
a variety of funding mechanisms based on the principle of
producer responsibility.
Via her surveys, Woolwich has found that solar companies
are using an annuity program, escrow, maturity bonds, annual
fixed contracts and pay as you go.
Krueger said First Solar uses a trust. "First Solar doesn't
have access to those funds except for collection and recycling,"
she said. "It's designed that way because of the long product
life. If something happens to First Solar, the industry won't
have to deal with orphan waste."
Some materials in solar modules such as silicon and rare
metals could be more valuable in the future, providing an
additional incentive to recycle. Material price spikes have
caused industry turmoil in recent years. For example, polysilicon
shot to $400 per kilogram between 2006 and 2008. It is now
down around $55.
Krueger said First Solar currently harvests cadmium and tellurium
from its recycling program to use in new modules, even though
buying it from a supplier is currently less expensive. She
said she expects harvesting costs to come down as recycling
scales up.
Mulvaney said that the industry would do well to plan now
for the recovery of rare metals such as indium and tellurium.
Of course, materials recovery has an environmental benefit
also. "We'll be able to reduce impact from mining and other
environmental hazards by collecting a lot of the metals and
other valuable minerals that are being used in panels," Davis
said.
Being truly sustainable - and maintaining that green credibility
- is a powerful motivator for renewable energy companies.
Santarris said the SVTC's scorecard was an "important step"
toward figuring out which manufacturers are the most environmentally
benign.
"There's not a lot of sophistication in the marketplace to
differentiate among products and manufacturers of varying
environmental performance," Santarris said. "Are solar modules
all the same? - they're not."
|
