Which Solar Panels Are the Greenest?

Solar power is supposed to be clean and green, but what happens to the dirty ingredients involved to make and dispose of solar equipment?

Two years since the Washington Post first reported that a maker of polysilicon for solar panels was dumping toxic waste into Chinese soil, a U.S. nonprofit has ranked the “green” aspects of 25 photovoltaic module makers. The Silicon Valley Toxics Coalition launched the Solar Scorecard (PDF) on Tuesday.

Installations of solar modules rose by 42 percent in 2009, according to SolarBuzz. If this growth continues, rooftop modules that wear out within two to three decades threaten to add toxic bulk to landfills, just as yesterday’s computer monitors and cell phones have created unwieldly piles of consumer electronics waste.

As with efforts to clean up consumer electronics, the Silicon Valley Toxics Coalition wants the solar industry to reduce toxic chemicals in manufacturing, ensure fair labor standards, and take responsibility for disposing of spent equipment by supporting mandatory recycling.

The nonprofit gave the best scores to German companies. Among the module makers that replied to the survey, Calyxo and SolarWorld earned the best, “sunny” scores. Sovello came in a “cloudy” third place. Solar cell maker Q-Cells earned a positive 96 on a scale of one to 100.

Module makers with middling, “cloudy” scores included Yingli of China as well as U.S.-based First Solar and Abound Solar.

The lesser, “rainy” rankings marked Solon of Germany, Solaire Direct of France, Solar Cells Hellas of Greece and JA Solar of China.

However, a “gold star” stamped Calyxo, First Solar, SolarWorld and Solon for their product takeback programs, policies against exporting waste and refusal to use prison labor.

As for potentially nasty ingredients in their products, six of the companies reported using lead and three said they use cadmium compounds. But none of the respondents said they use mercury, hexavalent chromium, PBBs or PBDEs.

Seven companies said they planned to offer free solar panel recycling to residential and commercial customers.

At the bottom of the rankings heap, earning zero points for not responding to the survey, were Best Solar, Canadian Solar, DayStar Technology, Global Solar, Konarka, Miasole, Nanosolar, Sharp, SolarFun, SoloPower, Solyndra, SunPower, SunTech, Trina and Uni-Solar. However, as the ratings are based on companies’ self-reports, they draw an incomplete picture.

The GetSolar blog nevertheless sees the rankings as a good start:

As with any company manufacturing products for the benefit of the environment—or any large company in general — the corporate social responsibility aspect of solar manufacturers’ operations is more important than ever, and it’s heartening to see an industry watchdog emerge. While the SVTC’s pool of information is still smaller than ideal — and the “green” nature of its survey questions was occasionally dubious (for example, what does prison labor have to do with a company’s commitment to environmental protection?) — chances are the 2011 Solar Scorecard will see an improved response rate, as well as a lot more buzz.

The rankings of solar manufacturers  parallel those of the annual Greenpeace Guide to Greener Electronics, which rates consumer gadget makers from Apple to Toshiba. Major players in consumer electronics have increasingly adopted product takeback programs, and keep pushing for a federal e-waste law to unite a patchwork of state and local rules.

Similarly, as for the solar sector, Greentech Media argues:

What really needs to occur to drive a recycling culture is the adoption of a takeback program by every solar module manufacturer.  Firms can go it alone like First Solar or they can get together, as in the PV Cycle Association, which is developing a voluntary solar panel recycling program in Europe.

photo: Lance Cheung