"Green" solar panels can have their dirty side in terms of disposal and manufacturing.  And what happens to the millions of solar panels planted in solar farms and installed on roofs once they've reached the end of their useful life in 20 or 25 years?

You might recall the outcry in 2008 when the Washington Post reported on the alleged dumping of silicon tetrachloride, a toxic byproduct of polysilicon production on farmland in China.  Lax environmental enforcement and the drive to save money on expensive recycling and treatment drove the polysilicon supplier to this irresponsible act.    

The Silicon Valley Toxics Coalition (SVTC) has called on the solar industry to adopt environmentally friendly measures for manufacturing and disposing of solar panels. Sheila Davis, executive director of the non-profit SVTC, believes that solar companies should start investing in recycling efforts now rather than waiting for their products to clog up landfills before taking action.

"It's an excellent time to do this considering that solar is an emerging industry," said Davis. "It will be an environmental advantage if you have panels that not only contribute to sustainability and reduce carbon emissions, but also use renewable and sustainable materials."  

To encourage solar manufacturers to do the right thing, SVTC just released its 2010 Solar Company Scorecard, which ranks manufacturers of PV modules according to environmental health and safety, sustainability, workers’ rights, and social justice. The responding companies self-reported on these areas and the results can serve as a resource for institutional purchasers, investors and consumers.   SVTC is funded by individuals and foundations. The scorecard was partially funded by Henderson Global and Boston Common.  
“Solar power is key to helping solve the world’s climate crisis,” offered Davis. “But the industry still faces serious issues that need to be addressed before it can be considered truly ‘clean and green’ and socially just.”

Fourteen companies representing 24 percent of the 2008 module market share and 31 percent of the cumulative market share responded to the inquiry. The top three scores were earned by German manufacturers Calyxo, SolarWorld and Sovello, which scored 90, 88 and 73 respectively. (Calyxo and Sovello, both funded by Q-Cells, likely have larger problems to worry about).

Two U.S.-based cadmium telluride manufacturers responded and scored in the mid-range: First Solar in Arizona received a score of 67 and Colorado-based startup Abound received a 63. 
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. 

SVTC is calling for mandatory takeback and responsible recycling by solar companies as a step toward reducing the solar industry’s environmental footprint.  Larger institutional customers and city or school districts can drive this process by insisting that there be takeback programs as well.

In Davis' words, "That's why we created the scorecard -- to see which makers are taking the panels back."

First Solar (FSLR), the largest maker of cadmium telluride solar panels, runs a recycling program and explains what it does with unwanted panels here.  There is a toxicity risk associated with cadmium telluride that First Solar has confronted with a 100 percent takeback program bonded by Swiss Re in the event that First Solar is not around in 20 to 30 years. 

The SVTC got started more than 25 years ago in response to water contamination caused by the semiconductor industry.  Their focus has been on electronics, but the rapid growth of the solar PV industry has spurred them into getting an early start on working with the solar panel manufacturers, and to avoid the late start that the semiconductor industry had. "We don't want that to happen in the solar industry," said Davis.

She added, "The waste stream is going to diversify and manufacturers need to be prepared."