Thursday, November 14, 2013
Antelope Valley Residents are Concerned with the Safety of First Solar’s CdTe Thin Film. Cancerous Cadmium Telluride?
Cadmium Telluride is a highly cancerous element. Recently, Foxnews reported that a bankrupt solar plant in Colorado (Abound Solar) which benefited from $400 million in federal loan guarantees in 2010 from the Obama administration left a toxic waste that may cost $3.7 million to clean up. The residents who live near Antelope Valley Solar Ranch One want to know whether the cadmium telluride (CdTe) thin film solar panels that First Solar has installed in their back yard will harm them. An article from Greentech.com indicated that according to First Solar Director of Environmental and Sustainable Development Dr. Parikhit Sinha explained to local leaders that cadmium telluride, “one of the best known semiconductors,” is not the same thing as cadmium. Here is the link regarding Abound Solar: http://www.foxnews.com/us/2013/10/30/bankrupt-solar-panel-firm-took-stimulus-money-left-toxic-mess-says-report According to First Solar A very thin layer of CdTe “allows you to absorb all the light needed to create electricity,” he explained. “This is the key to First Solar’s cost-effective and efficient manufacturing.” Greentech.com article goes onto say: A byproduct of mining, Sinha explained, cadmium is highly toxic and carcinogenic. Exposure can cause lung, kidney or liver pathology or failure. In the presence of tellurium, however, cadmium forms a crystalline lattice that is highly stable (high boiling point, low vapor pressure, low solubility). “It likes to be a solid,” Dr. Sinha said. “It is several orders of magnitude a factor of 100 less toxic than cadmium.” Dr. Sinha indicates that CdTe is still a potentially toxic material, but as it is within the glass panel it limits the possibility to inhale the toxin. “The semiconductor material is bonded to a sheet of glass under very high temperature,” Sinha explained. "An industrial laminate material, ethyl vinyl acetate, a type of plastic, encapsulates the semiconductor and seals it between a second piece of glass.” Freeing the CdTe from the laminate is the biggest challenge of recycling, Sinha said. It would take a very rare and daunting set of circumstances to both free the CdTe and release cadmium. Greentech also quotes an Assistant professor Dustin Mulvaney from San Jose State University who is part of the Silicon Valley Toxic Coalition (SVTC). Mulvaney indicated that First Solar is required to recycle the panels in a certain manner to prevent leakage, but the biggest risk is to the site workers if they get cut by the glass. AV residents were not fully satisfied as they felt First Solar is a new firm, and they may not know the full extent of the issues with CdTe. The site will have regular maintenance work done and inspections. They also will have prefunded end of life take back and recycling. Dr. Sinha also said that the maximum temperature on the solar panels will be 800 to 1,000 degrees Celsius for just a few seconds and CdTe is stable in the glass at 1100 degrees Celsius with only .4 % potential release of cadmium. Dr. Sinha indicated that such an occurrence can be handled by the company and emergency services. Greentech’s article said that some of the residents were satisfied with First Solar’s response and others were not. The company has given $350,000 in community benefits, and also provide two hundred full time construction jobs.