Solar Cells Info

by Martin LaMonica, Jan 14, 2009
Source: GreenTech
http://news.cnet.com/8301-11128_3-10142451-54.html

Imagine a manufacturer that took back its products after 25 years of use.  That’s exactly what watchdog group Silicon Valley Toxics Coalition is recommending that the solar industry do in a white paper released on Wednesday.   Solar is a renewable source of energy, and solar panels don’t pollute when they are generating electricity. But the upstream process of making solar panels involves a number of toxic chemicals.  Most solar cells are made out of silicon, the same material embedded in billions of electronic chips. As a result, the burgeoning solar photovoltaics (PV) industry faces an electronic-waste problem.

In its white paper, the Silicon Valley Toxics Coalition recommends that manufacturers phase out harmful chemicals while it seeks out more benign materials and develops “environmentally sustainable practices.” If the fast-growing solar business doesn’t plan ahead, it risks “repeating the mistakes made by the microelectronics industry,” according to the coalition.

“The electronics industry’s lack of environmental planning and oversight resulted in widespread toxic chemical pollution that caused death and injury to workers and people living in nearby communities. The high-tech industry’s legacy now includes the growing global tide of toxic electronic waste, or e-waste,” the report says.

A report from China by The Washington Post brought attention to this solar-waste issue to many people for the first time. A reporter visited a village where toxic silicon tetrachloride, a byproduct of silicon cell manufacturing, was dumped, making the land unsuitable for growing and posing a health risk to residents.

The coalition recommends that manufacturers test materials for toxicity before they are used in manufacturing and to step up take-back programs so that materials can be recycled.

By keeping solar panels out of the waste stream, municipalities can eliminate health and environmental risks, such as water contamination. Silicon-based panels typically last 20 to 25 years.

Alternative thin-film solar cells using different materials pose their own health challenges.

For example, First Solar (which has a recycling program), which is considered the cost leader in solar power, makes cells from cadmium telluride. Although the toxicity of the cadmium telluride is not well understood, there is risk of exposure to toxic cadmium compounds during the manufacturing process, according to the report.