End of Life for Solar Panels – What’s That Look Like?

June 6, 2022

Tommy Cleveland is author of “Health and Safety Impacts of Solar Photovoltaics”, a handy and authoritative guide from North Carolina State University, that covers all aspects of solar safety. I interviewed Mr Cleveland a few years ago, and this clip is one of many at my Sun101.org website, a repository of good materials for clean energy advocates.

You can also down load the publication there as well. It’s dense, but here’s a couple of relevant passages.

Health and Safety Impacts of Solar Photovoltaics:

As with many electronic industries, the solder in sil- icon PV panels has historically been a leadbased solder, often 36% lead, due to the superior prop- erties of such solder. However, recent advances in lead-free solders have spurred a trend among PV panel manufacturers to reduce or remove the lead in their panels. According to the 2015 Solar Scorecard from the Silicon Valley Toxics Coalition, a group that tracks environmental responsibili- ty of photovoltaic panel manufacturers, fourteen companies (increased from twelve companies in2014) manufacture PV panels certified to meet the European Restriction of Hazardous Substances (RoHS) standard. This means that the amount of cadmium and lead in the panels they manufacture fall below the RoHS thresholds, which are set by the European Union and serve as the world’s de facto standard for hazardous substances in man- ufactured goods.8 The Restriction of Hazardous Substances (RoHS) standard requires that the maximum concentration found in any homog- enous material in a produce is less than 0.01% cadmium and less than 0.10% lead, therefore, any solder can be no more than 0.10% lead.

Similar to silicon-based PV panels, CdTe panels are constructed of a tempered glass front, one instead of two clear plastic encapsulation layers, and a rear heat strengthened glass backing (to- gether >98% by weight). The final product is built to withstand exposure to the elements without significant damage for over 25 years. While not representative of damage that may occur in the field or even at a landfill, laboratory evidence has illustrated that when panels are ground into a fine powder, very acidic water is able to leach portions of the cadmium and tellurium,30 similar to the pro- cess used to recycle CdTe panels. Like many sil- icon-based panels, CdTe panels are reported (as far back ask 199831 to pass the EPA’s Toxic Char- acteristic Leaching Procedure (TCLP) test, which tests the potential for crushed panels in a landfill to leach hazardous substances into groundwater.32 Passing this test means that they are classified as non-hazardous waste and can be deposited in landfills.33,34 For more information about PV panel end-of-life, see the Panel Disposal section.


2 Responses to “End of Life for Solar Panels – What’s That Look Like?”

  1. rhymeswithgoalie Says:

    I tell you, if I find out that anyone expresses concern about waste from solar panels but who don’t personally properly dispose of all of their household batteries and e-toys, I’d tear them a new one.

    • rhymeswithgoalie Says:

      Also remember that Ye Olde Cathode Ray Tube (CRT) TVs and monitors contained 4-8 pounds of lead in the tube, including toxic phosphors.

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