Often funded by competing energy sources, opponents of renewable energy use misleading pseudo-science to stir up local opposition to projects. By scaring constituents with misleading information and inaccurate risk assessments, they hope to keep consumers hooked on dirtier, more expensive energy resources. One of the arguments they make most often involves “hazardous chemicals” in solar panels.
One chemical often maligned is Cadmium Telluride, (CdTe). The cadmium telluride (CdTe) layer of the solar panel is 3% of the thickness of a human hair and is sealed between two sheets of heat strengthened glass that are bonded together by an industrial laminate at greater than 700 pounds of pressure per square inch. The encapsulated panel design and the fact that CdTe does not dissolve in water prevents leaching in the event of panel breakage or natural disasters.
See our post, “What’s in a Solar Panel?”
Solar panels are consistently characterized as non-hazardous under the EPA’s Toxicity Characteristic Leaching Procedure (TCLP) which tests leaching of toxic chemicals. Such testing creates conditions much more extreme than in the field: chopping up solar panels into tiny pieces, submerging them in an acidic solvent, then agitating them. Even in these extreme conditions, solar panels do not represent a significant risk.’
The lead needed to join the crystalline silicon (c-Si) cells is roughly 1/750 of the amount used in a conventional car battery, or half of the amount in a single 12-gauge shotgun shell. These leaded portions of the panel are enclosed in nonporous, non-toxic substances like glass, which prevent the lead material from escaping or leaching into the ground.
When it comes to the question, USA Today addressed this topic well here: https://www.usatoday.com/story/news/investigations/2024/02/04/green-energy-fact-checked/72390472007/#:~:text=The%20short%20answer%3A%20Yes%2C%20wind,an%20enormous%20danger%20to%20birds.
The issue: Do solar panels contain toxic materials such as arsenic, cadmium and gallium? Will that leach out of them in the rain?
The answer: There are a couple different issues here, including questions of what’s really in the panels and also whether any of that stuff is actually risky. Here’s the breakdown.
Solar panels are mostly made of glass, aluminum and silicon – 77%, 10% and 3%, respectively. It’s true that trace elements are added to make them better conductors of electricity, usually cadmium and copper.
What’s less true is the idea of some other poisonous substances. Despite the fact that some states have gone so far as to ban use of these materials, there’s no evidence that today’s photovoltaic cells contain arsenic, germanium, hexavalent chromium or perfluoroalkyl substances. All of these items could, indeed, be poisonous, but they simply aren’t there.
The other question is whether it’s possible for any of those materials to exit the solar panel and poison something else.
Research published in the Journal of Hazardous Materials in 2017 found that it’s possible to release the trace amounts of cadmium in a solar panel – but to do so, you’d first have to crush up the panel and then put the resulting powder in an acidic environment over several weeks.
The bottom line: There’s just not evidence of toxic material leaching out of solar panels in the rain.
That hasn’t stopped this argument from taking root. In Horry County, South Carolina, in 2020, in response to a proposed 138 megawatt solar project, community members raised concerns about the leaching of cadmium telluride, questioning what would happen if the solar panels were damaged in a hurricane. County council members also raised concerns about decommissioning and whether landfills would accept solar panels. Although the developer agreed not to use solar panels that include cadmium telluride, the project was never built.