False Claim #2: Toxic heavy metals, such as lead and cadmium, leach out from solar panels and pose a threat to human health.
“Studies have shown the heavy metals in solar panels namely lead and cadmium, can leach out of the cells and get into groundwater, as well as affect plants.”38
Roughly 40% of new solar panels in the United States and 5% of new solar panels in the world contain cadmium,39 but this cadmium is in the form of cadmium telluride, which is non-volatile, non-soluble in water, and has 1/100th the toxicity of free cadmium.40 Most solar panels, like many electronics, contain small amounts of lead.41 However, the Massachusetts Department of Energy Resources (DER) has assessed that “because PV panel materials are enclosed, and don’t mix with water or vaporize into the air, there is little, if any, risk of chemical releases to the environment during normal use.”42 The Massachusetts DER has further assessed that, even in the unlikely event of panel breakage, releases of chemicals used in solar panels are “not a concern.”43
All materials in a solar panel are “insoluble and non-volatile at ambient conditions,” and “don’t mix with water or vaporize into air.”44 Moreover, they are encased in tempered glass that not only withstands high temperatures, but is also strong enough topass hail tests and is regularly installed in Arctic and Antarctic conditions.45 It is theoretically possible that, when exposed toextremely high heat exceeding that of a typical residential fire, panels “could emit vapors and particulates from PV panel components to the air.” But that risk is limited by the fact that “the silicon and other chemicals that comprise the solar panelwould likely bind to the glass that covers the PV cells and be retained there.”46 When a cadmium telluride panel is exposed to fireof an intensity sufficient to melt the glass on the panel, “over 99.9% of the cadmium [is encapsulated in] the molten glass.”47Furthermore, a 2013 analysis found that, even in the worst-case scenarios of earthquakes, fires, and floods, “it is unlikely that the [cadmium] concentrations in air and sea water will exceed the environmental regulation values.”48
One peer-reviewed study in the Journal of Natural Resources and Development found it unlikely for lead or cadmium to leach into the soil from functional solar panels.49 Measuring heavy metal concentrations in the soil at various distances, researchersfound no significant differences in lead or cadmium concentrations directly underneath solar panels, compared to soil 45 or 100 feet away.50 The study further found that “lead and cadmium were not elevated in soils near PV systems and were far below levels considered to be an imminent or future danger to environmental health.”51
Although the study did find higher levels of selenium in soil directly underneath solar panels, the study noted that the presence of selenium was possibly a “result of the cement used in construction,” rather than leaching from the panels themselves.52 In addition, the study noted that even the highest selenium concentrations observed were below the EPA’s risk threshold formammals.53 Finally, the study noted that fly ash, a product of coal combustion “commonly disposed of in landfills and as a soilamendment in agriculture,” contains significantly higher concentrations of lead (40x), cadmium (1.1x) and selenium (4x) than the soil samples taken directly underneath the solar panels in the study area.54
38 Emily Chantiri, The Dark Side of Renewable Technology: Fossil Fuels Are Used to Produce Solar Panels, AUSTRALIAN COMPUTER SOCIETY (Feb. 2, 2023), https://ia.acs.org.au/article/2023/the-dark-side-of-renewable-technology.html.
39 Polycrystalline Thin-Film Research: Cadmium Telluride, NAT’L RENEWABLE ENERGY LABORATORY, May 2022, https://www.nrel.gov/docs/fy21osti/76975.pdf; Taking Cadmium Telluride Technology to the Next Level, US-MAC, https://www.usa- cdte.org/(last visited March 25, 2024).
40 Health and Safety Impacts of Solar Photovoltaics at 7, NC CLEAN ENERGY TECHNOLOGY CENTER, May 2017, https://content.ces.ncsu.edu/health-and-safety-impacts-of-solar-photovoltaics.
41 Mark Hutchins, The weekend read: A lead-free future for solar PV, PV MAGAZINE, Oct. 26, 2019, https://www.pv-magazine.com/2019/10/26/the-weekend-read-a-lead-free-future-for-solar-pv/.
42 Massachusetts Department of Energy Resources et al., supra note 33 at 5.
43 Id.
44 Id.
45 Id.
46 Id.
47 NC CLEAN ENERGY TECHNOLOGY CENTER, supra note 40 at 7.
48 Yasunari Matsuno, Environmental risk assessment of CdTe PV systems to be considered under catastrophic events in Japan, FIRST SOLAR,Dec. 1, 2013, https://www.firstsolar.com/-/media/First-Solar/Sustainability-Documents/Sustainability-Peer-Reviews/Japan_Peer-Review_Matsuno_CdTe-PV-Tsunami.ashx.
49 Seth A. Robinson et al., Potential for leaching of heavy metals and metalloids from crystalline silicon photovoltaic systems,” 9 J. NAT. RES. AND DEV. 19, 21 (2019), https://doi.org/10.5027/jnrd.v9i0.02.
50 Id. at 21-22.
51 Id.; U.S. Environmental Protection Agency, Ecological Soil Screening Level (2018), https://www.epa.gov/chemical-research/ecological-soil-screening-level (last updated May 3, 2023).
52 Robinson et al., supra note 49, at 21-22.
53 Id.
54 Id.
55 NO TO SOLAR, supra note 7.
56 Heather Mirletz et al., Unfounded concerns about photovoltaic module toxicity and waste are slowing decarbonization, NATURE PHYSICS, October 2023, https://www.nature.com/articles/s41567-023-02230-0.