The truth is that solar panels are made almost entirely with abundant, earth-friendly materials like glass, aluminum, copper, and silicon. However, as the market for solar continues to expand, concerns have emerged about trace toxic compounds used in panels. The first, lead, is widely used for soldering electronic components together. Each standard solar panel contains about 14 grams of lead . That means about 4,400 tons of lead were used to make the 92 GW of solar panels installed in 2018 . This is a large amount but still comparatively small relative to the 9,000,000 tons used for batteries each year. But for an industry focused on sustainability, the goal is to remove lead altogether. By 2026, solar manufacturers plan to reduce the use of lead-based solder to less than 50% of panels  and to use lead in less than 20% cell manufacturing . These numbers should continue to shrink until lead is removed from the solar supply chain.
The other toxic material, cadmium telluride (CdTe), is a known carcinogen that is used in a specialized type of solar called thin film. Improvements in traditional silicon solar have reduced thin film’s market share to about 2% and it is expected to continue shrinking. Nonetheless, all CdTe cells are encapsulated and, even in extreme landfill conditions, very little of it escapes into the environment.
Solar panels are straightforward products to manufacture, with a wide set of scientific and manufacturing variations already in use. If concerns over lead and CdTe become larger, the industry can readily replace these materials with more earth-friendly alternatives or even remove some of them altogether.
Check out our other articles on the myths and truths about solar:
- Will waste from retiring solar panels overrun our future landfills?
- Does the intermittency of solar and wind make electricity more expensive?
- The earth gets more solar energy in one hour than the entire world uses in a year
- There are more US jobs in solar than all fossil fuels put together
- “Recent facts about photovoltaics in Germany,” Fraunhofer Institute for Solar Energy Systems, section 20.1
- Myths – Solar (smy), Freeing Energy, tab smy.5
- “Different technologies for cell interconnection”, International Technology Roadmap for Photovoltaics 2018 results (ITRPV), page 15
- “Lead free metallization paste”, International Technology Roadmap for Photovoltaics 2018 results (ITRPV), page 13