Do Solar Panels Contain Toxic Substances?

One common claim is that solar panels contain large amounts of cadmium (Cd). Cadmium is a heavy metal that can be toxic to the kidneys, cause bone demineralization, and is potentially carcinogenic. Because of this, the European Union strictly regulates its use under the RoHS directive (Restriction of Hazardous Substances). Most cadmium exposure comes from smoking, as tobacco contains small amounts of it. However, the solar panels installed by Zonnefabriek do not contain cadmium, so there is no reason for concern.

Why, then, do people associate solar panels with cadmium? That's because some types of solar panels do in fact contain cadmium, however these are very different from the ones Zonnefabriek installs. Zonnefabriek uses crystalline solar panels, which are primarily made of silicon (essentially, sand). In addition to crystalline panels, there's also a category known as 'thin-film panels' made from various materials. One specific type of thin-film panel is made from cadmium telluride (CdTe)—so these are the panels people refer to when they talk about cadmium in solar panels.

Are CdTe panels harmful to the environment? Since these are not the panels Zonnefabriek installs, we prefer to leave the answer to that question to the manufacturers and installers who use them. You can find more information on their website.

Lead is another well-known heavy metal with harmful effects on both humans and the environment. It is still widely used today, especially in lead-acid batteries. Proper disposal of lead-containing waste is essential.

But is lead used in solar panels? It is not needed for crystalline solar cells. However, lead can sometimes be found in solder, which connects the electrical components of a panel. In the EU, electronic solder must generally be lead-free according to the RoHS directive. The solar panels installed by Zonnefabriek are, in any case, lead-free.

So, no cadmium or lead in our solar panels. However, like inverters and optimizers, solar panels still contain electronic components and should not be thrown in the trash—just like your washing machine, fridge, TV, or mobile phone. What happens to solar panels and related equipment at the end of their lifespan?

Inverters and optimizers function like other household electronics. If they break, they can be disposed of as electronic waste. Some companies even recover components from broken inverters to repair other devices. At the facilities for electronic waste in the Netherlands, the recyclable material is taken out of the discarded devices and made ready for re-use.