30% of US solar farms contain dangerous chemicals that are about to expire

Like all electronic waste, the deluge of aging solar panels is a concern as they reach the end of their life. By 2030, we are expected to see more than 8.8 million tonnes of waste from photovoltaic (PV) panels. But there is one panel technology in particular that carries some pretty harmful and dangerous materials. Called cadmium telluride thin-film photovoltaics, or CdTe, they are relatively inexpensive to manufacture, efficient and account for more than 30% of the U.S. photovoltaic market. They have a lifespan of 20 to 30 years, but some of the oldest ones were installed in the early 2000s. This means that their expiration date is approaching soon and they cannot be thrown away like regular trash.

If these panels end up in landfills, the moisture can carry toxins from cadmium and tellurium – called landfill leachate – and enter groundwater, exposing the area to potential toxins. The chemicals are distributed inside a panel as a thin, solid semiconductor layer, but something like rainwater coming into contact with it can build up and wash away the toxins. Of course, this is less likely to happen if the panels remain intact, uninterrupted, and sealed, or if the facility has a proper leachate mitigation system, but there is no guarantee that this will happen when thrown into a disorderly landfill.

It’s not the panels themselves that are the problem, but rather the materials inside. Solar farms of all kinds have a hugely positive effect on local wildlife and the wider environment when in use. But given that 90% of expired or defective panels end up in landfills after running their course (it costs less to throw away than to recycle), concerns are justified.

Teams of researchers have developed ways to properly recycle and dispose of the materials inside CdTe panels. Using electrochemical solutions, cadmium and tellurium can be extracted. The big problem is that these methods require specialized solutions and the infrastructure to build and maintain large-scale facilities is not yet there. Then there is the question of education. Although it is easier and cheaper to throw the resulting panels into a landfill, that is absolutely not what should happen. Everyone needs to understand how to properly and safely deal with old panels.

The EPA recommends that homeowners contact state and local recycling agencies for advice on how to dispose of them. There are a few small recyclers that can accept CdTe panels, and some companies, like First Solar, are developing their technologies from the start so that they are suitable for recycling. Approximately 90% of the materials in First Solar modules can be recovered and reused once they have reached their end of life.

With proper care and maintenance, the expected life cycle of an average solar panel is formidable. It takes them about 30 years to reach 80% efficiency, which means you may not even need to completely replace them at that point. Many panels purchased, installed and used today have a distant expiration date. But if you have old signs, it’s important to understand how and where your local regulations apply. You can also find creative ways to reuse old solar equipment, but you should always be aware of the dangers.

The EPA recognizes cadmium as a toxic substance and considers it a carcinogen. Tellurium is known to cause organ damage in rats and humans. Therefore, exposing yourself to potential toxins is not recommended, which means staying away from broken, shattered, or damaged HP. Exposure to cracked cells may even warrant cancer screening.

If you are near solar panels or working near them, it’s a good idea to wear the appropriate protective equipment, including gloves, blankets, and even respirators. The Occupational Safety and Health Administration (OSHA) recommends wearing eye and face coverings and physical protective equipment around solar equipment. OSHA also recommends periodic inspections and testing of solar panel installations.

This will all be very different for individuals and if you are a homeowner working on or with your own solar installation. This is probably just you, with no one else measuring or testing before you get to work. But it’s important to be aware that you might be working with hazardous and toxic materials so you can take the necessary precautions.