How to Dispose of Solar Panels to Ensure That Your Green Investment Stays Green
January 29, 2025
Solar panels contain toxic heavy metals that will require RCRA hazardous waste management when it comes time to recycle or dispose of them. Q&As in this ‘How to Dispose of Solar Panels’ blog entry include:
1. Why do end-of-life solar panels require RCRA hazardous waste management?
2. What are heavy metals?
3. What exact heavy metals are found in end-of-life solar panels?
4. What other toxic materials are found in end-of-life solar panels?
5. Can end-of-life solar panels be land-filled?
6. Can end-of-life solar panels be recycled?
7. Does the EPA consider end-of-life solar panels a hazardous waste?
8. What kinds of solar panels require hazardous waste management?
9. How large a problem are end-of-life solar panels?
10. Is retro-liability a possibility?
11. Where can you find a comprehensive solution for solar panel disposal?
1. Why do end-of-life solar panels require RCRA hazardous waste management?
In spite of their perceived ecological virtue, solar panels contain many toxic materials that cannot be placed in the municipal trash stream without getting you into expensive trouble with federal, state, and local authorities. Particularly among these are heavy metals (see Q.2).
2. What are heavy metals?
Metallica and Megadeth notwithstanding, “heavy metal” is a broad term that describes a group of naturally occurring metallic elements that have higher densities, atomic weights, or atomic numbers than do those that are considered “light,” like magnesium, aluminum, or titanium (see source).
Interestingly enough, certain heavy metals in low concentrations (e.g., iron, zinc, copper, and manganese) are essential for human survival. (Thereby, they’re called “essential metals.”) But like all metals, essential metals are toxic at higher concentrations.
Other heavy metals (e.g., arsenic, cadmium, lead, thallium, and mercury) serve no biological role. However, they will inevitably enter the human body due to their presence in the environment. And similar to essential metals, they’re toxic once specific concentrations are reached (ibid).
3. What exact heavy metals are found in end-of-life solar panels?
Some of the heavy metals found in old solar panels are silver, lead, arsenic, and cadmium. In excess amounts in the body, these are notorious for:
- Silver—breathing problems, skin reactions, damage to cell membranes, and something called argyria, which causes one’s skin, eyes, nose, mouth, throat, and internal organs to turn a blue-gray color (see source).
- Lead—interfering with various biological processes by disrupting enzyme functions, impacting the formation of red blood cells, and damaging the kidneys, which can cause long-term health issues like developmental delays, cognitive impairment, and increased blood pressure (see source).
- Cadmium—cancer; kidney damage; bone disease; as well as respiratory, gastrointestinal, and other health issues (see source).
- Arsenic—just about all of the above (see source).
4. What other toxic materials are found in end-of-life solar panels?
Besides the above (see Q.3), solar panels also contain hexafluoroethane (C2F6), and polyvinyl fluoride (PVF). Add to that copper indium selenide (CIS) along with its over-achieving relative, copper indium gallium (di)selenide (CIGS). The latter is a variation of CIS, in which some indium atoms are replaced with gallium atoms, allowing for better light absorption across a wider spectrum. (So, who knew?) Useful stuff, but it’s all reported to be “highly toxic” by one David H. Nguyen, PhD, whose business card lists “cancer biologist” as his day job.
5. Can end-of-life solar panels be land-filled?
The Electric Power Research Institute is a nonprofit R&D organization that provides objective advice to utilities.
Its researchers conducted a study on behalf of utility companies that own and operate solar farms and therefore will need some sort of recycling or solar panel disposal plan for a future filled with end-of-life solar panels.
The report concluded that the solar panel disposal into regular landfills isn’t recommended because their components can break down and cause toxic materials to leach into the soil (see source).
6. Can end-of-life solar panels be recycled?
Not easily. Approximately 90 percent of most PV modules are composed of glass. But this glass often cannot be recycled because it contains impurities such as plastic, lead, cadmium, and antimony.
Basically, there are two categories of solar panels, neither of which is easily recycled.
a) Silicon-based panels are the most common because they have been around the longest and are more efficient than their thin-film counterparts (see b). Recycling requires mechanically separating the aluminum from the glass. Treatment of what’s left starts by heating it to 932o F in special equipment—and that’s just the beginning.
b) Thin-film solar panels are cheaper than silicon-based ones but less efficient and therefore less ubiquitous. Recycling them is even more demanding. They’re shredded and mechanically hammered to ensure that no one piece of rubble is larger than 4‑to‑5mm. Solids and liquids that remain need separation and further exotic treatments.
7. Does the EPA consider end-of-life solar panels a hazardous waste?
Unfortunately, the EPA is coy on how to dispose of solar panels. Per their applicable webpage:
“Some solar panels are considered hazardous waste, and some are not, even within the same model and manufacturer. Homeowners with solar panels on their houses should contact their state/local recycling agencies for more information on disposal/recycling (bold type in the original).”
So, consider:
Homeowners characteristically have only 20-to-25 spent solar panels on their roofs (see source). And they’re being ominously cautioned (in big bold print) to “contact their state/local recycling agencies for more information” before trying to dispose of them.
In comparison, a medium-sized business using an average amount of electricity needs approximately 70 solar panels—about triple that of houses (see source), which means it bears triple the potential for running afoul of one or more local, state, or federal environmental regulations.
Ergo, if you have a mess of under-performing solar panels on your roof that needs to be deep-sixed, you should get expert advice about how to dispose of them legally and safely.
Remember, if contractors cart away all those solar panels and dispose of them illegally, RCRA cradle-to-grave rules dictate that the legal, pecuniary, and even penal consequences are on you—not them!
8. What kinds of solar panels require hazardous waste management?
At first blush, we would say all kinds. But if our experts got to meet your aged solar panels up close and personal, we might be able to diagnose whether careful placement of the nearly‑deceased solar panels into your universal waste stream is a more economical option.
That said, we advise treating the following solar panels as hazardous waste:
- Many silicon solar panels for having hexavalent chromium coatings, which OSHA largely unloves. Over 90 percent of the current solar cell market is based on silicon, which has been an electrical component of solar cells since Elvis first became king (see source).
- CdTe solar panels for containing cadmium. CdTe solar cells are the second most common photovoltaic technology in the world. The letters “Cd” stand for cadmium and “Te” for tellurium (see source).
- Gallium arsenide (GaAs) solar panels for containing arsenic. GaAs solar panels are highly efficient and durable, thus desirable in challenging conditions (see source).
- Some thin-film solar panels for containing copper and/or selenium (see Q.6b).
Don’t know exactly what’s up there on your roof? We can help you with that. Get expert advice.
9. How large a problem are end-of-life solar panels?
Large. And getting larger. Manufacturers typically warrantee solar panels to retain 80 percent of their efficiency for about 20 years or so. Doing some simple arithmetic, that means they’re considered still within design specs if they lose about one percent of their original efficiency per year.
As U.S. solar installations began nearly 70 years ago, many legacy solar arrays are likely operating significantly below their out-of-the-box performance. This means your facility’s rooftop solar panels might be displacing much less fossil-fueled energy than you think.
This dilemma is especially true in states that started adopting solar energy earliest in the game—we’re looking at you California, Oregon, and Washington—suggesting that eco-virtue might not necessarily be its own reward.
10. Is retro-liability a possibility?
We think yes. While you might get away with landfilling spent solar panels at the moment, what’s merely frowned upon now might become criminally litigious later.
Also, many green-minded owners and managers are warehousing defunct solar panels until a more earth-friendly solution is invented: a laudable tactic that’s nonetheless fraught with its own dangers.
Recall that your exhausted solar panels contain arsenic, cadmium, silicon, copper, and lead. And according to the EPA, you’re responsible for the storage of any toxic waste you generate from “cradle to grave.”
So, while you’re undoubtedly trying to do the right thing, you could instead be storing hazardous waste out of RCRA compliance, which is always an expensive mistake.
11. Where can you find a comprehensive solution for solar panel disposal?
Hazardous Waste Experts is a proven comprehensive source for manufacturers, installers, and solar contractors who require solar panel disposal and recycling.
Our eco-friendly solar-panel recycling protocols will allow you to realize the residual value of your spent solar equipment—including inverters, batteries, and mounting racks—while simultaneously ensuring that you’re in compliance with all appliable state and federal environmental regulations.
That’s better business than just throwing these residual assets away—and a lot more Earth‑friendly.
Call Hazardous Waste Experts today at our new number 425.414.3485 or email us.
And thank you for reading our blog!