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Writer's pictureEmilie O'Leary

What Happens to Solar Panels Once They've Reached End-of-life?




Solar energy is a fast-growing energy system and the most popular renewable energy source. The solar energy movement began decades ago, but its popularity and utility have increased due to government promotions, organizations' support, and customer attempts to reduce the use of traditional energy sources like electricity and fossil fuels. 


According to the U.S. Energy Information Administration Monthly Energy Review and the U.S. Department of Energy’s Quarterly Solar Industry Update page in 2020, 40% of U.S. electric generation capacity is provided by solar energy. Due to rapid adoption and extensive use, this trend creates a new challenge for solar waste management after the end-of-life solar panels.


End-of-life solar panels


In May 2024, CNBC published an article about the upcoming situation regarding the use and harm of electric waste. The article underlines that the use of solar energy is increasing by 21% yearly, and by 2060, roughly 9.8 million metric tons of waste will accumulate. 


According to the U.S. Environmental Protection Agency, solar panels typically have a lifespan of 25 years. An expected question mark here is what should be done with solar panels that have reached end-of-life and are no longer usable.


If solar panels become hazardous waste or are no longer usable, they should be safely recycled or disposed of by following the regulations of the Resource Conservation and Recovery Act (RCRA). Click here to read about the common reasons for solar panel removal. 


What Happens to Solar Panels After Their Lifespan? Exploring Waste and Recycling Options

Before exploring waste and recycling options for solar panels, a keen eye on the types of solar panels is essential because waste and recycling options depend on the type of solar waste. So let's see:


Types of Solar Panels: 

There are mainly two types of solar panels: 


Silicon Solar

These solar panels represent over 90 percent of all solar panels sold today. They are made from crystalline silicon and contain solar cells embedded with silver and copper metals. They also have high efficiency and longer lifespans at low cost.


Thin-Film Solar

Thin-film solar cells contain thin layers of semiconductor materials, such as cadmium telluride and copper indium gallium diselenide. These materials are supported by glass, plastic, and metal, making for low-cost manufacturing processes. 


Waste and Recycling Options for Solar Panels

Lead, cadmium, copper, and other semiconductor materials are embedded in solar panels. The U.S. Environmental Protection Agency suggests every solar panel user contact their state or local recycling agencies to prevent hazards and manage electronic waste. 


Image Source: (National Renewable Energy Laboratory)


Silicon-based solar panel recycling

The process of recycling silicon-based PV (photovoltaic) panels starts with separating the product components, including aluminum and glass. All external metal parts are usable for re-molding cell frames, and almost 95% of the glass is also usable.


To ease the binding between the cell elements, materials are treated at 500°C in thermal processing. Due to this, encapsulating plastic evaporates, and the remaining silicon cells are ready to be further processed.


The green hardware is physically separated after the thermal treatment. Silicon particles—called wafers—are removed using acid and melted to be used again for manufacturing new silicon modules.


Thin-film-based solar panel recycling

The recycling procedure for thin-film-based solar panels is harsher than that for silicon-based solar panels. Thin-film-based panels are put in the shredder, and the hammermill ensures that all particles are undersized to 4-5mm. The remaining substance consists of solid and liquid materials, so a rotating screw separates them and keeps the solid parts inside the tube and the liquid in a container. 


After this, the dewatering process ensures the liquid's purity and the metal process separates the semiconductor materials completely. Finally, the materials, including glass, undergo rinsing, and 90% of them become usable. 


Managing End-of-Life Solar Panels: How Recycling Companies Handle Solar Panel Waste


As a preferred recycling company, Green Clean Solar uses a variety of methods to handle solar panel waste, including: 


Mechanical Recycling

Machines are used to break down the solar panel and its components. First, the aluminum frame is removed, and glass, silicon, wiring, and metals are ground into the "glass cullet." 


Thermal recycling

Treat the materials at high temperatures and separate the cell elements so the encapsulating plastic evaporates, leaving silicon cells for further processing. 


Chemical recycling

It uses reactions at a molecular level to separate the ingredients of a solar panel. Sometimes, a chemical process is used to extract the silver wires from silicon. 


The Bottom Line

As solar energy continues to grow, managing end-of-life solar panels is becoming more important. Solar panel disposal or solar panel recycling is a significant concern due to its typical age of 25 years.


Green Clean Solar recycles both silicon-based and thin-film panels using needed processes such as thermal, mechanical, or chemical recycling. An effective solar panel recycling and solar panel disposal practice of solar panels can minimize environmental impact and expand the sustainability of renewable energy systems. Read this article to know the safe way to dispose of solar panels.

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