Residential and Commercial properties are installing solar panels faster than ever. Some estimates show that there will be 70,000 solar panels installed every hour in the coming years. A solar panel is generally made up of 65 to 75 glass, 10 to 15% aluminium, 10% plastic and 3 to 5% silicon. These materials can be recycled. Solar panels are designed to last 25+ years, but what happens when they break and when they reach the end of their life cycle?
In the USA, the disposal of solar panels is not regulated. Some panels find their way into landfills. The recycling of solar panels will be an emerging industry in the coming years. In Europe, it is regulated, and there are operating facilities like the Veola facility in France. Companies in the US are starting to jump on board like First Solar, which is making an initiative to be involved in the afterlife of solar products. China is also opening solar recycling facilities.
During the life of PV panels, its power capacity might decrease by 20%. According to manufacturers, the maximum reduction in efficiency is 10% between the first 10 to 20 years and 20% when the panels are reaching 25 years. High-quality panels may last 30 to 40 years, but their efficiency will definitely decrease.
How Solar Panels are Recycled
Thin-film based and silicon-based solar panels can be recycled using different industrial processes. Silicon-based panels are disassembled to separate the glass and aluminium parts. All external metal parts of silicon-based panels can be used for re-molding cell frames. 95% of the glass can be recycled. The rest of the materials are treated at a 500° Celsius thermal processing unit to remove the binding between the panel’s cell elements.
The extreme heat causes the encapsulating plastic to evaporate. When this happens, the silicon cells can be further processed. This plastic is recycled as a heat source for thermal processing. The green hardware is then physically separated, and 80% of these can be reused right away, while the rest is further processed. Acid is used to remove wafers or silicon particles. Broken wafers can be melted and reused for doing new silicon modules. As such, 85% of the silicon material can be recycled.
Thin-film based solar panels, on the other hand, are processed differently. The panels are put in a shredder first. A hammer mill is used to cut the particles into sizes no larger than 4 to 5 millimetres. This is the size where the lamination that holds the inner components together breaks and can be removed. A rotating screw is used to separate the resulting liquid and solid materials. The liquid flows into a container, while the solid parts are kept inside a tube. Liquids undergo precipitation and de-watering to ensure its purity. It then undergoes metal processing to separate the semiconductor materials. 95% of the semiconductor material is usually recycled. The inter layer materials mixed in the solid parts can be removed via a vibrating surface. The material is then rinsed, leaving behind pure glass that can be reused for other purposes.
When it is time to replace or throw away your NJ solar panels, please look for a recycling facility. Don’t just throw it in the landfill. You will be doing yourself and the planet a favour.