With the massive growth in generating solar power using solar panels many are wondering if we are creating a big problem for the future. What are we going to do with all those solar panels when they reach their end of life.
Well, the good news is that solar panels are recyclable.
Solar panels typically last for 20 – 25 years and so most panels in use now will not be hitting the recycle bins for many years yet. When they do it is estimated that by 2050 recycled panels will release about 2 billion dollars’ worth of material for reuse. Mostly silicon and silver.
How are solar panels constructed
The way solar panels are constructed makes recycling them difficult.
Solar panels are made up in layers, much like a sandwich with the cells in the centre. Commercial solar panels making up about 90% of the market use silicon as the semiconductor. This converts the light it receives into electricity. Thin strips of metal, normally silver, crisscross the surface of silicon crystals in each cell and move electricity into the panel’s copper wiring.
The solar cells are encased in a protective barrier, usually a transparent plastic called EVA. Another layer of glass goes on top, and a different kind of plastic, like PET, covers the back. The whole thing is surrounded by an aluminium frame.
This layered construction protects cells from the elements while allowing sunlight through, but it can be difficult to deconstruct when the panels have reached the end of their life.
How are solar panels recycled.
The recycling process of silicon-based PV panels starts with disassembling the actual product to separate aluminium and glass parts. Almost all (95%) of the glass can be reused, while all external metal parts are used for re-moulding cell frames.
What is left is treated at 500°C in a thermal processing unit in order to loosen the binding between the cell elements. This process leaves the silicon free for further processing. This further processing of the silicon leaves about 86% of the silicon material ready for reuse.
Benefits of recycling solar panels By recycling solar panels, we will take the pressure off the need to mine the materials needed for solar panels. The mining process has an environmental cost. Recycled solar panels reduce these costs. All of this supports one of the main goals of solar panels, to support sustainable living. Also, by reducing our reliance on extracting new materials such as silver and copper increases the lifespan of mineral deposits. This improves security of raw materials and access for future generations