How a solar panel is made
These raw materials make up a solar panel:
- Aluminium is used in the frame of the solar panels, protecting the cells from damage
- Silicon is manufactured into the ultra thin silicon sheets that collect energy from the sun’s photovoltaic rays
- Steel can be found in the mounting material
- Tempered Glass is a stronger type of glass specifically designed to maximize the refraction of light and, as a bonus, shatters into tiny pieces as opposed to sharp shards, increasing safety
- Copper strips are used to connect each of the individual silicon cells in a solar panel to one other. These “fingers” are typically coated in tin
Once the raw materials have been extracted and collected, it is time to produce the solar panels. The silicon is heated at a high temperature and melted down. Thin slices are then made, which form the solar cells. Copper is added to conduct the electricity and the cells are coated to make the silicon reflect less.
The back of the solar panel is made of plastic, to which the solar cells and the copper are attached. A layer of glass is placed on top of the solar panels to protect the cells from the weather. Glass also lets heat through easily, which keeps the production capacity of the cells optimal. Like the solar cells, the glass is also coated with an anti-reflection layer.
The solar panel recycle process
SIlicon-based monocrystalline solar panels are first disassembled, to first separate the aluminum and glass; 100% of the aluminum from the frame and 95% of the tempered glass originally used to protect the panel are reused for other purposes2.
Once the panel has been disassembled, we are left with a solar panel wrapped in its protective EVA covering. The plastic EVA covering mentioned is evaporated through thermal processing at 500°C. With the covering gone, the individual silicon cells are physically separated from one another; 80% of these cells are reused in other applications, and the remaining 20% is processed further into its raw material form, as the complete cells are too broken to reuse. Because the raw silicon itself does not degrade, it can remain in commission infinitely and be used in other technologies.
Solar panels: almost completely circular
Solar energy has been utilized for decades due to its low-carbon emissions. Solar panels are complicated pieces of hardware that are difficult to recycle with 100% effectiveness, though we inch closer each day towards a perfect circular economy for solar panels with nothing going to waste. Achieving a circular economy for solar means that all end products and outputs are then new inputs for either new solar panels or for other industrial applications; essentially, little to no outputs are disposed of completely.
During the entire life-cycle of a solar panel, from raw material sourcing to recycling, sustainability and longevity are paramount. Solar panels are incredible devices whose circularity continues to be imperfect. In the coming years, as panels continue to reach the end of their lives, we hope to see a boost in research and development into improving the sustainability of solar panels.