A solar panel is a grid of photovoltaic cells (solar cells) linked together to convert sunlight
into electricity. In Australia, a single solar panel usually has 60 or 72 cells.
Over the last decade, Australia’s solar industry has grown by 50%. This increased demand
and a drop in the cost of components have made solar panels cheaper and more accessible
than ever.
But not many people know exactly how a solar panel is made and what materials are used.
Importantly, many solar panel owners aren’t sure if they can recycle them, so panels are
unnecessarily ending up in landfill.
With some solar panels starting to reach the end of their life, we should all know what
materials are in our solar panels, and find out how to recycle them to avoid creating a
mountain of environmental waste.
Materials Used in Solar Panels
Generally, solar panels are made of silicon, glass and solar cells. To create a solar cell,
crystalline silicon is sliced into paper-thin wafers, ground into shape, polished and brushed
with a coating to improve sunlight absorption. These cells are connected together on a
panel. Glass panelling covers and protects the cells, while an aluminium frame holds it
together.
Silicon is the ideal material to create solar cells, as it’s the second-most common element on
our planet after oxygen, so there’s no risk of it running out any time soon.
The silicon is basically in the form of sand.
The process for how to get from sand to solar cells and panels is interesting and a little complex, so we’ll try to keep it simple.
From Sand To Solar panels
1. First the sand is placed in a very hot furnace until it becomes crystallised silicone rocks.
2. The rocks are melted together to form cylindrical ingots. (Note: Solar panels can be
monocrystalline or polycrystalline. Monocrystalline cells are from a single silicon source and polycrystalline cells are from multiple silicon fragments.)
3. The ingots are ground and polished to create smooth flat sides.
4. The ingots are sliced into discs about the thickness of a sheet of paper.
5. A coating is added to the discs to improve sunlight absorption and reduce reflection.
6. A metal conductor like boron is added to the discs. Each cell has a positively charged
disc (boron) and negatively charged disc (phosphorous) which meet at a ‘conduction
junction’ to facilitate electricity flow.
7. A group of cells is connected in a circuit to create a solar panel. The solar cells are
imbalanced to conduct energy. To form the solar panel, cells are layered and
soldered together in a grid-like matrix.
8. EVA (Ethylene-vinyl acetate) is added between the layers, as well as a plexiglass
sheet and backing sheet, to protect the silicon. An aluminium frame holds the panel
together.
9. Finally, a solar inverter is attached. A solar panel creates DC electricity, but the
electricity used in households is AC 240 volts. A solar inverter converts the DC to AC
for use in homes and the electricity grid.
As well as monocrystalline and polycrystalline solar panels, you can also buy thin film panels. These cheaper panels are basically a thin layer of conductive material on a backing plate made of glass or plastic. They are much less efficient than crystalline panels and aren’t usually used in residential buildings, though they’re very inexpensive.
Reduce, Reuse and recycle solar panels
Now that we know what materials are used in solar panels and how they’re made, we need to consider what happens when we don’t need those panels anymore.
Solar panels have a long life span with many lasting more than 25 years. But many solar
panels are coming to the end of their life or have components that need replacing. Too
often, these are ending up in landfill.
Around 100,000–150,000 solar panels need to be replaced every year, which will produce
more than 900,000 tons of solar panel waste by 2050. Luckily, it’s not necessary for this to
happen. When solar panels fail or come to the end of their life, their materials can be
recycled and reused.
By thinking ahead, you can help recycle these materials so they can be reused in new solar
panels. This will help conserve the finite resources that we currently have and reduce the
amount of resources that we need to use in future.
Almost every part of a solar panel can be recovered and recycled, including crystalline
silicon, glass, plastic, aluminium and steel brackets. Wonder how it happens?
Recycling Process For Solar Panels
1. First the solar panel is shredded to break down the panel and expose all of its components.
2. Then the various pieces are separated into their groups. Detectors are used to find and separate the steel, aluminium, glass and other elements. This requires intricate equipment to do the job accurately and enable the materials to be recycled.
3. Once the materials are in their groups, they are returned to industry so manufacturers can reuse the materials in new items.
Unfortunately solar panel recycling is an expensive process, so recyclers are struggling to cover costs. Currently, recyclers need to charge for this recycling until the amount of solar panel recycling increases.
This is another reason that we need to start recycling more solar panels – the more panels
they get, the more cost effective it will be. Then recyclers will be able to sell the materials
back to industry in larger volumes and won’t have to charge for the recycling.
Another option is to make solar panel manufacturers responsible for ensuring solar panels
are collected and recycled at the end of their life. This process seems to work in Europe, so
perhaps it has potential for Australia too.
Want To Know More ?
More solar panel recycling plants are opening up in Australia every year. We suspect this will
become a booming industry over the next decade with the massive number of solar panels
coming to the end of their life.
Read more about how to choose the best solar panels for your home and contact us for a
free quote. We’re always happy to answer your questions!
