We’re all familiar with solar panels and the fact that they generate invaluable renewable energy from sunlight, but few of us know how they work.
What are solar panels made of that allows them to take light from the sun and transform it into an eco-friendly energy resource that powers our homes and businesses? This article attempts to explain the solar panel manufacturing process, what modern solar panels are made of, and the scientific principle behind them that allows them to do what they do.
Solar panels are large devices that can be installed on rooves or other large areas that absorb light from the sun through solar cells, also known as photovoltaic cells. These cells then transform this light into electricity that can be used by the building they are installed on or fed back into the electrical grid.
Solar power is one of the most popular and accessible forms of clean renewable energy. It is a common solution in Australia as it is sustainable and eco-friendly, creating zero emissions when used. Solar panels work via a scientific principle called the photovoltaic effect. This is where the name photovoltaic solar panels come from.
The photovoltaic effect is the scientific principle behind solar power. Solar energy takes advantage of the fact that electrically charged particles are released from or within certain material, such as silicon, when it is exposed to electromagnetic radiation, i.e. sunlight!
A well-balanced solar array will generate power continuously during the day and then store this power in solar batteries that can be used at night. But what are solar panels made from and how are they constructed?
In a nutshell, solar panels are constructed from multiple layers of materials chosen for their efficiency and durability, enabling the panel to last its entire average lifetime of 25 to 30 years. From top to bottom, solar panels materials include the following layers:
– Aluminum frame to support the structure of the assembled materials and hold everything together
– A layer of tempered plexiglass to protect the delicate internal cells
– A layer of encapsulant material such as EVA (ethyl vinyl acetate) to hold components together
– The actual silicon solar cells – can be monocrystalline cells or polycrystalline cells
– Another layer of encapsulant material
– A strengthening back sheet composed of various materials
– And finally, the 12v junction box used by the solar installer to connect the solar panels in an array
So essentially, each solar panel is made from layers of materials that work in tandem to generate solar power and protect internal components from becoming damaged by harsh weather or sunlight.
When we create solar panels, they are constructed from solar cells which are made from silicon cells.
A solar panel made with solar cells from a single silicon crystal is called monocrystalline cells. Solar panels that use solar cells made from multiple silicon crystals are called polycrystalline cells.
The main difference between the two crystalline silicon cells is in the manufacturing process. To make a single crystal for monocrystalline panels is a more intensive process, which makes them both more efficient at generating solar power and more expensive. The silicon wafers are black in colour and tend to have a better performing temperature coefficient (continues to operate well at higher temperatures).
Making polycrystalline cells is a more cost-effective process, using multiple silicon crystals to
Put simply, solar panels work to create electricity through the photovoltaic effect within the silicon cells that are triggered by exposure to sunlight. In Australia, most solar panels are set up in a group of either 60 or 72 cells. When the light from the sun interacts with these cells, electrons start buzzing about very quickly at an atomic level, creating DC electricity. The invertor, another component in the configuration of the solar panel array, converts this DC current into 240 AC volt current which can be used by the relevant household or electricity grid.
Some solar panel manufacturers build their solar panels completely from scratch while others will purchase pre-produced cell components from other suppliers and finalise the product themselves. The overwhelming majority of solar panels and modules are manufactured in China and distributed around the world.
The average solar panel will move through a collection of phases before finally being installed.
Step 1: The silicon compounds are extracted from the raw material after being heated to a boiling point of 1,410°C. Solar panels can either be monocrystalline or polycrystalline, the first of which is constructed using pure silicon crystals making it the more efficient option.
Step 2: The silicon is then cut into many thin sheets each about the width of a piece of paper. A coating is then applied to the sheets, improving their ability to absorb light and reducing the impact of reflection. Metal conductors, phosphorus, and boron are then added to instigate the flow of electricity and complete the solar cell. These make up the visible grid lines you can see on the panel.
Step 3: These individual cells are combined in groups of 60 or 72 to create one singular panel, which is then layered with plexiglass, protective material and backing, and the aluminium frame. Finally, the junction box is added, allowing the panel to be connected to many others in an array when installed.
Step 4: Once completely built, the panel must pass stringent testing and accreditation requirements before it can be sold to the distributor. In Australia, this is the Clean Energy Council. There are also independent testers, such as DNV GL who publish an annual list of top performers to help consumers choose the best quality manufacturer and product
Silicon is the primary material used in the production of solar panels. But why is this the case? There are several reasons why the material is the most used today.
Semiconductors are material products that conduct electricity well, but not completely, like copper and aluminium. Silicon is one of the best semi-conductors available when mixed with the correct components, such as phosphorus and boron, which improve the capacity of the material to convert sunlight into electricity.
Silicon solar cells can convert up to 20% of the sunlight that hits them into electricity. While this may seem like a low percentage, it is considerably higher than solar cells manufactured with other materials.
Silicon is also a good choice for solar panels as it is non-toxic, meaning it has a minimal environmental impact and is safer for use in production
Solar panels are an investment, and this means they need to last for a long time to pay themselves back and start positively contributing to the environment. (Link Carbon Positive Blog Here) The silicon dioxide layer gives the cells a higher corrosive resistance which makes them stronger against the effects of adverse environmental conditions and intense sunlight. A vital benefit when you consider that solar panels spend their entire product lifecycle out in the open.
Silicon is a popular major component of solar panels as there is plenty of it around. It is naturally abundant in nature, making up roughly 26% of the crust of the earth. So there is plenty of it around, and it is easy to access.
Other reasons why silicon is a favourable choice for solar panels are that its chemical composition means it is highly photoconductive, meaning that its electrical conductivity increases when exposed to sunlight, it is highly cost-effective which keeps costs down and it has a natural long outdoor life.
Silicon for solar just makes sense!
Researchers and manufacturers are always working to find ways to make solar panels more efficient and reduce their carbon footprint. Recently, some researchers have succeeded in creating financially viable panels from completely recycled materials. But why is this not already the case for all solar panels produced today? While it is certainly possible to create some components of solar panels from recycled materials, such as the aluminium frame, for example, creating entire new panels from discarded solar panels is not as simple. This is mostly because the silicon required to be mixed with the phosphorus and boron to create a new panel must be ultra-pure. Manufacturers can of course refine the recycled silicon, but this is an energy-intensive process that ultimately offsets the environmental benefits of the solar panels entirely. Hopefully, with further research and development manufacturers can mass-produce panels in an efficient and cost-effective manner from recycled materials, this will be sometime in the future.
Many people understand what solar panels are and a little bit about how they work but not so much about what they are made from and why. Silicon, the primary component of most photovoltaic solar panels, is the most popular resource used as it is cost-effective, readily available, and naturally suited for the task of taking light from the sun and turning it into eco-friendly renewable energy. When you choose to make an investment in solar panels or are considering having them installed it can help to understand a bit more about how they work to generate clean energy that is friendly for both your energy bill and the environment.
HCB Solar is proud to be Newcastle’s most trusted partner in solar installation, using only the highest quality products that will have your solar system providing a return on investment for decades to come.
Contact us today to learn more about how we at HCB Solar can help you benefit from installing a solar power system in your home or business today.