A solar panel contains a set of solar cells whose function is to convert the sun’s light into electric energy. The primary material in solar panel manufacturing is silicon. Many of the solar panels that you see on roofs are monocrystalline or polycrystalline. The solar panel manufacturing process determines its efficiency.
As people switch to solar energy, it is good to know a few things about how solar panels are made. In this article, we will look at a few things you need to know about solar panel manufacturing. Let’s get started.
Solar Energy Background
Due to research in this field, solar panels have changed in effectiveness since invention. Before the inception of the first silicon photovoltaic cells in 1954, several scientists contributed to solar growth as we know it today. The silicon cell produced in 1954 had 4% efficiency. As research grew, solar panel’s efficiency continued to increase.
Currently, the solar cells being used can meet commercial and homes electricity demand. Solar panels are also being installed to generate electricity to power business and manufacturing operations. As further research continues on solar energy, it could emerge as the preferred source to run economies.
Solar Panel Raw Materials
The first crucial component required to make solar cells is pure silicon. However, silicon is not pure in its natural state. It is derived from quartz sand in a furnace requiring very high temperatures. Natural beach sand is the main component in making pure silicon. Though it is an abundant resource in the world, the process of getting pure silicon comes at a cost and requires a lot of energy.
Solar Panel Manufacturing Process
The first process in solar panel manufacturing is purifying the silicon from quartz sand. Once silicon is purified, it is collected into solid rocks. These rocks are then molten together, forming cylindrical ingots. A steel and cylindrical furnace is utilized to achieve the desired shape. When manufacturing is underway, there is a keen attention to having all atoms align in desired orientation and structure.
To give the silicon positive electrical polarity, boron is included in the process. To make monocrystalline cells, the manufacturer only uses one silicon crystal. As a result, such solar panels have high efficiency. However, they come at a higher cost.
For polycrystalline cells, the manufacturers melt several silicon crystals together. These panels have a shattering glass appearance derived from the various silicon crystals. Once the formed ingot cools, it is shinned and polished to leave flat sides.
Making Wafers
The next step in solar panel manufacturing is after making ingots. To make wafers, the cylindrical ingot is thinly sliced into thin disks. It is done so one at a time using a cylindrical saw. Manufacturers can also use a multiwire saw to cut many at a time.
Thin silicon is shiny, and reflects light. A thin anti-reflective coating is put on the disks reducing the amount of sunlight lost. The anti-reflective coating is commonly made from titanium dioxide and silicon oxide, but other materials can also be used.
This coating material can be heated until the molecules boil, or it can go through spattering. Under the spattering process, the manufacturers use a high voltage to know the materials’ molecules and deposit them on the silicon.
The wafers can be further polished to remove saw marks. However, some manufacturers are choosing to skip these steps as the saw marks help increase efficiency.
Making Solar Cells
Manufacturers follow several steps to convert silicon wafers into usable solar cells. They treat each wafer and add metal conductors on the surface. The added conductors result in a grid-like matrix appearance on the surface. They ensure sunlight is converted into electricity.
The coating on the silicon wafers reduces sunlight reflection, ensuring the sun is absorbed, and leading to more production. In oven-like chambers, the manufacturer’s phosphorous is spread in a thin layer over the wafers’ surface. The phosphorous charges the wafers with a negative electrical orientation.
Solar Cells to Solar Panels
Once the solar cells are made, the manufacturers connect them using metal connectors. Solar panels are a combination of solar cells in a matrix-like structure. The market standard of solar panels are:
- 48 cell panels – ideal for small residential roofs.
- 60-cell panels – the standard size.
- 72-cell panels – suitable for large-scale installations
After the manufacturers combine the solar cells, thin glass casing is placed on the side to face the sun. They also use highly durable polymer-based material to make the back sheet. This prevents things such as water, soil, and others from getting to the solar cells.
To allow connections to the modules, a junction box is added. Once this step is complete, the manufacturer adds the frame, providing more protection to the cells. Ethylene-vinyl acetate or EVA is used to bind everything together.
Testing the Solar Panels
Once the solar module manufacturing is completed, testing is done to ensure it meets the expected performance. Normally, STC (Standard Test Conditions) is used. After testing, solar panels are now cleaned and inspected, and the model is shipped to homeowners.
Solar panels’ efficiency continues to increase. As many home and business owners choose clean energy, the solar manufacturing industry is expected to grow. There is hope that solar manufacturing costs will continue to reduce as research and development continue.
