How are solar panels made?

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Solar panels are manufactured with precision and checked for quality throughout the process. Image source: Solar Power World Online

Although solar panels do the challenging job of generating solar energy from the sun, building a solar panel is pretty simple when built professionally in a well-run factory. The main components of a solar panel are solar cells, silicon, metal, and glass. Each of these components is then compiled to form a solar panel that can generate renewable energy.

Allow us to take you through the step-by-step process of how and where solar panels are made, from the photovoltaic cells to the frame, before they are shipped out to be installed on your roof by a contractor.

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    Where are solar panels made?

    You can find solar panel manufacturers in many places, ranging from the United States to Europe, but most solar panels are made in various countries within Asia. Like many industries, switching manufacturing to countries with lower labor costs has become a standard practice in recent years.

    But, many higher-quality panels are manufactured within the U.S. so that each process within the manufacturing phases can be closely monitored for quality.

    Let's look at some examples of solar panels to get a sense of manufacturing locations. Top-quality brands include Panasonic and Mission Solar. Panasonic solar panels are manufactured in the U.S. and Malaysia, while Mission Solar is manufactured strictly in the U.S.

    Jinko Solar, a less expensive solar panel company than Panasonic or Mission Solar, manufactures their solar panels in China. While another lesser-known company, Candian Solar, manufactures its panels in Canada.

    The raw materials that make up a solar panel are not necessarily all manufactured in the same location since supply chains can stretch through many countries. While solar panels are manufactured globally, there are plenty of U.S.- manufactured options for you to choose from.

    What are solar panels made of?

    At the most basic level, the key components of a solar panel are solar PV cells, polysilicon or silicon, metal, and glass. The most important component is the solar cells which convert sunlight into usable energy. Solar cells are the photovoltaic (PV) component of solar panels, meaning they produce energy from the sun.

    Solar cells are made up of silicon and are protected by a sheet of glass over the panels which allows sunlight to be filtered to the cells. When exposed to sunlight, solar silicon dioxide cells generate an electric current, which is then converted to usable AC electricity via an inverter.

    Solar cells are assembled using wiring that transfers the electricity. This wiring is soldered to the cells which are then assembled between a backsheet and the glass that protects the cells. The entire panel is held together with a metal frame.

    This is an oversimplified process for how solar panels are made, so let’s break down the manufacturing process step by step for a better understanding.

    Diagram illustrating how solar panels are made from silicon, silicon ingots, and silicon wafers into solar cells

    Step 1: Build solar silicon cells that are either p-type or n-type, meaning positively or negatively charged. P-type silicon cells were the traditional structure of solar cells. A p-type silicon cell is built on a positively charged base, meaning the bottom layer is mixed with boron and the bottom layer is mixed with phosphorus.

    But the n-type cell is built oppositely, with the phosphorus serving as the base. The main difference is that n-type cells offer more efficiency and they are not affected by light-induced degradation, or reduction in output when exposed to extreme sunlight.

    Solar cells are made with crystalline silicon that is melted and mixed with gallium or boron to form wafers called silicon ingot. Phosphorous is then added to the silicon, and along with the gallium or boron, these substances give silicon its electrical capability.

    The silicon ingot is then cut into thin sheets and an anti-reflective coating is applied to capture the sunlight instead of reflecting it away from the panels. Thin lines are then cut into the cells to capture and move the electrical current within the cell.

    The solar cells become semiconductors of electricity which is generated by the photovoltaic effect, when the sunlight's photons are absorbed, electrons then drift within the solar cells to create energy.

    Monocrystalline solar panels are formed from one silicon fragment but for polycrystalline panels, many silicon fragments are melted together in one large sheet to form the silicon wafers for the solar panel.

    Step 2: Solder solar cells together to form one panel, usually 60 or 72 solar cells form one panel

    Step 3: Install the backsheet which protects the bottom of the solar cells

    Step 4: Install glass front. This allows light to filter through to the solar cells and provides a protective layer

    Step 5: Seal a metal frame around the panel with silicon to fuse all of the layers together

    Step 6: Install the junction box which protects the solar panel's electrical wires from damage

    Step 7: Test solar panel for quality and strength before shipping out for use

    After testing solar panels for quality, they are ready to be shipped out and installed on homes or for solar farm use. The manufacturing process for different types of solar panels is pretty similar, but there are a few types of solar panels and each type has its own strengths.

    What types of solar panels are there?

    Digitally rendered image of a thin film, monocrystalline and polycrystalline solar panel

    Thin film, monocrystalline and polycrystalline panels are the main types of solar panels available for purchase.

    The main types of solar panels are monocrystalline, polycrystalline, and thin-film panels.

    The difference between mono and poly panels is that monocrystalline silicon panels are made with solar cells from a single crystal of silicon while polycrystalline silicon panels are made from melting several silicon crystals together.

    Because they are made with a single crystal of silicon, monocrystalline panels are more efficient, yet more expensive than polycrystalline panels. Their main differences are the aesthetic appeal, cost, and efficiency, but either option is a good choice for your home solar system.

    Work with a solar installer to determine what type of panel is best for your home

    Thin-film solar panels are really only used for utility-scale projects within the solar industry because they are very low-efficiency panels. Because of this, you need a lot of them to generate electricity.

    Different from monocrystalline and polycrystalline panels, thin-film panels are not made up of solar cells but are made by depositing a thin layer of photovoltaic substance, like amorphous silicon or cadmium telluride, onto a solid substrate surface like glass.

    Although the manufacturing process for thin-film panels makes them cheaper and easier to install, they are not used for home solar installations because they are not as durable or efficient.

    Testing the quality of newly manufactured solar panels

    During the entire manufacturing process, the materials that are used to build the panels are monitored for any defects. For example, any cracked or bent solar cells are discarded.

    Once solar panels are built, they go through rigorous testing to make sure that they can stand up to intense weather conditions, heat, and normal wear and tear. Additionally, it is important to test that the electrical current travels through the panels efficiently.

    Finally, solar modules are tested for strength to make sure that they have a low likelihood of breaking due to hail or other falling debris. Testing the quality of solar panels is important to make sure they can generate electricity while being able to last their entire lifetime.

    Should you make your own solar panels?

    We do not recommend making your own solar panels, although it might seem easy to configure a panel with all of the proper materials. Errors in building your own panels, like starting a fire, outweigh the benefits of DIY solar panels.

    It is best to rely on professionally built solar technology because they are built with rigorous standards and tested for durability. Working with a professional solar installer is an important step to making sure your solar panels are made with high-quality materials that will provide solar power for their 25-year warranty, or more. Solar panels are one of the best energy sources for reducing carbon dioxide from fossil fuels so adding them to your home is a great way to be part of the clean energy future.

    Click here to find local solar installers

    Key takeaways

    • Solar panels are manufactured using silicon, glass, and metal. Silicon creates solar cells that can generate electricity from the sun.
    • The main types of solar panels are monocrystalline, polycrystalline, and thin-film panels. Their manufacturing process is slightly different, leading to different strengths for each type of panel.
    • Solar panels are manufactured all over the world, American made panels are generally the most expensive but they are high quality.
     - Author of Solar Reviews

    Ana Almerini

    Web Content Specialist

    Ana is a web content specialist at SolarReviews. She has 5 years of marketing experience blended with 2 years of experience in climate communications and holds a master of arts degree in climate and society from Columbia University. Ana frequently volunteers for environmental causes ranging from oyster reef restoration in NJ to expanding bike sharing in Naples, Italy.

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