Ever wonder how solar panels are constructed and what they are made with?
On the surface, solar panels may seem like very simple pieces of equipment, but they are complex marvels of science and engineering. To maximize the efficient collection of light energy and convert it to usable electricity, solar panels are manufactured using a diverse range of advanced materials. Join us as we explore the construction and design of solar power panels, and get to know the innovative materials used to manufacture them.
Within the category of solar power panels, there are two main styles to consider. Monofacial solar panels and bifacial solar panels. Monofacial solar panels absorb light energy from only one side of the panel, whereas bifacial solar panels are capable of absorbing light energy from both sides of the panel. While monofacial panels are generally less expensive, bifacial panels offer increased energy production when compared to monofacial panels. The type of panel that is best for you will be determined based on your energy needs and the installation location of your system.
Let’s take a closer look at the different components and layers used in solar panel construction. A typical solar panel consists of two main sections. The first is the panel component itself, which is a flat, multi-layered surface containing the cells through which light energy is collected. The second section is the junction box containing the electronic wiring and connectors that facilitate the transfer of the collected energy into the rest of the solar power system. Let’s look at each of these two sections in more detail.
A monofacial solar panel is typically constructed of five distinct parts. These parts include:
- Anti- Corrosion Frame
- Protective Tempered Glass
- EVA Film
- Photovoltaic (PV) Cells
- Backsheet
Bifacial solar panels are constructed using a very similar series of layers to those of a monofacial panel. However rather than a backsheet, the reverse side of a bifacial solar panel consists of another layer of tempered glass to allow the light energy to be absorbed from both sides of the panel.
Each of the layers performs a very important role in the function, durability, and efficiency of the solar panel. Here’s what you need to know about the materials and design of each solar panel layer.
- Anti-corrosion frame: The outer edge of the solar panel is surrounded by a protective metal frame designed to ward off corrosion and prevent damage to the edges of the panel from wind, water, and other environmental factors. These frames are most often either silver or black in colour and are made from lightweight aluminum alloy. Many people prefer the appearance of a black frame, as this matches the look of the solar cells themselves and can more effectively blend in with dark-coloured roofing materials.
- Protective Tempered Glass: The top surface layer of a solar panel is made from durable and shatter-resistant tempered glass. In most cases, this glass layer is about 3-4mm thick and is completely transparent to provide maximum efficiency of light transfer. Tempered glass is ideal for solar panel applications that are constantly exposed to the environment as it is incredibly tough and able to withstand even the harshest climate conditions. This glass layer must meet or exceed IEC's standards for standard impact testing, and be capable of withstanding hits from hailstones with a diameter of 1 inch (25mm) traveling at speeds of up to 60 mph (27 m/s).
- EVA Film: EVA (Ethylene Vinyl Acetate), is a highly efficient and transparent plastic coating used to encapsulate solar cells. EVA film is made of a transparent polymer and consists of laminated coverings that hold the individual solar cells together. This layer tolerates very high temperatures and humidity. The EVA layer is laminated on both the front and back surfaces of solar photovoltaic cells for optimum protection.
- Solar Photovoltaic (PV) Cells: Solar panel cells, also known as photovoltaic cells, are the part of the solar panel that transforms sunlight into direct current (DC) electric energy. The total power output is determined by the type and quantity of cells used in the construction of the panel. Photovoltaic cells are primarily made of silicon. There are two main forms of silicon: monocrystalline and polycrystalline. The base of the photovoltaic cell layer is typically about 0.1 mm thick and is made up of positive p-type and negative n-type silicon. There are multiple different types of PV solar cells, each with a different efficiency level based on size and design. These include half-cut (split cells), multi-busbar (MBB) cells, and shingled cells, which use thin, overlaying wafers. Maple Leaf Power Systems bifacial solar panels use innovative SunEvo solar cells which offer a superior efficiency rating of over 22% compared to other types of PV cells.
- Backsheet: The backsheet is the rearmost layer found on monofacial solar panels. This backsheet acts as a moisture barrier and structural support, providing insulation and protection for the solar cells. Backsheets are commonly made from a variety of polymer and plastic materials that thermal resistance and long-lasting UV protection. Traditionally, backsheet materials were most often white in colour, but many panels are now available with transparent or black backsheets. Bifacial solar power panels utilize a second layer of transparent tempered glass in place of the usual backsheet to facilitate dual-sided light energy collection.
Attached to the solar panel itself are additional components that are essential to the function and installation of the solar power system. These components consist of an electrical junction box, and the necessary cables and wires to connect the panel to the system.
- Junction Box: The junction box, located at the rear of the solar panels, is where the electrical connections of all the PV cells are combined and attached to the rest of the solar power array. Each junction box contains a series of diodes and electrical regulators to control the flow of electrical power generated by the PV cells of the panel.
- Cables and Connectors: Solar panels are built with climate-resistant cables and connectors. Solar panels that are completely waterproof will carry a designation of IP67 on the junction box. Considering the harsh weather circumstances, these components must be robust, reliable, resistant to UV rays, and capable of maintaining solid connections with minimal resistance across both low and high voltage levels. Typical solar panel cables are standard 4mm/6mm double-insulated solar DC cables, and are securely attached to the weatherproof connectors.
Quality Assurance & Testing for Solar Power Panel Manufacturers
The advanced materials and precise engineering of solar power panels necessitate strict adherence to quality control processes and testing to ensure proper function and maximum efficiency of each panel. Accordingly, solar panel manufacturers use a combination of automated production systems, environmental control technologies, and precision sensors to monitor and verify the quality of manufacturing in their facilities.
Throughout the critical stages of production, modern optical and image sensors are used to thoroughly inspect the photovoltaic cells and the construction of the panels to ensure proper installation of each component. Furthermore, protective measures are in place to guard the sensitive PV cell wafers against breakage or fragmenting during the assembly process.
In accordance with the quality assurance methods of the solar panel manufacturer, completed panels are thoroughly tested using a variety of approaches, including electroluminescent (EL) and flash testing. These testing and quality control procedures are designed to identify any potential flaws that could lead to malfunction after prolonged exposure to sunshine and high temperatures.
Advanced Materials & Precision Engineering for Optimum Solar Energy Production
What does all this mean for the owner of a solar power system? It means that you can be confident in the durability, longevity, and efficiency of your solar power panels and rest assured that your system will operate reliably for many years into the future.
If you’d like to learn more about solar power equipment or are interested in starting the process of getting your home or business equipped with a modern solar power solution, contact us today to have your questions answered and get a free solar power system quote!