Solar panels are an increasingly popular form of renewable energy, and they’re popping up on roofs worldwide. But how exactly do they work? What is inside a solar panel? In this article, we’ll dive into the inner workings of solar panels. Then, we will explore their history, production process, and different types available in the market today.
What Are the Types of Solar Panels?
Solar panels are devices that use solar energy to produce electricity. The most common type of solar panels uses photovoltaic cells consisting of a thin layer of semiconductor material, typically silicon. When sunlight hits the solar panel systems, the energy from the photons in the sunlight excites electrons in the semiconductor material. That creates an electrical current. Here are several types of solar panels available in the market today:
- Monocrystalline Solar Panels – These are rooftop solar panels made from a single, pure crystal of silicon and are typically the most efficient type of solar panels.
- Polycrystalline Solar Panels – The panels consist of multiple silicon fragments and are slightly less efficient than monocrystalline panels. However, they are generally less expensive.
- Thin-film Solar Panels – These are made by depositing a thin layer of photovoltaic material onto a substrate such as glass, plastic, or metal. They are lightweight and flexible, making them suitable for various applications.
- Concentrated Solar Panels – These use lenses or mirrors to focus sunlight onto a small area of photovoltaic material, increasing the panel’s efficiency.
Solar panel manufacturers typically use various techniques to create electricity from solar energy. For example, they may use monocrystalline or polycrystalline silicon to develop solar cells. They then wire them together to create a solar panel. Alternatively, they may use thin-film technology to design solar panels that are flexible and lightweight. In all cases, the goal is to maximize the electricity generated from the solar panel.
Researchers have been researching new types of solar panels that can generate electricity more efficiently in recent years. The National Renewable Energy Laboratory(NREL) in the United States is one of the leading research institutions working on this issue. As a result, researchers at NREL now know a range of new materials and techniques for generating electricity from solar energy. That includes advanced materials that can absorb more sunlight and more efficiently convert it into electrical energy.
So, What’s Inside Solar Panel?
Solar panels consist of several layers of materials that combine to convert sunlight into electrical energy. The main components inside a solar panel include:
Photovoltaic Cells
Photovoltaic (PV) cells are the heart of solar panels. These cells directly convert the energy from sunlight into electrical energy. The photovoltaic effect is the conversion of the sun into electrical energy. PV cells typically consist of semiconductor materials such as silicon. When sunlight hits the surface of a PV cell, it causes the electrons in the material to become excited and move from their regular positions. These electrons then move through the material, creating an electrical current.
Glass Cover
The glass cover is an essential component of a solar panel system. It is a layer of glass that protects the photovoltaic cells from damage due to weather and other environmental factors, such as wind, rain, and dust. The transparent glass cover allows sunlight to pass through to the photovoltaic cells, where it converts into electrical energy. The glass typically consists of tempered glass, solid and resistant to impacts and other types of damage.
Encapsulant
The encapsulant is a layer of material that covers the photovoltaic cells and helps to protect them from moisture and other environmental factors such as dust, temperature fluctuations, and mechanical stress. It typically consists of a polymer material, such as ethylene-vinyl acetate (EVA). Furthermore, it bonds the solar cells to the back sheet and the glass cover. The encapsulant also helps improve the solar cells’ efficiency by reducing the amount of reflected light and preventing the loss of electrical current due to moisture ingress.
Backsheet
The back sheet is a layer at the back of a solar panel, and it typically consists of a polymer material such as Tedlar or TPT. It protects the solar cells from environmental factors such as moisture, heat, and dust. The back sheets also provide electrical insulation and help maintain the solar panel’s structural integrity.
Frame
The frame provides support for the solar panel and helps to protect the other components from damage.
Wiring and Connectors
These components connect the solar panels and system to an inverter or other electrical components.
How Do Solar Panels Work?
Now that you know the basic science behind solar panels, let’s look at how they work in practice.
Solar panels consist of several solar cells connected in series to create a panel. Each solar cell consists of a layer of p-type silicon, which has an excess of positively charged holes, and a layer of n-type silicon, which has a surplus of negatively charged electrons. When light hits the solar cell, it excites the electrons in the n-type layer and causes them to move toward the p-type layer. This movement creates a flow of electricity, which the metal contacts collect on the solar cell’s surface.
The electricity generated by the solar cell is DC, which means it flows in one direction. However, most homes and businesses use AC electricity, which flows in two directions. An inverter converts the DC electricity from the solar panel into AC electricity that one can use in a home or business.
A Brief History of Solar Panels
The history of solar panels dates back to the early 19th century. That is when French physicist Alexandre-Edmond Becquerel had the privilege of discovering the photovoltaic effect. He found that certain materials, such as selenium, produced electricity when exposed to light.
In the following decades, there was the continuation of the experiment with photovoltaic technology by scientists. Still, it was in the 1950s that Bell Labs had the chance to develop the first practical solar cell in the United States. This solar cell consisting of silicon had an efficiency of around 4%.
Throughout the 1960s and 70s, the primary use of solar panels was in space applications. Their work was providing power to satellites and other spacecraft. However, it was in the 1980s that using solar panels began to happen on Earth, primarily in remote locations where it was difficult or expensive to run power lines.
Solar Panels Today
Today, solar panels are more affordable and efficient than ever, and one can use them in many applications. From small portable chargers to large utility-scale installations, solar panels are helping to power our world cleanly and sustainably.
From Solar Cell to Solar Panel
Several solar cells connect to create a solar panel to form a module. The number of solar cells in a module depends on the desired output voltage and current of the panel. Multiple modules can then be connected in series or parallel to create an array capable of producing enough electricity to power a home or business.
The Production of Crystalline Solar Modules
Crystalline solar panels are the most common type of solar panel used today. They consist of silicon wafers that are processed and assembled into modules. One can break down the production process for crystalline solar modules into several steps:
Silicon Ingot Production
The first step in producing crystalline solar panels is to create a silicon ingot, a large block of high-purity silicon. The Czochralski method produces this ingot, where they dip a seed crystal into molten silicon and slowly pull it up to create a single crystal.
Wafer Production
Once they produce the silicon ingot, it’s sliced into thin wafers using a wire saw. These wafers are then polished to remove any surface defects and cleaned to remove contaminants.
Cell Production
The next step is to create solar cells from the wafers. First, it involves adding a layer of phosphorus to the top surface of the wafer, which makes a negative charge. Next, one adds a boron layer to the bottom surface, creating a positive charge. These charges create a potential difference across the cell, which allows it to generate electricity when exposed to sunlight.
Module Assembly
Once they produce the solar cells, they assemble them into a module. The cells connect using metal contacts, then encapsulated in a layer of EVA (ethylene-vinyl acetate) and a layer of glass. The EVA layer acts as a glue to hold the cells together and protect them from the elements, while the glass layer provides protection and allows sunlight to pass through to the cells.
Quality Control
Before shipping the solar panels, they undergo a series of tests to ensure they meet the necessary specifications for efficiency and durability. These tests include measuring the output voltage and current of the panel and subjecting it to extreme temperatures and weather conditions.
160W Monocrystalline Solar Panel
The 160W monocrystalline solar panel is popular for residential and commercial applications. It consists of 36 individual solar cells connected in series to create a panel capable of producing up to 160 watts of electricity.
The panel measures approximately 62 x 25 inches and weighs around 28 pounds. Its design uses brackets and a mounting system to mount it on a roof or flat surface.
Renogy 300 Watt Monocrystalline Solar Panel
The Renogy 300-watt monocrystalline solar panel is a good option for larger applications. This panel consists of 72 individual solar cells connected in series to create a panel capable of producing up to 300 watts of electricity.
The panel measures approximately 65 x 39 inches and weighs around 60 pounds. It can be mounted on a roof or flat surface using brackets and a mounting system.
Renogy 100 Watts 12 Volts Monocrystalline Solar Starter Kit
For those new to solar power, the Renogy 100 watts 12 volts monocrystalline solar starter kit is a great way to get started. This kit includes a 100-watt monocrystalline solar panel, a charge controller, mounting brackets, and a cable set.
The panel measures approximately 42 x 21 inches and weighs around 16 pounds. It can also be mounted on a roof or flat surface using brackets and a mounting system.
Conclusion
Solar panels have come a long way since their invention in the 1950s. As a result, they’re one of the most popular forms of renewable energy today. They work by converting sunlight into electricity through a process that involves semiconducting materials, and they’re available in a wide range of sizes and capacities to suit various applications.
Crystalline solar panels are the most common type of solar panel used today, and they consist of silicon wafers that are processed and assembled into modules. The production process for crystalline solar modules involves the following:
- creating a silicon ingot
- slicing it into thin wafers
- creating solar cells from the wafers
- assembling the cells into a module
Solar panels come in various sizes and capacities to suit multiple applications. The 160W monocrystalline solar panel is popular for residential and commercial applications, while the Renogy 300-watt monocrystalline solar panel is a good option for larger applications. For those new to solar power, the Renogy 100 watts 12 volts monocrystalline solar starter kit is a great way to get started.
As the demand for renewable energy continues to grow, solar panels will become even more prevalent in the future. In addition, with technological advances and manufacturing processes, solar panels will likely become more efficient and affordable, making them an even more attractive option for consumers and businesses.