As we continue to search for sustainable energy sources, solar power has emerged as one of the most promising options. One of the key components of solar panels is the solar cell, which converts sunlight into electricity.
In this article, we will explore some important things you need to know about solar cells and solar panels.
We will also explore the different sizes of solar panels that can be produced in a solar production line, and discuss how to choose the optimal size for your needs.
Solar Cells Production
Solar cells, also called photovoltaic cells, are small electronic devices that convert sunlight into electricity using a phenomenon called "the photovoltaic effect." They are the building blocks of solar/PV panels, which are used to generate electricity from the sun. The solar panel manufacturing process involves assembling several solar cells together, connecting them with wires, and enclosing them in a protective casing.
A solar cell is made up of several layers of semiconductor materials, usually silicon. When sunlight hits the cell, it excites the electrons in the semiconductor material, causing them to flow through the cell and generate electricity. The process of making a solar cell involves several steps which include:
1. Growing pure semiconductor crystal (e.g., silicon).
2. Doping the crystal with impurities to create p-type and n-type regions.
3. Forming a junction between the p-type and n-type regions.
4. Appling electrodes to collect generated electricity.
5. Adding anti-reflection coating to maximize sunlight absorption.
6. Depositing a passivation layer to improve efficiency (optional).
7. Encapsulating the cell with protective materials for durability.
Types Of Solar Cells
There are several types of solar cells, each with its own unique characteristics. The most common types of solar cells are monocrystalline, polycrystalline, and thin film.
Monocrystalline Solar Cells
Monocrystalline solar cells are made from single-crystal silicon. Manufacturing monocrystalline silicon is very slow and expensive compared to polycrystalline. However, the demand for monocrystalline silicon continues to rise due to its superior performance.
The main advantage of monocrystalline solar cells is their higher efficiency compared to all other types of solar cells. The main disadvantage of monocrystalline solar cells is they are the most expensive.
Polycrystalline Solar Cells
Like monocrystalline, polycrystalline solar cells are made from silicon. The difference between them lies in manufacturing. Whereas monocrystalline cells are made from a single silicon crystal, polycrystalline solar cells are made from multiple silicon crystals melted together.
The main advantage of polycrystalline solar cells is they are cheaper compared to monocrystalline ones. However, these solar cells are a little less efficient than monocrystalline solar cells due to the way they are made.
Thin-Film Solar Cells
Thin-film solar cells are made by depositing a layer of photovoltaic material onto a substrate, such as glass, plastic, or metal. These solar cells are a few nanometers thick and are much thinner than the wafers used in either polycrystalline or monocrystalline cells.
This manufacturing method gives thin film cells one significant advantage over crystalline cells. Thin-film solar cells are lighter and more flexible due to their thin construction. They are also much cheaper to produce.
With that said, thin-film solar cells are not as efficient as silicon-based solar cells. Also, thin-film solar cells come in various forms which each form different in effectiveness and cost of production. These include: Cadmium Telluride (CdTe), Copper Indium Gallium Selenide (CIGS), etc.
You can find out more about the differences between monocrystalline, polycrystalline, and thin film solar cells in our article which explores what solar panel types manufacturers can produce.
Others
There are a few other cells in development, and they promise to be very efficient and cheap to produce. These include organic solar cells, perovskite solar cells, etc.
How Is a Solar Panel Made
The solar cell is the primary component of a solar panel. Once the solar cells have been manufactured, they are assembled into solar panels. The assembly process involves several steps, including:
1. Connect multiple cells in series or parallel to achieve desired voltage and current.
2. Secure the electrical connections between cells and create pathways for current flow via soldering and tabbing.
3. Encase the string of cells in protective materials like glass and polymers for weatherproofing and durability.
4. Secure the encapsulated cells onto a sturdy frame for structural support.
5. Install a junction box to connect the panel output cables and provide safety features.
6. Conduct rigorous testing to ensure electrical performance, safety, and durability.
7. Properly package and ship the finished solar panel to its destination.
All these steps are carried out by various machines such as stringers and tabbers, laminators, layup machines, etc. Here is a more detailed explanation of the solar panel machines that used in solar panel assembly.
Sizes Of Solar Panels
Solar panels come in three main sizes; namely 60-cell, 72-cell, and 96-cell. The 60 and 72-cell solar photovoltaic panel size are more commonly used for residential purposes, while a 96-cell solar panel size is more suited for commercial uses.
As you may have guessed, the more cells a solar panel has, the larger and more expensive it will be. 72-cell solar panels have more cells, so are larger than 60-cell panels. The same goes for 96-cell panels.
While panels with more cells are heavier and take up more space, they also produce more energy. A 96-cell panel has a higher wattage than a 72-cell solar panel, while a 72-cell PV panel has a higher wattage than a 60-cell panel. Due to the larger wattage power of 96-cell solar panels, they are more suited for larger commercial uses like factories or warehouses where energy demand is higher.
Advanced Solar Panel Technologies
From our discussion of solar panel size and efficiency, it’s clear how important squeezing the most energy from a solar panel is. This is why there is a lot of research and development of new solar technologies. There are several exciting developments in the solar industry, but some of the most interesting developments include bifacial solar panels, organic solar cells, tandem solar cells, and perovskite solar cells.
Bifacial Solar Panels
Bifacial solar panels are simply two-sided solar panels. They collect light on both sides of a panel and generate electricity from both the front and back sides of the solar panel. Under ideal lighting conditions, right environmental conditions, and the use of a solar tracker, bifacial solar panels are said to be able to produce up to 25% more energy than single-sided solar panels.
But due to factors such as its higher initial cost, complex installation, and environmental factors, bifacial solar panels are generally more suited for commercial purposes - however, it can also be used for residential purposes.
Perovskite Solar Cells
Perovskites are an emerging solar cell technology that is still under development. They are a promising replacement for silicon solar modules as they are cheaper to make and theoretically more efficient.
At present however, perovskites have a shorter lifespan compared to silicon modules and are also costlier due to production complexities. This is why they are yet to make it to mass production. Should they become viable, perovskite cells might offer offer a drastically cheaper and less resource-intensive solar cell.
Tandem Solar Cells
Tandem solar cells is an emerging solar cell technology that is still under development. Its production design involves stacking multiple layers of different semiconductor materials, each absorbing different wavelengths of light, achieving higher overall efficiency.
Theoretically, it has a much higher efficiency rate than the monocrystalline solar cells (which is the most effective form of silicon solar cells). It is currently more expensive and has a more complex production process; but with advancements in its development and constantly improving technology, this could be a very viable alternative to the silicon based solar panels that currently dominate the solar panel industry.