The demand for solar energy has increased due to an increase in the trend of using renewable resources of energy. Man is now more conscious about clean sources of energy. Due to increased demand, technology is getting highly innovative. The solar industry got a rise by 50% in the past decade alone. This rise is leading to an increase in competition as well. That’s why there are many types of solar panels.
In this article, you will know about different types of solar panels and their strengths and drawbacks in detail. Keep learning to know all about the different types of solar panels.
What is a solar panel?
“Solar energy from the sun is captured and transformed into electricity using solar panels”.
Individual solar cells, constructed of layers of silicon, boron, and phosphorus, make up the conventional solar panel. The positive charge is provided by the boron layer, the negative charge is provided by the phosphorus layer, and the silicon wafer serves as the semiconductor.
When photons from the sun hit the panel’s surface, they dislodge electrons from the silicon “sandwich” and introduce them to the electric field created by the solar cells. This produces a directed current that is subsequently captured and converted into useful electricity. Solar panels are sometimes referred to as photovoltaic panels, or PV panels because the entire procedure is known as the photovoltaic effect. Generally, 60, 72, or 90 individual solar cells are often found in a solar panel.
Main types of solar panels:
- Monocrystalline Solar Panels
- Polycrystalline Solar Panels
- Passivated Emitter and Rear Cell (PERC) panels
- Thin-film solar panels
- Monocrystalline solar panels:
Monocrystalline solar panels are manufactured from a single silicon crystal which is further divided into multiple wafers. Due to the use of pure silicon, the color of monocrystalline solar panels is dark black, which is used to recognize the panels. These panels have the longest working life and strength among all the types of solar panels due to the usage of pure silicon.
When talking about the cost, these panels are more expensive than others due to better quality and longer life. A lot of silicon is wasted while manufacturing these panels. The wastage may reach up to 50%, which makes it costly.
- Polycrystalline solar panels:
Polycrystalline is the opposite of monocrystalline solar panels. These are manufactured from different silicon crystals. The process of manufacturing begins by melting the different silicon crystals. The melted silicon is poured into molds to give a square shape. This square shape is the recognition quality of these panels. A very small quantity of silicon is wasted during the manufacturing process of the panels.
These are less efficient than monocrystalline solar panels because of their composition. The mixture of different silicon crystals decreases the efficiency of silicon. They are also less strong against heat which makes them unsuitable for areas of hot temperatures. Due to all these factors, polycrystalline solar panels are less costly.
- Passivated Emitter and Rear Cell (PERC) panels:
The passivated emitter and rear cell panels (PERC) are innovative variants of Monocrystalline solar panels. It adds a bit more efficiency to the panels. Now we see how PERC panels work:
“It increases the quantity of solar energy that is absorbed by reflecting light into the cell. It hinders the flow of electrons in the system and lessens their tendency to naturally recombine. PERC panels have a passivation layer that reflects the greater wavelengths of light. The greater wavelengths of light cannot be absorbed by the silicon cells and cause heating of the back sheet of panels. Due to this factor, the other solar panels become hot and less efficient. But PERC panels reflect the longer wavelengths by a passivating layer of cells. This design makes them more efficient than others”.
The PERC solar panels cost higher in manufacturing than other panels. This is due to the extra material needed to give them a passivating layer. They can reduce the carbon footprint because they can produce more energy in less area. Due to high efficiency, their average cost per watt is approximately the same as the other brothers in the family.
- Thin-film solar panels:
Thin-film solar panels are made up of a thin layer of cells. This layer is thin enough to be flexible. These panels do not need any frame. As a result, they are lightweight and easy to install. These panels have a flexible cell count, unlike crystalline solar panels. Thin-film solar panels can be fitted to any size as per your needs. Being flexible, lightweight, easy to install, and fit into any size makes them attractive and more suitable for congested spaces. However, these panels are less efficient than other solar panels.
Variants of Thin-Film Solar Panels:
Thin-film solar panels are made of up different materials. There is no usage of silicon in these solar panels. Following are the variants depending upon the material of composition:
- Cadmium telluride (CdTe)
- Amorphous silicon (a-Si)
- Copper indium gallium selenide (CIGS)
Cadmium Telluride (Cd-Te):
Cadmium telluride solar panels are less expensive than polycrystalline solar panels. They have less footprint and water requirement. But cadmium has a very toxic nature. Due to this, the recycling process of solar panels is not an easy task. It is a costly and dangerous process compared to others.
Amorphous silicon (A-Si):
In the composition of Amorphous Silicon solar panels, the silicon does not have a molecular structure, in contrast to mono and polycrystalline solar cells. A-Si cells often only need a small amount of silicon compared to conventional silicon cells. Sacrificing efficiency, enables them to have the lowest manufacturing costs. Because of this, A-Si panels are appropriate for low-power applications like pocket calculators.
Copper indium gallium selenide (CIGS):
Copper indium gallium selenide (CIGS) panels are more efficient due to the thin panels. These are composed of a thin layer of copper, indium, gallium, and selenium backed by glass plastic. These are also very thin panels but are not flexible. These are less efficient than crystalline silicon panels.
Types of Solar Panels and their Efficiency:
The efficiency of Crystalline solar panels:
Crystalline solar panels have the highest efficiency rate among all types of solar panels. It is very easy to understand the efficiency by the following table:
|Solar Panel||Efficiency Rating|
From the above table of efficiency ratings, we can see PERC panels are 5% more efficient than monocrystalline panels. It is due to the extra passivating layer. Polycrystalline is the least efficient due to the mixed composition of silicon crystals.
The efficiency of Thin-Film solar panels:
Thin-film solar panels are approximately 2-3% less efficient than crystalline solar panels. Consider the following table which describes the average efficiency rate of thin-film solar panels:
|Solar Panel||Efficiency Rating|
|Copper indium gallium selenide (CIGS)||13-15%|
|Cadmium telluride (Cd-Te)||9-11%|
|Amorphous silicon (A-Si)||6-8%|
Solar Panel Types by Cost:
Monocrystalline solar panels are expensive due to their composition and higher efficiency than polycrystalline solar panels. The material used to manufacture monocrystalline modules is expensive because it is used as it is without any mixing. A lot of material is wasted as well.
Polycrystalline solar panels are less expensive because manufacturing involves the melting and mixing of silicon crystals. Due to this mixing, efficiency decreases, however, it becomes more affordable. The residual crystals from monocrystalline panels are melted and used which lowers the manufacturing cost.
The most-costly thin-film solar panels are made of CIGS, followed by Cd-Te and amorphous silicon. In addition to having a reduced purchasing cost, thin-film modules may be simpler to install due to their flexibility and lighter weight, which reduces the cost of labor.
The following table shows the average cost per watt of all types of solar panels:
|Panel (Module) type||Average Cost per Watt|
|Monocrystalline||$1 – $1.50|
|Polycrystalline||$0.70 – $1|
|Copper indium gallium selenide (CIGS)||$0.60 – $0.70|
|Cadmium telluride (CdTe)||$0.50 – $0.60|
|Amorphous silicon (a-Si)||$0.43 – $0.50|
Effect of temperature on different types of solar panels:
The capacity of a solar panel to produce electricity can be impacted by its temperature. The temperature coefficient, a measurement of the panel’s reduction in power output for every 1°C increase over 25°C (77°F), reflects this output loss. Thin-film panels are closer to -0.2% / °C than monocrystalline and polycrystalline panels, which have temperature coefficients between -0.3% / °C and -0.5% / °C. This means that thin-film panels could be a feasible option for hotter climates or locations that get more sunshine all year round.
Effect of Hailing on different types of solar panels:
Thin-film solar panels have a lower rating due to their thin and flexible design, but crystalline solar panels carry a higher rating due to their thicker construction, which can resist hail impacting at speeds of up to 50 mph. People living in a stormy area where chances of Hailing are higher must choose crystalline solar panels.
There are different types of solar panels and a list of their advantages and drawbacks. However, all solar panels fit in a specific condition. We are grateful to solar technology due to which the impact of pollution being caused by the usage of fossil fuels is decreasing. Solar energy is the cleanest form of green energy.