Types of Solar Panels You Should Consider
Quick quiz: what are the types of solar panels that you know of?
While there are several types of solar panels out there, you have most likely seen one or more of the 4 most-common types of solar panels — monocrystalline, polycrystalline, thin film, and concentrated PV cell solar panels.
Each of these panels is powered by solar cells like mono-si, multi-si, CdTe and others. Technically, a solar panel is essentially a composition of solar cells, and so it is not unusual to see types of solar panels categorized based on generations of solar cells — first, second, and third generation. Before the end of this article, you will have better knowledge of the necessary truths about the dominant types of solar panels.
How does a solar panel work?
- The solar cells absorb sunlight
- Upon absorption, the photovolltaic cells produce electrical energy via the movement of electrons
- The cells convert this to electricity, and with the aid of an inverter
- After that, power is supplied to your home through solar panel systems.
The aforementioned is the basic procedure by which solar panels convert sun rays into electricity. Other technical processes of how solar panels work will be covered in subsequent works.
While all solar panels convert solar energy to electrical energy, they differ in the degree to which they perform this function. Below are some of the best types of solar panels you should know about.
Types of Solar Panels
1. Monocrystalline Solar Panels
Monocrystalline is one of the most common types of solar panels. This features a single silicon crystal, signature black (or sometimes bluish) color, and a curvy edge. It has one of the highest efficiency levels — 20% — compared to other first-generation solar panels. This makes it one of the best options for residential use.
Monocrystalline solar panels are cut from one silicon crystal. This is why they are purer than polycrystalline panels. Their electricity output on a smaller scale is better than poly or multi-crystalline solar panels. In terms of lifespan, monocrystalline panels have a long lifespan, usually about 40 years, but they also often come with a 25 year warranty.
Considering monocrystalline is space efficient, have longer lifespans, higher spectral response rates, higher output, and more efficiency than polycrystalline solar panels, they are often more expensive than the latter.
Recent innovations have seen types of monocrystalline solar panels with about 24% efficiency. However, in theory, crystalline solar cells are currently unable to exceed 29% efficiency levels in terms of energy conversion.
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How are monocrystalline solar panels made?
The Czochralski method is the process in which monocrystalline solar panels are manufactured.
A silicon crystal is first added to a vat of molten silicon. The molten silicon is allowed to harden after the crystal has been removed. The hardened silicon forms a crystal shell also known as an ingot. This silicon wafers are sliced from this ingot like from a loaf of bread and changed into a cell. These solar cells are soldered together and placed on a metal frame to form a solar panel.
2. Polycrystalline Solar Panels
Polycrystalline solar panels are among the dominant types of solar panels. These solar panels, also called multicrystalline solar panels, have photovoltaic cells with several silicon crystals. They are cheaper and slightly less efficient than monocrystalline solar panels because of how they are made. Polycrystalline solar panels are made by melting silicon into a vat.
Unlike the process for monocrystalline solar panels where the crystal is extracted before it cools, with polycrystalline solar panels the silicon is left to fragment and harden with the crystals intact. After this, they are sliced into square shapes. This method leads to less wastage of silicone than the former. Polycrystalline solar panels have a 15% conversion rate on average.
Many people assume that these panels are less efficient than monocrystallines because the latter is darker in color, but that is far from the truth. Again, while making monocrystalline solar panels, the crystals are removed before the molten crystals harden. While making polycrystalline solar panels, the crystal is left untouched. This means that the former is purer than the latter and thus gives more roof for the movement of electrons inside the cell. It is the movement of electrons inside the solar cell that determines efficiency levels in terms of electrical energy generation.
On the flip side, polycrystalline solar panels are more affordable, have lower heat tolerance, and are more eco-friendly than monocrystalline solar panels.
3. Thin-film Solar Panels
Thin-film solar panels are more flexible, lighter, and often less expensive types of solar panels. They evolved out of a need to produce solar panels that are cost-effective and require less silicon.
Solar panels, as noted, take their nature from solar cells. They have thus evolved to solar cells. It is pertinent to note that solar cells were first made from selenium until scientists in Bell Laboratory changed the status quo in 1950 when they discovered and popularized the use of silicon to make solar cells.
Nowadays, other alternative solar cell technologies have been discovered. Hence, thin-film solar panels are not reliant on silicon but use alternative materials like cadmium telluride (CdTe), amorphous silicon (a-Si), and copper indium gallium selenide (CIGS) to convert the sun’s energy to electricity.
Thin-film panels are relatively slimmer than polycrystalline and monocrystalline solar energy systems. Their layers are about 350 times thinner than the older generations of solar panels. The thickness of thin-films range from nanometers to a few micrometers.
Until about 50 years ago, the usage of these panels was restricted to watches and calculators. But the 21st century saw an unprecedented advancement in thin-film solar panel technology. Today thin-films sit on roofs and have a wider application.
How are thin-film solar panels made?
To make thin-film solar panels, light or photon-absorbing materials are deposited on substrates like glass, metal, or even plastic.
Types of Thin-film Solar Panels
- Amorphous Silicon (a-Si)
- Cadmium Telluride (CdTe)
- Gallium Aresenide (GaAs)
- Copper Indium Gallium Selenide (CIGS)
Amorphous Silicon Solar Panels
Amorphous Silicon solar energy systems are alternative forms of solar panels. They are emerging photovoltaic systems that are flexible and are predominantly made using non-crystalline silicon. While they feature silicon like traditional solar panels, amorphous panels are made by covering a substrate with non-crystalline silicon. This forms one of their many advantages: they require less amount of silicon to make.
Other advantages of amorphous solar panels are: they are more flexible than mono- and polycrystalline, are less likely to crack, have more versatility, and are obviously cheaper. However, they are generally less efficient than traditional solar panels. Their efficiency level is 7%. This is why they are only used for less energy-consuming things like streetlights, calculators, watches, etc.
Cadmium Telluride Solar Panels
These solar panel are made from cadmium telluride, a crystalline compound that is obtained from the combination of tellurium and cadmium. It is one of the most ideal semiconductors used in solar panel technology. CdTe is one of the most popular and most commercial thin-film solar panels. While the average CdTe has about 11% efficiency, if well-engineered, it can hit 18% efficiency.
CdTe panels have a high absorption rate. This makes it quicker to convert sunlight to electricity. They are also lighter and cheaper than traditional solar panels. However, there are pollution concerns. This concern is valid because cadmium is a heavy metal, and its disposal poses a problem. Another disadvantage of this is, CdTe cells suffer degradation under extreme stress. Plus, they are less efficient than poly- and monocrystalline solar panels.
Gallium Arsenide
Considering its unusual combination, it is not hard to see why this is perhaps the most efficient solar panel. Gallium arsenide is the result of combining arsenic and gallium. Gallium arsenide solar panels have a record of 29.1% efficiency, slightly higher than monocrystalline panels. It allows for even more electron movement, hence the high efficiency. They are also resistant to radiation and ultraviolet light. This is why they are ideally used in space.
When most people come across gallium arsenide, their first concern is safety. Arsenic is a known carcinogen. Gallium is not completely safe. However, they pose little or no danger as a compound.
GaAs solar panels are also found in cellular phones, satellites, radar mechanisms, etc.
Copper Indium Gallium Selenide
CIGS is a solar panel that features layers of selenium, indium, gallium, and copper lined on glass or plastic. They are usually accompanied by electrodes on both sides for transmitting electrical current. They are flexible and have moderate efficiency levels of about 20%. They can be made with various semiconductors including cadmium and zinc. But unlike CdTe, they feature less amount of the toxic cadmium.
While they are efficient and flexible, CIGS cost more to produce. This has limited mass production over the years. In addition, indium is a rare metal sourced from Asia, this is a significant limitation too.
Which Type of Solar Panel is Best for Residential Use?
Currently, monocrystalline panels are the best if you’re considering overall qualities—efficiency, affordability, and durability.
Factors to Consider When Choosing Solar Panels for Your Home
- The efficiency of the solar panel
- Warranty [this is absolutely important]
- Cost (in relation to efficiency)
- The reputation of the solar panel company
- Ease of maintenance
- Size of the solar panels
- Durability
Need Reliable Solar Panels in Indiana?
We have examined the various types of solar panels and analyzed their system of performance. You have also seen the best types of solar panels for residential use. Ohio Solar Valley provides the best solar panels in Indiana. Get a free estimate right away if you need solar panel installation in Indiana or Kentucky.