All solar panels are not the same. They differ in performance, appearance, price, material, application, and size. The types of solar panels you need for your home or office depends on the roof size, consumption, budget, efficiency, among other factors.
There are 3 common kinds of solar panels:
- Monocrystalline solar panels
- Polycrystalline solar panels
- Thin-film solar panels
Although there are other types of solar panels, most are not economically or technologically viable.
The types of solar panels are classified into 3 groups. The classification is based on the kind of materials used and the commercialization of the product.
- First-generation solar panels
- Second-generation solar panels
- Third-generation solar panels
First Generation Solar Panels
Monocrystalline and polycrystalline solar panels fall under this category. The cells are made of crystalline silicon and gallium arsenide (GaAs) wafers. They are the most common types of solar panels in commercial and residential solar panel installation. Because of their widespread use, they are also referred to as conventional or traditional solar panels.
First-generation solar panels are the oldest PV cells, and their fabrication and technological applications are well-known. GaAs is a better material than silicon because it has higher optical properties. Therefore, it requires thicker silicon wafers to harness the same amount of energy as GaAs.
But, gallium and arsenide are expensive and not commercially viable for the manufacture of solar panels. The materials are limited on the surface of the earth. Therefore, silicon remains the primary material in the manufacture of solar panels.
Let’s have a look at each of the solar panel types under the first generation.
Monocrystalline Solar Panels
The solar cells are made of the purest form of silicon. They have a uniform silicon composition, which gives them high efficiency. They have rounded edges because silicon crystals are cylindrical. You can identify the panels from the even rows and columns.
The silicon wafers used in monocrystalline cells have high efficiency (up to 20%) compared to other types of solar panels. Therefore, you require fewer monocrystalline solar panels; this makes them ideal for use in small-sized roofs. You can also use this type in pole mounts because the space is also limited.
However, the price of monocrystalline solar panels is higher. They are more costly to manufacture than the other types. The solar panels have a longer lifespan because of increased resistance to temperatures; thus, a more extended warranty. The monocrystalline solar panel system could last for more than 30 years.
Polycrystalline Solar Panels
Do you want to install cheap solar panels, and you have unlimited roof space? Polycrystalline solar cells have lower efficiency but are feasible for residential buildings where space may not be a problem. The panels are also referred to as multi-crystalline solar panels.
Although they are made from the same material as monocrystalline, they have lower efficiency, ranging between 15-17%. The solar panels have a speckled bluish color, which many homeowners consider unattractive. Another difference from the former type is the appearance. Polycrystalline solar panels have sharp wafer edges because of how they are manufactured.
A decade ago, polycrystalline solar panels were the most common type of solar panels. However, their popularity has dwindled because of low efficiency. The average capacity of an average polycrystalline solar panel system is approximately 300 watts. Therefore, you require around 20 for a 6 kW solar panel system.
The life expectancy of polycrystalline solar panels is lower. Thus, a shorter warranty period than monocrystalline solar panels. The choice between polycrystalline and monocrystalline solar panels is not outright. Each has its ideal application, depending on your situation. You should go for multi-crystalline solar panels if you want to cut on cost and the size of your roof or ground mounts is not limited. However, the panels are affected by high temperatures, which can lower their lifespan.
Second Generation Solar Panels
Thin-film solar panels make up the second generation of solar panels. some of the most common types of 2nd generation solar cells include:
- Amorphous silicon solar panels
- Cadmium telluride (CdTe)
- Copper indium gallium selenide (CIGS)
- Concentrated photovoltaic cells (CVP)
Thin-film solar panels have lower efficiency than the crystalline types because of the material used. They are common in utility-scale applications where space is plenty.
Amorphous Silicon
Amorphous silicon (a-Si) solar panels are made of hydrogenated silicon, which has low energy conversion efficiency. The material is deposited in flexible substrates like metal, plastic, and glass. The solar panels are less durable compared to crystalline silicon cells; thus, a shorter warranty period.
Cadmium telluride
CdTe solar panels are made from semi-conductors pressed between thin films of glass. There are concerns about cadmium safety, but studies show that a compound of the two elements has lower toxicity than Cd alone. Therefore, proper disposal of the material is advisable to prevent any adverse health effects. This type of solar panel is the most common in commercial thin-film applications.
Copper indium gallium selenide
CIGS solar panels are an exciting option because of their high efficiency. However, the cost of manufacturing solar cells makes them an expensive option. It is difficult for copper indium gallium selenide solar panels to compete with crystalline silicon cells. However, the solar panels have a higher efficiency than other kinds.
Thin-film solar panels are the most flexible. They can adopt different shapes for aesthetic value. There are many studies to improve solar panels’ efficiency and overcome the commercial and technological barriers of the solar cells.
Concentrated photovoltaic cells
CPV is a new technology that uses curved mirrors and lenses to concentrate sunlight to highly efficient solar cells. The solar panels can achieve an efficiency of up to 41%, which is double what the second most efficient type can harness. The technology’s commercial application will be a significant breakthrough in solar energy because it will reduce the cost and space required to install solar panels.
Third Generation Solar Panels
There is a limit to the efficiency of solar panels. Shockley-Queisser ranges between 31-41% for a single bandgap solar cell. The third-generation of solar panels seeks to overcome this limit and improve efficiency. The main objective of the technology is to convert solar cell non-compatible light frequencies to compatible frequencies.
There are promising products under development that could make solar energy more efficient. The solar panels seek to tap into the strengths of crystalline silicon and the 2nd generation PV technology. The most advanced third-generation solar panels include:
- Perovskite
- Copper zinc tin sulfide
- Organic solar cells
Which Type of Solar Panels Should I Buy?
There is no direct answer to this question without an evaluation of your situation. Some of the essential factors that affect the type of solar panels for your commercial or residential installation include:
- Size of the roof or ground mounting space.
- Budget.
- Aesthetic preferences.
- Size of the solar panel system.
Monocrystalline solar panels are the most ideal if you have limited space. On the other hand, polycrystalline cells are suitable when low on the budget. Thin-film solar cells are the most common in power purchase agreements because of the short lifespan. They are also ideal for utility-scale or communal solar energy installations.
Solar energy technology undergoes drastic changes in a short period because it is a developing technology. There are many feasibility studies to evaluate the application of different solar panels under review. Therefore, what is efficient today might be outdated within a year. You should keep an eye on the industry and do thorough research before settling for any solar panels.
