Most of the solar panel options currently available fit in one of three types: monocrystalline, polycrystalline (also known as multi-crystalline), and thin-film. These solar panels vary in how they’re made, appearance, performance, costs, and the installations each are best suited for. Depending on the type of installation you’re considering, one option may be more suitable than the others.
There are three major types of solar panels: monocrystalline, polycrystalline, and thin-film. Each type has its own unique advantages and disadvantages, and the solar panel type best suited for your installation will depend on factors specific to your own property and desired system characteristics.
Below, we’ll break down some common questions and concerns about solar panels and how different types of panels have varying characteristics.
The manufacturing processes differ between monocrystalline, polycrystalline, and thin-film; as such, each type of panel comes with a different price tag.
Of all types of solar panels, monocrystalline panels are likely to be the most expensive option. This is largely due to the manufacturing process – because the solar cells are made from a single silicon crystal, manufacturers have to absorb the costs of creating these crystals. This process, known as the Czochralski process, is energy-intensive and results in wasted silicon (that can later be used to manufacture polycrystalline solar cells).
Polycrystalline solar panels are typically cheaper than monocrystalline solar panels. This is because the cells are produced from silicon fragments rather than a single, pure silicon crystal. This allows for a much simpler cell manufacturing process, thus costing less for manufacturers and eventually end-users.
What you pay for thin-film solar panels will largely depend on the type of thin-film panel; CdTe is generally the cheapest type of solar panel to manufacture, while CIGS solar panels are much more expensive to produce than both CdTe or amorphous silicon.
Regardless of the cost of the panel themselves, the overall cost of a thin-film solar panel installation may be lower than installing a monocrystalline or polycrystalline solar panel system due to additional labor requirements. Thin-film solar panel installations are less labor-intensive because they are lighter weight and more maneuverable, making it easier for installers to carry panels up onto rooftops and secure them in place. This means reduced labor costs, which can help contribute to an overall less expensive solar installation.
To produce electricity, solar cells are made from a semiconducting material that converts light into electricity. The most common material used as a semiconductor during the solar cell manufacturing process is silicon.
Both monocrystalline and polycrystalline solar panels have cells made of silicon wafers. To build a monocrystalline or polycrystalline panel, wafers are assembled into rows and columns to form a rectangle, covered with a glass sheet, and framed together.
While both of these types of solar panels have cells made from silicon, monocrystalline and polycrystalline panels vary in the composition of the silicon itself. Monocrystalline solar cells are cut from a single, pure crystal of silicon. Alternatively, polycrystalline solar cells are composed of fragments of silicon crystals that are melted together in a mold before being cut into wafers.
Unlike monocrystalline and polycrystalline solar panels, thin-film panels are made from a variety of materials. The most prevalent type of thin-film solar panel is made from cadmium telluride (CdTe). To make this type of thin-film panel, manufacturers place a layer of CdTe between transparent conducting layers that help capture sunlight. This type of thin-film technology also has a glass layer on the top for protection.
Thin-film solar panels can also be made from amorphous silicon (a-Si), which is similar to the composition of monocrystalline and polycrystalline panels. Though these thin-film panels use silicon in their composition, they are not made up of solid silicon wafers. Rather, they’re composed of non-crystalline silicon placed on top of glass, plastic, or metal.
Lastly, Copper Indium Gallium Selenide (CIGS) panels are another popular type of thin-film technology. CIGS panels have all four elements placed between two conductive layers (i.e. glass, plastic, aluminum, or steel), and electrodes are placed on the front and the back of the material to capture electrical currents.
The differences in materials and production cause differences in appearance between each type of solar panel:
If you see a solar panel with black cells, it’s most likely a monocrystalline panel. These cells appear black because of how light interacts with the pure silicon crystal.
While the solar cells themselves are black, monocrystalline solar panels have a variety of colors for their back sheets and frames. The back sheet of the solar panel will most often be black, silver or white, while the metal frames are typically black or silver.
Unlike monocrystalline solar cells, polycrystalline solar cells tend to have a bluish hue to them due to the light reflecting off the silicon fragments in the cell in a different way than it reflects off a pure monocrystalline silicon wafer.
Similar to monocrystalline, polycrystalline panels have different colors for back sheets and frames. Most often, the frames of polycrystalline panels are silver, and the back sheets are either silver or white.
The biggest differentiating aesthetic factor when it comes to thin-film solar panels is how thin and low-profile the technology is. As their name suggests, thin-film panels are often slimmer than other panel ty[es. This is because the cells within the panels are roughly 350 times thinner than the crystalline wafers used in monocrystalline and polycrystalline solar panels.
It’s important to keep in mind that while the thin-film cells themselves may be much thinner than traditional solar cells, an entire thin-film panel may be similar in thickness to a monocrystalline or polycrystalline solar panel if it includes a thick frame. There are adhesive thin-film solar panels that lie as-close-as-possible to the surface of a roof, but there are more durable thin-film panels that have frames up to 50 millimeters thick.
As far as color goes, thin-film solar panels can come in both blue and black hues, depending on what they’re made from.
Bifacial solar panels can capture sunlight from both the front and back of the panel, thus producing more electricity than comparably sized, traditional solar panels. Many bifacial solar panels will have a transparent back sheet so that sunlight can go through the panel, reflect off the ground surface and back upwards towards the solar cells on the back side of the panel. These solar panels are typically manufactured with monocrystalline solar cells, but polycrystalline bifacial solar panels exist as well.
Each type of solar panel varies in the amount of power it can produce.
Of all panel types, monocrystalline panels typically have the highest efficiencies and power capacity. Monocrystalline solar panels can reach efficiencies higher than 20 percent, while polycrystalline solar panels usually have efficiencies between 15 to 17 percent.
Monocrystalline solar panels tend to generate more power than other types of panels not only because of their efficiency but because they have come in higher wattage modules as well. Most monocrystalline solar panels come with more than 300 watts (W) of power capacity, some now even exceeding 400 W. Polycrystalline solar panels, on the other hand, tend to have lower wattages.
This doesn’t mean that monocrystalline and polycrystalline solar panels aren’t physically the same size – in fact, both types of solar panels tend to come with 60 silicon cells each, with 72 or 96 cell variants (usually for large-scale installations). But even with the same number of cells, monocrystalline panels are capable of producing more electricity.
Thin-film solar panels tend to have lower efficiencies and power capacities than monocrystalline or polycrystalline varieties. Efficiencies will vary based on the specific material used in the cells, but they usually have efficiencies closer to 11 percent.
Unlike monocrystalline and polycrystalline solar panels that come in standardized 60, 72 and 96 cell variants, thin-film technology does not come in uniform sizes. As such, the power capacity from one thin-film panel to another to another will largely depend on its physical size. Generally speaking, the power capacity per square foot of monocrystalline or polycrystalline solar panel will exceed thin-film panel technology.
Though not as common as 60, 72, or 96 cell panels, some solar panel manufacturers produce solar panels with half-cut cells, essentially doubling the number of solar cells within the panel. Half-cut solar cells are monocrystalline or polycrystalline solar cells cut in half using a laser cutter. By cutting the solar cells in half, solar panels can experience marginal gains in efficiency and durability.
As you’re choosing the type of solar panel you’d like for your system, much of your decision will come down to the specifics of your property and situation. Monocrystalline, polycrystalline, and thin-film panels each have their own advantages and disadvantages, and the solution you should move forward with depends on your property and your goals for the solar project.
Property owners with a lot of space for solar panels can save money upfront by installing lower efficiency, lower-cost polycrystalline panels. If you have limited space available and are looking to maximize your electric bill savings, you can do so by installing high-efficiency, monocrystalline solar panels.
As far as thin-film panels go, it’s most common to choose this type of solar panel if you’re installing on a large, commercial roof that cannot handle the additional weight of traditional solar equipment. These types of roofs can also afford the lower efficiencies of thin-film panels because they have more area to place them on. Additionally, thin-film panels can sometimes be a useful solution for portable solar systems, like on RVs or boats.
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