Monocrystalline or Polycrystalline: Which Solar Panel Is Right For You?
Solar panels have revolutionized the way the world sees the sun. This big ball of hot gases provides the earth with abundant energy, on which all life sustains. Solar panel systems help generate clean electricity by converting the sun’s light into DC voltage.
The solar industry spans over 7.5 decades since Bell Labs created the first silicon solar cells with the help of three scientists: Daryl Chapin, Calvin Fuller, and Gerald Pearson, in the year 1945. Today the solar market blooms with a myriad of solar panel manufacturers innovating and producing residential as well as commercial solar panels.
Three solar panels types available on the market are mono crystalline, poly crystalline, and thin-film panels. Amid the three models, the mono crystalline and poly crystalline panels are more popular.
To decide on one between the mono crystalline and poly crystalline panel, you must first know the difference between the two. There are some visible differences between the two, and there are some obvious ones that will enlighten you. Let’s get on with it, shall we?
The manufacturing processof both mono crystalline and poly crystalline solar panels marks the first difference.
The process of manufacturing a mono crystalline panel includes dipping a single seed crystal of silica into the molten silicon. A silicon ingot forms as the result of the Czochralski method. This ingot or rod contains single-crystal silicon. Afterward, the manufacturers cut the ingot into thin discs that catch and convert the sun’s light into electrical energy.
The manufacturing of a poly crystalline solar panel uses the Floating Zone (FZ) method. In this method, the molten silicon mix, which contains many different silicon crystals, is poured onto a smooth surface and allowed to cool. Once the molten silicon becomes cold and hardens, manufacturers cut it into rectangular discs that go into a solar panel.
Since mono crystalline solar cells contain a single type of crystal throughout, it is more efficient than any other solar panel, when it comes to obtaining consistent electrical outputs.
Due to the presence of many different silicon crystals, this type of solar panel is a little less efficient than mono crystalline counterparts.
Anyhow, almost every solar panel available on the market has 15 to 20% efficiency. However, the single crystal (mono) panels prove to be more efficient in areas under poor irradiation conditions. Contrary to single-crystal panels, poly crystalline solar panels are much more suited to use in the regions that offer a massive installation space. (fields, wastelands, etc.)
In general, a one square meter module of mono crystalline panels will provide 190W of DC output. Whereas, a poly crystalline solar panel module of the same dimensions will put out 180W.
Note that, the output generation depends on various factors such as irradiation conditions, panel placement, heat tolerance, etc.
Heat tolerance of any solar panel plays a vital role in its overall efficiency. Higher tolerance levels indicate that a solar panel will perform even under the hot summer sun. All Solar panels come with a temperature coefficient label that indicates the heat tolerance level.
Understand the temperature coefficient as a panel’s susceptibility to temperature. It is the percentage decrease in the panel’s output for every one-degree Celsius (°C) increase in the temperature from 25°C. (77°F) Solar panel efficiency tests take place in standard test conditions, meaning at room temperature, i.e., 25°C, hence it becomes a reference point.
Among all of the solar panel types, the mono crystalline ones have the least heat tolerance.
Poly crystalline These solar panels have a lower temperature coefficient than the single-crystal counterparts, which means that these panels are less affected by rising temperatures.
The difference in the heat tolerance of mono and poly crystalline panels should not be a significant concern, as with every solar panel, the increased heat renders a decrease in the output. Thus, regardless of the type of solar panel you choose, there will still be some energy loss.
Consider a solar panel that provides an efficiency of 17% and has a temperature coefficient of -0.45. The panel will lose 0.45% of efficiency for every degree above 25°C. Meaning that if the temperature rises to 30°C, the efficiency falls to 16.7%.
Note that cold-sunny days are the best times for solar energy, as, during the winters, the temperature coefficient becomes positive.
There is a notable difference in the pricing of mono and poly crystalline solar panels.
Since these panels contain the purest grade of silicon, they are expensive in comparison with the other panel types.
In comparison with mono crystalline solar cells, these are much more economical.
The fact that both mono and poly crystalline solar panels are the result of different manufacturing processes brings a visible difference in their appearance.
The color of a solar panel that uses single-crystal cells will appear darker than a poly crystalline panel. In general, the color of these panels will be anything from dark blue to black. Also, mono crystalline panels will have a very smooth or non-patchy appearance. In general, these panels will have a gap between individual cells. (white dots) It is because silicon wafers (Solar cells) in mono crystalline panels are cut from a cylindrical silicon ingot, making them round. (rod)
Solar panels that consist of poly crystalline cells will appear lighter in color. The color of these panels can be anything from purple to lighter shades of blue. Also, the panels may have some patches that form as a result of using many different silicon crystals during their manufacturing. Most panels will not have any gaps (white dots or dashes) in between individual cells.
What Should you Choose?
With all the information on the two most popular types of solar panels, you can decide on one. However, the parameters that you must consider will depend on your geographical location, irradiation conditions, and the surface area (among other factors) available for installing a solar power module.
Mono crystalline panels are most effective in the areas that offer smaller installation areas, as they are more efficient. Such modules will provide enough energy while using lesser panels. Hence they are better for residential use. Also, most people will prefer these panels over the poly crystalline ones for their aesthetic appearance.
The downsides of using mono crystalline panels is that they are more susceptible to circuit breakdowns. Dust and shade on any single point of the panel will have an impact on the entire module’s power output.
Nonetheless, using an MPPT device can help solve this problem. Also, the heat tolerance of these panels increases with the use of thermally conductive substrates to house the panels that help vent the heat away. Installers must mount these panels a few inches above the roof, allowing proper air-flow and heat dissipation.
Poly crystalline panels are best for places that offer larger installation area. Unlike the single-crystal variants, these panels do not face circuit breakdowns in case a single cell (or more) cover in dust or shade.