Monocrystalline Vs Polycrystalline Solar Panels

Solar photovoltaic (PV) panels are the world's fastest-growing sources of renewable energy in the world and the most popular ones in Australia due to the yearly savings and many other benefits.

Solar panels use photovoltaic cells, made out of silicon semiconductor materials to generate electrical power. PV solar panels are widely used for power generation in locations that receive abundant and constant solar radiation, such as Australia.

Perth Solar Company solar panel installer installing a monocrystalline solar panel on a house in Fremantle

Currently, there are two types of solar panels that stand out from the rest: Monocrystalline and polycrystalline.

With this article, you will learn about the manufacturing process, cost, main characteristics, differences between both solar panels and more!

Solar Farm in Tennant Creek's Desert

Figure 1. Solar Farm in Tennant Creek's Desert. Source: The Guardian

Monocrystalline Solar Panels

 

This type of solar panel is made out of monocrystalline solar cells, which are made from a single crystal of silicon that is turned into an ingot with cylindrical shape in a process known as Czochralski method.

In this process, a rod of pure crystal of silicon, called a seed crystal, is placed in molten silicon. It is then slowly pulled and rotated upwards, turning it into the cylindrical silicon ingots previously mentioned. Then, the ingot is sliced into circular wafers and a layer of phosphorus is added to each of them.

This type of solar panel is made out of monocrystalline solar cells, which are made from a single crystal of silicon that is turned into an ingot with cylindrical shape in a process known as Czochralski method.

Figure 2. Czochralski Method. Source: Research Gate

To maximize cell space, the circular wafers are cut in an octagonal shape, which provides these cells their unique look.

Currently, all new improvements of solar panels, such as All-black, PERC, or Half-cut cells, are based on this type of solar panel.

This type of solar panel is made out of monocrystalline solar cells, which are made from a single crystal of silicon that is turned into an ingot with cylindrical shape in a process known as Czochralski method.

Figure 3. 50W Monocrystalline Solar Panel. Source: Eco Power Shop

 

Polycrystalline Solar Panels

These solar panels consist of several silicon crystals in a single solar cell instead of one. The silicon is melted and then cools as fragments, which are molded together before being cut for the panel. The finishing process of manufacture is similar as for the monocrystalline panels, both types of solar panels are made by the Czochralski method.

Polycrystalline solar panels have a mosaic-like surface, these panels have a square shape and  have a  blue color because they are made of several silicon crystals.

These solar panels consist of several silicon crystals in a single solar cell instead of one. The silicon is melted and then cools as fragments, which are molded together before being cut for the panel. The finishing process of manufacture is similar as for the monocrystalline panels, both types of solar panels are made by the Czochralski method

Figure 4. A close-up of a Polycrystalline Solar Panel. Source: Envato

Differences Between Monocrystalline and Polycrystalline Solar Panels

Both types of solar panels have the same purpose of generating electricity using sunlight as a source of energy and both of them are suitable for use in Australia. However, the crystalline silicon structure of individual solar cells affects their performance and appearance. Let’s see how some of these facts differentiate monocrystalline from polycrystalline solar panels.

Appearance

The silicon structure of solar cells has an important effect on their appearance since it determines how the solar cell will interact with sunlight and how the human eye perceives them.

Monocrystalline panels tend to be much darker, almost black in appearance due to their single-crystal structure. On the other hand, polycrystalline panels have a light blue tone and the texture of the multiple silicon crystals is visible in the panel.

High-end houses tend to use monocrystalline panels due to the better-looking. The aesthetic aspect also gave development to all-black solar panels. These are basically monocrystalline solar panels with a technically total black appearance that provides a more elegant and cutting-edge design.

Efficiency

The rate at which a panel converts sunlight into electricity is known as solar panel efficiency. The  standard in the industry is that monocrystalline panels are more efficient than polycrystalline modules. The monocrystalline panels typically have an efficiency rate between 18 - 22%, meanwhile polycrystalline panels generally achieve efficiencies between 16 - 19%. However, as technologies continue to improve, the differences in efficiency between these two technologies are getting shorter.

Even though polycrystalline panels tend to have a lower efficiency than monocrystalline panels, this does not mean that polycrystalline solar panels are inferior at all. On both types of modules you can find high-quality products. Actually, you may find out that in some cases, efficiencies from poly and mono modules from the same manufacturer may even get quite close to each other. Important differences can be seen mostly when comparing two different types of brands.

Here are a couple of facts to know about efficiency:

  • Higher efficiency means that a solar panel will have higher electricity production when exposed to sunlight.
  • A higher efficiency of the panel means that you will need less PV area to provide the same amount of energy.

Temperature Coefficient

The temperature coefficient indicates the effect of increased or decreased temperature in the voltage, current and power values of the solar panels.

The temperature coefficient varies slightly between both types of panels, assuming they are from the same manufacturer. Monocrystalline panels are rated to perform between 0.5 – 1% better than polycrystalline panels in hot temperatures.

This means that polycrystalline solar panels can generate less energy when they heat up than monocrystalline ones. This is because they have higher temperature coefficients in general.

Space and Size

Space is directly related to the efficiency of the module and also to the power output of the panel. Monocrystalline panels are generally more efficient which means they need less space to achieve the desired system size when compared with polycrystalline panels.

Dimensions of solar panels depend on their manufacturer and model, but most common dimensions are close to 69 inches by 39 inches, equivalent to nearly 18.5 square feet per panel. This is associated with 300-370W panels which are the most commonly used in the market today.

Following what we have mentioned before, monocrystalline panels will generally offer more watts per square foot when compared with polycrystalline ones.

Cost Price

The main factor that determines the price difference between solar panels is their silicon structure. On a solar system the main factor affecting the cost is the number and type of panels installed. Depending on the system size, you will get a certain cost per kW installed.

Monocrystalline panels are made from a single pure silicon crystal. The use of single silicon crystals provides higher efficiency for this type of panel. However, a lot of silicon is wasted to manufacture monocrystalline cells and the process must be carefully controlled, leading to a higher price.

On the other hand, to produce polycrystalline panels, manufacturers must simply pour molten silicon made of crystals fragments into square molds, then cut the resulting wafers into individual cells. Since the process is easier to implement and there is hardly any wastage, these cells are cheaper than monocrystalline ones.

The average cost per watt for monocrystalline panels is $1 to $1.50 meanwhile for polycrystalline modules it ranges from $0.90 to $1 per watt.

What Kind of Solar Panel Should I   Use?

 

As silicon solar panels have their own pros and cons, the choice of solar panel ultimately comes down to your specific property and condition settings.

Those with a sufficiently larger property can save on upfront costs by using polycrystalline panels, where a larger PV system can offset a lower panel efficiency when compared with monocrystalline panels. These are used widely in large scale PV applications.

On the other hand, those who are living in densely populated areas with limited roof space should opt for monocrystalline panels to make the most of the physical space and maximize utility savings even. Some panel types based on monocrystalline technology, such like PERC panels, can lower energy generation costs even more in the long run.

Furthermore, because of the black color of mono panels, they are widely used on houses with high-end design, the opposite case of poly panels that have a not-so-popular blue color for homeowners.

Whatever type you choose to go with, make sure to do your investigations to ensure that it’s the best option for your needs. Keep in mind that both solar panels are designed for long-term installations, which can be as long as 25 years and even some brands come with a 30-year warranty coverage.

Whatever type you choose to go with, make sure to do your investigations to ensure that it’s the best option for your needs. Keep in mind that both solar panels are designed for long-term installations, which can be as long as 25 years and even some brands come with a 30-year warranty coverage.

Figure 5. House Rooftops With Solar Panels. Source: PV Magazine Australia

Conclusion

 

We learned about the two main types of solar panels  (monocrystalline and polycrystalline) and how their manufacturing differences  gives them different performances and appearance.

Summarizing, monocrystalline solar panels have solar cells made from a single silicon crystal while polycrystalline solar panels have solar cells made from multiple silicon fragments melted together.

Although monocrystalline panels are more expensive, they also produce more energy and work better in higher temperatures than polycrystalline panels, which offsets their additional cost. In addition, their black color is better looking in high-end houses.

Nevertheless, since Australia is one of the best countries to invest in solar power and counts with cheaper costs per kW, polycrystalline solar panels will definitely be a great option too if your budget better fits this type of module.