When it comes to choosing the most suitable photovoltaic modules for a project, I am faced with countless choices in terms of quality, performance and price.
As with most things in life, I do try to get the best deals for our clients, often sacrificing performance for a competitive price. However trying to keep costs low is understandable, but sacrificing performance over price can severely affect our project. That is why here I have created this little guide to help you navigate the sea of information related to solar panels. In this article, you will see most aspects you need to know about the differences between monocrystalline modules and polycrystalline modules.
What are monocrystalline modules?
This is the technology that initiated the photovoltaic revolution. Originated in the 1950s, monocrystalline solar panels are the oldest and most developed system to date. As the name implies, they are made from a single crystal of pure silicon. Manufacturers use the Czochralski method to slowly pull a single crystal seed of molten monocrystalline silicon and form an ingot. A glass seed is a small piece of silicone that is used as the basis for molten molecules. By providing the proper infrastructure, the molten molecules can be connected to form an ingot. While the seed is being prepared, the temperature is gradually lowered to help form a cylindrical shape.
Monocrystalline modules can be recognized by their uniform colour and appearance, which indicate the high purity of the silicon.
What are polycrystalline modules?
Polycrystalline solar panels are made up of multiple crystals. Instead of going through a slow and very expensive process of creating a single crystal, manufacturers simply put a crystal seed into a molten silicon mould and allow it to cool. Because of this casting method, the crystal surrounding the seed is not uniform and grows in multiple small crystals.
What is the difference between monocrystalline and polycrystalline?
The differences between the monocrystalline modules and the polycrystalline modules derive from the process they are created. Mono solar panels are made from a single crystal seed, either in nature or created in a laboratory. As a result, they look more uniform and softer than polycrystalline modules. Poly solar modules, on the other hand, are created from blocks of crystals that give the module a metal scaling effect.
Advantages and disadvantages of monocrystalline modules
• Monocrystalline solar panels have the highest efficiency rate (usually around 10-15%);
• The mono modules are space-efficient. Because these modules offer the highest output power, they require the least amount of space compared to other solar panels,
• They have a long life - most manufacturers offer a 25-year warranty on their mono solar panels;
• Its performance is better than other types of solar modules in low light conditions (North Spain, Britain).
• Monocrystalline modules are the most expensive;
• If they are covered with dirt or snow, the whole system is affected;
Advantages and disadvantages of polycrystalline modules
• The process used to make poly solar panels is simpler and, therefore, less expensive.
• They generally have a lower tolerance to heat than monocrystalline modules.
• Because silicon purity is lower than mono modules, poly solar panels are less efficient than their mono counterparts. Its efficiency is usually around 10% -15%.
• Not only are they less energy efficient, but also have a low spatial efficiency. You need to cover a larger surface to get the same power as you would with monocrystalline modules.
Which should I choose?
Obviously the larger and purer the glass, the more efficient the solar cells. As a result, monocrystalline modules are about 10% to 15% more energy efficient than their poly counterparts.
On the other hand, polycrystalline modules were often considered inferior to mono solar panels because they are less efficient. But, here's the catch: because of the cheaper process, it costs about 20% less to create solar modules with monocrystalline structures. More than that, poly modules have been steadily improving their performance in recent years, pushing the standard to greater limits.
So which one is better?
The answer depends on the requirements of your project. Poly modules, for example, are ideal for buildings with large roof or earth space. They are also ideal for consumers on a tight budget looking for ways to keep installation costs to a minimum.
Mono solar panels, on the other hand, are perfect for small roof or properties with limited open space. Since the monocrystalline modules are very efficient, you will get more power on the same area. In addition, these types of panels have a lower temperature coefficient than the poly modules.
Monocrystalline modules are more expensive than poly modules, but they take up less space. For example, if you have a mono solar panel and a poly, both with 240 watts, you would generate the same energy, but the monocrystalline solar module would take up less space.
If cost is your primary concern and you want to pay as little as possible for installation, then you should opt for solar PV panels. It will not achieve the same efficiency as with monocrystalline modules, but will drastically reduce the initial costs.