Monocrystalline and polycrystalline photovoltaic panels

Polycrystalline and monocrystalline panels are the two main types of solar modules that are currently used in solar power generation around the world. Both types of modules have their own unique characteristics and applications, and the choice between them depends on a number of factors, such as cost, efficiency and installation configuration.

Photovoltaic panel manufacturing processes

The manufacturing process for polycrystalline photovoltaic panels begins with the crystallization of silicon. Several blocks of silicon are combined to form a large block, which is then melted at 1500 °C. This process makes it possible to remove impurities from the silicon. Once cooled, the lump is cut into thin slices, which are processed to create photovoltaic cells. The process involves cleaning, applying a special anti-reflective coating and placing electrical wires. This process is relatively easy and inexpensive compared to the production of monocrystalline modules. Polycrystalline modules have a slightly lower efficiency than monocrystalline ones, which means they require more surface area to produce the same amount of energy.

Monokryształ krzemu otrzymany metodą Czochralskiego — Fig. 1. Monocrystalline silicon obtained by the Czochralski method

Monocrystalline modules are produced by the Czochralski method. The production process uses high-quality silicon polycrystals, which are dropped into a crucible and melted at 1500 °C. Then, a crystal embryo (a single block of silicon) is introduced into the molten silicon, which will serve as the base for the entire crystal. The result is a large, cylindrical silicon monocrystal, which is then cut into round slices. However, stacking the circular slices next to each other results in large voids, which is not beneficial from the standpoint of module performance. Therefore, in order to optimize the spaces, shapes similar to a square are cut out of them. The individual photovoltaic cells are arranged side by side, forming a photovoltaic panel ready for installation. These modules have a higher efficiency than polycrystalline modules, which means that a smaller area is required to produce the same amount of energy.

Monocrystalline or polycrystalline panels?

One of the main factors in choosing between polycrystalline and monocrystalline panels is cost. Polycrystalline panels tend to be cheaper to manufacture and usually have lower installation costs. However, due to their lower efficiency, they need a larger surface area, which can increase the cost of installation if space is limited. Monocrystalline panels tend to be more expensive, but due to their higher efficiency, they can be more cost-effective for limited installation space.

In addition to cost, other factors such as installation configuration and environmental conditions also influence the choice between polycrystalline and monocrystalline modules. For example, polycrystalline panels are more resistant to weather conditions, such as cool temperatures or low levels of sunlight, making them more suitable for use in areas with less favorable climatic conditions. Monocrystalline panels are more prone to damage from shock and vibration, so they tend to be less recommended for applications on moving objects such as campers. When installing photovoltaic systems on rooftops, monocrystalline modules are usually chosen due to the fact that the higher efficiency allows for greater energy production with limited space.

moduły fotowoltaiczne dah solar — Figure 2: Example of a monocrystalline photovoltaic panel from Dah Solar

Environmental impact of photovoltaic panels

An important aspect when choosing solar modules is also their environmental impact. Both polycrystalline and monocrystalline modules are produced using processes that consume significant amounts of energy and generate greenhouse gas emissions. However, when in use, the energy generated from solar modules is emission-free.

Summary

In summary, monocrystalline and polycrystalline panels are the two main types of solar modules, which have their own unique characteristics and applications. The choice between the two depends on many factors, such as cost, efficiency, installation configuration and environmental conditions. Depending on your needs, you can choose one or the other type, or combine them to optimize solar energy production. Regardless of the choice, solar energy is one of the cleanest and greenest energy sources.

Below is a short video in English describing the difference between monocrystalline and polycrystalline modules: