Types of Solar Modules and How They Affect Energy Output
A solar module, also known as a photovoltaic module, is the central component of a PV system. It consists of several solar cells connected in series or parallel (usually 36 72, 60, or 120 pieces). These convert sunlight into electricity. In connection with photovoltaic systems, the term solar panel is often used. Ultimately, however, solar panels are also another name for solar modules or photovoltaic modules.
THE SOLAR COLLECTOR
The solar collector, which is also frequently mentioned in connection with solar systems, is completely different. It is part of a solar thermal system, but it does not produce electricity. Instead, it generates hot water and/or supports the heating system with the help of solar energy. It is therefore a different technology that also uses the sun as an energy source, but generates heat instead of electricity.
HOW DOES A PHOTOVOLTAIC MODULE WORK?
From a physical point of view, photovoltaic technology is based on the so-called photoelectric effect. During this process, electrical energy is generated inside the solar cells, thus converting the sun’s light into direct current.
When the solar system is irradiated (sunlight), photons, also known as light particles, strike the surface of the metal of the solar cell. This is a semiconductor. The photons excite the excess electrons there. These then migrate from a negatively charged silicon phosphorus layer through a separation layer (p-n junction) into a positively charged silicon boron layer. This produces a current flow that is available in the form of direct current. With the aid of an inverter, this can be converted to alternating current and can thus be used for household purposes.
STRUCTURE OF SOLAR MODULES
Solar modules contain — as described above — solar cells connected in parallel or in series. These in turn consist of a negatively and a positively charged silicon layer in combination with the element boron (electron deficiency) or the element phosphorus (electron surplus). Both silicon layers also have a metal electrode for current conduction. The two silicon layers are separated by a layer of boron that has already accepted an electron — the so-called p-n junction.
In most cases, the layers on the side facing the sun are coated with an anti-reflective layer, which ensures that less light is reflected and thus more electrical energy can be generated. This anti-reflective layer is also the reason why solar modules are often blue. In addition, the outer layers are covered with a pane of toughened safety glass and the solar cells are embedded in a transparent plastic layer.
The solar cells are connected to each other by solder ribbons or copper wires. The back of the module is also protected by a plastic film. If necessary, this is supplemented by a further plastic or glass layer, which serves to protect against the weather. In addition, there are free-wheeling diodes and, if necessary, an aluminum profile frame to protect the solar panel.
COMMON TYPES OF SOLAR MODULES
There are different types of solar panels. Basically, we can distinguish between three varieties of solar panels: Monocrystalline solar cells, Polycrystalline solar cells, and Thin film modules.
POWERFUL: MONOCRYSTALLINE SOLAR MODULES
Monocrystalline modules are the most powerful solar panels on the market. They consist of pure silicon crystals. However, their production is very costly. Therefore, monocrystalline solar modules are also the most expensive to purchase. They cost about 200 to 350 euros per module and are particularly suitable for buildings that have little usable roof space on which to mount solar modules.
THE INEXPENSIVE ONES: POLYCRYSTALLINE SOLAR MODULES
Polycrystalline solar panels are not quite as powerful as monocrystalline ones. In practice, this means that you need more roof space to generate the same amount of PV electricity with polycrystalline solar panels. However, they also have an advantage: they are significantly cheaper to manufacture and therefore to purchase. Polycrystalline solar panels cost about 150 to 250 euros per module.
CONCLUSION
It is difficult to make a blanket statement about which solar module is best. Different models come into consideration depending on what power and yield you want to achieve. The type of construction and the location of your home also plays a role in choosing the right photovoltaic modules.
