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Solar panels and how they work

The operation of solar panels is not as complicated as it may seem. We tell you in this article how the plates work and which are the most recommended for self-consumption.

The production of solar energy, both in the case of large solar parks and in the case of small self-consumption installations, has increased in Spain in recent years. More and more households opt for photovoltaic panel installations for various reasons: from the savings it represents on the electricity bill, to the environmental responsibility that the times demand .

If you are considering taking the step towards clean energy, you should know how the facilities work .

How do photovoltaic solar panels work?

The operation of solar panels is mainly based on the photovoltaic solar cell that transforms solar energy directly into electricity using photoelectric energy. Photovoltaic generation is precisely the property that certain materials (for example, silicon) have to generate electric current when they are subjected to solar radiation. It occurs when energy from sunlight (photons) “releases” electrons, creating a flow of electrical energy.

A solar panel or module is made up of a series of photovoltaic cells , these are layers of silicon “doped” with phosphorus and boron, which, thanks to solar radiation, generate an electrical charge and it is common to serialize them in a module (or panel) so that the voltage conforms to a usable DC (direct current) system.

This energy by connecting to an inverter will be transformed into AC (alternating current) so that the energy you consume during the day can be supplied by the solar panels.

It should be noted that the voltage provided by the solar cells is always quite regular and linear, however the current supplied depends on the intensity of the light. Therefore, the performance provided by a solar panel will depend largely on how powerful the light received is, being different depending on the time of day and time of year.

How is the power of a solar panel calculated?

To understand how solar panels work , it is important to also know how the power of a module is calculated. When it comes to measuring or being able to calculate the performance of the panels, the measurement used in solar modules is peak watts (Wp) . This measurement is used as a reference with which to measure the performance of the solar panels and thus be able to establish comparisons between them. Since the amount of sunlight falling on the panels varies depending on the time of day and time of year, the generated current fluctuates considerably and this makes it difficult to measure. As a solution to this problem, the measurement of peak watts (Wp) is used, which represents the performance provided by the panels given standard solar radiation and temperature.

This makes it very important when sizing a photovoltaic installation to analyze how many peak watts (Wp) should be installed to obtain the maximum possible self-consumption capacity.

t Otovo, when calculating the size and performance of an installation, we take into account all these factors, both your geographical area and the orientation and angle of the roof. In this way, by entering your address and subsequently analyzing your consumption and expectations, we can estimate the size of the installation that best suits your needs.

Taxonomy and characteristics

The photovoltaic industry has evolved a lot since Einstein wrote about the photoelectric effect in 1905 and later, in 1954, Bells Laboratories manufactured the first silicon panel.

Today, solar modules are manufactured with more advanced materials and are much more efficient. In this way, it has been possible to multiply its performance enough to position itself as a profitable energy alternative . That said, the entire process that occurs inside solar cells once the sun shines is still largely subject to the same effect described by Einstein back in 1905.

When comparing silicon-based solar panels, these can be mainly divided into two categories: Amorphous, Polycrystalline and Monocrystalline . These panels are made of silicon and fulfill the same function in a photovoltaic system, capturing the sun’s energy and transforming it into electricity. However, when analyzing how each of these solar panels works and the performance of each one, there is some difference between these two technologies, mainly focused on the manufacturing process and the type of silicon cell incorporated in the plate. solar.

amorphous solar panels

Amorphous panels , less and less used, are characterized by not having a defined structure and losing a lot of efficiency during the first months of operation.

polycrystalline solar panels

Polycrystallin solar panels are made up of differently oriented crystals and are distinguished by their bluish hue. This manufacturing process has the advantage of being cheaper but the disadvantage of being a less efficient product.

monocrystalline solar panels

Monocrystalline modules are generally considered a higher quality product. In them, the cells that make up the panel are made up of a single high-purity silicon crystal that solidifies at a homogeneous temperature. This results in greater efficiency and performance of the panel, since it allows the electrons to move more freely. The manufacturing process, although slightly more expensive, gives the modules greater efficiency and performance. They are generally considered a higher quality product.

Which solar panels are better?

The most recommended solar panels are monocrystalline . Amorphous plates are becoming obsolete as they rapidly lose effectiveness. On the other hand, the only advantage that polycrystalline panels have is a slightly lower price, due to the aforementioned less expensive manufacturing process.

The main advantages of monocrystalline solar panels

  • The main advantage is a higher degree of efficiency (approximately 5% more), they work better in environments with less exposure to light, cloudy days or simply in an area where there is less sun.
  • On the other hand, it also has a slightly higher performance, this means that for the same installed surface of solar panels, monocrystalline provide greater power.
  • They tolerate heat better, at high temperatures the panels lose efficiency, monocrystalline tolerate heat better and this is an advantage in the face of high temperatures in summer.
  • Finally, at an aesthetic level, the modules are black and visually they are better adapted to the roofs.

3 Features and Components


In addition to silicon cells, for the proper functioning of the solar panels, they have a glass frame that provides protection and durability.

Inside the glass, the panel has a layer of insulation and a safety film that works as a protection against heat dissipation and humidity inside the module. Adequate insulation is of utmost importance as it protects the panel from temperature changes, which reduce its efficiency and optimal performance.

Some modern solar panels incorporate a technology called PERC . It is an anti-reflective layer that increases the performance of the module in low light conditions (cloudy days, sunrise and sunset), allowing the silicon cells to receive maximum exposure to sunlight and provide you with more self-consumption hours.

Additionally, by acting as a reflective layer, they prevent the module from getting too hot and therefore improve its performance by keeping the panel’s temperature coefficient stable. Because in the photovoltaic industry all solar modules follow the same manufacturing process, at Otovo we are aware of the importance of installing modules with quality components. That is why we only work with TIER 1 certified brands that have monocrystalline modules and incorporated PERC technology.