Photovoltaic modules

How photovoltaic panels work

Photovoltaic panels are composed of several photovoltaic cells made from semiconductor materials, most commonly crystalline silicon. In these cells, when exposed to incident sunlight, a photovoltaic reaction occurs. In simple terms, we can think of it as energetic photons from sunlight knocking electrons out of the atoms of the semiconductor material, forming freely charged particles. In other words, photovoltaic cells can absorb sunlight and generate an electric current through the interaction of photons with the material structure.

The three main types of photovoltaic panels

The main types of photovoltaic panels on our market include monocrystalline, polycrystalline, and thin-film (amorphous). Monocrystalline photovoltaic panels are among the most widely used and most efficient, as their efficiency reaches up to 23%; the other two types have lower efficiency, with polycrystalline at 20% and amorphous around 12%.

In our range you will find the following:

• Monocrystalline cells

Monocrystalline solar cells are easily identifiable by their black colour and cut edges. They are made from very pure silicon, which makes them a very efficient material for converting light into energy. They are also the most space-efficient form of silicon solar cell: even in a small space, you can obtain a large amount of energy. They perform better at low sunlight levels, so if you want to use them in areas with lower sunlight levels, they are the ideal choice. They also have a decent level of efficiency in all weather conditions. Monocrystalline cells are among the longest-lasting, with a lifespan of about half a century.

• N-type monocrystalline

For a better explanation of the N-type panel, we will help with a comparison. There are several types of panels; we can distinguish P-type panels and N-type panels. The main difference between the two photovoltaic panels is the number of electrons they contain. Both are made of silicon wafers, but in each case (P and N) they are mixed with other chemical substances. In the case of the P-type panel, it is boron, while the N-type cell uses phosphorus. Boron has one fewer electron than silicon, which makes it a positively charged cell. For phosphorus, it is the opposite; it has one more electron than silicon and the N-type cell is, therefore, negatively charged. N-type solar panels are an increasingly popular alternative. P-type panels have been the standard for years, but there is a reaction between boron and oxygen that sometimes reduces performance by up to 10%. N-type panels, doped with phosphorus, are immune to this reaction and performance is not reduced, so we can speak of greater durability and higher efficiency.

• TOPCon

TOPCon or Tunnel Oxide Passivated Contact. TOPCon technology belongs to N-type cells. In the production of a TOPCon cell, a layer of insulating material (a "tunnel" oxide layer) is added to the back, located between the metal contact and the solar cell. This layer allows better transport and collection of electrons, which also increases the efficiency of the cell. TOPCon panels, therefore, also perform better in low-light conditions. They are, therefore, the ideal choice for use in areas with less sunlight or in more shaded locations.

N-type also includes PERT, TOPCon, HJT, and IBC technologies.

• HJT (Heterojunction)

Heterojunction cells were developed for even greater efficiency to obtain more energy from the same amount of light. They combine two technologies in a single cell: crystalline silicon and thin-film amorphous silicon. These layers form a thin film on the crystalline silicon cell. The combination of these technologies makes it possible to obtain even more energy than would be possible using only one or the other.

Photovoltaic panel performance

The power of a solar panel is measured in watts. Most photovoltaic panels today have an output between 380 and 660 watts per hour. The amount of energy a panel can produce depends on its production and various other factors and conditions.

What affects the efficiency of solar panels

In real-world, non-laboratory conditions, the efficiency of panels depends on several external factors. Local conditions can reduce the efficiency of panels and the overall performance of the system. The main factors affecting the efficiency and performance of photovoltaic panels include:

• Solar radiation (W/m2)
• Shading
• Panel orientation
• Temperature
• Location (Latitude)
• Season
• Dust and dirt
• The direction the panel faces
• Roof angle

How much power do you need

There is no clear answer to this question, as it depends on your average electricity consumption and the extent to which you want your home to be powered by panels.

For those with low electricity consumption who want to use panels mainly to supplement their consumption, panels with lower power (min. 380 W) should be sufficient. For households with high consumption or for those who want to rely exclusively on solar energy, it is better to choose panels with a power of around 445 W. The correct output power is an essential parameter in selecting a photovoltaic panel.

You can determine it based on the annual electricity consumption of your home.

Return on investment or economic benefits of solar energy

In addition to the sustainability and cleanliness of the energy we obtain from the sun through photovoltaic systems, one of the main reasons people turn to this type of energy is the economic benefits. The initial investment in solar panels can be high, so it is important to choose efficient and tailored solutions and monitor the return on your investment. You can read more about the economics of solar energy on our blog.