There are many types of different photovoltaic panels. Here you can learn about the most popular types of technology in use nowadays. Each of them has a purpose of solving different issues and improving the performance of any PV system they are a part of.

On this page you can find information about the following types of photovoltaics:

• Polycrystalline and Monocrystalline Solar Panels
• Solar Panels Using the PERC Technology
• Solar Panels Using the TOPCon Technology
• P-type and N-type Photovoltaic Panels
• Solar Panels Built With the ‘Half Cut’ Technology
• Shingled Photovoltaic Panels
• MWT (Metal Winding Technology) Solar Panels
• Bifacial Solar Panels

Polycrystalline and Monocrystalline Solar Panels

Solar panels are split into two main categories based on the structure of their building cells – poly- and monocrystalline.

With polycrystalline panels, each cell is build up of multiple silicon crystals, which are joined together during the manufacturing process. One can recognize photovoltaics with this structure by their blueish color. They provide lower efficiency, which usually degrades quicker, but they are more affordable.

Their alternative are the monocrystalline solar panels. With this type, each solar cell is built of a single silicone crystal. This allows more movements for the electrons. As a result, the gains from the whole PV installation goes up. In addition, manufacturers guarantee a longer lifespan for monocrystalline photovoltaics. Their structure makes them visibly stand out with their black color. This type of panels are generally recognized as the better investment, as their returns are higher and they can go significantly longer without needing to be replaced.

The types of panels described below combine the monocrystalline technology with their particular specifics.

Solar Panels Using the PERC Technology

Modern photovoltaic panels usually build upon the poly- and monocrystalline cells with the PERC (Passivated Emitter and Rear Cell/Passivated Emitter and Rear Contact) technology. In short, a reflective layer is added to the back of the solar cell, which brings a string of benefits. Some of them are:

• Light is reflected from the cell’s back and passes through it one more time, which allows for more of the solar radiation to be absorbed
• The electrons can move even more freely, which additionally boosts the amount of power produced
• The reflection of the light prevents the solar panel from heating, which would normally lead to decreased productivity of the PV installation

Solar Panels Using the TOPCon Technology

The TOPCon (Tunnel Oxide Passivated Contact) photovoltaic manufacturing technology is a more advanced and efficient form of the PERC approach.

The photovoltaic panels of the TOPCon and PERC type share an extremely similar structure and therefore rather similar strengths. One of their advantages is keeping more light in the solar cell so that more of the solar energy can be absorbed. Another plus is the better distribution of temperature on the photovoltaic’s surface, which decreases the energy losses caused by very hot or cold weather.

TOPCon takes the basic structure of PERC solar cells and builds on that. This is done by adding an extremely thin layer of silicon dioxide at the cell’s back and using a different material for the back’s topmost layer. These changes allow for keeping more light in the cell and improved efficiency of the photovoltaic.

P-type and N-type Photovoltaic Panels

The difference between these two types comes from the building structure of the solar cells.

The name P-type comes from the fact that the solar cells are built upon a positively charged silicon basis, which is mixed with boron. The significantly thinner upper layer is mixed with negatively charged phosphorus.

With N-type photovoltaic cells the building structure is reversed and they have a negatively charged basis and a positively charged upper layer.

Under the continuous exposure to sunlight, P-type solar panels are predisposed to having diminishing efficiency over time due to their upper boron layer. This particular issue is not present with the N-type photovoltaics. Thanks to this, their productivity degrades far slower, resulting in a longer lifespan of the solar panel.

Nowadays, most manufacturers use the N-type technology for producing solar panels.

Solar Panels Built With the ‘Half Cut’ Technology

This type of photovoltaics optimizes efficiency by decreasing the size of solar cells and additionally splitting the solar panel into two halves.

Making the photocells smaller is done by the very precise splitting of the classical solar cells in two equal halves. This process allows for fitting twice as many elements in a single solar panel. In addition, the voltage that flows through the cells is also halved, which leads to decreased losses in result of high resistance within the circuit. The final result is a higher gain from every individual solar cell.

The other peculiarity of the half cut technology is that the panel is split in two. Thanks to this, the building solar cells of the photovoltaic are distributed across twice as many rows. If a single photocell from a row is not producing power – be it due to a malfunction or a lack of sunlight – the whole row stops producing. Spreading the cells amongst more segments means that such a situation would affect the productivity of the whole installation a lot less. That makes this type of photovoltaics optimal for locations where a part of the solar panels array would be shaded for some part of the day.

The main drawback of the half cut photovoltaics is the higher price, result of the more sophisticated manufacturing process. Despite this, they bring a whole variety of benefits:

• They greatly improve the productivity of the whole PV installation
• Due to the solar cells’ structure, they usually boast a significantly higher power output
• The size of the photovoltaic cells lowers considerably the losses of gains due to high voltage in the circuit
• The division of energy between hot spots and cooler parts of the solar panel is a lot more efficient, which is far less damaging for the panel and increases productivity

Shingled Photovoltaic Panels

The most notable difference between this type of solar panel and the rest is the way the segments of solar cells are connected. Here, the photocells are aligned in slightly overlapping rows, which are connected where the overlap takes place. The principle is analogous to how shingles are put on a house’s rooftop, hence the name.

This structure removes the need for any visible bus bars and other fastening and connecting elements. In traditional solar panels, these take place from the surface area of the solar panel. As a result, shingled photovoltaics can fit more solar cells. Another benefit is that the shading of the solar cells by their own fastening elements is significantly decreased, which allows for far more sunlight to be reach the cells in situations where the sun beams are hitting the panel surface at a very low angle.

This structure provides a very high tolerance to shaded and hot spots on the solar panel, surpassing even the achievements of the half-cut technology.

All of this leads to significantly increased gains from the whole installation.

The highly segmented rows of photocells and the way of connecting them provides an ever higher resistance to mechanical damages caused by harsh weather conditions like winds and hail storms. The structure also allows accumulated snow to fall off quicker.

Apart from those purely functional advantages, the lack of any visible elements from the supporting frame and electronics allows shingled solar panels to boast a sleeker black outlook.

MWT (Metal Winding Technology) Solar Panels

MWT (Metal Winding Technology) solar panels are an alternative approach to many of the issues also addressed by shingled photovoltaics. Therefore, a significant part of the benefits of both technologies overlap.

With MWT panels, all the busbars and other elements needed for fastening and transport of electricity are hidden under the photovoltaic’s surface. With traditional solar panels, the metal contacts that collect the electricity are on the front side of the solar cell, facing the sun. Here the contacts are placed on the back of the cell.

This structure leads to having a greater surface area exposed to the sunlight and significantly reduced shading, caused by the photovoltaic itself on its own surface. The reduced amount of shading allows for significant improvements in the efficiency of the solar in situations where the sunbeams are hitting the panel surface at a low angle.

Removing those elements from the surface layer also helps extend the expected life duration of the PV. Amongst the beneficial factors is the fact that there is no pressure on the solar cells caused by the fastening elements. In addition, the manufacturing process does not include high temperature soldering in close proximity to the solar cells, which can cause issues with conventional photovoltaics. Due to the fact that there are no metal elements exposed to direct sunglight next to the solar cells, the temperature is distributed more evenly over the solar panel’s surface. As a direct result of this, the risk of getting hot spots, which can reduce efficiency and cause quicker degradation, is reduced.

This technology is compatible with other technologies mentioned before – such as PERC.

Just like with shingled photovoltaics, the lack of any additional element’s on the top layer leads to a cleaner and more stylish outlook of the whole solar panel.

Bifacial Solar Panels

Classical solar panels are one-sided and only generate energy from the side directly facing the sun. An improved version of those are bifacial photovoltaics. Apart from doing everything a single-sided solar PV does, they also absorb reflected sunlight with their backside, which can improve the performance of the installation greatly.

Amongst the optimal conditions for placing a solar system of this type are:

• A location with the least possible shading
• A location where there is sufficient space behind the panels, allowing the sunlight to be reflected back to them
• Above light and reflective surfaces

Generally, using bifacial photovoltaics can boost the efficiency of an installation by 5 to 30%. Considering that there are a lot of factors at play here, a more accurate estimate of how much of an improvement can be expected can only be given by looking at a particular project.

Which Type of Photovoltaic Should I Choose?

Having in mind the various circumstances that go with every individual project, no one could give a universal answer to this question. Each type of technology comes with its benefits, which aim to boost the returns from a photovoltaic system as much as possible.

Get in touch with, so that we can design and build the optimal photovoltaic installation for your needs together.