POLYCRYSTALLINE SOLAR PANELS

POLYCRYSTALLINE SOLAR PANELS

5 abril, 2019 Off By admin

In this article we will analyze one of the most common types of solar panels in the market of panels, polycrystalline solar panels .

The polycrystalline solar panels , also known as multicrystalline solar panels, can be recognized by the deep blue color. These are fused crystals made of silicone, the raw material of solar panels. 

SOLAR PANELS POLYCRYSTALLINE

POLYCRYSTALLINE SOLAR PANELS

Polycrystalline solar panels achieve an efficiency between 14% and 16%, which is significantly lower than monocrystalline solar panels. 

They are cheaper and, with a sufficient surface area, they also achieve better € / Wp than polycrystalline solar panels.

The first polycrystalline solar panels were produced in 1982 for commercial use by Kyocera. 

In recent years they have become much more popular and nowadays they are the most used type of solar panel , especially in commercial installations where the surface plays a less important role. 

Polycrystalline solar panels have a market share of approximately 56% (monocrystalline 35%, thin film 8%).

How are polycrystalline solar panels manufactured?

The production process of polycrystalline solar cells is surprisingly simple. The simple production process is also the reason why polycrystalline solar panels are significantly cheaper than  monocrystalline solar panels  . 

First, several blocks of silicon are fused and crystallized in a large block. The large silicon block is then cooled to a solid whole. Once cooled, the block is cut into thin slices. This is the beginning of the solar cell. The fusion at high temperature (1500 degrees) completely eliminates the impurities of silicon.

The slices are then processed in solar cells. This process includes cleaning, the application of an antireflective coating and electrical conductors. 

The result is the dark blue solar cell in which several crystals are clearly visible (hence the alternative name for multicrystalline solar cells). A solar cell is perfectly square and measures 16 cm on all sides.

POLYCRYSTALLINE SOLAR PANELS

 

1. Raw silicone raw material 2. Fusion 3. Cutting 4. Finishing 5. Solar panels

These days, we try to make the crystals as large as possible during the production process. When there are many crystals in a solar cell, there is less freedom for the electrons to move, resulting in less efficiency.

What is the efficiency of polycrystalline solar panels?

As mentioned above, polycrystalline solar panels achieve an efficiency of between 14% and 16%. The efficiency here is the percentage of electricity that can be generated from sunlight. 

This is lower than with monocrystalline solar cells but higher than with thin-film solar cells.

The lower efficiency is due to the purity of silicon, which is lower than with monocrystalline solar cells. On the other hand, the polycrystalline solar cells are perfectly square, whereas the monocrystalline cells are not (cut edges).

Some solar panel manufacturers, such as the Chinese Suntech, have recently achieved a 19.1% performance with polycrystalline solar cells.

Unfortunately, these solar panels are not yet available for private installations. For comparison with monocrystalline cells where the maximum yield is currently 25.6%.

What are the advantages of polycrystalline solar panels?

  • A simpler production process results in a lower sales price  and € / Wp, which is also the most important measure to compare  prices  . In other words, more electricity at a lower price.
  • More surface of solar cells per panel. Because the polycrystalline solar cells are perfectly square, the cells connect very well. The monocrystalline cells are cut in a cylindrical shape, resulting in a loss at the corners of the solar cells. 
  • Less residual waste  . Due to its simple production process, there is less residual waste.

POLYCRYSTALLINE SOLAR PANELS

 

Polycrystalline solar cell (left) and monocrystalline solar cell (right)

What are the disadvantages of polycrystalline solar panels?

  • A lower return. Polycrystalline solar panels, with the exception of some atypical values, achieve a performance between 14% and 16%. This means that 14% to 16% of sunlight can be converted into electricity. With monocrystalline solar panels this is between 15% and 20%. Polycrystalline solar panels achieve a lower efficiency due to the lower purity of the silicon and because there are several crystals in a solar cell where, with monocrystalline solar cells, this is only a crystal, so that the electrons can move with greater freedom.
  • A higher temperature coefficient than monocrystalline solar cells  . This means that at warm temperatures, polycrystalline solar panels have more loss of efficiency as a result of heat. The difference is minimal, between -0.01% / C to -0.03% / C. 
  • Less aesthetic Due to their blue color, polycrystalline solar panels are often seen as less aesthetic. The blue reflection does not fit on many roofs, so that   black and less reflective, monocrystalline or  thin film solar panels are  chosen more often for purely aesthetic reasons.
  • More surface needed  . Regardless of the location (roof, floor, etc.) where the solar panels are placed, more surface will be needed for polycrystalline solar panels due to their lower efficiency. When the surface is not an obstacle, polycrystalline solar panels may be the most interesting option. With an average installation of 4Kw, approximately 1 to 3 additional solar panels are needed, depending on the type of solar panel and the efficiency to achieve the same performance.

What is the price of polycrystalline solar panels?

The good news with polycrystalline solar panels is that they cost significantly less than monocrystalline solar panels. The cost is approximately 10% to 20% lower per panel. This is mainly due to the most efficient production process that reduces the price. 

When comparing prices between polycrystalline and monocrystalline solar panels, the most important factor is the price per Wp.

Price comparison of polycrystalline and monocrystalline solar panels.
Solar panelPricePowerKindPrice for Wp
LG Neon2 320WEUR 279320WMonocrystallineEUR 0.88
Bisol BMO-300EUR 219300WMonocrystallineEUR 0.73
SolarWatt 290WPEUR 335290WMonocrystallineEUR 1.15
SolarWatt 280WPEUR 240280WPolycrystallineEUR 0.85
BENQ AUOEUR 190265WPolycrystallineEUR 0.71
VIESSMANN 260WPEUR 200260WPolycrystallineEUR 0.76
Average price and power per type of solar panel.
Average price per WpMedium power
Monocrystalline solar panelsEUR 0.93303W
Polycrystalline solar panelsEUR 0.77268W

With this sample, the average price of a polycrystalline solar panel is 15% lower, while the power difference is only 11%.

Installing more solar panels means higher installation costs. For example, the installer will spend more time in the installation, and more wiring and support structure is also required.

POLYCRYSTALLINE SOLAR PANELS

 

What brand of polycrystalline sun panel to choose?

Many brands of solar panels specialize in polycrystalline solar panels, although there are also many brands that offer all kinds of solar panels. 

The main brands that offer polycrystalline solar panels include Trina Solar, Canadian Solar and  Yingli  .

Especially Trina Solar is a leading company in both total numbers and efficiency. The star product of Trina Solar, the ALLMAX-PD05.08, reaches an efficiency of 17.1%, which is better than many monocrystalline solar panels. 

When we look at Canadian Solar, we see that the best polycrystalline solar panel, the CS6K-275P, obtains a yield of 16.8%. Hanhwa also has a higher than average score with a performance just above 16% for most solar panels. 

At the bottom is SolarWorld, whose polycrystalline solar panels achieve an efficiency of around 14%.

REC also has a series of solar panels, the REC Peak Energy, of which the REC270PE has an efficiency of 16.4% that is above average. 

Finally, it is also worth mentioning Suntech. Suntech is the largest manufacturer of solar panels, with a focus on primarily commercial installation. Its best polycrystalline solar panel, the SUNTECH STP275 achieves an efficiency of 16.9% and, therefore, is one of the best solar panels of this type.

List of the best brands of known polycrystalline solar panels:

  • Hanwha (Q-Cells)
  • Canadian Solar
  • Kyocera
  • Hyundai
  • Solar World
  • Trina
  • Yingli
  • REC
  • Suntech
  • Yes solar

Conclusion: whether polycrystalline solar panels are or not?

All of the above ultimately leads us to the most important question: are polycrystalline solar panels good? Our answer is simple: yes!

Our advice is to opt for polycrystalline solar panels when there is enough space available for the solar panels. It is also important that none of these solar panels are not in the shade.

In general, an installation with polycrystalline solar panels will be cheaper and the power will weigh less against the best price.

Finally, it is more important to look at the big picture. For example, it is advisable to choose a tier1 brand with a good reputation and accompaniment guarantee. 

It is also recommended to install only solar panels in good conditions, especially a south, southwest or southeast roof that is recommended and this without or little shade. 

If there is still a partial shadow in the installation, it is advisable to add  microinverters  or  power optimizers  to the solar panel installation.