MONOCRYSTALLINE SOLAR PANELS

MONOCRYSTALLINE SOLAR PANELS

8 abril, 2019 Off By admin

The monocrystalline solar panels are also known as ‘black solar panels’. They achieve better performance than blue polycrystalline solar panels, but their cost is also higher. 

MONOCRYSTALLINE SOLAR PANELS

The  monocrystalline solar panel has excellent technical characteristics for climates that usually have clouds, storms and with not very high maximum temperatures.

This is because the sensitivity of the monocrystalline solar panel  achieves maximum solar radiation at low temperatures and does not resist overheating too well.

These solar panels were often used in the past when there is less space available, but nowadays they are almost the norm with more than 80% of the installations.

How is a monocrystalline solar panel?

Characteristics and fundamental aspects of this type of panel:

The way of knowing how to  recognize a monocrystalline solar panel  is relatively simple. At a visual level we should look at two things:

The shape of the solar cell and the color of the cell. The monocrystalline solar panels have a cell of black color (although in fact it is a very dark blue), and the edges are trimmed as with a kind of chamfer.

In the following image we can appreciate the difference that we are indicating:

MONOCRYSTALLINE SOLAR PANELS

Example comparison monocrystalline and polycrystalline solar panel

As we said, we appreciate the visual differences that we have commented on the color and shape of the cell. But this is not the only feature that differentiates monocrystalline solar panels, then we summarize other more technical characteristics and more important from the point of view of  performance .

Highlights of a monocrystalline solar panel:

  • More efficient : Monocrystalline solar panels are  more efficient  than the other types of panels that exist. In the current market, models with around 17% efficiency are already easily found, and even 20% if we are talking about Panasonic Sanyo HIT technology   (which is a special type of cell with monocrystalline part and an amorphous part), or there are also models already with 21% and 22% manufactured by  SunPower .
  • Better use of available space:  This is because, as they are more efficient, they can generate more energy in less space than if we use another type of panel.
  • Better integration in houses and buildings:  There are also models called  “Mono Black”,  which come to be a type of standard monocrystalline solar panel but with black frame and background. This is an element to take into account for issues of  integration in buildings , houses, etc. .. where you want to give priority to aesthetics so that the photovoltaic system does not have a negative impact visually.

On the contrary, and to put a negative point, they are always  somewhat more expensive  than the other models available in the market, although their improvement in performance and stability compensates in the medium term that initial price difference.

Therefore, a monocrystalline solar panel is always the best option for a photovoltaic system that wants to obtain the best results.

How are monocrystalline solar panels formed?

Monocrystalline single panels are formed by a multitude of cells, also called photovoltaic cells, which are what make this transformation possible.

The most common materials in its manufacture are gallium arsenide (GaAs), used for more complicated electronic devices; and silicon (Si), which is also used in the microelectronics industry and which, in addition, is much cheaper.

How are monocrystalline solar panels made?

As the word monocrystalline suggests, solar cells consist of 1 crystal. When the polycrystalline solar cells are formed by several fused silicon blocks, in the monocrystalline cells they are made of the same crystal. 

Everything begins with a small block of silicon, also called germ or seed. This is immersed in pure quality cast silicon at a temperature of 1500 degrees. 

Slowly, a process that takes up to 48 hours, the germ is eliminated from the molten silicon while turning. The final result is a large pure cylindrical silicon crystal that has grown farther from the yolk. 

This production process is also known as the ‘Czochralski’ process, named after the Polish scientist Jan Czochralski who invented this method of fusion in 1915.

Monocrystalline solar panels are not only recognizable by their dark color. When you look more closely at solar cells, you see 2 differences compared to polycrystalline solar panels:

  • The  solar cell has a uniform color  and clearly notes that it consists of a solid whole (crystal). This has to do with the fusion process, where everything merges into a large crystal. At the same time, this is the reason why they achieve better returns. With a large crystal, the electrons can move better inside the cell and not collide with other crystals, resulting in a loss of efficiency
  • The solar cell is not square, but has  cut corners  (which are slightly circular in the original shape of the cylinder). This is also due to the fusion process in which the silicon has a cylindrical shape from which the solar cells are cut. The first monocrystalline solar panels consisted of round solar cells, but too much surface is lost between the solar cells.

MONOCRYSTALLINE SOLAR PANELS

Characteristics of Monocrystalline Solar Panels

The  monocrystalline solar panels  differs from the polycrystalline solar panel  in the sensitivity for the capture of solar energy, because for practical purposes, the  monocrystalline solar panel  is recommended for climates with tendency to storm, weather instability, fog and rain, because although they absorb better the heat are not prepared for overheating.

 

Advantages of monocrystalline solar panels 

  • The biggest advantage of monocrystalline solar panels is the  greater efficiency  . With efficiency, the percentage of sunlight that can be converted into electricity. With polycrystalline solar panels, this is on average between 14% and 16%, while with monocrystalline panels it is between 16% and 20%. The high-efficiency solar panels of Sunpower, LG and Panasonic even exceed 20%, where Sunpower’s X-23 series reaches almost 23% efficiency. Per panel, this translates into a performance of 270Wp to 330Wp, with the latest new panels of up to 340 to 370Wp (LG Neon 2 and Sunpower X-22 series) for a standard solar panel with 60 solar cells.
  • Aesthetic solution  . Monocrystalline solar panels are often chosen for their aesthetic appearance. Due to their dark color they are more suitable for dark ceilings. In recent years, many brands of solar panels have responded intelligently by offering “all black” solar panels where the backsheet and the frame are also black.
  • Less area required  . Monocrystallines are recommended for ceilings with less surface area (ideal). Due to the higher efficiency, less surface is needed.
    • Example: a family of 4 people with an annual consumption of 4000kWh and a roof gabled from north to south with a south-facing side of 32 square meters (8 m wide by 4 m long). There is space for a maximum of 14 panels.
      • Polycrystalline panel of 270Wp * 14 panels = 3400kWh (3780Wp)
      • Simple glass panel of 330Wp * 14 panels = 4150kWh (4620Wp)
    • Conclusion: only with monocrystalline solar panels can generate enough electricity to cover 100% of annual consumption. With polycrystalline solar panels, 3 additional panels are needed to achieve the same performance.

MONOCRYSTALLINE SOLAR PANELS

What are the disadvantages of monocrystalline solar panels?

  • Higher cost  . The reason for this is that the production process is more expensive than with monocrystalline solar panels. This is due to the higher melting temperatures and the more complicated melting process that takes up to 48 hours. Monocrystalline solar panels cost around 15% more per solar panel, although due to the better efficiency and the relative EUR / Wp, it is almost the same.
  • More residual waste from production  . Although this is not really a disadvantage for the consumer, there is more residual waste in the production of monocrystalline solar cells. This is because the final cylindrical silicone bar is cut on four sides so that it acquires a (almost) square shape, so that the surface on the panel itself can be used to the maximum.

What are the brands of monocrystalline solar panels?

Almost all brands offer monocrystalline solar panels. Some brands that specialize mainly in this type of panels are Sunpower, LG and Panasonic. 

What are the powers of monocrystalline solar panels?

The capacity of most solar panels (brands that offer unique glass panels) is around 300Wp to a maximum of 330Wp. Below, a summary of the best known brands and the maximum capacity of your solar panel with the best performance:

  • SunPower
  • JA Solar (310 Wp)
  • LG (370Wp)
  • Panasonic (330Wp)
  • Axitec (300Wp)
  • Solar watts
  • SolarWorld (300Wp – Sunmodiule Plus SWA)
  • Beno AUO (330Wp – SunBravo and SunForte models)
  • Canadian Solar

High efficiency solar panels.

Some brands also offer high efficiency solar panels, these are always monocrystalline solar panels. Some of the most famous brands are Sunpower and LG.

  • LG Solar  : with the LG NeON R, LG has developed a solar panel with a capacity of up to 370Wp and an efficiency of 21.4%. Together with the Sunpower X series, this is the solar panel with the most power in the residential market. LG Solar also offers a 25-year product warranty on this panel and an 88.4% power warranty for 25 years. 
  • Sunpower  : with Sunpower’s X-22 series, the company has developed a rugged solar panel with high power. With 360Wp of standard power and a positive tolerance of 5%, it can deliver up to 378Wp. This makes the panel, along with the LG NeON R, the high performance and higher performance panel that is available in the residential market today.

There are still panels that provide more power in WP, although these are mainly commercial panels that have 72 solar cells and are larger.

Full black solar panels (all black)

Many installers have been offering “completely black” solar panels for several years. These are monocrystalline panels in which the back sheet (to which the solar cells join and form a solar panel) and the frame are black. 

This gives you a completely black (or dark) solar panel without a silver-colored aluminum edge or a back sheet (tedlar sheet) that is usually white but here it is black.

These solar panels are mainly used for aesthetic reasons with black or dark ceilings. The only (small) disadvantage of these solar panels is that they are heated due to their black backsheet and frame, which means they have a small loss in efficiency, since warm temperatures have a negative effect on efficiency.

Some brands that are known for their black panels are:

  • SunPower
  • Panasonic
  • Axitec
  • Solar watts
  • Solar World 
  • BenQ