Post By
Samarth Gara

What are bifacial solar modules?

February 28, 2021

Bifacial solar panels can generate power from both sides of the panel, and thus, increase the total energy generated by a solar module. Traditional solar panels, on the other hand, are monofacial, as they come with opaque backsheets, which allows solar energy to be trapped only by one side. As a consequence, bifacial panels are fast becoming popular for both home and office installations. These panels also offer a greater degree of durability because both sides are UV resistant. Moreover, frameless bifacial solar modules reduce concerns related to potential-induced degradation (PID). 

Installing bifacial solar panels on a highly reflective surface, such as a white TPO roof, or on a ground with light colored stones can help increase energy generation up to 30 percent, in comparison to monofacial panels. In addition, since more power can be generated, bifacial panels also lead to a reduction in Balance of Systems (BOS) costs. 

Bifacial solar panels are available in various designs. The following are some of the design variants of bifacial modules:

  • Framed bifacial panels 
  • Frameless bifacial panels
  • Bifacial panels with dual glass
  • Bifacial panels that use clear backsheets
  • Monocrystalline design solar cell panels
  • Polycrystalline design solar cell panels 

It is important to note that there are frameless, dual glass modules, which expose the backside of the cells, but are not bifacial panels in the true sense of the term. What distinguishes true bifacial panels from these frameless, dual glass modules panels is that the former have contacts/bust bars on both the back and front sides of their cells. 

How do bifacial solar panels work?

The top solar cells of a bifacial solar panel work along the same principle as any conventional, monofacial panel. They face the sun directly, and capture sun rays directly by absorbing only certain wavelengths. IThe bottom solar cells, however,  have a slightly different operating principle. They absorb the light that is reflected off the ground surface. This light is known as albedo light. Since white or light colours offer a better reflection than dark colours, it is advisable that you should paint the surface of the roof white or silver. A concrete driveway under the panels can also be a good option, and is capable of producing a similar effect. Some studies have shown that white surfaces reflect more than 80 percent of albedo light (By comparison, grass only reflects 23 percent of albedo light). 

Besides, the use of superior silicon in monocrystalline solar cells is preferred, as it optimizes the operation of the underside cells. Monofacial solar panel systems are placed in racks parallel to the ground surface for optimum performance, because  that way, the maximum amount of sunlight is captured. However, bifacial panels work differently, and thus, they must be angled correctly on the roof or ground at varying degrees for optimum energy production.

Are bifacial solar panels worth it?

Bifacial solar panels offer a great deal of advantages over the monofacial solar panels. Following are some of the advantages and disadvantages of bifacial solar panels:

Advantages of Bifacial Solar Panels

  • Ability to generate a greater amount of energy, while consuming no extra space than any regular monofacial panel. This means a further reduction in carbon footprints.
  • Ability to produce electricity from reflection of sunlight on the surface, alongside producing electricity using the direct sun rays. 
  • Better performance at a similar project size. While bifacial panels are expensive, the expenses are offset by the higher level of energy generation, and the reduction of costs in the long run. 
  • Unlike the traditional opaque back sheets used on monofacial panels, bifacial panels make use of dual tempered glasses or transparent back sheets, adding to their durability. 
  • Frameless bifacial solar modules reduce concerns related to potential-induced degradation.
  • Bifacial panels offer a longer warranty period of 30 years than the traditional solar panels which come with a warranty period of 25 years. 
  • The use of glass on both sides in the bifacial panels helps in preventing threats associated with moisture permeability and UV exposure. 
  • The use of strong glass offers a dual advantage for the bifacial solar panels. The high glass strength makes these modules resistant to chemical corrosion. Besides, it makes the panels resistant to crack. 
  • Frameless bifacial solar panels do not require grounding. In this way, it lowers environmental costs, saves aluminiu, and reduces the time required during the installation process. 
  • Bifacial panels are an optimum choice for large solar parks situated in sites with high albedo, such as deserts with sand, gravel, etc. 
  • Since they are placed at varying angles, they look more aesthetically pleasing than the traditional, monofacial panels. 

Disadvantages of Bifacial Solar Panels

  • The upfront installation cost of bifacial solar panels is higher than installing a traditional, monofacial panel. Thus, it requires a higher level of initial investment.
  • The use of glass on both sides makes it much more expensive than a monofacial panel. 
  • The glasses also increase the weight of the panel. 
  • Besides, bifacial panels cannot offer optimum performance on a cloudy day, because the reflection is not enough for the rear panels to capture solar energy. 

Who makes bifacial solar in India?

The following are some of the major companies that manufacture bifacial solar panels in India:

  • Adani Solar - Adani Solar is one of the biggest solar panel manufacturers in India. The company sells bifacial solar panels under its Elan series. These are monocrystalline panels, which come in the range of 355-390Wp with 72 cells. 
  • Waaree Group - Waaree group has solar module manufacturing plants in Surat and Umbergaon in Gujarat with a capacity of 2 GW. The company makes bifacial solar panels under its AHNAY series. It comes in a range of 350-395Wp. 
  • LG - LG also makes bifacial solar panels under its NeON series. They come in a range of 390-405Wp with 19.5 to 21.2 percent efficiency.
  • Vikram Solar - Vikram Solar is a global manufacturer of high efficiency solar PV modules. Its solar panels are made in India with technology and materials sourced from Germany, Switzerland, Japan and the US. Vikram Solar makes monocrystalline bifacial panels, which are available in both framed and frameless variants. 
  • Patanjali Renewable Pvt Ltd. - this is a relatively new company but is fast becoming popular because of the  highly efficient solar panels that it makes. The company makes monocrystalline bifacial panels in the range of 350-380 Wp with 18-20 percent efficiency and offers a 30 year warranty on these panels. 

Conclusion 

In this article, thus, we talked about bifacial solar modules, and how they offer a comparative advantage over the traditional solar modules. We listed down the pros and cons of these panels, and also the name of the companies which make bifacial panels in India. Go through this article thoroughly to better understand your requirements - whether you’re considering bifacial panels for your home or office. 

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