This special interest group is for professionals to connect and discuss all types of carbon-free power alternatives, including nuclear, renewable, tidal and more.


Factors Affecting Yield Gain Using Bifacial Modules

Ahmad Elghobashy's picture
Technical Manager Solargy Renewables

• I am an electrical engineer with +8 years of experience. • I have more than 5 years of experience as a solar PV design engineer. • I have accumulated experience in designing +50 MWp projects. •...

  • Member since 2020
  • 1 items added with 1,247 views
  • Mar 23, 2020

Bifacial modules are modules that can produce power from both sides, thus increasing total energy generation. They expose both the front and backside of the solar cells to the sun light. Some manufacturers claim up to a 30% increase in production just from the extra power generated.


However, this extra gain is affected by many factors

Ground albedo

The irradiance received by the rear side is directly proportional to the ground albedo, in other words the higher the albedo, the higher the bifacial gain in a linear correlation



Installation height

Increasing the height of the modules will increase the incident irradiance on the rear side of the module, however this increase is not linear in nature, it has been noticed that the power gain from the rear side increases significantly between 0-1 meter in height. After 1 m the gain slows down. Another point here is the irradiance uniformity, it has been shown that increasing the module installation height above 1m makes the irradiance uniform, which allows the module to yield more energy.

Ground Coverage Ratio (GCR)

GCR is the ration of module to land area, when GCR decreases, the irradiance reflected on the rear side will increase. Some conducted studies, have shown that when the GCR increases from 0.25 to 0.5 the correlation is linear. However, when the GCR increases from 0.1 to 0.25, the slope of the yield increase decreases. To conclude, the bifacial gain increases with the increase of array pitch.



In most of the installation, shading cannot be eliminated from the rear back of the modules. The thickness of the supporting rails and height will cause shading, which will affect the irradiance on the rear side of the module.



Ahmad Elghobashy's picture
Thank Ahmad for the Post!
Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.
More posts from this member
Spell checking: Press the CTRL or COMMAND key then click on the underlined misspelled word.
Matt Chester's picture
Matt Chester on Mar 23, 2020

Really fascinating-- love seeing tech like this develop. What are the cost differences of bifacial modules compared with traditional ones with just one face?

Get Published - Build a Following

The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »