GoodWe Analysis on Trend of Bi-facial Modules

Author: Craig

2021-09-16 13:42

Bi-facial solar module is able to absorb additional sunlight by rear surface, which is a significant advantage compared to traditional mono-facial solar module. With the additional solar radiation accumulated by the rear surface, it will bring more electrical power generation. As the interests in bi-facial module grows, a worldwide map of their potential performance can help assess and accelerate the global deployment of this emerging technology.

 

1. Market Trend of Bi-facial Module

As the most promising technological breakthrough in PV industry, the annual deployment of bi-facial modules has grown from 97 MW in 2016 to 5.42 GW in 2019, and the cumulative capacity has reached 8.2 GW, which had taken nearly 8 years for mono-facial module since the implementation of Germany's feed-in tariff program in 2000.

Based on current trend, the annual bi-facial module capacity will exceed 21 GW by 2024, accounting for 17.2 percent of the total installed capacity in that year, quadrupling the share of bi-facial solar in 2019.

As the demands grow following the market's prediction, most mainstream manufacturers have joined the team by deploying resources for bi-facial production. Thus, the price of bi-facial module keeps in a downtrend that the price has reduced 9.3% since January 2019, which keeps shortening the price difference with the high efficiency and mainstream modules.

 

2. The Working Principle of Bi-facial Module

As the name suggests, bi-facial module is consisted of glass sheets on both sides of a solar module. The bi-facial module could absorb both direct and indirect sunlight.

Compared with the standard PV module, the extra yield is themost obvious and realistic advantage of bi-facial module. By installing the bi-facial modules at certain height above the surface with high albedo, the whole system will generate extra power compared with the traditional design.

Also, the installation of the bi-facial module is different from traditional practice. In order to absorb more lights, the frames used will not block the backside of the panel.

 

3. Benefit Variation of Bi-facial System

To better understand the extra benefits from bi-facial module, here we use two simulated systems to explore the difference. Here are two PV system simulations in PVSyst - one is with the traditional mono-facial module LR6-71 HIBD 385M plus GW60KN-MT; another is with bi-facial module LR6-72 HBD 385 M Bifacial plus GW60K-BF, which is especially developed for the application of bi-facial modules.

With the same number of PV modules and inverters deployed, the system capacity is completely same located in the Valencia and the estimated ground albedo is 30%. However, due to the usage of bi-facial modules together with GoodWe's 60KW inverter applicable for bi-facial modules, there is additional 6MWh generation compared with the regular mono-facial modules after the simulation in PVSyst. From the following comparison of Loss Diagram, before considering the power loss of PV and Inverter, there is additional 12.38% power generated from the direct beam and diffuse light absorbed by the rear of the bi-facial modules, which is about 8.6MWh per year.

 

Conclusion

As bi-facial modules generate more power than mono-facial modules in PV system, it will become the mainstream choice for most of the utility-scale projects, but the market will need more practical data from the previous installation to prove its potential for the investors.

Notice

The information in this document is subject to change without notice, all information in this document do not constitute any kind of warranty. Please check with GoodWe Solar Academy 'academy@goodwe.com' for the latest version.

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