The high energy output of bifacial modules has revolutionized the solar power arena. Bifacial technology is impacting the design of PV fixed tilt and tracker structures as well as the design of PV power plants. Features that are considered negligible in the design of PV power plants that use monofacial modules are relevant when using bifacial modules. These elements mark the difference between an efficient or inefficient bifacial plant. The appropriate consideration of such features in plant design can translate into millions of dollars.
Bifacial plant designs strive to optimize the energy output from both the front and rear sides of a module. In other words, the energy gain generated in the rear module with regard to the front module would be affected by parameters like the albedo, module height, the shading, module temperature, and distance between module rows.
Bifacial Tracker Evaluation Center
With the purpose of analyzing all parameters affecting bifacial gain, Soltec inaugurated the Bifacial Tracker Evaluation Center in California on July 2018. Soltec’s goals are to expand the bifacial tracker performance knowledge base, refine bifacial energy forecasting and further bifacial solar tracker technological development. This research center is equipped with 18 solar trackers capable of deploying around 300 kWp of modules. The trackers are located in areas with different albedo, pitch, and height.
To this end, Soltec is working with the National Renewable Energy Laboratory (NREL), Black&Veatch and the Renewable Energy Test Center (RETC), as well as top module manufacturers: Canadian Solar, Hanwha Q CELLS, Jinko, LG, LONGi y REC.
BITEC has enabled Soltec to measure the solar trackers’ bifacial gain under real conditions. Furthermore, it compared the two most common tracker configurations in the market today: 1-in-Portrait (1P) and 2-in-Portrait (2P). Initial results show that individual modules deployed in SF7 Bifacial tracker in 2P configuration exhibit a Bifacial Gain that is 2.4 percent higher than that of the same modules in 1P configuration.
Economic advantages of bifacial modules
Measurements taken at BiTEC between September and November 2018 show Bifacial Gains of over 19 percent for individual bifacial modules on a SF7 Bifacial tracker over a white ground cover with an albedo of 63 percent.
The Bifacial Gain of individual bifacial modules on a SF7 Bifacial tracker is 2.4 percent higher than that of the same modules on a 1P solar tracker, according to data collected at BiTEC.
The higher Bifacial Gain on the SF7 Bifacial tracker is because the rear of the modules are free from shadows and the modules operate at a lower temperature.
Results obtained at BiTEC, indicate that the use of bifacial modules instead of monofacial modules in PV plants may be economically advantageous thus improving investment profitability. These estimations are based on the results obtained at BiTEC.
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