Soltec, a leading manufacturer and supplier of single-axis solar trackers and related services for large ground-mount PV projects, is performing field tests at BiTEC, the world’s first evaluation center specializing in bifacial trackers. Among the tests, the company is comparing bifacial production of 1x configuration solar trackers versus Soltec’s SF7 Bifacial, a 2x configuration tracker.
Soltec’s SF7 trackers have a standard height of 7.71 ft, while 1x-configuration trackers have a height of 4.43 ft. Preliminary electric performance measures over bifacial modules reveal a short-circuit current difference of more than 2.3% between 1x and 2x trackers, indicating height has a significant influence over the energy output of bifacial panels. The capture of diffuse irradiance below and around the tracker is increased by height while the shadow cast on the ground is softened.
In addition, the SF7 includes a gap between modules at the torque tube location that avoids shadowing on the back side of the module. With 1x trackers, on the other hand, the torque tube casts a shadow regardless of whether it is round or quadrangular in shape. Preliminary measurements have shown that up to 38% of reflected light does not reach the center of bifacial modules, compared to the edge, due to the torque tube shadow of the 1x configuration.
BiTEC will be officially inaugurated on July 9 in Livermore, California. The center counts on the collaboration of the main bifacial module manufacturers and American organizations specializing in renewable energy, such as the NREL [National Renewable Energy laboratory] and the RETC.
Soltec’s experience of bifacial tracking dates back to 2015, when a customer needed a test-bed for utility-scale bifacial tracking. Soltec responded with the La Silla solar power plant in Coquimbo, Chile. The plant is comprised of Soltec trackers with 2x configuration and has exhibited a 14.9% gain against monofacial tracking, with a bifacial ratio above 17%.