2x configuration solar trackers are more advantageous for bifacial modules.
According to preliminary measurements carried out at the Soltec bifacial research centre, 1x trackers waste part of the radiation.
Soltec, a leading manufacturer and supplier of horizontal single-axis solar trackers, is conducting several field tests, including the comparison of 1x configuration PV trackers against the Soltec SF7 Bifacialin a 2x configuration. These measurements are being carried out at BiTEC (Bifacial Tracker Evaluation Center), the world's first research centre specialising in bifacial solar tracking.
Soltec SF7 trackers have a standard height of 2.35 metres. With the 1x configuration, the modules stand at a height of 1.35 metres. Preliminary electrical performance measurements on the bifacial modules reveal a short-circuit current difference of more than 2.3 percent between the 1x and 2x trackers, which means that the height has a significant influence on the power output of the bifacial panels. The diffuse radiation entering from below the tracker increases as the shadow cast on the ground becomes lighter.
In addition, in the SF7s, a gap between the modules at the height of the axis has been intentionally included to avoid shadowing on the rear face of the module. In the 1x tracker, on the other hand, the axis casts a shadow, irrespective of whether it is round or square in shape. A preliminary radiation distribution measurement shows that 38% of reflected light is lost at the centre of the module with respect to the end due to the shadow of the shaft, as opposed to the increase that occurs in the 2x tracker due to the irradiation entering through the shaft gap.
BiTEC has the collaboration of the main manufacturers of bifacial modules and US organisations specialised in renewable energies such as NREL or RETC. This centre will be officially opened on 9 July in Livermore, California.
Soltec has extensive experience in bifacial technology. In 2015, it manufactured the first photovoltaic tracker specifically designed for mounting bifacial panels at the La Silla solar plant in Coquimbo (Chile). In this installation, which consists of trackers with 2x configuration, a 14.9 percent gain has been achieved with respect to single-facial tracking, with a bifacial ratio of more than 17 percent.