A Study on the Effect of Mounting Parameters on the Performance of Bifacial Solar Modules

Abstract

Bifacial Photovoltaic (bPV) is a technology that is fast gaining traction and has the potential to enhance overall electricity generation. Unlike conventional modules, bPV can capture the sun's rays and convert them into useful electricity from both the front and back of the module. Due to this, they have attracted attention in recent years. On the flip side, there hasn't been a lot of research carried out on these kinds of modules, particularly in developing countries like Kenya which are located in equatorial zones. The optimal elevation from the ground and tilt angle to install these modules vary from place to place. There haven't been many in-depth studies done on the cited area in the equatorial region, which is where the sun is directly overhead all year. This research fills that gap by giving a detailed look at how well bifacial modules work in equatorial zones. The main aim of this research was to see how varying the elevation above the default ground level and the angle of inclination affected the performance of bifacial solar modules. The study also looked at how different backgrounds affect how well a bifacial solar module works. Two solar modules were mounted back-to-back to form a double-sided solar module (bifacial solar cell configuration), with one facing the sky (front side) and the other facing the ground (back side). The module performance was examined at various elevations above the ground level and at different inclination angles by measuring parameters like solar irradiance, modules’ temperature, current, and voltage both on the front and the back of the module. An HT304N reference cell was used to measure the amount of solar irradiance, and an HT instrument PT300N temperature sensor was used to measure the temperature of the module. Using an HT current-voltage (I-V) solar analyzer, the module's current and voltage were measured. At the optimized elevation and angle, the influence of different reflective backgrounds on the performance of the module was investigated using Metallized polyethylene terephthalate, MPET, iron sheet, and Mylar windshield sunshade as reflectors. Data was collected every day between 10.0 am and 3.0 pm. East African Time zone, EAT at an interval of 30 minutes for 2 months and 15 days between January and March. Data analysis and visualization were done using Python and Origin software. The findings revealed that the optimal installation elevation for bifacial modules within the equatorial zone will be 1.2 m with reference to ground level and at a tilt angle of approximately 30 degrees with north orientation. A direct proportionality relationship between power output and solar irradiance was also noted. The maximum power output for the module's front side was 53.87 W at a solar irradiance of 1060.00 W/m2, while the minimum power output was 34.30 W at a solar irradiance of 718.00 W/m2. The highest power output for the module's backside was 4.82 W at a solar irradiance of 94.00 W/m2... As the tilt angle increased, solar irradiance generally decreased on both sides of the module. It was determined that the front side received a maximum of 1060.00 W/m2 of irradiance (at a tilt angle of 30º) and a minimum of 110.00 W/m2 (at a tilt angle of 90º). The maximum irradiance was 88.00 W/m2 at 30º and the lowest irradiance was 62.00 W/m2 at 90º for the module's backside. The short circuit and maximum current were found to increase as solar irradiance increased, with a coefficient of determination, R2 of about 0.97 for the front side of the module and about 0.92 for the backside. The findings additionally validated that the utilization of reflective backgrounds significantly enhances the power generation of bifacial solar panels. Metalized polyethylene terephthalate, MPET reflectors produced the most irradiance of the tested three reflector samples, followed by the Mylar sunshade and iron sheet. MPET increased irradiance by 84.62%, Mylar by 77.21%, and iron sheets by 22.95%. It was concluded that an elevation of 1.2 m above ground level and a tilt angle of 30º would be appropriate for bifacial module installation in equatorial zones. Moreover, due to its high reflectivity, the MPET reflector was recommended for usage as a reflecting surface.