Analysis of photovoltaic reflectors characterizes improved tilt parameters in tropical climates

Next-generation photovoltaics look to incorporate bifacial designs, allowing electricity production from both the front and rear of a solar cell. Vertical designs have shown promise in tropical regions for their reduced footprint, functionality even when not fully in sunlight and alignment with grid demand peaks. Experimental comparisons of reflector geometries in such systems, however, remain underexplored.

Haseen Shaikh and Balwant Bhasme compared the vertical bifacial modules of flat and curved reflectors at various tilt angles in tropical conditions. By assessing the power output, module surface temperature, and incident irradiance effects of tilt angles from 0 to 40 degrees between the types of reflectors, the group found that flat reflectors trumped curved ones and moderate tilt angles consistently produced higher daily energy yields and more uniform diurnal power profiles.

“The outcomes of this study offer practical guidance for the design of vertical bifacial photovoltaic systems intended for tropical and urban applications,” Shaikh said. “By demonstrating that flat-reflector-assisted configurations can increase daily energy yield while distributing power generation more evenly throughout the day, the results support solar installations that are both operationally stable and more compatible with grid requirements.”

The group found that tilting flat reflectors between 20 and 30 degrees most consistently delivered improved power, with reflectors achieving 51 percent gain at noon when positioned at 20 degrees and a daily mean output boost of 15 to 20 percent when angled at 30 degrees.

While curved reflectors conferred minor benefits in specific situations, they tended to introduce uneven illumination, leading to higher operating temperatures and worse performance overall.

The group next looks to optimize reflector materials and surface treatments to further enhance performance.

Source: “Experimental analysis of vertical bifacial photovoltaics with flat and curved reflectors under tropical climatic conditions,” by Haseen Shaikh and Balwant Bhasme, Journal of Renewable and Sustainable Energy (2025). The article can be accessed at https://doi.org/10.1063/5.0303489 .