Potential of tensegrity racking structures for enhanced bifacial PV array performance

Abstract

Bifacial PV has emerged as the de-facto choice for utility-scale ground-mounted PV arrays due to their ability to collect solar irradiance from both the front and rear surfaces. However, conventional racking structures were not designed to minimize shadowing of the rear surface since they were developed with only monofacial panels in mind. In this study, we explore the utilization of tensegrity racking structures as an alternative to conventional PV rackings. Tensegrity structures are comprised of rods and cables that achieve structural integrity while minimizing mass, form factor, and possibly cost. In order to explore the potential of tensegrity structures, Radiance optical ray-tracing simulation was used to compare the bifacial performance between the two types of racking solutions. The simulation model was built using the on-site array configurations and the racking geometry obtained from a commercial array that features both monofacial and bifacial panels. High-level results show that the racking and mounting structure contribute to about 18% shading. With other parameters kept unchanged, the tensegrity structure is found to enable up to 60% increase in rear surface irradiance by mainly reducing the rear surface shading caused by the on-site racking structures. The work, through its novel approach of detailed modeling of racking geometry, demonstrates the potential of tensegrity racking structures for bifacial PV arrays.