Vertical Bifacial Photovoltaic Balustrade System for Building Edges
This innovative solar balustrade system integrates bifacial photovoltaic panels and represents an excellent solution for "cool roof" applications. Research indicates that roof reflectivity and module positioning significantly impact system performance.
A research team has developed a photovoltaic balustrade designed specifically for installation on building rooftop perimeters.
"The system incorporates vertical bifacial PV modules directly onto rooftop balustrades," according to the lead researcher. "A notable feature is the optional reflective surface that enhances reflected light. The vertical orientation minimizes shadow effects between modules and maximizes space utilization, while the edge placement ensures minimal interference from nearby structures."
In the published study "Vertical bifacial solar photovoltaic balustrades for low-carbon buildings: A numerical analysis of energy performance," the system is highlighted as having significant potential for widespread urban implementation, particularly with the increasing adoption of high-reflectivity "cool roofs" and radiative cooling technologies.
The research setup featured vertical bifacial PV modules with different orientations and bifaciality characteristics. The modules were based on three cell technologies: passivated emitter rear contact (PERC), heterojunction (HJT), and tunnel oxide passivated contact (TOPCon).
Using comprehensive multi-physics modeling, the team simulated realistic performance across various conditions by integrating optical, thermal, and electrical dynamics.
"Our numerical analysis revealed several key findings," the researcher explained. "First, roof reflectivity and module orientation were primary performance factors. High reflectivity surfaces increased bifacial gain up to 2.04 for HJT modules, significantly outperforming PERC technology. This gain exceeds typical values reported in literature due to the system's ability to capture roof-reflected light on one side."
Additionally, the researchers discovered that the system shows directional versatility.
"North-facing orientations maximized bifacial gain, while east/west orientations maximized power output, making the system adaptable across different latitudes," the researcher noted.
"Compared to PERC technology, TOPCon and HJT technologies demonstrated power output increases of approximately 8% and 17%, respectively. Additionally, bifacial gain improved by 15% and 30% for TOPCon and HJT," according to the research paper.
For future developments, the team plans to explore spectrally engineered coatings that can direct solar photons to enable simultaneous reflectivity enhancement and spectrum conversion.
"These coatings offer a promising approach to further amplify roof-reflected light for bifacial PV systems by not only increasing surface reflectivity but also optimizing the spectral matching between reflected light and PV cell sensitivity," the researcher stated.
"Our next phase will focus on applying newly developed spectrally engineered coatings to rooftops, enhancing bifacial PV balustrade performance and accelerating practical implementation through demonstration projects," the researcher concluded.
