In the quest for more efficient solar power collection, researchers have turned to an innovative design that could significantly boost the performance of bifacial solar cells. A study led by Floriana Morabito from the CNR-Institute for Photonics and Nanotechnologies in Milan, Italy, has unveiled a novel asymmetric four-terminal solar concentrator that promises to enhance power collection in bifacial solar cells. This breakthrough, published in the journal Energies, could reshape the future of photovoltaic (PV) technology, particularly in integrated and building-integrated PV (BIPV) systems.
Bifacial solar cells, which collect sunlight from both their front and rear sides, have long been recognized for their potential to maximize solar energy conversion per unit area. However, one of the major challenges has been the effective collection of backscattered diffuse light from the ground, often hindered by self-shading. Morabito and her team have addressed this issue with a unique optical design featuring a wedged right-prism geometry. This design not only reduces self-shading but also optimizes the collection of diffuse light, leading to a substantial increase in power conversion efficiency (PCE).
The researchers used commercial ray-tracing software to analyze the performance of their conceptual design across four different latitudes. The results were striking. At a latitude of 25° north, the system achieved a Relative Optical Power Increase (ROPI) of 293% during the winter solstice compared to standard flat bifacial configurations. “The key advantage of our design is its ability to leverage both direct and diffuse light, making it particularly effective in lower latitudes and during winter months,” Morabito explained.
The study also estimated the photocurrent and total PCE in a four-terminal (4T) configuration, assuming the use of commercial silicon heterojunction (HJT) bifacial cells and gallium arsenide (GaAs) cells. The findings indicated a global increase in PCE of up to 23% compared to the best-performing trackless standard bifacial configuration. This significant improvement could have profound implications for the energy sector, particularly in urban environments where space is at a premium.
The asymmetric four-terminal solar concentrator is designed to be a versatile “tile” that can be integrated into various PV systems. Its potential applications range from building-integrated PV solutions to portable PV devices, vehicles, and vessels. The design’s ability to maintain high efficiency without the need for azimuthal sun tracking makes it an economically attractive option, potentially offsetting the increased manufacturing complexity.
Morabito’s research suggests that the future of PV technology lies in the integration of high-performance, high-bandgap solar cells in 4T configurations. As the energy sector continues to seek cost-effective and efficient solutions, this innovative design could pave the way for more advanced and versatile PV systems. The study, published in Energies, opens the door to further exploration and development, with the ultimate goal of implementing a prototype for outdoor testing.
The implications of this research are far-reaching. As the demand for renewable energy grows, the need for efficient and space-saving PV solutions becomes ever more critical. Morabito’s work offers a glimpse into a future where solar power is not just a supplementary energy source but a primary one, integrated seamlessly into our daily lives. The energy sector stands on the brink of a new era, and this innovative design could be the catalyst for a solar revolution.
