Power from shaded photovoltaic modules through bypass-diode-assisted small-area high-voltage structures

Abstract

Photovoltaics have high potential as a renewable energy source in urban environments. A major challenge in implementing urban photovoltaic systems is the unpredictable shading of photovoltaic modules. Architectural barriers and safety concerns, including fire hazards from partial shading, necessitate innovative photovoltaic system designs. To address this challenge, the small-area high-voltage concept was introduced, facilitating the use of pseudo-high-voltage low-current cells in parallel connections. This research is a continuation of the small-area high-voltage concept, which has a flexible design with shading tolerance proven to be thrice that of conventional modules. This research explored the optimal number of bypass diodes in a module. Two power measurement methods were adopted because a diode causes multiple peaks in the power curve, making it difficult to obtain maximum power. Simulations were conducted under various shading intensity and shape scenarios, and the results were validated experimentally. The small-area high-voltage modules, even without diodes, outperformed the conventional and shingled modules with one diode per cell. This study concludes that when combined with diodes, the small-area high-voltage concept exhibits remarkable improvements in shading tolerance and stable power production, offering a promising way to improve the adaptability and efficiency of solar energy systems in urban environments.