Analysis of Power Loss Mitigation Effects using BIPV Module-Level Power Optimizer under Partial Shading Conditions

The expansion of zero-energy building requirements has intensified the interest in Building Integrated Photovoltaic (BIPV) systems as a solution to the limited installation space for renewable energy sources in urban environments.BIPV systems serve both as building envelope elements and power generators.Partial shading from surrounding buildings and structures often causes significant power losses in these systems.Module Level Power Electronics (MLPE), such as power optimizers, can reduce these power losses by optimizing individual module performance; however, conventional products designed for standard photovoltaic (PV) modules are limited when applied to BIPV modules.These limitations occur because BIPV modules have lower electrical specifications owing to custom designs that meet the architectural requirements of various sizes and colors.This study develops a power optimizer specifically for BIPV modules to mitigate power loss, featuring hardware improvements with a buck converter for low-voltage operation and firmware enhancements for optimized shadow detection and Maximum Power Point Tracking (MPPT) control.Comparative experiments were conducted under various shading conditions (10%, 25%, 50%, and 75%) on vertically installed BIPV modules.Results indicate that the developed power optimizer improved performance under high shading conditions, demonstrating reduced power loss by 12.1% compared to that of conventional products under 75% shading.These findings confirm that the developed power optimizer can maintain power generation under partial shading in urban environments, thereby facilitating the adoption of zero-energy buildings through enhanced BIPV system reliability.