Bio-adaptive reflective photovoltaic (BARP) facade system: a multimodal energy-saving solution based on light reflection

Abstract

Buildings account for approximately 40% of global energy consumption, creating an urgent need for innovative solutions that enhance energy efficiency while maintaining occupant comfort. Traditional photovoltaic (PV) façades are often constrained by low energy output, limited intelligence, single functionality, and poor environmental interaction. This study presents a Bio-Adaptive Reflective Photovoltaic (BARP) facade system incorporating dynamic reflection technology with smart control systems to substantially improve both energy generation and indoor environmental quality (IEQ). The system employs biomimetic finger-like adaptive reflective blades that precisely track solar trajectories through a specialized mechanical structure. These blades dynamically redirect incident sunlight onto strategically positioned PV panels while supporting multimodal operation, including an indoor light-guiding mode that optimizes natural illumination. The design methodology combines computational fluid dynamics simulation, parametric optimization, and physical prototyping. A novel ray-tracing algorithm was developed to optimize the reflective panel geometries and motion control parameters. Experimental validation conducted at 31.65°N, 120.75°E demonstrates that the BARP system achieves peak power outputs 2.4 times higher than conventional fixed PV panels, with daily energy generation approximately 1.8 times greater. The system’s biomimetic mechanism effectively mitigates efficiency losses from self-shading while maintaining stable performance across seasonal variations. Indoor light measurements confirm that the system’s guidance mode improves illumination uniformity by 40% compared to traditional façades. This research establishes a comprehensive framework for integrating adaptive reflection technology with PV systems, with significant implications for green building adoption in urban environments. Implementation in commercial buildings could reduce energy consumption while providing flexible control over IEQ, though widespread adoption will require addressing challenges related to maintenance costs, durability under extreme weather conditions, and integration with existing building management systems.