Analysis of Power Enhancement in Facade-BIPV Systems Through Module-Level Power Optimizer: Evaluating Performance Under Shading Conditions

To combat climate change and achieve global carbon neutrality, photovoltaic (PV) systems have been widely used in the building sector, particularly in zero-energy buildings. In urban areas, space constraints make building-integrated photovoltaic (BIPV) systems appealing, as they combine building materials with power generation and are designed with aesthetics in mind. However, BIPV systems are often affected by partial shading from surrounding structures. Moreover, unlike general PV modules, BIPV modules are custom-designed, resulting in poor electrical specifications. To address these challenges, this study developed a new prototype power optimizer for the module-level power electronics used in BIPV systems. The performance of BIPV systems was evaluated without a power optimizer, with a conventional power optimizer, and with the new prototype power optimizer through simulations and experiments under different shading conditions. Compared with the non-optimized system, power optimizers effectively alleviated shading loss and significantly increased the power efficiency, and the prototype power optimizer achieved a 2.8-fold average improvement in efficiency. This confirms the optimizer function in enabling shaded and non-shaded modules to operate independently at maximum power. Although further research is needed, these optimizers can improve BIPV performance and promote zero-energy buildings.