Experimental Evaluation of Double Skin BIPV Façades: Balancing the Energy Performance and Indoor Light Comfort

To respond to global carbon neutrality goals and promote the sustainable transformation of the building industry, the application of Building-Integrated Photovoltaics (BIPV) is garnering significant attention.High-rise office buildings with glass curtain walls, as landmarks in metropolitan Central Business Districts (CBDs), consume substantial amounts of energy to maintain indoor environmental comfort.To address this issue, the integration of Double-skin Facades (DSF) with BIPV is considered promising, as it can generate clean electricity onsite while simultaneously enhancing the thermal performance of the building envelope and improving indoor environmental comfort.This paper presents the development of a prototype for a double-skin BIPV facade applied to glass curtain walls, based on modular office units.The prototype incorporates both opaque and semi-transparent photovoltaic (PV) elements.It explores the impact of design parameters on the overall energy performance of the BIPV facade system and the indoor natural light environment.Design optimization is conducted using data obtained from simulations and outdoor experiments.Under conditions where the modular frame size and the area of opaque PV panels are the same, the power generated by the opaque PV in the baseline prototype accounts for approximately 54.7% of the total facade power.By rotating the opaque portion of the facade from the vertical surface by 60 degrees, the total power generation is more than doubled, with the opaque PV contributing over 75% to the total power output.In the closed system (Prototype 1), the surface temperature of the opaque PV is higher than that of the open system (Prototype 2), with an average of 1.19 and 1.26 times that of the baseline.However, the temperatures of the semi-transparent PV in these three prototypes are similar.Furthermore, the amount of side light entering the interior has a significant impact on # This is a paper for the 17th International Conference on Applied Energy (ICAE2025), December 8-12, 2025, Bangkok, Thailand.indoor illuminance; removing the side cover plate results in an increase in indoor illuminance, around 193% to 212% of the pre-removal levels.