Thermal Study of Photovoltaic Embedded Hollow Concrete Block

This study presents the Photovoltaic Hollow Concrete Block (PVHCB), a novel building-integrated photovoltaic (BIPV) system that integrates a thin photovoltaic film within the internal cavity of a standard hollow concrete block. The proposed block configuration consists of an external transparent and/or translucent layer that permits the transmission of incident solar radiation to the embedded photovoltaic element, coupled with a conventional opaque concrete inner layer that preserves the structural and thermal characteristics required for building envelopes. Thermal resistance network models are developed to evaluate heat transfer through the PVHCB, from which U-values are derived for various hollow concrete block geometries and material configurations. To enable location-specific performance assessment, a simple, universally reproducible methodology for generating solar radiation data is adopted, allowing the creation of representative seasonal solar profiles for Beirut, Lebanon. These data are subsequently used to analyze the transient thermal behavior of a south-facing wall constructed from insolated PVHCB units under seasonal operating conditions. Detailed energy balance equations are employed to estimate the temperature distribution within the block and the operational conditions of the photovoltaic film. The results suggest that a 20 m² south-facing PVHCB wall in Beirut could generate between 794 W (39.7 W/m²) and 846 W (42.3 W/m²) of electrical power, depending on seasonal variations and thermal conditions. Although the present investigation is preliminary and does not yet address mechanical performance, economic feasibility, or long-term material durability, the findings demonstrate the PVHCB's potential to function simultaneously as a structural building component and a supplementary on-site power generation system, thereby contributing to the development of sustainable and energy-efficient building envelopes, particularly in detached rural homes.