Solar Energy Utilization Potential in Urban Residential Blocks: A Case Study of Wuhan, China

In dense, energy-demanding urban areas, the effective utilization of solar energy resources, encompassing building-integrated photovoltaic (BIPV) systems and solar water heating (SWH) systems inside buildings, holds paramount importance for addressing concerns related to carbon emission reduction and the balance of energy supply and demand. This study aimed to examine the interplay between urban residential blocks and their solar energy potential, with the objective of promoting environmentally sustainable development within urban residential areas. The primary focus of this study was the hot summer and cold winter zone of China, which serves as a representative case study. Methodologically, we employed Rhinoceros and Grasshopper (GH) software version GH6.0 tools to simulate the solar radiation potential within residential blocks and translated this information into the potential utilization of BIPV and SWH systems. Subsequently, our focus was directed towards identifying optimal locations for mounting BIPV modules and water heaters on roofs and building facades. The study results revealed the following: (1) The floor area ratio (FAR), building density (BD), average building height (ABH), and space layout (SL) exerted substantial influences on the solar potential of a residential block, with correlations of up to 75%, 71%, 78%, and 50%, respectively, concerning the overall solar potential of the entire plot. (2) It is essential to emphasize that, with regard to the BIPV installation potential, facades account for 80% of the overall residential block potential, whereas rooftops contribute only 20%. Both south- and west-facing facades exhibited a BIPV installation ratio of approximately 34%. (3) In the realm of solar water heating, the potential for installations on building facades accounted for 77% of the total living area of the residential blocks, 23% on the rooftops, and 35% on the south-facing facades. This study furnishes practical guidelines for harnessing the potential of BIPV and SWH systems within residential blocks, thereby contributing to the advancement of sustainable urban development practices.