Southern University of Science and Technology's (SUSTech) Ye Bin team makes progress in the field of building-integrated photovoltaics

Recently, the Ye Bin team from the Department of Environmental Science and Engineering at Southern University of Science and Technology published a research paper titled “Energy-economy-environment evaluation of building-integrated photovoltaic considering facade factors for representative megacities in China” in Applied Energy, a top journal in the field of engineering technology. Applied Energy The study developed a comprehensive assessment model for energy saving and carbon reduction of building-integrated photovoltaic (BIPV) systems, evaluating the solar energy resource endowment and energy-saving and carbon-reduction potential of BIPV in ten megacities in representative climatic regions of China. The study innovatively assessed the power generation potential of building facade photovoltaic systems using multi-dimensional images and three-dimensional building footprint methods. In addition, it explored the coupling and interconnection of building-integrated photovoltaic systems and electric vehicles to evaluate the role of electric vehicles in reducing the peak-valley difference of the power grid.

Graphical Abstract

Megacities in China provide a good environment for the development of distributed BIPV. These systems can be integrated into building elements such as roofs, facades, and shading structures, and are highly adaptable. This study aims to develop an "energy-economy-environment" potential assessment system to measure the potential of BIPV, including rooftop and facade photovoltaics. Ten megacities in China were selected to represent different types of building design across different regions. Each megacity is a major urban center with high population density and intensive energy consumption within its representative climatic and geographical region in China. Based on climate type, the following cities were selected in five climate zones: freezing zone (Harbin); cold zone (Beijing, Lhasa, and Xi'an); hot summer and cold winter zone (Chongqing, Nanjing, and Shanghai); warm zone (Kunming); hot summer and warm winter zone (Guangzhou). The power generation of BIPV and power grid supply in these cities were calculated. The study quantifies the BIPV potential of megacities in China and the peak-shaving and valley-filling potential of electric vehicles through urban building datasets, solar radiation, and electric vehicle datasets, which has significant reference significance for the development of urban photovoltaic power plants.

Research Framework

The results show that the annual power generation of BIPV systems in the ten megacities varies from 14.19 TWh (Lhasa) to 108.92 TWh (Shanghai). When the BIPV potential is maximized, it accounts for 34.97%-80.46% of the total power generation of the city, indicating the huge power generation potential of BIPV. Among them, the integration of facade photovoltaics significantly improves the BIPV potential. Taking Beijing as an example, due to the higher average building height in Beijing, facade photovoltaics increased the power generation potential by 149%. In addition, the BIPV power generation potential improvement rate in the other nine cities is also between 37% and 65%, which further confirms the important role of facade photovoltaics in improving the power generation potential of BIPV.

Figure 1: Building-integrated photovoltaic power generation and grid power supply in ten major cities in China

With the popularization of electric vehicles in various cities, the electricity consumption of electric vehicles accounts for 6.39%-16.46% of the total power generation. Therefore, the study also considered the absorption capacity of electric vehicle systems in BIPV. The synergistic effect of BIPV-EV can significantly improve the proportion of self-generated power of building-integrated photovoltaics. Taking the BIPV in Urumqi as an example, the absorption capacity of electric vehicles reduced the surplus power of the distributed system by 13.81%. Compared with the deployment of BIPV alone, electric vehicles can effectively act as an additional load, absorbing surplus power from the distributed system, thereby reducing the surplus power ratio and grid back-selling ratio of the power system.

Figure 2: Reduction rate of grid back-selling and surplus power caused by electric vehicle consumption

This study can provide theoretical support for the development of BIPV. By constructing a comprehensive assessment model for energy saving and carbon reduction, it comprehensively evaluates the power generation potential of BIPV systems from three aspects: energy, economy, and environment, providing a scientific basis for future research and practice. At the same time, exploring the coupling and interconnection of BIPV and electric vehicles opens up new ideas for research on multi-energy complementary energy systems. This study has great practical guiding value, providing a scientific basis for urban planners and decision-makers to promote building-integrated photovoltaic technology and achieve energy saving and emission reduction goals, and also providing a new perspective for the development of the electric vehicle industry, improving its energy utilization efficiency and environmental benefits. Under the pressure of urbanization and climate change, adopting BIPV and electric vehicle absorption strategies is crucial for the transformation of urban energy production towards sustainable and low-carbon development.

Ye Bin, assistant professor of the Department of Environmental Science and Engineering at Southern University of Science and Technology, is the corresponding author of the paper. Yu Zhe, a master's student in 2023, is the first author, and Southern University of Science and Technology is the first author unit. Collaborators on the paper also include Chen Cuiying, a master's student in Ye Bin's research group; Lou Duo, a postdoctoral researcher; and Professor Jiang Jingjing from Harbin Institute of Technology (Shenzhen). This research was supported by the National Natural Science Foundation of China (72173058 and 72394391), with Ye Bin as the principal investigator and participant, respectively.