Integrating Solar Photovoltaics in Residential Buildings: Towards Zero Energy Buildings in Hail City, KSA

Abstract

In recent years, most cities have faced great demand for electricity supply due to rapid population growth and industrialization. Supplying sufficient electrical energy, while reducing greenhouse gas emissions, is one of the major concerns of policymakers and scientists all over the world. In Saudi Arabia, local authorities are increasingly aware of the necessity of reducing the environmental impact of nonrenewable energy by exploring alternative sustainable energy sources and improving buildings’ energy efficiency. Recently, building-integrated photovoltaic (BIPV) technology has been regarded as a promising technology for generating instantaneous sustainable energy for buildings. To achieve a substantial contribution regarding zero energy buildings, solar energy should be widely used in residential buildings within the urban context. This paper examines how to achieve an appropriate model for integrating photovoltaics on the rooftop of residential buildings in Hail city to provide alternative energy sources. The estimated rooftop areas in Hail city, utilizable for PV application were calculated. Using PV*SOL simulation software, the performance ratio and the system efficiency, as well as the annual energy output in several tilt angles, were determined and presented. The amount of energy expected when using all effective roof area in the city was also calculated. The amount of CO2 emissions that could be reduced as a result of using a PV system was estimated. The results show a significant area of rooftop suitable for PV system in residential buildings in Hail city, which exceeds 9 million square meters. On the other hand, the performance ratio and the system efficiency are affected by the tilt angle of the PV module, where the efficiency increases with higher tilt angle, this is due to the PV module temperature, where, with the decrease in the PV module temperature its efficiency increases. The results indicate that the 30° tilt PV produced the highest amount of energy, whereas the 75° tilt PV records the smallest one although it achieves the best possible efficiency. There is a significant amount of energy produced from the use of all residential rooftops in Hail, and there is also a significant reduction in the amount of CO2 emissions. It is expected that this research would develop innovative building design strategies and specifications allowing for better climate and energy efficiency as well.