| Title |
Development of a Solar Insolation Calculation Module in Urban Context Using the Sunlit Fraction and Sky-view Factor |
| Keywords |
Urban insolation ; Shading ; Polygon Clipping Method ; Sunlit Fraction ; Sky-View Factor |
| Abstract |
Recently, development of detailed urban energy consumption prediction tools becomes a rising issue as it can provide more quantitative and qualitative information for planning a sustainable city. One of the target physical phenomena related to the urban case is to correctly calculate the solar irradiance on building envelops with taking into account the shading and mask effects. The sunlit fraction(SF) is commonly used to calculate the effective beam solar irradiance, and the sky-view factor(SVF) is used for the precise diffuse irradiance in the urban context. Both indicators are also employed in this work, and they are calculated using the polygon clipping method. The proposed solar insolation calculation module is implemented in Python, and results from the module are compared with existing SketchUp Plug-in tools. Results show that SF and SVF obtained from the module are almost the same as the existing tools, giving only less than 2% errors over the year. A case study is also carried out for comparison between the urban case and the single building case. As expected, total monthly insolation in the single building case is overestimated with a mean difference of about 20%. |