Solar radiation modelling for urban environments

In this paper we briefly describe three alternative techniques for modelling solar radiation in the urban context. These include the use of: (i) simple morphological parameters as indicators of radiation availability, (ii) a ray-tracing program in conjunction with a cumulative sky radiance distribution model for accurate calculation of annual incident solar irradiation, (iii) a simplified radiosity algorithm (SRA) for efficient calculation of (sub-)hourly incident solar irradiance. Although each of these techniques has advantages, we suggest that the SRA should be used in preference to the two alternatives, either for reasons of accuracy or efficiency