LAUSR

Solar energy utilization in buildings can significantly contribute to energy savings and enhance on-site energy production. However, excessive solar gains may lead to overheating, thereby increasing cooling demands. Accurate calculation of sunlit and shaded areas is essential for optimizing solar technologies and improving the precision of building energy simulations. This paper provides a review of the solar shading calculation methods used in building performance simulation (BPS) tools, focusing on the progression from basic trigonometric models to advanced techniques such as projection and clipping (PgC) and pixel counting (PxC). These advancements have improved the accuracy and efficiency of solar shading simulations, enhancing energy performance and occupant comfort. As building designs evolve and adaptive shading systems become more common, challenges remain in ensuring that these methods can handle complex geometries and dynamic solar exposure. The PxC method, leveraging modern GPUs and parallel computing, offers a solution by providing real-time high-resolution simulations, even for irregular, non-convex surfaces. This ability to handle continuous updates positions PxC as a key tool for next-generation building energy simulations, ensuring that shading systems can adjust to changing solar conditions. Future research could focus on integrating appropriate modeling approaches with AI technologies to enhance accuracy, reliability, and computational efficiency.