Paper Conference

Proceedings of Building Simulation 2011: 12th Conference of IBPSA


Solar Availability: A Comparison Study Of Six Irradiation Distribution Methods

Diego Ibarra, Christoph Reinhart

Abstract: Several approaches have been developed to date to model monthly or annual solar irradiances with different results in terms of time cost and numeric accuracy. This paper presents a comparative study of six irradiation distribution calculation methods of increasing complexity. The study compares the different calculation approaches accounting for solar angles, time series and sensor-grid orientations. Methods are analyzed in terms of their numeric accuracy, reliability and appropriateness for application in architectural practice. Two test scenes were developed. A first simulation case compared methods against unobstructed hourlymeasured data for all cardinal orientations in Freiburg, Germany. The second simulation case characterized a dense urban context in New York City and involved calculations at three different heights (i.e. 2m, 100m, 220m). Significant variation in MBE and RMSE were reported between the two test cases. The design practice applications explored show that these discrepancies may crucially influence the final design recomendations based on the different simulations results.
Pages: 2627 - 2634