Fast Horizon Approximation: Impacts on Integrated Photovoltaic Irradiation Simulations

In applications that utilize detailed solar resource assessments with high-resolution topography data, calculating the topographic horizon is critical for accurate shading calculations. In particular, the horizon calculation significantly influences the time needed to model solar irradiation in integrated photovoltaic applications. The new approximate horizon algorithm was developed to balance accuracy and computation time. This study evaluates the algorithm's performance in modeling vehicle- and building-integrated photovoltaics, considering the impact of surface orientation and elevation. It is demonstrated that the proposed horizon algorithm achieves the same level of accuracy four times faster than previously known approaches for vehicle-integrated applications. Moreover, for building-integrated applications, the proposed approach performs better at elevations higher than 10 m on facades and roofs. Finally, the impact of maximum sampling distance on irradiation for high- and low-resolutions topography is studied.