Variability of Diffuse Daylight Due to the Diversity of Cloud Arrays

Illuminance modeling that allows us to mimic or even replicate the dynamics of daylight changes is increasingly becoming a challenge for development more accurate prediction systems natural light availability in building interiors variations insolation at arbitrarily oriented façades. We demonstrate illuminance amplitude due random cloud arrangement can vary over wide range when other atmospheric parameters remain unchanged. It follows from our systematic numerical diffuse predictions be significantly improved by incorporating coverage, mean size, and base altitude into models. show any model homogeneous luminance patterns would fail amplitudes we expect on horizontal vertical planes under partial coverage with individual clouds distributed randomly. However, these situations occur high frequency most regions worldwide, thus results obtained here are relevance solar energy as well.