Spatial and temporal irradiance variations over large array fields

Transient irradiance modeling techniques were developed, and experimental observations which resulted from cloud passages over thirty 2000 W grid-connected residential photovoltaic systems spread over a 50-acre neighborhood are reported. The site is described, and a variety of effects that influence the fluctuations of irradiance at a given point under cloud-passage conditions are discussed. Observations have quantified the degree to which the rates of PV system generation change are higher for a single system than for the aggregate site. These techniques could be applied to larger array fields to study the impact of their transient generation effects on electrical power system operations.