Minute-Scale Models for the Diffuse Fraction of Global Solar Radiation Balanced between Accuracy and Accessibility

The separation models are tools used in solar engineering to estimate direct normal (DNI) and diffuse horizontal (DHI) irradiances from measurements of global irradiance (GHI). This paper proposes two empirical that stand out owing their simple mathematical formulation: a rational polynomial equation. Validation the new was carried against data 36 locations, covering four major climatic zones. Five current top minute-scale were considered references. tests performed on final products estimation: DNI DHI. first model (M1) operates with eight predictors (evaluated GHI post-processed clear-sky counterpart estimates) constantly outperforms already established models. second (M2) three based only measurements, which gives it high degree accessibility. Based statistical linear ranking method according models’ performance at every station, M1 leads hierarchy, both DHI estimation. accessibility M2 does not compromise accuracy; is proving be real competitor race best-performing