1. A computer implemented method of estimating at least one solar irradiance component, the method comprising: obtaining a sensor measurement from an instrument to provide a measured global horizontal irradiance (GHI measured ), wherein the measured global horizontal irradiance (GHI measured ) consists of at least an estimated diffuse horizontal irradiance (DHI estimated ) and an estimated direct normal irradiance (DNI estimated ); providing at least one modeled component, wherein at least one of the modeled components is a modeled global horizontal irradiance based on an atmospheric model (GHI model ); calculating an irradiance estimate modifier (IMOD) in a computing device according to the measured global horizontal irradiance (GHI measured ) and the modeled global horizontal irradiance (GHI model ); providing at least one estimated solar irradiance component by a computing device according to the irradiance estimate modifier (IMOD) and at least one modeled component.