2.1 Solar field
Accurate radiation data are critical in performance prediction and sizing and selection of CSP equipments, which are obtained from a combination of ground measurements and satellite data [22]. To overcome the difficulty of data availability, the radiation models for direct normal irradiation (DNI) are an alternative recourse, which are simple models requiring less than three inputs such as: Hottel, Liu and Jordan (HLJ) [23], Meinel [24], Kumar [25] and ASHRAE [26], while more inputs are for the complex models: Davies and Hay model [27] and Iqbal [28] etc. The present power plant corresponds to operating conditions in Hassi-R’mel (Algerian Sahara) of latitude of 33.8 deg. The adopted estimate of DNIis that of HLJ [23] model as below, which has been frequently used to assess clear sky solar radiation for numerous locations and among them the Saharan regions.