Revised solar maps of Algeria based on sunshine duration

Highlights: • The global solar irradiation maps for Algeria are drawn. • We performed an independence test using year 1992–2002 data. • The highest intensity of the solar radiation is located around the area of Djanet. • The less intense area is located around the area of Ksar Chellala. - Abstract: Solar irradiation data is generally required in modelling a system's thermal performance, and evaluation of long-term effects of climatological changes. In Algeria, measurements of solar irradiation have been carried out for a few locations because the measuring instruments are expensive to purchase and install. The only alternative to obtain solar irradiation data is to estimate it by use of an appropriate solar irradiation model. The present study attempted to draw global solar irradiation maps for Algeria, witch are generated for all types of sky. The incident solar radiation on a horizontal surface, on a surface tilted at the latitude angle and for a vertical plane facing east, south, west, south-east, south-west was determined using numerical models. To obtain a solar radiation map of a certain zone it is necessary to know the solar radiation of a huge number of sites spread wide across the zone. The comparison between the measured and the computed values is satisfactory; the relative error is less than 7%. The results allow to view information about 48 provinces of Algeria, and are presented in the form of an annual solar radiation map. The solar maps developed in this paper provide information about the levels of total solar radiation which can be used as a database for future investments in the solar sector in Algeria