The annual diagrams of solar irradiance and the annual sum of global irradiation energy are the results of climatic and meteorological matters that depend on local and seasonal conditions. The principal climate database used in the simulation software’s come from Meteonorm program, which has an extensive world-wide database and time series data of adequate quality, are simply to use. For the present application in this case study the solar irradiance date come from IAMEST. — Joint Research Centre GIS based solar radiation database which used the r. sun solar radiation models. In this model we can obtain the solar irradiance curves using the geographical latitude of the site.

This database can estimate the photovoltaic potential of the regions we can obtain PV maps about the yearly electricity generation. The application site radiation date come from this database what presents the annual total yield.

The yearly variation of the date indicate that the average radiation value fluctuates from year to year, the deviation from the long term average are generally about 15%, but extremely values up to 40% have been observed. In the following figures the solar radiation date of the applications sites are presented (Figure 1). In different inclination degree.

Using the expression E=365*Pk rpGP to compute the annual total electricity output from the PV system where the Pk, is a peak power installed rp is the efficiency, analogous to the performance ratio, the typical value is 0.75,and Gi is the annual of daily global radiation on the horizontal and inclined solar panel facing, oriented to South. Figure 2 shows the variation of the monthly PV potential of a 1 kWp PV system