## 2 Materials and Methods
### Case Study Definition and Data Collection and Validation  
In order to cover a significant extent of the Moroccan territory, an extensive set of 23 representative cities of this country was chosen to carry out the analysis, listed at Table 2. Each one of the cities pertains to a different climatic zone, as defined in the map presented  
Figure 3: Flow chart of the proposed methodology. Source: own elaboration. in [57; 58], shown at Figure 4. The map was created using the degree day criteria and has been adopted for the Thermal Regulation of Construction in Morocco [59]. Measured solar irradiation data at ground level are not available for all cities and since there are no stations that belong to the BSRN in Morocco, only satellite data from different \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Zone** & **City** & **Latitude [Degrees]** & **Longitude [Degrees]** \\ \hline \multirow{6}{*}{\(1\)} & Agadir & 30.383 & \(-9.567\) \\  & Casablanca & 33.567 & \(-7.667\) \\  & Essaourira & 31.517 & \(-9.783\) \\  & Kenitra & 34.300 & \(-6.600\) \\  & Laayoune & 27.160 & \(-13.210\) \\  & Rabat & 34.050 & \(-6.767\) \\  & Safi & 32.283 & \(-9.233\) \\  & Sidi Ifni & 29.360 & \(-10.180\) \\ \hline \multirow{6}{*}{\(2\)} & Al Hoseima & 35.180 & \(-3.850\) \\  & Larache & 35.180 & \(-6.130\) \\  & Nador & 35.150 & \(-2.910\) \\  & Tanger & 35.733 & \(-5.900\) \\  & Tetouan & 35.580 & \(-5.330\) \\ \hline \multirow{6}{*}{\(3\)} & Beni Mellal & 32.360 & \(-6.400\) \\  & Fes & 33.933 & \(-4.983\) \\  & Meknes & 33.883 & \(-5.533\) \\  & Oujda & 34.793 & \(-1.933\) \\  & Taza & 34.217 & \(-4.000\) \\ \hline \multirow{2}{*}{\(4\)} & Ifrane & 33.500 & \(-5.167\) \\  & Midelt & 32.683 & \(-4.733\) \\ \hline \multirow{2}{*}{\(5\)} & Marrakech & 31.617 & \(-8.033\) \\  & Er-Rachidia & 31.930 & \(-4.400\) \\  & Ouarzazate & 30.933 & \(-6.900\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Distribution of the analyzed cities in the different climatic zones of Morocco. Source: own elaboration based on [59; 60]. Figure 4: Climatic zones of Morocco. Source: own elaboration based on [57]. data sets are used [61]. Therefore, all data was collected through the PVGIS website [62]. The web application allows to obtain data using high spatial time and resolution. It allows to know the solar conditions from different regions around the world. The data can be obtained from different sets. Three out of four data sets are used, all of which have been validated using ground station measurements. The data sets used are PVGIS-SARAH, PVGIS-ERA5 and PVGIS-CMSAF. For PV applications, the GHI is used to assess the feasibility of solar projects that use this technology, since these use both diffuse and direct radiation. For CSP applications, however, the diffuse irradiation is not relevant, which implies that only the DNI is considered for this technology [63]. An hourly time scale is necessary when analyzing specific projects for a duration that takes no longer than a year. This paper intends to present data for the assessment of solar projects for their whole lifetime, as carried out when evaluating their bankability in long-term planning. Thus, monthly rather than hourly intervals are used [64]. With all the above, the type of data used in this paper are the monthly irradiation data from each city, for the cases of global horizontal irradiation and direct normal irradiation. A quality control (QC) was carried out to check whether the data are good for use or not. Because of the unavailability of ground solar irradiation data for some of the cities chosen in this study, the QC will be carried out between the three different data sets mentioned before. The QC will consist of computing the relative deviation between the solar irradiation measurements of each data set. There are statistical tools that are used to compute these deviations, and it is given by a single number. The higher the number, the higher the deviation between the measured values.