## 1 Introduction  
Nowadays the world is heading towards an energetic transition phase where the main goal is to reduce the dependency on carbon-based sources of energy and increment the integration of new technologies that can utilize renewable sources as the main fuel to produce usable energy. A high interest is given to solar energy technologies, since it is a power source that is not limited to a few regions around the world. However, solar irradiation available on the Earth surface on solar power premises is not easily manageable due to the unpredictability of weather conditions, such as cloudiness and humidity.  
One of the regions where solar energy is playing an important role in the energy sector is the MENA (Middle East and North Africa) region. The Middle East Solar Industry Association (MESIA) has reported that in the MENA region energy investments are going to reach USD 1 trillion in the period 2019-2023 [1]. Driven by pure market forces, many MENA regions have stated their intentions to increase renewable energy (RE) production, as these technologies have become cheaper than burning fossil fuels. Another reason for further augmenting the RE production in the region is the expected growth in the energy demand, along with the depletion of the fossil fuel reserves. In this line, due to the water scarcity issue that these countries experience, energy-intensive desalination operations are increasingly being adopted [2].  
Due to their geographical location, the MENA countries have a huge potential in terms of solar energy projects, as solar energy is quite abundant in the region. As such, multiple countries in the region devised national energy plans, where an increase in solar energy production is a vital part of them. Concentrated solar power (CSP) capacity, for instance, has experienced a considerable growth in the MENA region. Some of the highlighted countries where CSP deployment has increased over the last years are Algeria, Egypt, Israel, Kuwait, Morocco, Saudi Arabia and the United Arab Emirates (UAE) (see Figure 1).  
Following this momentum, future plans about increasing solar investment are becoming more popular. Egypt, for instance, established the goal of increasing renewable production up to 20% by 2022. The country also expects a national capacity of solar energy of 3.5 GW by the year 2027. Saudi Arabia devised a plan in which by the year 2023, 9.5 GW of the country's energy production will come from clean energy. The United Arab Emirates (UAE) set an ambitious goal of 1 GW of solar capacity by 2020 and 5 GW by 2030.  
In this regard, the Kingdom of Morocco stated, through the National Solar Plan in 2009, the goal of reaching 2 GW of installed capacity by 2020. Recently, this goal was updated to 4 GW by 2030. According to it, it is expected that up to 52% of electricity production will be based on renewable technology. As a result, Morocco is considered to be an important actor concerning solar energy development in the future of the MENA region and, consequently, it has been chosen as an object of study.  
The Kingdom of Morocco enjoys a considerable solar energy resource due to its latitude. For a successful implementation of these solar projects, the use of reliable solar irradiation data is essential. In this regard, determination and validation of the irradiation is mandatory for the techno-economic valuation of solar projects--current [4; 5; 6] and future--since working on inaccurate data may lead to significant deviations between the predicted and the actually achieved results.