During the past decade, most governments have been promoting energy eciency programs and the integration of renewable energy sources into the majority of energy uses. Among the diferent sectors, the agricultural sector is becoming a more active participant to reduce fossil fuel dependence and improve environmental sustainability. Indeed, agriculture usually combines both a high energy demand and water problems associated with over-exploited aquifers, providing great potential and remarkable opportunities to change the energy mix and maximize the use and integration of natural resources in a rational way. Considering this framework, the present paper describes and compares the solar resource integration and its e ects on agricultural pumping purposes in two Mediterranean countries, Spain and Morocco, with signi cant di erences in terms of energy mix, climatic conditions and energy policies. As a novel contribution in this paper, we propose the use of GIS to analyze the spatial and temporal variability of the solar resource through real data of both locations, as well as to study groundwater resources. With this aim, two technical proposals for irrigation purposes are compared in terms of environmental bene ts, CO 2emissions and agriculture energy model changes: diesel equipment and photovoltaic system. Results based on solar radiation resource, pumping requirements and aquifer depth are included in the paper. Keywords: Solar Energy Resource, Applicability Solar Energy, Solar Water Pumping, Sustainable Rural Development, Geographic Information Systems (GIS), Photovoltaic Systems. 1. Introduction Fossil fuels have met most energy needs since the 1st Industrial Revolution, providing remarkable industrial ad- vances in newly developing countries. These changes had signi cant in uences on most sectors, including the mod- ernization and industrialization of agricultural processes: tasks related with growing, harvesting, processing or de- livering became high energy-demanding. During the 2nd Industrial Revolution, both fossil fuel dependence and en- ergy consumption were increasing considerably. Industrial and developing countries then continued to meet their en- ergy needs by expanding the supply-base, without regard for ecient use or sustainability [1]. Nowadays, the world energy demand increased at a rate of 5% in 2010, and according to the International Energy Agency (IEA) it will continue increasing until 2050 [2]. This tendency is also motivated by the recent industrialization of countries where demography has soared along with their develop- ment, such as China or India [3]; involving further deple- tion of energy resources and uncertain scenarios for fossil fuel prices and energy demand [4]. As a consequence, en- ergy is currently at the core of the discussion, since energyproduction and use account for two-thirds of the world's greenhouse-gas emissions [2], certain dependency can be established between the use of fossil fuels and global warm- ing problems. Indeed, emissions have been traditionally linked to SO 2and CO 2concentrations, which are con- sidered relevant variables to characterize the greenhouse e ect [5]. Taking the nite fossil energy resources into account as well as the severity of pollution emissions, several coun- tries have promoted initiatives related to renewable source integration and the promotion of a more sustainable envi- ronment. The main objective is to move from a high CO 2 emission mix generation towards a low{emission model, maintaining long-term sustainable economic and social de- velopment [6]. Di erent programs have been promoted with this aim, such as the United Nations Environment Programme (UNEP), the World Meteorological Organi- zation (WMO) and the Intergovernmental Panel on Cli- mate Change (IPCC). In addition, a series of sustainable policies and strategies have been proposed to give an in- ternational support, including both the Kyoto Protocol and European Union policies [7]. The use of renewables Preprint submitted to Solar Energy Materials & Solar Cells http: // dx. doi. org/ 10. 1016/ j. solmat. 2016. 06. 045 May 17, 2020 throughout Europe and elsewhere in the rest of the world complies with clear objectives for energy saving and emis- sion reduction [8]. In reference to the road-map of renew- ables in Spain, signi cant results have been obtained as a result of subsidies and policies contributing to provide suitable conditions for the integration of renewable solu- tions, such as PER 2005-2010 [9] and PANER 2011-2020 [10] promoted by IDAE (Spanish Institute for the Energy Diversi cation) [11]. Additionally, and due to the contin- ued implementation of policies supporting renewable en- ergies in the European Union, around 12% of the total energy in Spain is provided by renewables, with 20% of energy from renewable sources being established by 2020 and considerably reducing greenhouse gas emissions. The location of Spain contributes signi cantly to the high levels of solar radiation, supposing a clear advantage for the in- tegration of solar PV solutions [12]. However, and despite Morocco having favorable conditions of solar radiation and also wind resource, the low price of electricity and fuel sup- poses a major drawback for the integration of renewables in this North African country. In fact, this sector is cur- rently becoming strategic and relevant for the government in Morocco, especially for the large scale integration of solar thermal and wind power solutions [13]. Agriculture in both countries has been modernized and upgraded with more and more energy requirements, usu- ally supplied by fossil fuels. In Spain, a speci c subsi- dized diesel for agriculture is available for the sector. In Morocco, fuel is not di erentiated depending on applica- tions and uses, with the price being considerably lower than in Spain. Therefore, solutions based on diesel equip- ment still remain as a very common practice for pumping groundwater purposes. Under this scenario, agricultural emissions have been increased from 4.7 billion tons of car- bon equivalent (CO 2eq) in 2001 to more than 5.3 billion tons in 2011 [14]. Moreover, the equipment usually used in the agriculture sector commonly presents low energy ef- ciencies and other factors such as obsolescence, and wear and tear. On the other hand, there are well-known water scarcity problems in both Mediterranean countries. For the speci c aquifers to be analyzed, an over-exploitation situation of aquifers has been detected, where farmers are using a larger and larger share of their pro ts to a ord fuel for pumping purposes. To provide an alternative so- lution for the agriculture sector, and according to current programs promoting the integration of renewables, a con- version of irrigation systems from fossil fuel to solar energy source should be addressed [15] [16, 17]. These initiatives lead to a sustainable environment, providing environmen- tal and social-economic bene ts [18], at local and regional levels [19]. Among the di erent resources, solar energy has been widely extended as an alternative resource during the last decades. Both eciency improvements and process optimization in Silicon production and manufacture have become a mature industry, supporting a high demand of PV modules and reducing the Wp price to lower than 0.5 Euro=Wp . Consequently, solar resource is considered asan alternative and competitive solution [20, 21]. With the aim of exploring the solar resource in detail, a Geograph- ical Information System (GIS) is proposed in this paper to integrate, analyze and eciently represent geographical information and physical conditions. The GIS application allows us to depict the solar radiation spatial variability due to the topography of the area [22] under di erent lev- els: global, regional or local level. Indeed, the success and competitiveness level of solar technology is based on analyzing the available solar resource throughout its tem- poral, spatial and spectral characteristics [23, 24]. Conse- quently, the geographical analysis of the solar resource in these two Mediterranean areas provides signi cant infor- mation regarding the solar resource distribution. A suit- able evaluation model is proposed taking into account ge- ographical characteristics, optimal locations for solar en- ergy solutions, environmental concerns, as well as social- economic factors associated with solar resource integration into agriculture [25, 6]. In addition, the combination of so- lar energy with other energy sources (hybrid applications) is also considered by including feasibility and cost analy- sis [26, 22]. According to the speci c literature, di erent contributions about solar atlas and solar pumping can be found aiming to analyze the viability of these systems [23]. Previous GIS application studies are focused on discussing the vulnerability of aquifers or their emissions, including solar resource evaluation [27]. However, there is a lack of contributions addressed to jointly evaluating solar and wa- ter resources in the agricultural sector [28], being desirable to include CO 2emission reductions. In [29], the feasibility or alternative solutions are analyzed from several aspects: technical, economic and environmental; without including GIS technical and economic information nor analyzing the applicability concept of solar resource in the studied eld. In comparison with recent studies, [29], the present paper focuses on an exportable and exible methodology based on a GIS solution, which provides an extensive solar re- source analysis in an easily understandable manner thanks to software at regional scale. The rest of the paper is structured as follows: Section 2 describes the energy requirements and solar resource potential in agriculture for the selected areas, including geographical description and water resources for both lo- cations and countries. The proposed methodology is de- scribed in Section 3, where the collected data are analyzed from a statistical, geographical and technical point of view. Results are discussed in Section 4. Finally, the conclusion is given in Section 5. 2. Energy Requirements and Solar Resource Po- tential in Agriculture: a Mediterranean Case Study 2.1. Location of Areas: General Description From the geographical and geological point of view, the study region of La Mancha (Spain) is a vast plain (around 2 Figure 1: Location of study areas: La Mancha (Spain) and the Saiss plain (Morocco) 5500 km2) dependent on Aquifer 23 (04.04 hydrogeological unit or the Western-La Mancha). It is located in the Cen- tral area of the high Guadiana river, a sedimentary basin mainly dominated by a limestone ('karst') region [30, 31]. The relief of the Morocco region, the Saiss plain (2100 km2) [32], also known as the Fez-Meknes plain, resem- bles the La Mancha plain on karst [33, 34, 32]. Regard- ing weather conditions, La Mancha area is considered as a continental BskMediterranean climate (K oppen-Geiger climate classi cation), typically associated with dry and hot summers (over 43C) and high solar radiation levels (over 4500kWh/m2per day), as well as cold winters with most days below 0C, see Figure 1 for geographical loca- tion. A signi cant low rain-fall (between 300-400 mm) and very high evaporation during most months clearly re ect the arid climate conditions in this Spanish area. The Saiss region has a CsaMediterranean climate (K oppen-Geiger climate classi cation), with annual average temperatures about 17.3C [32], dry and very hot summers (over 40C) and also with high solar radiation levels. By contrast, winters are milder than in the Spanish region, and winter and spring seasons present higher rainfall values (490-560 mm per year) [32]. This region can be thus classi ed as a semiarid-zone according to the Martonne index . In the region of La Mancha (Spain), the Aquifer 23 mainly comprises medium{sized cities, accounting for fewer than 400000 people, with a low population concen- tration and minor requirements supported by the aquifer. However, in the Maghreb region, the population is over 1.5 million of people, thus increasing the requirements on the Saiss aquifer in comparison with the Aquifer 23. Both areas belong to the Mediterranean agricultural landscape: olives, wheat and grapes; as well as other tree dry land crops (almonds, gs. . . ) and small orchards (fruit, vegeta- bles. . . ) In particular, La Mancha Region o ers a remark- able example of vast plains and dry land, supporting irriga- tion crops during the last centuries. In the area located in Meknes (Morocco), agriculture contributes signi cantly to economic aspects by promoting jobs and improving ruralincomes [35]. The landscape is still dominated by wheat, along with irrigation of vegetables, total 45%, and fruit (citrus, olive and vine) with 36% [35]. The area comprises an agricultural surface area of approximately 191000 Ha, around 80% of the total area. The irrigation crops account for less than a quarter of the land use (about 37000 Ha), the land with irrigation potential commissioning is over 123000 Ha [35]. 2.2. Water Resources for Irrigation Purposes The Mediterranean region is undergoing rapid local and global social and environmental changes. All indicators point to an increase in environmental and water scarcity problems with negative implications towards current and future sustainability [36]. The risk of water scarcity is proposed to be managed by preparedness rather than by a crisis approach, along with the importance of local man- agement at basin scale [37]. Moreover, several researchers have even pointed out the links between social-political re- lations and water management, including power-plays in irrigation policies [38, 39, 40]. In both areas, irrigation is a crucial aspect directly linked to the agricultural pro- duction and with signi cant impact on the environment. In Spain, the awareness to natural resources and agricul- tural modernization has led to irrigation methodologies based on drip and sprinkler solutions. However, gravity irrigation methods still remain in Morocco, being at this moment the most popular solution. In both cases, high water demand and inecient irrigation methods should be improved, proposing alternative solutions in line with the hydrological cycle characteristics of the area. Additionally, unsustainable irrigation patterns should be modi ed, pro- moting new policies from government and organizations responsible for the care of water resources [41]. In this way, the groundwater levels have dropped dramatically during the last years, with scarcity problems and diculties to reconcile agriculture with the environment. In La Mancha (Spain), the piezometric evolution of Aquifer 23 during the period 1980-2008 can be summa- rized as a sort of declining level periods, with the presence of notable but isolated partial recovering intervals mainly due to wet periods, see Figure 2 [42, 43]. As a consequence of a continuous over{exploitation of the Aquifer, pumping is currently the only way to extract water [44]. Therefore, rigid constraints and requirements have been issued for ir- rigation, such as a maximum of 1500m3/(Ha-per-year) for vineyard crops. The hydrogeological map of the Saiss aquifer (Fez- Meknes) was published in 1960 [45]. The Saiss aquifer |with contributions by in ltration of rainwater among other processes of 296-346 million m3/year| is currently estimated to provide an annual demand between 275 and 400 million m3/year due to rivers, drought and desiccation of some springs, drinking water and intensive agriculture (mainly since the 1980's). The aquifer currently has water de cit conditions with non-pumping limitations, with the average water demand of crops per hectare being between 3 Figure 2: Evolution piezometry upper aquifer of the La Mancha plain (Spain) [42] and the Saiss plain (Morocco) [35] 3500 m3/Ha and 5600 m3/Ha, see Figure 2 [35]. The Saiss aquifer presents a large depth variability as a consequence of geological in uences. Indeed, near Fez located at the East of the Ain Taoujdate line, it is over 60 m deep, even reaching over 350 m in some piezometers [34]. The chrono- logical evolution of the Saiss aquifer gives a clear imbal- ance between exploitation and recharge of water resource [33, 34]. 2.3. Energy Requirements and Solar Resource Potential Both areas are located in the 'sun belt' area [23], between 40N and 40S latitudes, with high solar radiation levels throughout the year. Spain is a country with a high en- ergy dependence, around 71% in 2013 of primary energy [46] and 27.3% of power demand covered by renewables [47]. Energy demanded by agriculture was 3.3% in 2013 of total primary energy, and over 76% is covered with fossil fuels. As mentioned before, this great energy dependence and the fuel price increasing is leading Spanish agriculture to an unsustainable situation. To overcome these draw- backs, the Spanish government promotes initiatives to sub- sidize fuel for agricultural applications, as a way to reduce the pressure on Spanish farmers. Until 2011, the Spanish government also nancially supported the integration of renewables, with a large economic contribution in R&D. Although the renewable energy sector has always been ex- panding during the last decades, the crisis has a ected it strongly, mainly driven by the reduction of programs and initiatives. The price of fuel in Morocco is fully regulated by the Mo- roccan government. In that country, fuel prices are 30-40% cheaper than in Spain, and a few programs and initiatives can be found to promote the renewable energy source in- tegration, despite Morocco being highly dependent on im- ported energy, with over 90% dependence on other coun- tries [48]. Nevertheless, there are few solar thermal sys- tems and photovoltaic installations connected to the grid, and few projects promoting renewable energy source in- tegration. Today, several specialized weather stations canbe found in the country. To overcome technological de - ciencies, Morocco has already started di erent initiatives to characterize the solar radiation resource in the country. The objective is to analyze and study accurately the solar resource conditions in each region of Morocco. Nowadays, the Meteorological Institute of Morocco has some weather facilities in di erent parts of the country, and the IRESEN (L'Institut de Recherche en l'Energie Solaire et Energies Nouvelles) and MASEN (Moroccan Agency for Solar En- ergy) are also promoting the installation of new stations for solar radiation studies. In line with the great development of photovoltaic technology, it would be desirable to have an extended knowledge of the geographical distribution and variability of the solar resource [28, 17]. Furthermore, an accurate database of suitable locations for renewable en- ergy facilities is suggested by some authors as a relevant tool to optimize the integration of these renewable solu- tions [25]. 3. Methodology: GIS Solution for Solar Resource Comparison and Applicability Purposes 3.1. Preliminaries Energy resources are usually spatially distributed, and GIS applications can be used as suitable solutions provid- ing a logical environment to analyze a variety of spatially related data in a cost-e ective way [49]. For the devel- opment of the maps, Quantum GIS (QGIS) (version 2.14 ESSEN) was selected by the authors. It is a GIS Open- Source solution, lightweight and with a friendly graphical interface, and is exible and easy to use. It can be freely installed and modi ed according to the speci c function- ality required by the application. It has a great interop- erability and works with all operating systems [50, 51]. QGIS provides a growing range of capabilities through ba- sic functions and accessories. It also allows to manage, edit and analyze data and design printable maps; per- forming map algebra, terrain analysis, hydrological models and supports a series of formats of raster and vector data. As remarkable advantages, the possibility of integrating 4 Figure 3: Proposed methodology based on solar resource analysis and comparison for irrigation purposes GRASS (Geographic Resources Analysis Support System) in QGIS, and the ease connection as PostGIS database can be highlighted. GIS can handle geo-referenced information to assess technical and economic feasibility of the source exploita- tion. Since the 1970s, di erent contributions have been developed, considerably solving problems in land manage- ment, such as evaluation of natural resources, agricultural land management, water management and control, or en- vironmental planning [15, 52, 53]. According to [54], the application of geomatics to renewable resource assessment, in particular to the solar resource, is a topic worth investi- gating [55]. GIS is thus a suitable solution for spatial anal- ysis of solar resources, considering spatial distribution of the potential, dependence on geographical locations, and levels of use according to the technology [6]. Moreover, an e ective selection of locations depends on consider- ing several independent factors concerning geomorphology, aquifer depths and solar radiation. The proposed methodology includes the analysis of three di erent types of data, which gives an extended compara- tive of the solar resource possibilities: (i)statistical data of aquifers and solar resource; (ii)geographical data in both areas; and (iii) technical analysis data. As can be seen in Figure 3, the proposed methodology can be summa- rized as: Comparison of installations and CO 2emissions; Comparative tables and graphs; GIS comparative of solar resource; and Comparison of applicability layer.3.2. Data Sources In line with the previous section, the Spanish data corre- sponding to the studied area can be divided into three cat- egories: statistical, geographical and technical data. The solar resource has been provided through SiaR data-base of Castilla La Mancha Region, an agricultural organization in charge of collecting data to provide this information for irrigation purposes ( http://crea.uclm.es/siar/ ). In our case study, a historical series of data from January 2001 to December 2014 is considered with the values in MJ/m2per day. The historical data are used to analyze the incident solar resource in the area of the aquifer. An- nual data from nineteen stations allow us to determine a detailed map of solar radiation under a GIS environ- ment. Geographic data including the geo-positioning of all pyranometer stations is also available. The solar radiation layer can be matched with data concerning the aquifer, thus it is possible to propose a layer with a GIS area of the aquifer. Another source of data provides the aquifer depth estimated in February 2014 for di erent points of the study area through information given by 26 piezo- metric stations with their corresponding UTM (Univer- sal Transverse Mercator) position. This information is supported by the Confederaci on Hidrogr a ca del Guadi- ana, in collaboration with the irrigation Community of Aquifer 23. Figure 4 shows the pyranometer station lo- cations. Similar types of data corresponding to the Mo- rocco location were collected as a result of a collabora- tion with the Meknes University. A historical solar radi- ation data series from February 2004 to December 2013 was provided by l Institut de Recherche en Energie So- laire et en Energies Nouvelles in Rabat (IRESEN) ( http: //www.iresen.org/fr/index.html ), inWh=m2per day, corresponding to seven pyranometer stations, see Figure 5. Geographical data are also available from geo-referenced data stations, including contour and piezometric stations with their UTM locations for the aquifer. These data have been provided by the Agence du Bassin Hydraulique du Sebou (Morocco). Technical data were collected from pre- vious contributions and other installations in a similar way to the Spanish case. 3.3. Statistical Analysis of Solar Resource Solar resource data for both areas are analyzed in de- tail to determine average monthly data as well as station variability. Firstly, a classi cation of the data collected in both countries and a selection of common units is car- ried out. In our case, all data are expressed in Wh/m2 per day, determining maximum, minimum and monthly average values for each station. Secondly, a summary of variability and range of the data including standard de- viation between stations are compared by using monthly values of each year. Data variation between stations is lower than 10% for both locations. An equivalent average value is considered as valid for all stations, and variability 5 Figure 4: Location of measuring Piezometric Stations by reference to the aquifer Figure 5: Location of measuring Pyranometer Stations by reference to the aquifer 6 Figure 6: Annual average and standart deviation among measure- ment stations between stations is also depicted in this study, see Fig- ure 6. From the monthly average values per station, an equivalent average monthly value from all measured sta- tions is estimated to compare both countries. In a sim- ilar way, an annual average value is determined for each station, and the corresponding annual equivalent average value can be calculated for each study area and country. The geographical analysis inputs are the monthly average values per station and per country [26, 56]. 3.4. Geographical Analysis of Solar Resource With landscape scales, topography is a key factor de- termining the spatial variability of radiation. Variation in elevation, orientation (slope and aspect), and shad- ows cast by topographic features all a ect the amount of radiation received at di erent locations [25]. The rst step is focused on limiting the study area and the ex- tension of both aquifers, based on maps and table in- formation including coordinates of the aquifers provided by the Confederaci on Hidrogr a ca del Guadiana (Spain) [43, 44, 57] and the Agence du Bassin Hydraulique du Se- bou (Morocco)[58, 59]. The estimation of the aquifer out- line is related to a dynamic mass of water in uenced by two main factors: the high water table and the geological materials that serve the continent, which can be used as waterproo ng or otherwise can be permeable and present a very narrow boundary line. Data corresponding to the statistical analysis (monthly and annual solar radiation for each measurement station at their own UTM coordinates) are then exported to the geographical analysis. To give an example of the proposed methodology, only characteristics of representative months are considered in the Results sec- tion: January, April, July and October; as well as the an- nual values o ering additional geo{referenced information. Data from piezometers and aquifer depths corresponding to each study area give the groundwater status by a simple yet adequate estimation.The next step is to determine the aquifer maps and so- lar radiation distributions corresponding to both locations. The GIS process deals with radiation data and geograph- ical locations to determine the study area layer and es- timate the space-temporal data. A depth map of each aquifer is calculated in a similar way [60]. Information regarding the aquifer borderlines, solar radiation resource and aquifer depths is then used to determine the distribu- tion of the water resource and energy needs, see Figure 7. The results involve a comparison of both monthly and an- nual solar resource as well as an applicability layer. This layer provides an index of the applicability as the role of solar radiation resources and the water table, or expressed di erently, a map showing the areas with the best sun- aquifer conditions to implement a solar pumping system. This map does not indicate the viability of the system as it is necessary to consider other important factors such as crop irrigation, irrigation frequency, energy prices, etc. This technology has already proven its reliability [61]. The IDW (Inverse distance weighting) interpolation method is applied to estimate values between stations. The sampling points are weighted during the interpola- tion and then the in uence of a point relative to another is decreasing with the distance from the new point to be estimated, determining an IDW surface [62]. The weight- ing is assigned to the sampling points using parameters and weighting coecient modeling how the in uence of the weighting decays as the distance to the new point in- creases. As the ratio increases, the value of the unknown points approximates the value of the closest observation point. It is important to point out that the IDW interpo- lation method presents several drawbacks: the maximum and minimum values in the interpolated surface can be drawn only at points of sample data. This often results in small peaks and wells around the location of the data. 3.5. Technical Analysis of Solar Resource In addition to the previous analysis, and for a more com- plete comparison of both areas, an extended study of the agricultural sector is also proposed. Subsequently, and af- ter analyzing the applicability layer, a comparison based on physical data for two installations in terms of CO 2sav- ing emissions and energy needs by using photovoltaic and diesel solutions is carried out. The same Mediterranean crops in these areas are considered, assuming similar sur- faces to ensure such comparability. From these areas, crop needs and irrigation pro les for the design of agricultural pumps are determined from both points of view: diesel solution and PV installation. 4. Results 4.1. Statistical Analysis of Solar Resource For both study areas, Figure 8 depicts the solar resource values through the statistical analysis. Considering win- ter months, Morocco has higher solar resorces than Spain. 7 Figure 7: Depth aquifers: distribution of water resource Figure 8: Solar resource in both locations: Spain and Morocco 8 Figure 9: Monthly, maximum, minimum and standart deviation of the measurement of each month Spring and autumn months present solar values almost similar in both countries. During the summer, solar ra- diation levels in Spain are higher than in Morocco, with even more daily sun hours. In terms of average levels, the Spanish annual average is 4.8 kWh/m2per day, lower than the annual average of Morocco (5.3 kWh/m2per day), see Figure 9. Regarding the spatial variability among sea- sons, the Spanish standard deviation is higher (135.74) than in Morocco. This di erence is due to the e ect of a larger area for the Spanish case, a height di erence of 94 m, as well as a distance of around 160 km between the Spanish western and the eastern part. In Morocco, with 10.10 standard deviation, a smaller study area is consid- ered, with 100 km width and a di erence in elevation of over 200 m. 4.2. Geographical Analysis of Solar Resource: GIS Com- parison Figure 10 compares solar resource data corresponding to di erent months for both locations. In the Spanish area, a clear distinction between the east and west parts can be observed, with a global variability below 10%. The east zone presents less solar radiation and coincides with an upper height. In the region of Meknes-Fez (Morocco), the results show a very slight spatial variability in most months with a decreasing radiation in the South part. The East-northeast (ENE) gives less solar radiation and higher values around Meknes. These data provide a spatial vari- ability and distribution of solar resources in both areas. An additional map is shown in Figure 11, where a com- parison between average annual solar resource for both study areas is depicted. Figure 10: Solar resource for di erent months: comparison of maps Figure 12 compares the applicability layers for both study areas. This layer provides an index of applicability associated with the relationship between the solar radia- tion values and the water level measured in Wh m/m2 per day. Through the comparison of these two areas, it can be deduced that solar radiation values are almost con- stant along the aquifer areas, with the aquifer depths be- ing a more decisive variable. In this way, groundwater data corresponding to the Moroccan aquifer show it to be deeper than the Spanish aquifer (named Aquifer 23). In Saiss (Morocco), data with greater applicability lev- els correspond to values closer to the borderlines of the plain, near three rivers in the basin of the Sebou river. On the contrary, the Spanish data show aquifer depths almost uniform on the Western-side, being deeper than on the Eastern-side. These results point out the Guadi- ana river band nearby areas, lagoons and its tributaries as areas with remarkable rates of applicability. The results provide relevant information regarding the potential of so- lar energy in such areas, meaning that the applicability of solar water pumping depends on the location. In line with these results, the investments will be higher or lower. It is possible to establish a comparison between these eco- nomic requirements and the current expenses incurred by farmers in pumping diesel, see [63] for further information. In order to provide additional information about the 9 Figure 11: Annual solar resource: comparison of maps Figure 12: Geographical Analysis of Solar resource: Comparison of applicability layers Figure 13: Histogram study of applicability of La Mancha (Spain) and Saiss (Morocco) 10 applicability layer, Figure 13 shows the histogram results for these values. As can be seen, for the Spanish case over 80% of the values are between 44.21 and 486.36 Wh m/m2 per day, with an average value of 223.37 Wh m/m2per day. Regarding the Saiss plain (Morocco), these values show that 81.77% of data are between 44.50 and 222.54 Wh m /m2per day, presenting a lower standard deviation and an average value of 105.40 Wh m/m2per day. 4.3. Technical Analysis of Solar Resource and CO 2emis- sions A comparison of energy needs and emissions for both locations is carried out in this section. Indeed, the Span- ish aquifer has an average applicability value of 223.37 Wh m/m2per day corresponding to an average annual radiation of 4.87 kWh/m2per day and with an average aquifer depth of 21.82 m. For the aquifer located in Mo- rocco, the average value of applicability is estimated to be 105.40 Wh m/m2per day, corresponding to an aver- age annual radiation of 5.34 kWh/m2per day and with an average depth of 50.76 m. Therefore, and by considering both study areas and previous analysis, Figure 14 sum- marizes the water pumping design to support the require- ments, estimating water needs for the same crops. These water requirements are slightly higher for the Saiss plain (Morocco), mostly due to higher average temperatures and higher solar radiation levels. According to the results, the study area of Saiss (Morocco) needs more irrigation time and thus, a higher energy demand in comparison with the Spanish case. By considering these water necessities, Figures 15 and 16 present an extensive comparison between the proposed solutions based on diesel equipment and PV installation. Di erent economic costs are estimated for both countries, as a consequence of their energy policies and the increas- ing pressure on the farmer's life. Moreover, in terms of CO2emissions, the Saiss plain in Morocco is higher than the same crop in La Mancha (Spain) [64, 65, 66]. If PV solution is selected for pumping purposes, and consider- ing the same pattern of crop water demands, in 82.73% of cases (455015 Ha), La Mancha (Spain) requires a PV- installation with a power rate of 2800 W. By considering the Morocco case study and also assuming a crop demand- ing the same amount of irrigation as the vineyard, with the climatic conditions of the Saiss plain, in 81.77% of cases (179894 Ha), a PV-installation of 8160 W rate power is necessary [67]. Both systems are designed in terms of the power demanded by the crops according to the energy required for the three months that the plant water de- mand for growth lasts in time interval, coinciding with the hottest summer months in both areas, and it corresponds to the time period between the owering and maturation of the crop chosen (from June to August). Through the system demand, it is possible to estimate CO 2emissions [68, 69, 70]. Comparing both systems and estimating the emission reduction provided by the energy model change toward a model based on renewables.Comparing Figures 15 and 16, the energy consumption in the Saiss plain is higher than in the Spanish aquifer, and thus a larger PV installation is required for the same use per Hectare. Along with that, CO 2emissions would be three times higher in the case of a diesel generator in Morocco than in La Mancha (Spain), mainly due to the depth: 72% higher in Saiss (Morocco) against La Mancha. Nevertheless, it is necessary to point out the low price of fossil fuels in Morocco, which means that this coun- try can still be based on diesel generators for agricultural pumping systems. Finally, the CO 2emission savings for photovoltaic technologies is very favorable with the use of Mono-Si in both countries, although the savings in CO 2 emissions are much more desirable in the case of the Saiss plain, being possible to save up to ve times more CO 2 than in La Mancha (Spain). 5. Conclusions A proposed methodology based on GIS is described to analyze and compare two areas in di erent Mediterranean countries suitable for the installation of pumping systems by using PV plants through the aggregation of qualita- tive and quantitative criteria related to both solar resource and aquifer depth. Signi cant di erences in terms of en- ergy mix, climatic conditions and energy policies have been considered, with the aim of providing an extensive and real comparison. From real data corresponding to both loca- tions (Spain and Morocco), a GIS environment is proposed to analyze spatial and temporal variability of the solar re- source, as well as the underground aquifers for both ar- eas for pumping irrigation purposes. Additional energy, economic and environmental savings attributed to the re- placement of diesel pumps by solar PV installations are also included in the paper. The results assess the proposed methodology based on GIS to be able to solve multi-dimensional problems related to agriculture sector and energy requirements applied to ir- rigation processes based on aquifer, water resource control and solar resource integration. In addition, the replace- ment of current diesel systems by solar pumping installa- tions is also included, estimating the CO 2emission sav- ings for both locations. According to the results, the Saiss aquifer (Morocco) has a higher energy demand to obtain water in comparison with La Mancha (Spain). In terms of CO 2emissions, they would be three times higher in the case of a diesel generator in Morocco than in La Mancha (Spain). Future work is proposed to assess the degree of clustering of plots through agro-energetic cooperatives in order to create irrigation storage facilities. 6. Acknowledgements The authors appreciate the EU Marenostrum-Erasmus Mundus Program, which allows us to collaborate with the Moulay Ismail University in Meknes (Morocco) This 11 Figure 14: Water requirements and pumping design in both areas Figure 15: Diesel equipment design and CO 2emissions in both areas Figure 16: PV system design and CO 2emissions in both areas 12 work has been partially supported by funds, DGICYT and Junta de Andaluc a under projects TIN 2014-55024-P and P11-TIC-8001 respectively, and S eneca Foundation 19882- GERM-15.