Optimum Sites for Solar Energy Harvesting in Egypt Based on Multi-Criteria GIS

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1 Optimum Sites for Solar Energy Harvesting in Egypt Based on Multi-Criteria GIS Gomaa M. Dawod Survey Research Institute National Water Research Center Cairo, Egypt Mosaad S. Mandoer Geography Department Mansoura University Mansoura, Egypt Abstract Egypt faces an electricity sacristy recently, since it depends mainly on fossil fuels in electricity production. Thus, it initiated an ambitious plan to increase the renewable energy share from 2% (now) to 20% of the total demand by year This study focuses on utilizing the Multi-Criteria Analysis (MCA) within a Geographic Information Systems (GIS) environment to locate optimum locations for solar energy projects. Several physical and environmental spatial databases have been built up and an integrated GIS system have been developed. Ten different criteria have been selected and weighted to represent the favorite conditions for solar energy new investments. The attained suitability model represents the optimum locations for solar energy harvesting on a national scale. It has been found that the entire Egyptian territories is almost suitable for solar energy harvesting with varying suitability index. The suitability value range from 4.5 to 9.3, with an average equals 7.4 on a scale of 10. Moreover, areas of suitability index more than 80% have identified, and found to have a total area of square kilometer, which is a significant indicator about the potential of solar energy harvesting in Egypt. It is recommended that the developed suitability model being considered by decision makers in the future plans of energy development in Egypt. Keywords Solar energy, Geographic Information Systems, Multi-criteria analysis, Egypt I. INTRODUCTION The global requirement for sustainable energy provision becomes increasingly significant over the next years as the environmental effects of fossil fuels become apparent. Additionally, the rapid growth of population in developing countries increase the need for electric generation and distribution. Renewable energy, such as solar energy, wind energy, biofuel energy,...etc, is becoming a fundamental source for green energy worldwide. Solar power technologies are advancing and making a strong argument to be considered the next step towards the future of renewable energy production. On a national scale, the Egyptian Cabinet has approved, in 2012, an ambitious plan to increase the percentage of renewable energy to 20% by 2020 [1]. Some current solar energy projects include the solar water heaters project for hotels in Red Sea and south Sinai governorate, the Kurimat 140 MW (mega watt) integrated solar power plant, and the 100 MW solar thermal power plant at Kom Ombo [1]. However, selecting appropriate sites for harvesting solar energy is not a single-criteria task. Basically, it is based on several sets of physical, environmental, and socio-economical criteria in order to decide optimum geographic locations. GIS has been utilized extensively in the last decades for sighting optimum locations for a variety of objects, such as groundwater [2], touristic infrastructures [3], urban development [4], earthquake refugee camps [5], water harvesting [6], solid waste disposal [7], and wind turbine [8]. Finding a suitable location for solar energy development affects purchase price, solar power efficiency, and environmental impacts. The GIS-based multi-criteria approach has proven to be an efficient decisionsupport tool for locating optimum spatial sites particularly for solar energy harvesting. For example, Wanerer and Herle [9] has developed a web-based spatial decision support system based on a multi-criteria analysis in Spain. Also, Tahri et al. [10] combined GIS and multi-criteria method to assess the suitability of some locations in Morocco to carry out a renewable energy project. Similarly, Brewer et al. [11] utilized the GIS-based multi-criteria approach to determine socially acceptable and economically viable locations for utility-scale solar projects in Idaho, USA. Moreover, Matejicek [12] utilized multi-criteria GIS approach to locate optimum sites of renewable energy projects in Czech republic. This paper aims to locating appropriate sites for solar energy harvesting in Egypt utilizing the GIS-based multi-criteria scheme. II. MULTI-CRITERIA GIS A criterion is a measureable phase of a judgment, that makes it achievable to differentiate and quantify choices in the decision-making process. Decision makers can use multicriteria approach to judge various subjective and conflicting criteria whereas evaluating the suitability of a specific area with regards to a certain development. The method is often utilized within a GIS environment where the suitability of an area is represented with visual aids. 450

2 Several GIS-based multi-criteria approaches have been proposed and utilized, such as binary overlay (Boolean logic), Analytic Hierarchy Process (APH), and the weighted linear combination. The first method can be though of as overlaying many transparencies each represents a certain condition or criterion. In a GIS software, this method is adopted as a grid analysis procedure using an AND function to combine all layers of criteria. The result of this method comprises the sites that meet the whole set of the required conditions. On the other hand, the AHP multi-criteria method involves several steps including: calculation of the criteria scores, calculation of the criteria weights, local priorities and consistency of comparisons, and the determination of suitable alternatives [e.g. 18, and 11] The weighted linear addition method is based on the concept of computing a weighted average for each cell in a raster. In order to obtain the suitability map, the following summation is obtained: S n i 1 w x i i / w where S denotes the suitability index, wi is the weight of criteria i, xi is the criterion of factor i, n is the number of criteria. A simplified form of equation 1 may be obtained if the weights are scaled so that their sum equals one. Finally, the attained suitability model assigns a suitability index for each cell representing its suitability degree regarding the designed set of criteria. Finding a suitable location for solar energy development affects purchase price, solar power efficiency, and environmental impacts. The GIS-based multi-criteria approach has proven to be an efficient decision-support tool for locating optimum spatial sites particularly for solar energy harvesting. For example, Castillo et al. [18] evaluated the potential of solar power generation within the European Union utilizing a multi-criteria assessment approach. In addition, Wanerer and Herle [19] has developed a web-based spatial decision support system based on a multi-criteria analysis in Spain. Also, Tahri et al. [20] combined GIS and multi-criteria method to assess the suitability of some locations in Morocco to carry out a renewable energy project. Similarly, Brewer et al. [21] utilized the same approach to determine socially acceptable and economically viable locations for utility-scale solar projects in Idaho, USA. Moreover, Matejicek [22] applied the multicriteria GIS method to locate optimum sites of renewable energy projects in Czech republic. (1) acquired input data contain a Digital Elevation Model (DEM) for Egypt, annual average of solar radiation map, and several topographic and remote sensing imageries. The first step in the data processing stage include data manipulation, such as slope extraction from the available DEM, digitization of required datasets including the road and electricity distribution networks, and unification of geodetic datums for all raster and vector data types. Figure 1 depicts the processing scheme in this primary step in order to construct a number of digital spatial databases. Fig 1: Input Data Processing Methodology The utilized SRTM (Shuttle Radar Topography Mission) global DEM indicates that the terrain heights of Egypt range from -135 m to 2603 m with an average of 300 m (Fig. 2). The Arc GIS v. 10 software has been applied to extract terrain slopes, that is found to vary from 0 to 71 degree, with a mean of 2 degree (Fig. 3). Shapefiles for main urban features, particularly main cities and airports, have been also constructed utilizing the available topographic maps and remote sensing imageries (Fig. 4). A total of 98 major city and 15 major civilian airports have been exploited. Furthermore, the road and electrical distribution networks have been developed (Fig. 5). The total length of main road network has found to be more than 10 thousand kilometers, while the main electrical distribution network has a total length of 8500 km approximately. III. INPUT MATERIALS In the current research, a number of processing procedures have been performed in order to apply the multicriteria approach within a GIS environment. Basically, multicriteria analysis aims to optimize spatial locations to meets a number of conditions or limiting factors. Hence, the input datasets consist of several geospatial databases, each represents a specific criterion. In the current research, the 451

3 Fig. 4: Cities and Airports Distribution Fig. 2: Topography of Egypt Fig. 5: Electrical And Roads Networks Fig. 3: Slopes of Egypt The solar atlas of Egypt, issued in 1991, showed that the annual average of direct solar radiation range between 5.5 kwh (kilowatt-hour)/m 2 /year to 9.3 kwh/m 2 /year (NREA, 2013). These data, depicted in Figure 6, have been converted to a raster dataset and have been utilized in the current research study. 452

4 IV. PROCESSING METHODOLOGY Based on several literatures and case studies concerning solar energy harvesting, ten criteria have been selected to be processed in the current research [e.g. 18, 25, 26, and 27]. Table 1 presents the adopted criteria, that can be divided generally into two groups: technical criteria (potential of solar radiation, terrain slopes, and distances from the electrical distribution network); and economical criteria (distances from roads, coastlines, cities, and airports). Additionally, the protected areas' type have been imposed as constraints in the processing multi-criteria stage. For each criterion, a reclassification has been performed in order to evaluate its particular suitability for solar energy harvesting. A specific weight strategy has been applied in treating the utilized criteria while processing the final suitability model (Figure 8). The selected weights, as shown in the last column of Table 1, assign a sum of 60% to the technical criteria and a total of 40% to the economical conditions. Fig. 6: Annual Average Solar Radiation Furthermore, digital spatial databases for protected areas including the agricultural lands, lakes, and valleys have been created (Fig. 7). Their total area exceeds almost 61 thousands of square kilometers. The agricultural areas contain both the traditional lands in the Nile valley and Delta along with the lands of the undergoing development project for reclaiming a million faddans (a faddan is approximately 4200 square meters). Fig. 8: Multi-Criteria Processing Algorithm Fig. 7: Protected Areas TABLE 1: UTILIZED CRITERIA AND WEIGHTS Criteria Type Criterion Categories Suitability Weight Solar Radiation (kwh/m2/day) 0.30 Technical Economical Constraints > < 4.5 Slope (degree) > 10 Electrical Network (km) Roads (km) Coastlines (km) Cities (km) Airports (km) Land Use > 20 > 5 < 5 > 5 < 5 > 5 < 5 > 3 < 3 Agricultural Other Lakes Lakes Valleys Valleys High Medium Low High Medium Low High Medium Low

5 V. RESULTS AND DISCUSIONS Proximity-to-feature raster datasets have been constructed for each selected limiting factor. So, several primarily suitability models have been developed according the classification schemes applied. Re-classification function has been carried out to convert values of each raster on a scale of 10 points, where 10 represents the highest suitability index. Figures 9, 10, and 11 depicts examples of such models particularly for the terrain slopes, distances from electrical distribution network, and distances from the road network respectively. Fig. 10: Suitability of Distances from Electrical Network Fig. 9: Suitability of Terrain Slopes Fig. 11: Suitability of Distances from Roads Network Lastly, all raster suitability models representing the whole criteria have been combined in a weighted scheme according to the designed weights. The resulted model multiplies the weighted value by each raster layer value that sums each corresponding cell. Again, a reclassification function was applied in order to scale the attained weightedsum model on a 10-point scale. The accomplished final suitability model, depicted in figure 12, shows that the entire Egyptian territories is almost suitable for solar energy harvesting with varying suitability index. The suitability value range from 4.5 to 9.3, with an average equals

6 TABLE 2: HIGH-SUITABILITY AREAS BY GOVERNORATES Governorates High- Locations Area (km2) Percentage New Valley % Aswan % Suez % Marsa Matrouh % Giza % Others Governorates % Sum % VI. CONCLUSIONS Fig. 12: Final Suitability Model Moreover, areas of suitability index more than 80% have identified and represented in figure 13. It has been concluded that these high-suitability sites have a total area of square kilometer, which is a great indicator about the potential of solar energy harvesting in Egypt. Table 2 represents the major areas of high-suitability according to governorates. It can be seen that the New Valley governorate contains 20 % of these promising locations, while Aswan governorate posses 15 %. Hence, it is recommended that priority of future plans for solar energy projects should be given to these two specific governorates. Energy is fundamental force that affects all aspects of development social, economic, and environmental issues. Renewable energy, particularly solar energy, becomes an essential clean energy source worldwide. This paper focused on the utilization of multi-criteria GIS approach for locating optimum sites for solar energy harvesting in Egypt. Based on ten technical and economical criteria, a suitability model has been developed representing the spatial variation of solar energy potential over the Egyptian territories. It has been found that almost all the Egyptian lands are promising in solar energy harvesting with variable suitability index. Highsuitability locations have been identified with a total area of more than 25 thousand square kilometers. The New Valley, Aswan, and Suez governorates posses almost half of such promising locations. Hence, it is recommended that the accomplished suitability model being considered by decision makers in the future plans of energy development in Egypt. REFERENCES Fig. 13: High-Suitability Sites [1] NREA (Egypt's New and Renewable Energy Authority) (2013) Annual report, , 56 pp. [2] Cradden, L., Kalogeri, C., Martinez Barrios, I., Galanis, G., Ingram, D. and Kallos, G., (2016) Multi-criteria site selection for offshore renewable energy platforms, Renewable energy, No. 87, pp [3] Lemana, N., Ramlia, M., and Khirotdinb, P., (2016) GIS-based integrated evaluation of environmentally sensitive areas (ESAs) for land use planning in Langkawi, Malaysia, Ecological indicators, No. 61, pp [4] Fraile, A., Larrodé, E., Magrenan, A., and Sicilia, J. (2016) Decision model for siting transport and logistic facilities in urban environments: A methodological approach, Computational and applied mathematics, No. 291, pp [5] Hofer, T., Sunak, Y., Siddique, H., and Madlener, R. (2016) Wind farm siting using a spatial analytic hierarchy process approach: A case study of the Stadteregion Aachen, Applied energy, No. 163, pp [6] Colantoni, A., Delfanti, L., Recanatesi, F., Tolli, M., and Lord, R. (2016) Land use planning for utilizing biomass residues in Tuscia Romana (central Italy): Preliminary results of a multi criteria analysis to create an agro-energy district, Land use policy, No. 50, pp [7] Dawod, G., 2013, Suitability analysis for tourist infrastructures utilizing multi-criteria GIS: A case study in Al-Hada city, Saudi Arabia, 455

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