# GIS-Based Solar Radiation Mapping, Site Evaluation, and Potential Assessment: A Review
## 4 Solar Potential Assessment Using GISs
### Radiation Modeling Tool  
Solar radiation modeling enables prediction of the average daily and hourly global horizontal radiation, beam radiation, and diffuse radiation. GISs were utilized to map and analyze the effects of the sun over a geographical area for specific time periods. In general, GIS-based radiation modeling was implemented, on the national or regional scales to calculate the insolation across an entire landscape (area) or to calculate the amount of radiant energy for a given location (point).  
[PERSON] and [PERSON] [69] discussed solar power prospects to assess a large CSP plant in Wilayat Duqum, Oman in a geospatial context. A solar radiation map of Wilayat Duqum was generated by employing solar radiation tools in ArcGIS software and DEM data. Subsequently, the yearly electric power generation potential was calculated according to the type of CSP technology. In a similar manner, [PERSON] et al. [70] mapped the solar radiation over Wilayat Duqum by employing the aforementioned identical tools and data to investigate the potential of implementing a combined CSP electric power and seawater desalination plant. This study dealt with two options (i.e., the combination of a CSP plant with a thermal desalination unit and exploitation of only the electricity output of a CSP plant with a reverse osmosis desalination unit) and showed where each concept is preferable considering local conditions. [PERSON] and [PERSON] [71] estimated the annual PV electricity production in kilowatt-hours per building in the urban areas of Bardejov in eastern Slovakia. In this study, 3D city model input data, the r.sun solar radiation model, and PVGIS estimation utility, an open-source solar radiation tool, were utilized to assess the PV potential of each building. The analysis revealed a high PV potential that could cover about two-thirds of the current electricity consumption of the city.  
Meanwhile, [PERSON] et al. [72] modeled the vertical facades of buildings as well as solar radiation on roofs to inspect the potential of building an integrated PV system in the region of the University of Lisbon, Portugal. To achieve this objective, a 3D building model and DSM data were employed as input data for the self-developed software. The DSM data indicated the digital surface height, including objects (e.g., buildings, facilities, and trees), while the DEM data excluded the built (e.g., power lines,buildings, and towers) and natural (trees and other types of vegetation) elements. [PERSON] et al. [73] listed hierarchical methodologies for potentials such as the physical, geographic, technical, economic, and social potentials. The horizontal irradiance on roofs was derived by using radiation computed based on the geometry of the sun-earth system, land use maps, and building maps. Subsequently, considering the PV arrangement and model, the technical potential of a roof-integrated PV system in Spain was estimated. [PERSON] et al. [74] presented maps of the solar resources in Vietnam and the solar potential for CSP and grid-connected PV technology. GHI and DNI maps were derived from the Meteosat Indian Ocean Data Coverage satellite imagery based on the Heliosat method. Subsequently, the solar potential was assessed by performing simple simulations. GISs were used to combine the solar potential with the land availability determined based on the slope conditions and to map the technical solar potential.