Document Type : Research Article


1 Department of Geography, Razi University, P. O. Box: 67144-14971, Kermanshah, Kermanshah, Iran

2 Department of Remote Sensing and GIS, Faculty of Geographical Sciences, University of Kharazmi, P. O. Box: 15719-14911, Tehran, Tehran, Iran


One of the most important characteristics of site selection for solar energy system installations and optimum solar energy harvesting in the hilly or mountainous terrains is knowledge about the amount and duration of solar radiation within such topographic terrains. Solar radiation data are not readily available for most mountain terrains because of their rugged topography. For these areas, solar radiation data can be obtained through alternative methods such as the Hemispherical Viewshed Algorithm in which spatial and temporal variations of radiation are calculated in terms of elevation, slope, and terrain. In this study, this algorithm was used to estimate and model solar radiation in the Paraw Mountain in Kermanshah. The inputs for this method were ASTER Digital Elevation Model (DEM) with a spatial resolution of 30 m and meteorological parameters that affect solar radiation. The slope and aspect maps were created from ASTER DEM and layers for monthly direct, diffuse, global, and radiation periods were generated for the year 2016. The results showed that in the Paraw Mountain, the amount of solar radiation received was dependent on the slope orientation, as the north and northeast-facing slopes received the lowest and the south and southwest-facing slopes and the flat areas received the highest direct and global radiation (i.e., in terms of this factor, these landscapes can be recommended as the best site for solar energy system installations and optimum solar energy harvesting). The sum annual radiation period varies from 382.67 to 4310.9 hours, the total radiation received annually varies between 1005.56 and 7467.3 MJ/m2, and the sum monthly solar radiation is the highest in July (181.49-842.26 MJ/m2) and lowest in December (25.42-319.90 MJ/m2). Statistical error comparisons between station-based measurements and model-based estimates were performed via R2, measures. As a result, this model was recommended for solar radiation estimation with acceptable accuracy, especially in high areas with rugged topography where solar radiation data are not readily available.


Main Subjects

1.     Mostaufiolmamaleki, R., Essentials of astronomy Earth in the universe, Scientific Publication Center of Islamic Azad University Press, (1996). (
2.     Tavousi, T., The climatic application of solar radiation in environmental planning, Sistan and Baluchestan University Press, Zahedan, (2017). (
3.     Sabziparvar, A., Khatar, B. and Mohebzadeh, H., "Assessment of GIS ability in zonation of the seasonal and annual distribution of total solar radiation (Case study: Central provinces of Iran)", Iranian Journal of Geophysics, Vol. 9, No. 2, (2015), 14-29. (In Farsi)(
4.     Liu, B. and Jordan, R., "Daily insolation on surfaces tilted towards equator", ASHRAE Journal,Vol. 10, (United States), (1961). (
5.     Hay, J.E., "Calculation of monthly mean solar radiation for horizontal and inclined surfaces", Solar Energy, Vol. 23, No. 4, (1979), 301-307. ( (79)90123-3).
6.     Steven, M.D. and Unsworth, M.H., "The angular distribution and interception of diffuse solar radiation below overcast skies", Quarterly Journal of the Royal Meteorological Society, Vol. 106, No. 447, (1980), 57-61. (
7.     Reindl, D.T., Beckman, W.A. and Duffie, J.A., "Evaluation of hourly tilted surface radiation models", Solar Energy, Vol. 45, No. 1, (1990), 9-17. ( (90)90061-G).
8.     Tian, Y.Q., Davies-Colley, R.J., Gong, P. and Thorrold, B.W., "Estimating solar radiation on slopes of arbitrary aspect", Agricultural and Forest Meteorology, Vol. 109, No. 1, (2001), 67-74. ( (01)00245-3).
10.   Valizadeh Kamran, K. "Estimation of potential evapotranspiration with Estefnz method and GIS techniques in Eastern Azerbaijan", Journal of Geography and Planning, Vol. 18, No. 49, (2014), 317-334. (In Farsi) (
11.   Hofierka, J. and Suri, M., "The solar radiation model for open source GIS: Implementation and applications", Proceedings of The Open Source GIS-GRASS User’s Conference, Vol. 2002, (2002), 51-70. (
12.   Dozier, J. and Frew, J., "Rapid calculation of terrain parameters for radiation modeling from digital elevation data", IEEE Transactions on Geoscience and Remote Sensing, Vol. 28, No. 5, (1990), 963-969. (
13.   Ramachandra, T.V., "Solar energy potential assessment using GIS", Energy Education Science and Technology, Vol. 18, No. 1/2, (2006), 101. (
14.   Pons, X. and Ninyerola, M., "Mapping a topographic global solar radiation model implemented in a GIS and refined with ground data", International Journal of Climatology, Vol. 28, No. 13, 1821-1834. (
15.   Batlles, F.J., Bosch, J.L., Tovar-Pescador, J., Martinez-Durban, M., Ortega, R. and Miralles, I., "Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map", Energy Conversion and Management, Vol. 49, No. 2, 336-345. (
16.   Gastli, A. and Charabi, Y., "Solar electricity prospects in Oman using GIS-based solar radiation maps", Renewable and Sustainable Energy Reviews, Vol. 14, No. 2, (2010), 790-797. (
17.   Wong, M.S., Zhu, R., Liu, Z., Lu, L., Peng, J., Tang, Z. and Chan, W.K., "Estimation of Hong Kong’s solar energy potential using GIS and remote sensing technologies", Renewable Energy, Vol. 99, (2016), 325-335. (
18.   Zhang, Y., Chang, X. and Liang, J., "Comparison of different algorithms for calculating the shading effects of topography on solar irradiance in a mountainous area", Environmental Earth Sciences, Vol. 76, No. 7, (2017), 295. (
19.   Zhang, Y.L., Li, X., Cheng, G.D., Jin, H.J., Yang, D.W., Flerchinger, G.N., Chang, X.L., Wang, X. and Liang, J., "Influences of topographic shadows on the thermal and hydrological processes in a cold region mountainous watershed in northwest China", Journal of Advances in Modeling Earth Systems, Vol. 10, No. 7, (2018), 1439-1457. (
20.   Moreno, H.A., Ogden, F.L. and Alvarez, L.V., "Unstructured-mesh terrain analysis and incident solar radiation for continuous hydrologic modeling in mountain watersheds", Water, Vol. 10, No. 4, (2018), 398. (
21.   Choi, Y., Suh, J. and Kim, S.M. "GIS-based solar radiation mapping, site evaluation, and potential assessment: A review", Applied Sciences, Vol. 9, No. 9, (2019),1960. (
22.   Buffat, R., Grassi, S. and Raubal, M., "A scalable method for estimating rooftop solar irradiation potential over large regions", Applied Energy, Vol. 216, (2018), 389-401. (
23.   Hoseinzadeh, S. and Azadi, R., "Simulation and optimization of a solar-assisted heating and cooling system for a house in Northern of Iran", Journal of Renewable and Sustainable Energy, Vol. 9, No. 4, (2017), 045101. (
24.   Hoseinzadeh, S., Hadi Zakeri, M., Shirkhani, A. and Chamkha, A.J., "Analysis of energy consumption improvements of a zero-energy building in a humid mountainous area", Journal of Renewable and Sustainable Energy, Vol. 11, No. 1, (2019), 015103. (
25.   Yousef Nezhad, M.E. and Hoseinzadeh, S., "Mathematical modelling and simulation of a solar water heater for an aviculture unit using MATLAB/SIMULINK", Journal of Renewable and Sustainable Energy, Vol. 9, No. 6, (2017), 063702. (
26.   REN21, Renewables 2016 global status report, (2016). (
30.   Kavyani, M.R. and Alijani, B., The foundation of climatology, Tehran: Samt Press, (2005). (In Farsi). ( %D9%87%D9%88%D8%A7%D8%B4%D9%86%D8%A7%D8%B3%DB%8C)
31.   Rich, P.M., Dubayah, R., Hetrick, W.A. and Saving, S.C., "Using viewshed models to calculate intercepted solar radiation: Applications in ecology", American Society for Photogrammetry and Remote Sensing Technical Papers, (1994), 524-529. (
32.   Rich, P.M. and Fu, P., "Topoclimatic habitat models", Proceedings of the Fourth International Conference on Integrating GIS and Environmental Modeling, (2000). (
33.   Fu, P., "A geometric solar radiation model with applications in landscape ecology", Ph.D. Thesis, Department of Geography, University of Kansas, Lawrence, Kansas, USA, (2000). (
34.   Fu, P. and Rich, P.M., "The solar analyst 1.0 manual", Helios Environmental Modeling Institute (HEMI), USA, (2000). (
35.   Fu, P. and Rich, P.M., "A geometric solar radiation model with applications in agriculture and forestry", Computers and Electronics in Agriculture, Vol. 37, (2002), 25-35. ( (02)00115-1).
36.   Bakirci, K., "Correlations for estimation of daily global solar radiation with hours of bright sunshine in Turkey", Energy, Vol. 34, No. 4, (2009), 485-501. (
37.   Besharat, F., Dehghan, A.A. and Faghih, A.R., "Empirical models for estimating global solar radiation: A review and case study", Renewable and Sustainable Energy Reviews, Vol. 21, (2013), 798-821. (
38.   Chen, J.L., Li, G.S., Xiao, B.B., Wen, Z.F., Lv, M.Q., Chen, C.D., Jiang, Y., Wang, X.X. and Wu, S.J., "Assessing the transferability of support vector machine model for estimation of global solar radiation from air temperature", Energy Conversion and Management, Vol. 89, (2015), 318-329. (
39.   Zolfaghari, H., Earth's climate, Razi University Press, Kermanshah, (2014). (
40.   Alijani, B., Iran's climate,Tehran: Payame Noor University Press, (2012). (
41.   Li, D., "Using GIS and remote sensing techniques for solar panel installation site selection", Master's Thesis, University of Waterloo, (2013). (