MONTHLY DESIGN DATA FOR MAXIMUM SOLAR RADIATION FALLING ON COLLECTOR ARRAYS IN BAGHDAD CITY

Abstract

Increasing use of solar energy as a clean and free solution for energy demand necessitates proper use of its equipment, enhanced spatial planning and distribution of solar collectors, optimum directional facing and tilt angle to ensure maximum solar radiation falling, and decreasing as possible as the shading effects of panel arrays. Most existing references lack comprehensive data about shading effects that varied along the year and design of solar array. In the present work, enhanced theoretical design data of solar collector arrays were tabulated for each month in Baghdad. MATLAB program was used to calculate the maximum clear sky solar radiation per unit area per day. The tabulated data yields an economically saved design of solar field or rooftop collector systems. The results indicated that, the shading effect on panel arrays almost vanishes when the distance between two panel rows to panel height ratio is greater than 1 in summer and greater than 2 in winter.

Keywords

• Solar field designs,panel shading effect,solar collector arrays,mutual shading

References

1. [1] Sultan, F., Ali F. A., and Razaq, T. K., "Tilt Angle Optimization of Solar Collectors for Maximum Radiation in Three Iraqi cities," International Journal of Engineering and Industries(IJEI), vol. 3, no. 4, pp. 99-107, December 2012.
2. [2] Dimitrios Passias and Bengt Kallback , "Shading Effects in Rows of Solar Cell Panels," Solar Cells, no. 11, pp. 281-291, 1984.
3. [3] Volker Quaschning and Rolf Hanitsch, "Shade Calculations in Photovoltaic System," in ISES Solar World Conference, Harare / Zimbabwe, September 11-15, 1995.
4. [4] Volker Quaschning and Rolf Hanitsch , "Increased Energy Yield of 50% at Flat Roof and Field Installations with Optimized Module Structures," in 2nd World Conference and Exhibition on Photovoltaic Solar Energy Conversion, Vienna · Austria, 6-10 July 1998.
5. [5] Elsayed, Moustafa M. and Al-Turki, Abdullah M., "Calculation of Shading Factor for a Collector Field," Solar Energy, vol. Vol. 47, no. No. 6, p. 413—424, 1991.
6. [6] Vignola, F., "Using Sun Path Charts to Estimate the Effect of Shading on PV Arrays," in American Solar Energy Society Conf, Portland, OR., 2004.
7. [7] Jouri Kanters and Henrik Davidsson , "Mutual shading of PV modules on flat roofs: a parametric study," Energy Procedia, no. 57, p. 1706 – 1715, 2014.
8. [8] Weissenbacher, M., Towards New Renewable Energy Policies in Urban Areas: The Re-definition of Optimum Inclination of Photovoltaic Panels, J. sustain. dev. , "energy water environ. syst., 3(4), pp 372-388,," 2015. [Online]. Available: http://dx.doi.org/10.13044/j.sdewes.2015.03.0028.

9. [9] Castellano, N. N., J. A. G. Parra, J. Valls-Guirado, and F. Manzano Agugliaro.,, "Optimal displacement of photovoltaic array's rows using a novel shading model," Appl. Energy , vol. 144, pp. 1-9, 2015.
10. [10] Maleki S. A. M, Hizam H., and Gomes, C., "Estimation of Hourly, Daily and Monthly Global Solar Radiation on Inclined Surfaces: Models Re-Visited," Energies, vol. 10 (1), no. 134, 2017.
11. [11] ASHRAE 2005, ASHRAE Handbook of Fundamentals, American Society of Heating, Refrigerating, and Air Conditioning Engineers..
12. [12] J. A. a. B. W. A. Duffie, Solar Energy Thermal Processes, New York: John Wiley and Sons, 1980.
13. [13] Lunde, P. J., Solar Thermal Engineering Space Heating and Hot Water Systems, New York: John Wiley and Sons, 1980.
14. [14] Joudi, K. A., "Some Aspects of Solar Irradiance Calculations," in Proceedings of the 3rd Arab International Solar Energy Conference, SRC, Baghdad, Feb., 1988.
15. [15] Farber, E. A. Morrison, C. A., "Clear-Day Design Values of Solar Energy," ASHRAE GRP 170, Application of Solar Energy for Heating and Cooling of Buildings, Edited by Jordon, R. C. and Liu, B. Y. H, 1977.
16. [16] O. Bara, M. Conti and E. Santamata, "Shadows Effect in a Large Scale Solar Power Plant," Sol. Energy, vol. 19, pp. 759-762, 1977.
17. [17] J. Appelbaum and J. Bany , "Shadow Effect of Adjacent Solar Collectors in Large Scale Systems," Solar Energy, vol. 23, pp. 497-507, 1979.
18. [18] R. E. Jones, JR. and J. F. Burkhart , "Shading Effects of Collector Rows Tilted Toward The Equator," Solar Energy, vol. 26, pp. 563.-565, 1981.
19. [19] Klein, S.A., "Calculation of Monthly Average Insolation on Tilted Surfaces," Sol. Energy, vol. 19, p. 325–329, 1977.