1 Department of BIM Center, China Architecture Design Institute Co. Ltd., Beijing, China. 2 College of Landscape Architecture and Arts, Northwest A&F University, Yangling, China.
Solar collectors can provide clean, renewable, and domestic energy. The tilt angle and horizontal direction of solar collectors significantly affect its efficiency. There are many good methods to search the optimum tilt angle and horizontal direction to realize the maximum total radiation on the solar collector within a particular day or a specific period. However, it is hard to realize it when solar collectors are placed under obstacle’s shadows; especially when some obstacles, such as trees, have irregular shapes. This paper presents algorithms to achieve the best tilt angle and horizontal direction for solar collector’s performance under the free-form surfaces 3D obstacle’s shadow. The solution process is composed of 4 steps. First, it creates a 3D scene, in which a unique color is given to the solar collector. Second, it employs orthographic projection from the point of view to get an image of the scene. Third, the number of pixels is used to represent the efficiency of the solar collector by counting the pixels of the unique color. Fourth, the efficiency of solar collector in each direction in a period of time is calculated with many images to further select the best direction.
Solar Collector, Tilt Angle, Horizontal Direction, Solar Radiation, Optimum Design, Orthographic Projection
Wang, S. and Hong, B. (2015) Optimum Design of Tilt Angle and Horizontal Direction of Solar Collectors under Obstacle’s Shadow for Building Applications. Journal of Building Construction and Planning Research, 3, 60-67. doi: 10.4236/jbcpr.2015.32007.
[1] Penrod, E.B. (1964) Solar Load Analysis by Use of Orthographic Projections and Spherical Trigonometry. Solar Energy, 8, 127-133. http://dx.doi.org/10.1016/0038-092X(64)90073-8
[2] Capeluto, I.G., Yezioro, A. and Shaviv, E. (2003) Climatic Aspects in Urban Design—A Case Study. Building and Environment, 38, 827-835. http://dx.doi.org/10.1016/0360-5442(81)90061-X
[3] Moon, S.H., Felton, K.E. and Johnson, A.T. (1981) Optimum Tilt Angles of a Solar Collector. Energy, 6, 895-899. http://dx.doi.org/10.1016/0360-5442(81)90061-X
[4] Markvart, T. (1994) Solar Electricity. John Wiley & Sons, Chichester.
[5] Yakup, M.A.B.H.M. and Malik, A.Q. (2001) Optimum Tilt Angle and Orientation for Solar Collector in Brunei Darussalam. Renewable Energy, 24, 223-234. http://dx.doi.org/10.1016/S0960-1481(00)00168-3
[6] Elminir, H.K., Ghitas, A.E., El-Hussainy, F., Hamid, R., Beheary, M.M. and Abdel-Moneim, K.M. (2006) Optimum Solar Flat-Plate Collector Slope: Case Study for Helwan, Egypt. Energy Conversion and Management, 47, 624-637. http://dx.doi.org/10.1016/j.enconman.2005.05.015
[7] Dave, J.V. (1977) Validity of the Isotropic-Distribution Approximation in Solar Energy Estimations. Solar Energy, 19, 331-333. http://dx.doi.org/10.1016/0038-092X(77)90002-0
[8] Temps, R.C. and Coulson, K.L. (1977) Solar Radiation Incident upon Slopes of Different Orientations. Solar Energy, 19, 179-184. http://dx.doi.org/10.1016/0038-092X(77)90056-1
[9] Perez, R., Stewart, R., Arbogast, C., Seals, R. and Scott, J. (1986) An Anisotropic Hourly Diffuse Radiation Model for Sloping Surfaces: Description, Performance Validation, Site Dependency Evaluation. Solar Energy, 36, 481-497. http://dx.doi.org/10.1016/0038-092X(86)90013-7
[10] Bugler, J.W. (1977) The Determination of Hourly Isolation on an Inclined Plane Using a Diffuse Irradiance Model Based on Hourly Measured Global Horizontal Isolation. Solar Energy, 19, 477-491.
http://dx.doi.org/10.1016/0038-092X(77)90103-7
[11] Shariah, A., Al-Akhras, M.-A. and Al-Omari, I.A. (2002) Optimizing the Tilt Angle of Solar Collectors. Renewable Energy, 26, 587-598. http://dx.doi.org/10.1016/S0960-1481(01)00106-9
[12] Ozgenera, O. and Hepbaslib, A. (2005) Performance Analysis of a Solar-Assisted Ground-Source Heat Pump System for Greenhouse Heating: An Experimental Study. Building and Environment, 40, 1040-1050.
http://dx.doi.org/10.1016/j.buildenv.2004.08.030
[13] Löf, G.O.G. and Tybout, R.A. (1973) Cost of House Heating with Solar Energy. Solar Energy, 14, 253-278. http://dx.doi.org/10.1016/0038-092X(73)90094-7
[14] Heywood, H. (1971) Operating Experiences with Solar Water Heating. Journal of the Institute of Heating, Ventilation and Energy, 39, 63-69.
[15] Gunerhan, H. and Hepbasli, A. (2007) Determination of the Optimum Tilt Angle of Solar Collectors for Building Applications. Building and Environment, 42, 779-783.
http://dx.doi.org/10.1016/j.buildenv.2005.09.012
[16] Shaviv, E. and Yezioro, A. (1997) Analyzing Mutual Shading among Buildings. Solar Energy, 59, 83-88.
http://dx.doi.org/10.1016/S0038-092X(96)00103-X
[17] Reda, I. and Andreas, A. (2004) Solar Position Algorithm for Solar Radiation Applications. Solar Energy, 76, 577-589. http://dx.doi.org/10.1016/j.solener.2003.12.003
[18] Kroner, W.M. and Abrey, D. (1985) From the Sun’s Point of View. 10th National Passive Solar Conference, Raleigh.