Theoretical Analysis of Solar Thermal Collector with a Flat Plate Bottom Booster Reflector

Hiroshi Tanaka


A theoretical analysis of a solar thermal collector with a flat plate bottom reflector is presented. The bottom reflector extends from the lower edge of the collector. The variations of daily solar radiation absorbed on the collector with inclinations from horizontal for both the collector and reflector throughout the year were predicted, and the optimum inclinations of the collector and reflector which maximize the daily solar radiation absorbed on the collector were determined for each month at 30oN latitude. The effects of the size of the collector and reflector on the daily solar radiation absorbed on the collector were also investigated. The optimum collector inclination is lower in summer and higher in winter, while the optimum reflector inclination is higher in summer and lower in winter. The average daily solar radiation absorbed on the collector throughout the year can be increased about 20%, 27% and 33% by using a bottom reflector if the ratio of reflector length to collector length is 0.5, 1.0 and 2.0, respectively, when the collector’s length is equal to its width.

 Key words: Solar energy; Solar thermal collector; Bottom reflector; Collector-reflector; Optimum inclination


Key words: Solar energy; Solar thermal collector; Bottom reflector; Collector-reflector; Optimum inclination

Full Text:



[1] Rao, A.V.N., Chalam, R.V., Subramanyam, S., & Rao, T.L.S. (1993). Energy Contribution by Booster Mirrors. Energy Convers Manage, 34, 309-326. doi:10.1016/0196-8904(93)90115-Q

[2] Hussein, H.M.S., Ahmad, G.E., & Mohamad, M.A. (2000). Optimization of Operational and Design Parameters of Plane Reflector-Tilted Flat Plate Solar Collector Systems. Energy, 25, 529-542. doi:10.1016/S0360-5442(00)00003-7

[3] Pucar, M.D.J., & Despic, A.R. (2002). The Enhancement of Energy Gain of Solar Collectors and Photovoltaic Panels by the Reflection of Solar Beams. Energy, 27, 205-223. doi:10.1016/S0360-5442(01)00081-0

[4] McDaniels, D.K., Lowndes, D.H., Mathew, H., Reynolds, J., & Gray, R. (1975). Enhanced Solar Energy Collection Using Reflector-Solar Thermal Collector Combinations. Solar Energy, 17, 277-283. doi:10.1016/0038-092X(75)90044-4

[5] Taha, I.S., & Eldighidy, S.M. (1980). Effect of Off-South Orientation on Optimum Conditions for Maximum Solar Energy Absorbed by Flat Plate Collector Augmented by Plane Reflector. Solar Energy, 25, 373-379. doi:10.1016/0038-092X(80)90349-7

[6] Arata, A.A., & Geddes, R.W. (1986). Combined Collector-Reflector Systems. Energy, 11, 621-630. doi:10.1016/0360-5442(86)90110-6

[7] Dang, A. (1986). Collector, Collector-Reflector Systems – an Analytical and Practical Study. Energy Convers Manage, 26, 33-39. doi:10.1016/0196-8904(86)90028-2

[8] Bollentin, J.W., & Wilk, R.D. (1995). Modeling the Solar Irradiation on Flat Plate Collectors Augmented with Planar Reflectors. Solar Energy, 55, 343-354. doi:10.1016/0038-092X(95)00058-Y

[9] Hellstrom, B., Adsten, M., Nostell, P., Karlsson, B., & Wackelgard, E. (2003). The Impact of Optical and Thermal Properties on the Performance of Flat Plate Solar Collectors. Renewable Energy, 28, 331-344. doi:10.1016/S0960-1481(02)00040-X

[10] Chiam, H.F. (1982). Stationary Reflector-Augmented Flat-Plate Collectors. Solar Energy, 29, 65-69. doi:10.1016/0038-092X(82)90281-X

[11] Garg, H.P., & Hrishikesan, D.S. (1988). Enhancement of Solar Energy on Flat-Plate Collector by Plane Booster mirrors. Solar Energy, 40, 295-307. doi:10.1016/0038-092X(88)90002-3

[12] Kostic, L.T., Pavlovic, T.M., & Pavlovic, Z.T. (2010). Influence of Reflectance from Flat Aluminum Concentrators on Energy Efficiency of PV/Thermal Collector. Applied Energy, 87, 410-416. doi:10.1016/j.apenergy.2009.05.038

[13] Kostic, L.T., Pavlovic, T.M., & Pavlovic, Z.T. (2010). Optimal Design of Orientation of PV/T Collector With Reflectors. Applied Energy, 87, 3023-3029. doi:10.1016/j.apenergy.2010.02.015

[14] Tanaka, H. (2011). Solar Thermal Collector Augmented by Flat Plate Booster Reflector: Optimum Inclination of Collector and Reflector. Applied Energy, 88, 1395-1404. doi:10.1016/j.apenergy.2010.10.032

[15] Tanaka, H. (2011). Tilted Wick Solar Still with Flat Plate Bottom Reflector. Desalination, 273, 405-413. doi:10.1016/j.desal.2011.01.073

[16] Japan Solar Energy Soc (1985). Solar Energy Utilization Handbook (p. 33). Tokyo: Onkodo Press.

[17] Tanaka, H., Nosoko, T., & Nagata, T. (2000). A Highly Productive Basin-Type – Multiple-Effect Coupled Solar Still. Desalination, 130, 279-293. doi:10.1016/S0011-9164(00)00092-8




  • There are currently no refbacks.

Copyright (c)

Share us to:   


If you have already registered in Journal A and plan to submit article(s) to Journal B, please click the CATEGORIES, or JOURNALS A-Z on the right side of the "HOME".

We only use three mailboxes as follows to deal with issues about paper acceptance, payment and submission of electronic versions of our journals to databases:;;

 Articles published in Energy Science and Technology are licensed under Creative Commons Attribution 4.0 (CC-BY).


Address: 1020 Bouvier Street, Suite 400, Quebec City, Quebec, G2K 0K9, Canada. 
Telephone: 1-514-558 6138 
Website: Http:// Http://;

Copyright © 2010 Canadian Research & Development Centre of Sciences and Cultures