Comparative Study of Antireflection Coating Materials for Solar Thermal Collectors

  • Fana Filli
  • Petros Gebray
  • Ashenafi Kebedom
Keywords: Thermal collectors, Antireflection, Absorptance, Ethiopia.


Locally available absorber and antireflection coating materials for solar thermal collectors have been assessed and tested for performance compared to ordinary commercial black paint used in solar water heaters and solar cookers. Absorber plates made of aluminum and iron sheet metals coated with blackboard paint, commercial black paint, and black ABRO spray were prepared. These materials were tested for thermal performance on a natural circulation flat plate solar water heater and plastic bottles. Comparison has been made separately for both absorber material and coating materials which showed that the iron sheet and black ABRO spray to have the highest absorptance. On a clear sky radiation of 973.5W/m2, a maximum stagnation temperature of 99.2°C and 107.5°C is achieved on the black ABRO spray painted aluminum sheet metal and iron sheet metal respectively. This is because ABRO black paint has the highest absorptance for wavelengths of below 2.5μm and low thermal emittance for wavelengths above 2.5μm. During the testing of solar water heaters, an increase in temperature of 14.9°C at the outlet from absorber plate and 7.5°C at the surface of storage tanker has been achieved when using ABRO black spray. This is attributed to the highest absorptance for wave lengths of below 2.5μm and low thermal emittance for wave lengths above 2.5μm of ABRO black paint. As can be concluded, iron sheet metal which is cheap and easily available is best for solar thermal applications and provides significant benefit in cost reduction. Furthermore, the cost for ABRO black paint is similar to other coating materials and it can easily be applied on the surface of absorber materials.


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AlShamaileh, E. 2010. Testing of a new solar coating for solar water heating applications. Solar Energy, 84:1637–1643.
Asfafaw H. T., Mulu B. K & Ole J. N. 2014. Solar Powered Heat Storage for Injera Baking in Ethiopia. Energy Procedia, 57:1603–1612.
Akintola, O. A & Sangodoyin, A. Y. 2015. Design, Development, and Performance Evaluation of Solar Heating System for Disinfection of Domestic Roof-Harvested Rainwater. International Scholarly Research Notices, doi: 10.1155/2015/529527.
Duffie, J. A & Beckman, W. A. 1980. Solar engineering of thermal processes. ISBN: 978-0-470-87366-3, Wiley, pp.236-240.
Friz, N & Waibel, F. 2003. Coating materials. Springer Series in Optical Sciences. 88:105-130.
Garg, H.P & Prakash, J. 2006. Solar energy for industrial process heat, in: Solar energy fundamentals and applications. Tata McGraw-Hill, ISBN 0-07-463631-6, pp.229-230.
Gautam, A., Chamoli, S., Kumar, A & Singh, S. 2017. A review on technical improvements, economic feasibility and world scenario of solar wáter heating system. Renewable and Sustainable Energy Reviews, 68: 541-562.
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