Residential solar thermal performance considering self-shading incidence between tubes in evacuated tube and flat plate collectors

Esteban Zalamea-Leon, Edgar A. Barragán-Escandón, John Calle-Sigüencia, Mateo Astudillo-Flores, Diego Juela-Quintuña

Research output: Contribution to journalArticlepeer-review


The performance of solar thermal technology under high-altitude equatorial climatic and solar path conditions has not been determined. Evacuated tube solar collectors are more efficient than flat plate collectors in cold and cloudy regions; however, due to their dependence on orientation, the irradiation incidence between the tubes of these collectors can be blocked. In this study, the performance of these types of collectors was analyzed to determine the implications of their orientation under these specific climate conditions. Four solar thermal systems were installed: two of the systems used evacuated tube collectors, and two used flat plate collectors. Each collector was connected to storage and discharge points to simulate residential consumption when observing the real performance of the four systems in terms of irradiation availability. The evacuated tube collectors were more efficient and reduced the backup energy requirement by up to 20.6% more on average than the flat plate collectors. In addition, the performance of the evacuated tube collectors increased by up to 9.8% when the tubes were arranged parallel to the solar path, compared to when they were arranged perpendicular to the solar path, verifying that the blockage effect is an important parameter to consider for evacuated tube technology. The main novelty of this research is the comparison of these two technologies under different orientations, with perpendicular and parallel dispositions toward the solar path, in a high-altitude equatorial location where solar collectors are not typically oriented in any particular orientation. To the best of our knowledge, this is the first complete analysis of real systems deployed under these conditions.

Original languageEnglish
Article number13870
JournalSustainability (Switzerland)
Issue number24
StatePublished - 1 Dec 2021

Bibliographical note

Funding Information:
Funding: This work was developed with funding from the Research Department of the Universidad de Cuenca (VIUC) and the Energia Group of the Universidad Politécnica Salesiana. This work is part of the project “Calibration of the F-chart model for solar thermal collectors with parameterization and validation according to typical layouts for architectural integration in equatorial Andean climates”.

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.


  • Andean equatorial climate
  • Domestic hot water
  • Evacuated tube collectors
  • Flat plate collectors
  • Solar thermal collectors


Dive into the research topics of 'Residential solar thermal performance considering self-shading incidence between tubes in evacuated tube and flat plate collectors'. Together they form a unique fingerprint.

Cite this