Diploma Thesis Defense by Ms Evagelia Dialyna

«Optimization of the thermal behavior and energy efficiency of photovoltaic panel with the use of phase change materials»

Thesis Title: «Optimization of the thermal behavior and energy efficiency of photovoltaic panel with the use of phase change materials»

Friday  27 September 2019, at: 13:00, Venue: Hall Κ2.A3

Examination Committee

  • Professor Theocharis Tsoutsos (advisor)
  • Professor Mihalis Lazaridis
  • Assistant Professor Maria Mandalaki

Abstract

The operating temperature of the photovoltaic panel is one of the most crucial factors that determine the amount of produced electricity. An increase of the temperature reduces the electric output of the panel, so it is significant to develop methods of controlling the temperature of the surface.

 

 The aim of this particular thesis was to study the passive cooling of photovoltaic panels using phase change materials. In particular, the thermal behavior and the electrical efficiency of four identical panels were examined. Special containers were installed on the rear and of three of the panels and were filled with phase change materials, whereas the fourth panel was used as a reference photovoltaic panel. All studied panels had a nominal wattage of 10W and on each on, a different phase change material was attached. The materials that were studied were PCM RT 27, PCM RT 31, PCM RT 35 HC of Rubitherm, with melting points of 27°Ϲ, 31°Ϲ and 35°Ϲ respectively.

 

  The photovoltaic panels were studied in real environmental conditions for six months (February 2019 – July 2019). In total, 50 daily measurements were conducted in which voltage, amperage, density of solar power, rear and frontal surface temperature was recorded. With appropriate processing of the experimental data, the daily power production and the average daily efficiency of the panels was calculated. Next, the operating temperature and the energy efficiency of the reference panel were compared with the ones of the three panels with phase change materials. The results indicated that the photovoltaic panel with PCM RT 27, had the optimal energy behavior, showing an increase of 0.34% on average at its efficiency compared to the reference photovoltaic panel. The respective increase for the PCM RT 31 panel was 0.12%, while the PCM RT 35 did not achieve an increase and had the worst efficiency in 64% of the experimental tests