ABSTRACT
Solar Photovoltaic (PV) technology is an upcoming technology for harnessing solar power. The performances of the PV modules are affected by incident solar radiation and mainly due to the rise in surface temperature in the hot environmental conditions. To manage the PV module temperature, passive cooling technology is adopted in this work. The integration of phase change materials (PCMs) as a thermal regulating medium into the PV module’s rear surface is intended. Two inorganic hydrated salts, Sodium Carbonate Decahydrate (SCD) -Na2CO3.10H2O and Magnesium Sulfate Heptahydrate (MSH) – MgSO4.7H2O are used to form the binary eutectic PCM. The binary eutectic PCM was integrated on the backside of the 25 W polycrystalline silicon PV module and tested for temperature regulation under the outdoor conditions of Kovilpatti (9°10′0′′N, 77°52′0′′E), Tamil Nadu, south India. The thermophysical properties of the eutectic PCM, including the latent heat of fusion and, temperature of phase change were estimated using Differential Scanning Calorimeter (DSC). The melting and freezing point of the 70:30 SCD-MSH eutectic mixture was 35.6 °C and 31.1 °C, respectively, with a latent heat value of 230.5 J/g. The PV-PCM system showed an instantaneous temperature reduction up to 7°C with an increase of 1.21% in the daily average efficiency. An increase in the daily DC power output by 12.5% than the reference PV module is observed in the PV-PCM system.
Nomenclature
PV | = | Photovoltaic |
PCM | = | Phase change material |
SCD | = | Sodium Carbonate Decahydrate |
MSH | = | Magnesium Sulfate Heptahydrate |
DSC | = | Differential Scanning Calorimeter |
TGA | = | Thermogravimetric Analyzer |
WPJ | = | White petroleum jelly |
BIPV | = | Building Integrated Photovoltaic |
p-Si | = | Polycrystalline silicon |
Tof | = | Onset freezing point of the salt hydrate (°C) |
Tf | = | The freezing point of the salt hydrate (°C) |
Tom | = | Onset melting point of the salt hydrate (°C) |
Tm | = | The melting point of the salt hydrate (°C) |
TEof | = | Onset freezing point of the eutectic (°C) |
TEom | = | Onset melting point of the eutectic (°C) |
TEf | = | The freezing point of the eutectic (°C) |
TEm | = | The melting point of the eutectic (°C) |
A | = | PV cell area (m2) |
Voc | = | PV panel open-circuit voltage (V) |
PDC | = | DC power of the PV panel (W) |
= | Conversion efficiency of the PV panel | |
cp | = | Specific heat capacity of the PCM (J/g°C) |
λ | = | Thermal conductivity of the PCM (W/m°C) |
ρ | = | Density of the PCM (g/cm3) |
m | = | Mass of the sample (g) |
β | = | Heating rate (°C/min) |
x | = | Thickness of the PCM layer (mm) |
η | = | PV efficiency at STC |
h | = | specific enthalpy of the PCM (J/g) |
t1, t2 | = | operating temperature range (°C) |
TPV | = | Back surface temperature of PV panel (°C) |
Eday | = | Energy value to be drained from the PV surface (Wh/m2day) |
Acknowledgments
The authors extend their gratitude to Tamil Nadu State Council for Science and Technology (TNSCST), Chennai, India for the financial grant under the Student Projects scheme [Sanction No.TNSCST/SPS/AR/2018-19 dated 18/02/2019] and National Engineering College, Tamil Nadu, India for generous support in this work.
Additional information
Notes on contributors
Ramanan Pichandi
Mr. Ramanan Pichandi is a teaching faculty and research scholar in the faculty of Mechanical Engineering. His research area includes field performance study of various photovoltaic technologies, solar thermal technologies, and energy storage.
Kalidasa Murugavel Kulandaivelu
Dr. Kalidasa Murugavel Kulandaivelu received his Doctor of Philosophy in the field of Solar desalination from Anna University, Chennai in 2009. He has wide hands of research experience on modeling and enhancing the productivity & effectiveness of solar stills. His research area includes performance improvement of other solar thermal systems such as spiral flow passive solar water heater, double pass solar air heater, compressed water thermal energy storage and performance & economic viability of Solar Photovoltaic systems.
Karthick Alagar
Dr. A. Karthick received his Doctor of Philosophy in the field of Building Integrated Photovoltaic (BIPV) from Anna University, Chennai in 2018. He has received Best Paper Award for his research articles in Biomass conversion. His research area includes Solar Photovoltaic, Bioenergy, Zero energy buildings.
Hari Kishan Dhevaguru
Hari Kishan Dhevaguru received his graduation in the faculty of Mechanical Engineering in 2019. His research interests include synthesis and characterization of eutectic phase change materials.
Suriyanarayanan Ganesamoorthy
Suriyanarayanan Ganesamoorthy received his graduation in the faculty of Mechanical Engineering in 2019. His research interests include modeling and analysis of grid-tied solar PV systems.