Advancements in PV-thermal systems with and without phase change materials as a sustainable energy solution: energy, exergy and exergoeconomic (3E) analytic approach

2020 ◽  
Vol 4 (10) ◽  
pp. 4956-4987
Author(s):  
Imtiaz Ali Laghari ◽  
M. Samykano ◽  
A. K. Pandey ◽  
K. Kadirgama ◽  
V. V. Tyagi

Photovoltaic thermal (PVT) systems are increasingly becoming an essential part of the solar application systems integrating the photovoltaic (PV) and solar thermal collectors into a single unit to produce heat and electrical energy from the intermittent solar irradiation.

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 724
Author(s):  
Macmanus Chinenye Ndukwu ◽  
Lyes Bennamoun ◽  
Merlin Simo-Tagne

The application of thermal storage materials in solar systems involves materials that utilize sensible heat energy, thermo-chemical reactions or phase change materials, such as hydrated salts, fatty acids paraffin and non-paraffin like glycerol. This article reviews the various exergy approaches that were applied for several solar systems including hybrid solar water heating, solar still, solar space heating, solar dryers/heaters and solar cooking systems. In fact, exergy balance was applied for the different components of the studied system with a particular attention given to the determination of the exergy efficiency and the calculation of the exergy during charging and discharging periods. The influence of the system configuration and heat transfer fluid was also emphasized. This review shows that not always the second law of thermodynamics was applied appropriately during modeling, such as how to consider heat charging and discharging periods of the tested phase change material. Accordingly, the possibility of providing with inappropriate or not complete results, was pointed.


2018 ◽  
Vol 8 (12) ◽  
pp. 2613 ◽  
Author(s):  
Lihong He ◽  
Hao Wang ◽  
Hongzhou Zhu ◽  
Yu Gu ◽  
Xiaoyan Li ◽  
...  

This paper mainly concentrates on the thermal conductivity and photo-thermal conversion performance of polyethylene glycol (PEG)/graphene nanoplatelets (GNPs) composite phase change materials (PCMs). The temperature-assisted solution blending method is used to prepare PCM with different mass fraction of GNPs. According to the scanning electron microscope (SEM), GNPs are evenly distributed in the PEG matrix, forming a thermal conduction pathway. The Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD) results show that the composites can still inherit the crystallization structure of PEG, moreover, there are only physical reactions between PEG and GNPs rather than chemical reactions. Differential scanning calorimeter (DSC) and thermal conductivity analysis results indicate that it may be beneficial to add a low loading ration of GNPs to obtain the suitable latent heat as well as enhance the thermal conductivity of composites. To investigate the change in the rheological behavior due to the effect of GNPs, the viscosity of the composites was measured as well. The photo-thermal energy conversion experiment indicates that the PEG/GNPs composites show better performance in photothermal energy conversion, moreover, the Ultraviolet-visible-Near Infrared spectroscopy is applied to illustrate the reasons for the higher absorption efficiency of PEG/GNPs for solar irradiation.


2020 ◽  
Vol 23 (3) ◽  
pp. 213-220
Author(s):  
R Prakash ◽  
B Meenakshipriya ◽  
S Vijayan ◽  
R Kumaravelan

Thermal and Electrical performance of solar PV/T hybrid water heating system using salt mixture phase change materials in storage tank is analyzed in this study. Compare to all conventional type heaters, the solar PV/T hybrid module collector has ability to produces both electrical energy from PV module and utilizes incident solar energy to heat the water. The sheet and tube type absorber is used to heat up the tube which is attached at the back side of PV module and transfer the heat to flowing water and the electrical energy is tested by connecting the DC load on the PV terminals under glazed and unglazed modes respectively. To enhance the thermal performance, energy storage medium is used as phase change materials at good proportion in the tank. The thermo physical properties of PCM are analyzed by Differential Scanning Calorimetry. This experimental testing is conducted from 8.00 to 17.00 IST in various sunny days and results are compared for glazed and unglazed conditions. The results shows that the average water temperature easily reaches 38-45°C and the final temperature of water never dropped below 34°, the temperature of PCM is 45.6oC, which is 5oC higher than outlet. The amount of heat stored using PCM in tank is 16.86% greater than no-PCM in the tank for constant 0.01 kg/s mass flow rate. The daily average electrical efficiency is 6.4% under glazed mode and 8.8% under unglazed conditions.


Author(s):  
Andrew H. Rosenthal ◽  
Bruna P. Gonçalves ◽  
J. A. Beckwith ◽  
Rohit Gulati ◽  
Marc D. Compere ◽  
...  

This paper investigates the use of phase-change material (PCM) for temperature regulation of a rack-mounted photovoltaic (PV) solar panel. PV panels exhibit a significant decrease in electrical efficiency as temperature trends higher. Current PV panels are approximately 10–16% efficient at harnessing incident solar irradiation into effective electrical power. The remaining solar irradiation that is not converted to electricity will heat the PV panel and decrease efficiency. Using PCM for temperature regulation and temporary heat storage in photovoltaic/thermal systems (PVT) is an emerging technology that has attracted attention recently. The PCM absorbs heat and regulates peak temperature, which allows the PV panel to operate at lower temperatures during peak solar conditions. Further, the waste heat stored in the PCM can be used for other applications. The main focus of this paper is to experimentally evaluate the heat dissipation of four different PCM containment configurations from a simulated PV panel.


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