Cooling the operating surface is a key operational factor to take into consideration to achieve higher efficiency when operating solar photovoltaic systems. Proper cooling can improve the electrical efficiency, and decrease the rate of cell degradation with time, resulting in maximisation of the life span of photovoltaic modules. The excessive heat removed by the cooling system can be used in domestic, commercial or industrial applications. This paper presents a review of various methods that can be used to minimize the negative impacts of the increased temperature while making an attempt to enhance the efficiency of photovoltaic solar panels operating beyond the recommended temperature of the Standard Test Conditions (STC). Different cooling technologies are reviewed, namely Floating tracking concentrating cooling system (FTCC); Hybrid solar Photovoltaic/Thermal system cooled by water spraying; Hybrid solar Photovoltaic/ Thermoelectric PV/TE system cooled by heat sink; Hybrid solar Photovoltaic/Thermal (PV/T) cooled by forced water circulation; Improving the performance of solar panels through the use of phase-change materials; Solar panel with water immersion cooling technique; Solar PV panel cooled by transparent coating (photonic crystal cooling); Hybrid solar Photovoltaic/Thermal system cooled by forced air circulation, and Solar panel with Thermoelectric cooling. Several research papers are reviewed and classified based on their focus, contribution and the type of technology used to achieve the cooling of photovoltaic panels. The discussion of the results has been done based on the advantages, disadvantages, area of application as well as techno-economic character of each technology reviewed. The purpose of this review is to provide an understanding for each of the above-mentioned technologies to reduce the surface temperature of the PV module. The study will focus on the surface temperature reduction array bound by each of the cooling technologies. The performance of each cooling technology will also be highlighted. In addition to this study, this review will include a discussion comparing the performance of each cooling technology. The outcomes of this study are detailed in the conclusion section. This paper has revealed that any adequate technology selected to cool photovoltaic panels should be used to keep the operating surface temperature low and stable, be simple and reliable and, if possible, enable the use of extracted thermal heat to enhance the overall conversion efficiency. The presented detailed review can be used by engineers working on theory, design and/or application of photovoltaic systems.

A review of solar photovoltaic systems cooling technologies

Cold plasma treatment is a promising intervention in food processing to boost product safety and extend the shelf-life. The activated chemical species of cold plasma can act rapidly against micro-organisms at ambient temperatures without leaving any known chemical residues. This review presents an overview of the action of cold plasma against molds and mycotoxins, the underlying mechanisms, and applications for ensuring food safety and quality. The cold plasma species act on multiple sites of a fungal cell resulting in loss of function and structure, and ultimately cell death. Likewise, the species cause chemical breakdown of mycotoxins through various pathways resulting in degradation products that are known to be less toxic. We argue that the preliminary reports from cold plasma research point at good potential of plasma for shelf-life extension and quality retention of foods. Some of the notable food sectors which could benefit from antimycotic and antimycotoxin efficacy of cold plasma include, the fresh produce, food grains, nuts, spices, herbs, dried meat and fish industries.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1541-4337.12398

Cold Plasma for Effective Fungal and Mycotoxin Control in Foods: Mechanisms, Inactivation Effects, and Applications.

Comprehensive study on nanofluid and ionanofluid for heat transfer enhancement: A review on current and future perspective

Advanced cooling techniques of P.V. modules: A state of art

https://hull-repository.worktribe.com/preview/1636046/1612634.pdf

Comparative study of a concentrated photovoltaic-thermoelectric system with and without flat plate heat pipe

Performance of solar cells using thermoelectric module in hot sites

Experimental evaluation of photovoltaic DC refrigerator under different thermostat settings

Atmospheric pressure large volume air plasma was generated by applying 100 ns, 1-kHz high voltage pulse between two parallel electrodes separated by 48-mm gap. The high voltage power electrode has uniformly distributed pens and ground electrode shaped as a flat disc. Glow discharge ignition is initialized at the outer pens to form luminousness circle. By applying higher voltage, the glow expands to ignite the internal pens and to fill the gap between the two electrodes. Each pen forms glow discharge plasma with the ground electrode. The increase in voltage or frequency enhances the plasma intensity and homogeneity. The generated plasma showed efficiency against the fruit borne fungi of grapes.

Generation of Large Volume Atmospheric Pressure Air Plasma

Cold atmospheric pressure plasma jet (CAPPJ) has been approved by several investigators as anti-microbial agent [1]. In this experiment, CAPPJ in air is generated by applying AC voltage 7–14 kV (peak-to-peak), with frequency of 21–29 kHz to Al 2 O 3 tube. The tube has 150 mm length with a 4 and 6 mm inner and outer diameter, respectively. Argon flow rates ranged from 0.1 to 10 SLM were blown through the tube to form the plasma jet. The addition of oxygen to argon as operating gases enhances the generation of O and OH radicals. The electric and spectroscopic characteristics of the generated plasma jet were investigated. The generated plasma jet length and mode of operation varied as a function of oxygen flow rate percentage, applied voltage and frequency. The plasma jet length increases with argon flow rate to reach its maximum at 5 SLM then ceases to reach saturation at 8 SLM. The energies consumed by the discharge were estimated using the charge-voltage curve (Lissajous figure). The consumed energy increased with increasing the input power. Regarding the decontamination, the data indicate an optimum condition of E. coli sterilization at 0.02% of oxygen.

Characteristics of cold atmospheric pressure plasma jet and its antimicrobial activity

Large volume atmospheric pressure air plasmas [1,2] were generated by applying ∼ 100 ns high voltage pulse between two parallel electrodes separated by 48 mm gap in air The generated plasma frequencies can be varied from single pulse to 2000 Hz A uniformly distributed stainless steel pens were welded to the high voltage electrode while the grounded electrode is a metallic flat disc The pens have 32 mm length and 048 mm radius and separated by 87 mm to form a brush-shape The pin tips are cut to form sharp ends to enhance the applied electric field and reduced the ignition voltage The atmospheric pressure large volume glow discharges plasma ignite first at the outer pens forming luminousness circle then the internal pens ignited with the increase in the applied voltage The glowed plasma expanded to cover the gap by increasing the applied voltage Each pens form glow discharge with the ground electrode The plasma intensity and homogeneity enhanced with increasing the applied voltage or the plasma frequency The emission spectra investigations declared the main presence of nitrogen bands, second positive band and first negative band in the investigated range between 200 nm and 800 nm The generated plasma was successfully proved as an efficacious tool for sterilizing a wide range of fruits from the naturally occurring bacterial and fungal contamination

http://ieeexplore.ieee.org/iel7/7154561/7179488/07179602.pdf

Ahmed A. Almashraqi

Papers

Performance of solar cells using thermoelectric module in hot sites

Experimental evaluation of photovoltaic DC refrigerator under different thermostat settings

Generation of Large Volume Atmospheric Pressure Air Plasma

Characteristics of cold atmospheric pressure plasma jet and its antimicrobial activity

Large volume air plasma for fruit sterilization