Showing papers by "Nasrudin Abd Rahim published in 2018"

Novel approaches and recent developments on potential applications of phase change materials in solar energy

Abstract: Phase change materials (PCMs) can be applied to several different solar energy systems for the extended heat energy storage which is quite useful as the solar energy is intermittent in nature and is unavailable during the night period Application of PCMs in solar energy systems allows the solar energy to be used at any time even in the absence of the natural solar radiation Thus, the use of PCMs in the solar energy systems can bridge the demand and supply gap of the normal electrical energy This paper deals with the recent advances in PCMs application in different solar energy systems and presents almost all of the emerging areas where the applications of PCM in solar energy systems are urgently required The novel and most recent developments of PCMs in solar thermal energy systems, such as, solar thermal power plants, solar air heater, solar water heater and solar cooker have been duly covered Furthermore, the application of PCMs in heating and cooling of buildings have been presented as well as the investigation of the PCM application in the solar photovoltaic systems for the performance enhancement of PCMs Intrinsically important, from the study it has been found that PCMs have been in use in almost all of the solar energy systems even though their uses are still limited and commercially not available due to several economic and environmental constraints Thus, the paper attempts to present recent and novel approaches by the authors around the world on PCMs applications in the solar energy in well documented forms Based on the findings, future recommendations have also been given to provide the idea and pragmatic concepts for the researcher to work on the areas of research for further improvements in the systems

Recent progress and development on power DC-DC converter topology, control, design and applications: A review

Abstract: Over the last few decennia, power DC/DC converters have been the subject of great interest due to its extensive increment of utilization in different applications. A thorough review on recent developed power DC/DC converters is presented in this paper. The study is focused on the topologies in different applications such as renewable energy, automobile, high-voltage and medium-voltage DC power systems, telecommunication, etc. In addition, an overview of the modulation techniques, the state-of-the-art of control strategies of well-established converters are discussed. Photovoltaic (PV) systems as the noticeable renewable energy resources generally suffer from poor conversion efficiency with instability and intermittent characteristics. Therefore, DC/DC converter with Maximum Power Point Tracking (MPPT) algorithm is essential to ensure maximum available power harnessed from the PV. Important features of DC/DC converters with MPPT are also figured with various performances. Furthermore, the design and optimization of different parameters are addressed systematically. Finally, the researcher’s future challenges and focusing trends are briefly described. For the next-generation converters design and applications, these are considered in details, and will provide useful framework and point of references.

A review on development of solar drying applications

Abstract: Drying is an essential process in the preservation of agricultural crops and in industries, such as textile production, dairy processing, cement production, clay brick production, tile production, wood and timber processing, wastewater treatment, and biomass treatment. The energy requirement for drying can be supplied from various sources, namely, electricity, fossil fuel, natural gas, wood, bark forest residual, and solar. Although the use of solar radiation for drying has existed since antiquity, it has not yet been widely commercialized, particularly in the industrial sector. Considering the rapid depletion of natural fuel resources and because of the rising fossil fuel cost, solar drying is expected to become indispensable in the future. Moreover, environmental considerations and damages caused by human beings due to increasing consumption of fossil fuel prompt governments and industries to use renewable energies as a clean and sustainable resource, thus, the use of solar energy for drying. The numerous solar drying applications are classified into two main categories, that is, agricultural and industrial. Many benefits could be exploited from solar energy for drying applications. Solar energy enables the industries and agricultural sectors to modify their energy requirement, improve their energy stability, and increase energy sustainability, which lead to improvement in the system efficiency. We review the role of the drying system in industry and agriculture, the energy consumption capacity, and the availability of the required energy for the products to be dried. In addition, the economical, environmental, and political aspects of using solar dryers are discussed. Special attention is given to industrial drying and in finding opportunities to use compatible dryers for a certain industry. In short, we conduct a comprehensive review of the new approach to use solar energy in industrial drying sector.

Global modern monitoring systems for PV based power generation: A review

Abstract: Photovoltaic system is widely installed to increase the share of renewable energy as well as to reduce the environmental impact of fossil fuel based energy. Photovoltaic (PV) is one of the most potential renewable energy based power generation systems. Monitoring of PV system is very important to send information that allows owners to maintain, operate and control these systems to reduce maintenance costs and to avoid unwanted electric power disruptions. Different monitoring systems have been introduced with the time following different requirements. Circuit complexity, availability of friendly graphical user interface, easy to understand system architecture, maintenance facility and customization ability for end user differ from system to system along with cost issues. This paper provides an overview of architectures and features of various PV monitoring systems based on different methods. There are various technologies for PV monitoring and control, developed as for commercial use or research tasks. It has been seen that a large portion of the work is done on classifications, for example, Internet based Monitoring using Servers, TCP/IP, GPRS and so forth. There are various methodologies for data acquisition, for example, PLC (Power Line Communication), PIC, Reference cell, National Instruments etc. Various requirements are considered while selecting a proper monitoring system for an application. Review of various monitoring technologies with system attributes and working structures have been discussed to get a clear view of merits and demerits of existing PV monitoring systems. All the systems discussed in this paper have pros and cons, and these systems were developed following different requirements. In the end, a particular cost effective monitoring system using Arduino microcontroller has been proposed considering both research and user level requirements from perspectives of cost, availability of parts/modules and features, compatibility with sensors and end-devices etc.

Effect of high irradiation on photovoltaic power and energy

Abstract: Solar photovoltaics (PV) is a promising solution to combat against energy crisis and environmental pollution. However, the high manufacturing cost of solar cells along with the huge area required for well-sized PV power plants are the two major issues for the sustainable expansion of this technology. Concentrator technology is one of the solutions of the abovementioned problem. As concentrating the solar radiation over a single cell is now a proven technology, so attempt has been made in this article to extend this concept over PV module. High irradiation intensity from 1000 to 3000 W/m2 has been investigated to measure the power and energy of PV cell. The numerical simulation has been conducted using finite element technique. At 3000 W/m2 irradiation, the electrical power increases by about 190 W compared with 63 W at irradiation level of 1000 W/m2. At the same time, at 3000 W/m2 irradiation, the thermal energy increases by about 996 W compared with 362 W at 1000 W/m2 irradiation. Electrical power and thermal energy are enhanced by about 6.4 and 31.3 W, respectively, for each 100-W/m2 increase of solar radiation. The overall energy is increased by about 179.06% with increasing irradiation level from 1000 to 3000 W/m2. It is concluded that the effect of high solar radiation using concentrator can significantly improve the overall output of the PV module.

Superhydrophilic Smart Coating for Self-Cleaning Application on Glass Substrate

Abstract: In general, superhydrophilic coating on glass substrate possesses water contact angle (WCA) below 10° and contains high self-cleaning properties in outdoor environment as compared to noncoated glass substrate panels. In this study, the superhydrophilic coating behavior on glass substrate has been developed. The micro- and nanosized titanium dioxide (TiO2) particles have been utilized to improve the surface roughness, and the polypropylene glycol (PPG) has been utilized to increase the surface energy of glass substrates. The wettability of coating surface shows the coating possess water contact angle (WCA) as low as 5° and suddenly reduce to 0° after 10 s. Superhydrophilic coated glass clearly shows excellent dirt repellent against dilute ketchup solution due to the absence of dirt streak on the glass surface. Meanwhile, the dirt streak is present on the bare glass surface indicating its weak self-cleaning property. The developed superhydrophilic coating on glass substrate was also found to have great antifog property compared to the bare glass substrate. Superhydrophilic surfaces have showed free tiny droplet even at 130°C of hot boiling bath for 10 min and completely dry after 1 min. The superhydrophilic coating surfaces have demonstrated free water streak after impacting with harsh water spraying for 5 min confirming that the superhydrophilic coating on glass substrate is antiwater streak.

Photovoltaic Integrated Shunt Active Power Filter with Simpler ADALINE Algorithm for Current Harmonic Extraction

Abstract: This manuscript presents a significant work in improving the current harmonics extraction algorithm and indirectly improving the injection current produced by a single-phase Photovoltaic Shunt Active Power Filter (PV SAPF). Improvement to the existing adaptive linear neuron (ADALINE) technique has been carried out, leading to the formation of a simpler ADALINE; it is expected to perform as fast as the current harmonics extraction algorithm. Further analysis on the DC link capacitor control algorithm, called “self-charging with step size error cancellation”, was also done to inspect the performance of the algorithm in a single-phase photovoltaic shunt active power filter system. Both algorithms, configured in single-phase PV SAPF, were simulated in MATLAB/Simulink (R2012b). A laboratory prototype was developed, and the algorithms were computed on a TMS320F28335 Digital Signal Processing (DSP) board for hardware implementation purposes. From the acquired results, the simpler ADALINE algorithm has effectively performed with lower total harmonic Distortion (THD) and outstanding compensation. The established algorithm of self-charging with step size error cancellation works well with single-phase PV SAPF and has shown less overshoot, a fast response time, and minimal energy losses.

Effect of Nanodiamonds on the Optoelectronic Properties of TiO$$_{ }$$ Photoanode in Dye-Sensitized Solar Cell

Abstract: Low charge transfer resistance and high light absorption ability of TiO $$_{2}$$ -based photoanodes are the crucial challenges in the field of dye-sensitized solar cells (DSSCs). In this study, nanodiamonds (NDs) have been introduced in TiO $$_{2}$$ matrix to investigate their effect on the performance of DSSCs. Colloidal suspension method has been employed for the synthesis of TiO $$_{2}$$ /NDs nanocomposites. Various concentrations of NDs, i.e., TiO $$_{2}$$ –0.2 wt%NDs, TiO $$_{2}$$ –0.5 wt%NDs, TiO $$_{2}$$ –1 wt%NDs, TiO $$_{2}$$ –3 wt%NDs and TiO $$_{2}$$ –5 wt%NDs, have been trialed for the fabrication of nanocomposite photoanode using doctor blade method with D719 dye as sensitizer. Scanning electron microscopy and X-ray diffraction methods were used to study the morphology, composition and dispersion of NDs in TiO $$_{2}$$ matrix. UV–visible absorption spectroscopy, photocurrent–voltage characteristics and electrochemical impedance spectroscopic measurements were conducted to characterize the performance of DSSCs. The results show that the photoconversion efficiency is highly dependent on the concentration of NDs in the photoanode due to high light absorption, dye loading and heterojunction symmetry of the system. A solar cell based on a photoanode containing 3 wt% NDs showed a power conversion efficiency of 0.47% compared to 0.26% efficiency of unmodified photoanode.

Improved electron density through hetero-junction binary sensitized TiO2/ CdTe / D719 system as photoanode for dye sensitized solar cell

Abstract: The combined effect of dual sensitization and hetero-junction symmetry has been investigated on the performance of TiO 2 based dye sensitized solar cell. CdTe nanoparticles have been introduced in TiO 2 matrix to function as sensitizer as well as act as hetero-junction between D719 dye and TiO 2 nanoarchitecture. Four concentrations of CdTe i.e. 0.5 wt%, 2 wt%, 5 wt% and 8 wt% have been investigated. Morphological and compositional studies have been conducted using scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. Light absorption characteristics have been investigated by employing Uv–vis spectroscopy and the overall performance has been studied using solar simulator and electrochemical impedance spectroscopy (EIS). Performance has been found to be increased with the addition of CdTe due to high electron density and reduction in recombination reactions. An increase of 41.73% in incident photo conversion efficiency (IPCE) and 75.57% in short circuit current density ( J sc ) have been recorded for the specimens containing 5 wt% CdTe compared to bare TiO 2 based DSSCs. Further addition of CdTe leads to reduction in overall performance of DSSCs.

Heat transfer and pressure drop characteristics of a plate heat exchanger using water based Al 2 O 3 nanofluid for 30° and 60° chevron angles

Abstract: Nanofluid is a new class of engineering fluid that has good heat transfer characteristics which is essential to increase the heat transfer performance in various engineering applications such as heat exchangers and cooling of electronics. In this study, experiments were conducted to compare the heat transfer performance and pressure drop characteristics in a plate heat exchanger (PHE) for 30° and 60° chevron angles using water based Al2O3 nanofluid at the concentrations from 0 to 0.5 vol.% for different Reynolds numbers. The thermo-physical properties has been determined and presented in this paper. At 0.5 vol% concentration, the maximum heat transfer coefficient, the overall heat transfer coefficient and the heat transfer rate for 60° chevron angle have attained a higher percentage of 15.14%, 7.8% and 15.4%, respectively in comparison with the base fluid. Consequently, when the volume concentration or Reynolds number increases, the heat transfer coefficient and the overall heat transfer coefficient as well as the heat transfer rate of the PHE (Plate Heat Exchangers) increases respectively. Similarly, the pressure drop increases with the volume concentration. 60° chevron angle showed better performance in comparison with 30° chevron angle.

Effect of Different Factors on the Leakage Current Behavior of Silicon Photovoltaic Modules at High Voltage Stress

Abstract: Leakage current is one of the determinants of potential-induced degradation (PID) of the photovoltaic (PV) module. Effects of different parameters such as module surface temperature, surface wetting, salt and dust accumulation, and aging condition on high-voltage-stress (HVS) leakage current of the crystalline PV module are investigated in the laboratory. In this research, a novel notion on HVS-leakage-current-modulating parameters has been introduced, which is useful to assess the HVS degradation at different climates. The leakage current increases moderately with the increase of module surface temperature, and it increases drastically during the surface wetting condition. The leakage current under 1000-V stress is 5.04, 5.82, and 35.55 μA/m2 at 25 °C (50% relative humidity), 60 °C (8% relative humidity), and 45 °C (wet) conditions, respectively. The presence of salt also increases the leakage current almost linearly. A slight amount of dust (2 g/m2) on the module surface was found to trigger the wet leakage current to a considerable limit. Tiny dust particles have a capability to attach with some ionic compounds, where Na ions are dominant from the coastal area that prompts the leakage current of the PV module. Long-term field operation known as aging of the PV module reduces the electrical resistance of ethylene vinyl acetate; consequently, the leakage current, as well as PID, increases significantly.

Study on self-cleaning performance and hydrophobicity of TiO2/silane coatings

Abstract: Purpose The paper aims to investigate the effect of Degussa P-25 Titanium Dioxide (TiO2) nanoparticles on hydrophobicity and self-cleaning ability as a single organic coating on glass substrate. Design/methodology/approach Two methods have been used to enhance the hydrophobicity on glass substrates, namely, surface modification by using low surface energy isooctyltrimethoxysilane (ITMS) solution and construction of rough surface morphology using Degussa P-25 TiO2 nanoparticles with simple bottom-up approach. The prepared sol was applied onto glass substrate using dip-coating technique and stoved in the vacuum furnace 350°C. Findings The ITMS coating with nano TiO2 pigment has modified the glass substrate surface by achieving the water contact angle as high as 169° ± 2° and low sliding angle of 0° with simple and low-cost operation. The solid and air phase interface has created excellent anti-dirt and self-cleaning properties against dilute ketchup solution, mud and silicon powder. Research limitations/implications Findings will be useful in the development of self-cleaning and anti-dirt coating for photovoltaic panels. Practical implications Sol method provides the suitable medium for the combination of organic–inorganic network to achieve high superhydrophobicity and optimum self-cleaning ability. Originality/value Application of blended organic–inorganic sol as self-cleaning and anti-dirt coating film.

High voltage-gain full-bridge cascaded dc-dc converter for photovoltaic application.

Abstract: Over the past few years, high step-up dc-dc converters have been drawn substantial attention because of their wide-ranging application not only in the renewable energy sector but also in many other applications. To acquire a high voltage gain in photovoltaic (PV) and other renewable energy applications, a high step-up dc-dc converter is proposed in this paper. The proposed converter structure consists of a full-bridge (FB) module along with an input boost inductor and a voltage multiplier based on the Cockcroft-Walton (CW) principle with a parallel inductor. The key features of the proposed converter are: 1) high voltage gain with lower voltage stress on the switches, diodes and other passive elements without affecting the number of cascaded stages, 2) a minimum size of boost inductance and cascaded stage capacitance that ensures its compactness and low cost, and 3) a minimal number of major components. Circuit operation, steady-state analysis and various design parameters of the proposed converter are explained in details. In order to prove the performance of the theoretical analysis, a laboratory prototype is also implemented. The peak voltage gain and the maximum efficiency obtained are 11.9 and 94.6% respectively with very low input current ripple and output voltage ripple generated.

Analysis of Current Harmonics Compensation and the Effect of Frequency Variation for Single-Phase Stand-Alone PV Inverters using PR Controller

Abstract: This paper presents the analysis of current harmonics compensation using the proportional-resonant controller for single-phase stand-alone photovoltaic inverter applications. The effect of frequenc...

Dynamic Economic Dispatch of Isolated Microgrid with Energy Storage Using MIQP

Abstract: This paper presents a mixed integer quadratic programming to minimize the operation cost of isolated microgrid using diesel generator and energy storage. The deployment of energy storage with the distributed generators is an effective method for storing the energy for utilization during high load periods. The proposed method is applied on a power system with 3 diesel generators and energy storage serving as backup to meet the required load. The cost of microgrid is optimized by optimal dispatch of generators and power discharged by energy storage during peak load periods. The results show that the optimum cost of microgrid is achieved when the diesel generators dispatch the maximum power to load and the energy storage is used only during the peak load periods when the generators capacity is insufficient to fulfil the load demand.

Enhanced Current Density Through Addition of CdTe in TiO 2 Based Photoanode for DSSCs

Abstract: The combined effect of duel sensitization and heterojunction architecture has been investigated on the performance of TiO2 based dye sensitized solar cell. CdTe nanoaprticles have been introduced in TiO2 matrix to function as sensitizer as well as act as hetero-junction between D719 dye and TiO2 photoanode nano-architecture. Morphological and compositional studies have been conducted using scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. Light absorption characteristics have been investigated by employing Uv-vis spectroscopy and the overall performance has been studied using solar simulator and electrochemical impedance spectroscopy. The overall performance has been increased with the addition of CdTe due to high electron density and reduction in recombination reactions. An increase of 33.99% in incident photo conversion efficiency (IPCE) has been recorded for the samples containing CdTe compared to bare TiO2 based DSSCs.

Experimental investigation of on-site degradation of crystalline silicon PV modules under Malaysian climatic condition

Abstract: Photovoltaic (PV) power plant capacity is growing very fast in Malaysia. The operating capacity of a PV plant digresses from the installed capacity after several years of operation. The degradation rate of different poly and mono crystalline silicon PV modules due to real field aging at various time spans has been detected by EL imaging, maximum power measurement and dark I - V analysis. The obtained degradation values of PV modules are 1.78, 7.06, 13.92, 17.04 and 17.42% due to ageing at a period of 8 months, 16 months, 4 years, 9 years and 11 years, respectively. The reason behind this degradation is attributed to the reduction of shunt resistance which declines gradually as result of aging. The degradation rate of a PV module has been estimated as 18.61% after 21 years of aging. Temperature coefficient of maximum power of PV module also degrades due to aging. And the rate of temperature coefficient of maximum power degradation decreases with the increase of aging period.

Control of switch-sharing-based multilevel inverter suitable for photovoltaic applications

Abstract: Owing to the higher amount and the better quality of power transferred, three-phase multilevel inverters have strengthened their presence in low-power photovoltaic (PV) applications. However, the existing topologies investigated for low-power PV systems are basically meant for medium- and high-power applications, thus making them underutilized for low-power range. In order to address this shortcoming, this paper proposes a three-phase multilevel inverter with a switch-sharing capability and its control solution. It combines the characteristics of the two-level full-bridge topology and the diode-clamped multilevel structure. As a result, the inverter can be used with full capacity and without being underutilized, and significantly improves the output quality. A control strategy that is able to maximize the full potential of the inverter is developed. A digital proportional-integral (PI) controller with a new tuning algorithm is designed to effectively deal with the load changes. The result reveals that the load current is always retained at the intended quality level despite the variations in load. The performance of the inverter is validated from the experimental work conducted on a laboratory prototype under closed-loop conditions.