Showing papers by "Nasrudin Abd Rahim published in 2021"

Analysis of energy consumption and potential energy savings of an institutional building in Malaysia

Abstract: The building sector is one of the major energy users and greenhouse gasses emitter. An energy audit is one of the effective approaches to identify efficient energy usages and energy savings. A details walk-through energy audit has been conducted to analyse the energy consumption pattern and potential energy conservation opportunities (ECOs) in Research and Development (R&D) building at Universiti Malaya from March to May 2017. Eight different appliances were categorised to analyse and the audit results were verified with the building’s utility bill which on average were between 160 MWh to 250 MWh and RM 80 k to RM 120 k per month. In this case, it was found that the air-conditioning (34%), lighting (18%) and PC/laptops (10%) are the main appliances that contributed to the total energy consumption for the building. The replacement to LEDs light in three different stages marked as Level A, Level A + B and Level A + B + C revealed to be a good solution for energy conservation which resulted in annual energy savings of 72,750 kWh, 110,381 kWh and 144,386 kWh. It concurrently contributes to annual savings of RM26554, RM40289 and RM52701 based on 9 h daily operating time with the payback period of about 1 year.

Functionalized graphene quantum dots for dye-sensitized solar cell: Key challenges, recent developments and future prospects

Abstract: One of the pioneering materials nowadays is graphene quantum dot (GQD), which possesses outstanding electrical, thermal, and mechanical properties followed by less toxicity and robust photoluminescence. These commendable properties allow GQD to be suitable enough to apply in dye-sensitized solar cells, incapacitating current material limits. Nevertheless, pure GQDs have many challenges in reaching their full potential in DSSC. Chemical modification and functionalization tune the physical and chemical properties, driving GQD towards high-performance DSSC. This is an ideal way of modifying GQD because the chemical adsorption of atoms or molecules prevents the destruction of the carbon network without substitutional impurities. Here, we deliver a short outline of progress in understanding GQD functionalization from theoretical/computational perspectives. This chemically modified GQD is then linked with the performance of DSSC. The review also summarizes the electron transport in GQD-DSSC to minimize back-electron transmission recombination at the photoelectrode/electrolyte edge. The impact, outlook, and future prospects of the GQD-DSSC are included as a conclusion in this review.

Preparation, characterization and thermophysical properties investigation of A70/polyaniline nanocomposite phase change material for medium temperature solar applications

Abstract: The ever-present demand for energy from various application in industrial and domestic processes has led to the consumption of fossil fuel at a rapid rate with adverse effect due to global warming. This study focuses on the thermal energy storage aspect intended for medium temperature applications. A novel composite A70 and PANI was prepared and characterized. The study investigates the composites thermophysical and optical properties. Differential Scanning Calorimetry and Transient Hot Bridge measured thermal storage capacity and thermal conductivity of the composite, respectively. The heat storage capacity of the composite remained stable within 4% whereas a highest rise of 11.96% in thermal conductivity was measured. The composites thermal, chemical, and physical stability were analysed from Thermogravimetric Analyser, Fourier Infrared Transform, and Scanning Electron Microscope, respectively. The composites were thermally stable up to a temperature of 250 °C. No chemical reaction occurred between the nanomaterial and base PCM matrix. The microscopic visuals did not show any considerable change in the microscopic structure of the material. In the case of optical properties, the composites showed significant reduction in transmittance of solar spectrum with respect to pure A70. The maximum decrement in transmission was around ~89% compared to A70. As the composite prepared were thermally stable till 250 °C, hence may be utilized for solar thermal and low concentrated photovoltaic application but not limited to these.

Assessment of electric vehicle charging infrastructure and its impact on the electric grid: A review

Abstract: Electric vehicles (EVs) have a huge potential to dominate over the conventional combustion engine vehicles and become the future of road transport while conserving this planet from threatening cala...

PV Inverter with Decoupled Active and Reactive Power Control to Mitigate Grid Faults

Abstract: Low power distributed Photovoltaic (PV) systems would be a dominant power generator in future grids. This PV penetration significantly influence the grid stability, especially in an event of grid faults. Traditional PV inverters disconnect themselves from grid on detecting a low voltage at their point of common coupling (PCC). A temporary low voltage grid fault can lead to outage, if PV inverters are not equipped with low voltage ride through (LVRT) feature. During a low voltage grid fault PV inverter can assist the grid recovery process by not only staying connected to grid but also injecting reactive power into the grid. Many grid code standards have issued guidelines to inject reactive power during a low voltage fault. Development of low voltage ride through inverters require decoupled power flow control. In addition to maximum power point operation and standardized current injection to the grid, modern PV inverters should be able to deal with LVRT and loss of grid (LoG) ride through features, as demanded by the regulating grid codes. Reduction in grid outages can be achieved, if the PV inverters stay connected during LVRT, LoG and short circuit faults. Most of previous studies on LVRT control of PV inverters have not short circuit faults and loss of grid faults at PCC. This work proposed a PV inverter controller capable of controlling complex power into the grid. A decoupled current regulator with feed forward compensation is modelled. A short circuit grid fault is also tested with the developed PV inverter. It is found that the PV inverter ride through the low voltage and short circuit faults. The system is simulated in MATLAB(Simulink), the designed controller can provide decoupled active and reactive power to the grid during the fault events.

Energy, economic, and environmental analysis of 10-MW biomass gasification based power generation in Malaysia:

Abstract: Biomass gasification based power plants can play an important role in power sector in Malaysia with her abundant agricultural and forest resources. In this research energy and economic feasibility,...

Concentrated Photovoltaic Thermal (CPVT) systems: Recent advancements in clean energy applications, thermal management and storage

Abstract: Solar spectrum utilization can effectively deliver a significant stake in the next century's energy demand, which lies in tandem with Sustainable Development Goals. Solar energy is a promising, sustainable, and cleaner energy source. The photovoltaic thermal system is a solar spectrum utilization technique that can generate thermal and electrical energy, but the recovered thermal energy can primarily contribute to low-temperature utilizations. This study's motivation lies in the great potential of Concentrated Photovoltaic Thermal systems in providing high-grade thermal energy and increasing the overall system efficiency. This paper collectively reviews advanced thermal management techniques such as using phase change materials and nanofluids to avert overheating of the solar panel. A comprehensive review of Concentrated Photovoltaic Thermal systems like desalination, greenhouse heating which help in attaining Sustainable Development Goals, is also summarized. Heat transfer fluid selection is critical in thermal management, and accordingly, a comparison of various cooling methods is also made. The current article is a novel attempt to deliver a comprehensive review of the recent advancements in thermal management, commercial applications involving clean energy usage, technical challenges involved, economic and environmental impacts of Concentrated Photovoltaic Thermal systems. Multigeneration Concentrated Photovoltaic Thermal systems are environment-friendly, and the carbon dioxide emission per kilowatt-hour is almost half for concentrating systems compared with photovoltaic systems. The locational and environmental dependency of these systems makes them unattractive for some general applications. For better validation of analytical results, more experimental researches are essential in this area.

Usage of on-demand oxyhydrogen gas as clean/renewable fuel for combustion applications: a review

Abstract: The extensive and inefficient utilization of fossil fuels leads to high environmental concerns and energy security. Scientists are merely emphasizing on renewable energy sources and their appropria...

A Predictive Approach to Optimize a HHO Generator Coupled with Solar PV as a Standalone System

Abstract: Production of hydrogen by means of renewable energy sources is a way to eliminate dependency of the system on the electric grid. This study is based on a technique involving coupling of an oxyhydrogen (HHO) electrolyzer with solar PV to produce clean HHO gas as a fuel. One of objectives of this study was to develop a strategy to make the electrolyzer independent of other energy sources and work as a standalone system based on solar PV only. A DC-DC buck convertor is used with an algorithm that can track the maximum power and can be fed to the electrolyzer by PV while addressing its intermittency. The electrolyzer is considered to be an electrical load that is connected to solar PV by means of a DC-DC convertor. An algorithm is designed for this DC-DC convertor that allows maximization and control of power transferred from solar PV to the electrolyzer to produce the maximum HHO gas. This convertor is also responsible for operating the electrolyzer in its optimum operating region to avoid overheating. The DC-DC converter has been tested under simulated indoor conditions and uncontrolled outdoor conditions. Analysis of this DC-DC convertor based on maximum power tracking algorithm showed 94% efficiency.

Effect of WS2 nano-sheets on the catalytic activity of polyaniline nano-rods based counter electrode for dye sensitized solar cell

Abstract: The performance and commercialization of dye sensitized solar cells is very much dependent on cost effective and robust catalyst. In this study, polyaniline (PANi) nano-rods have been synthesized and the effect of tungsten disulfite (WS2) nanosheets has been investigated for the catalytic and electronic properties of polyaniline. Various concentrations of WS2 nanosheets i.e., 1 wt%, 2 wt%, 5 wt% and 7 wt% have been used to examine the effect of concentration of WS2 on overall electronic properties of PANi. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (TEM) have been employed for morphological studies. X-ray diffraction (XRD) patterns have been studied for compositional analysis. Fourier transformed infrared (FTIR) along with cyclic voltammetry (CV) have been utilized to investigate the catalytic activity in specified electrolyte and to identify unsaturated redox-active functionalities respectively. Sun simulator has been employed to study incident photo conversion efficiency (IPCE), open circuit voltage (Voc) and short circuit current (Isc). Finally, electron impedance spectroscopy has been employed to study the electronic resistance at the interfaces. An increase in overall electronic and device performance has been observed. The specimens containing 5 wt% WS2 in PANi exhibited 7.32% IPCE which is 92.14% equivalent to platinum (Pt) counter electrode based reference DSSC.

Performance Investigation of Tempered Glass-Based Monocrystalline and Polycrystalline Solar Photovoltaic Panels

Abstract: Solar photovoltaic (PV) converts sunlight into electricity and is an appropriate alternative to overcome the depletion of conventional fuels and global warming issues. The performance of a PV panel may vary with respect to PV cell technology, fabrication methods, and operating conditions. This research aims at performing an experimental study to investigate the electrical performance of novel tempered glass-based PV panels using two different types of solar cells: monocrystalline and polycrystalline. Tempered glass-based panels are modified forms of commercial PV panels, in which ethylene-vinyl acetate (EVA) and Tedlar are not utilized. This new fabrication method was carried out in this research. Real-time data recordings regarding the PV electrical characteristics ( - curve) and solar irradiance were conducted under Malaysian weather conditions on clear sunny days. Results indicated that, at solar irradiance of 900 W/m2, the outputs from the fabricated polycrystalline and monocrystalline PV panels were 67.4 W and 75.67 W, respectively. However, at the highest average solar irradiance (634.61 W/m2), which was obtained at 12:30 PM, the outputs from both panels were 47.87 W and 54.89 W. An - curve was obtained for the real-time weather. The electrical efficiencies of the two PV panels were analyzed to be 10.54% and 12.23%.

Indoor and Outdoor Performance Study of Metallic Zinc Particles in Black Paint to Improve Solar Absorption for Solar Still Application

Abstract: In this study, the effects of metallic zinc (Zn) particles were studied to increase surface temperature on a solar-still absorber, which is a major component of increased production. Various concentrations of Zn particles were mixed in black paint and applied to the absorber plate. SEM and XRD were used to examine and confirm the surface morphology and phase identification of as-received powder. UV-Vis spectroscopy was used to examine light-absorption properties. Finally, extensive indoor testing (using an improvised solar emulator) and outdoor testing were conducted to optimize the concentration. The specimens containing 10 wt% Zn in black paint showed the highest increase in temperature, i.e., 103.53 °C in indoor conditions at 1000 W/m2 irradiation, which is 59.17% higher than a bare aluminum plate and 17.57% higher than an only black-paint-coated aluminum plate. On the other hand, specimens containing 10 wt% Zn reached just 87.53 °C, compared to 80.00 °C for an only black-paint-coated aluminum plate and 60.62 °C for bare aluminum.

High-Rate and Long-Life Cycle of Nano-LiMn2O4 Under High Cut-Off Potential

Abstract: Nano-LiMn2O4 was successfully synthesized by a low-temperature hydrothermal route with the absence of post-calcination treatment. Employing ethanol as an organic reagent triggers the formation of nanostructured particles approximately 30.39 nm in diameter, associated with 0.007 lattice strain. The pure phase of nano-LiMn2O4/Li displays outstanding electrochemical performances. Under 4.6 V versus Li+/Li cut-off potential, 74.3% of capacity is reserved when C-rate is increased by 50 times, while excellent capacity restoration of 96.9% after cycled again at 1 C. After 331 cycles, a capacity retention of 84.3% is harvested by nano-LiMn2O4/Li, implying the absence of phase transformations in spinel structures under such abuse conditions. This remarkable structural stability can be attributed to the small lattice strain, associated with high Li+ diffusion coefficient, which is estimated to be 10−9.76 cm2 s−1 by the EIS technique. Additionally, Li+ extraction is more favorable when nano-LiMn2O4/Li is charged up to 4.6 V versus Li+/Li, interpreted by the polarization resistance (Rp) of the cell.

Capacitor Voltage Balancing with Online Controller Performance-Based Tuning for a Switch-Sharing-Based Multilevel Inverter

Abstract: Switch-sharing-based multilevel inverters offer great advantages in terms of efficiency improvement and output quality enhancement for low-power photovoltaic (PV) applications. However, the capacitor voltage balancing issue may critically deteriorate the output voltages, and thus could nullify the aforementioned benefits. Hence, this paper proposes a capacitor voltage balancing solution based on a buck-boost converter with performance-based tuning controllers to address the issue. The proposed controllers are designed based on the proportional-integral (PI) configuration equipped with an online tuning mechanism. The main purpose of the online tuning mechanism is to fine tune the proportional gain according to the DC input voltage, based on the measured output current total harmonic distortion (THD) performance of the inverter, while at the same time preventing the controller from reaching a state of saturation. By using the actual measurement of current THD performance, online tuning accuracy can be improved since no ideal condition is assumed, and thus, the associated error can be minimized. Simulation and experimental results reveal that the capacitor voltages can be balanced at high modulation indexes with improved current harmonic performance able to be be acquired at the inverter’s output.

Spectral response and quantum efficiency evaluation of solar cells: a review

Abstract: The performance of solar cells has been verified by current–voltage (I–V) characterization and spectral response measurements. These characteristics of solar cells are dependent on cell design, material, fabrication technique, junction depth, and/or optical coatings. Generally, I–V curves are given preference when measuring the performance of solar cells and less emphasis is given to spectral response, internal quantum efficiency (IQE), and external quantum efficiency (EQE) quantum. In this chapter, an attempt has been made to understand the concept of spectral response and its importance, along with the relation of IQE and EQE. Other than spectral response, there are many other factors, i.e., weathering, mishandling, aging, etc., that could contribute to the inefficiency of solar cells and this can be projected clearly by obtaining a solar cell’s quantum efficiency as well as its spectral response. By studying the solar spectrum for each solar cell, ways to broaden the spectrum region to maximize the use of the spectrum could be found. A literature review is presented in this chapter to understand the whole concept of IQE and EQE and their effect on the performance of silicon-based solar cells. Many recent papers have been compiled and simplified in a compact way so that this can be a convenient reference to other researchers in this field. Also, various techniques have been discussed to increase the efficiency of solar cells, which are proposed by a number of authors in the chapter.

Design of a small scale fluidized-bed incinerator for MSW with ability to utilize HHO as auxiliary fuel

Abstract: Waste incineration has become a mature technology and widely accepted due to its environment friendliness, easy operation and ability to reduce more than 95% mass fraction. There are some inherent limitations associated with incinerators such as high fuel consumption and cite feasibility. In this study, we propose a novel design concept of small scale fluidized bed incinerator for household use, with the ability to consume brown’s gas (HHO) as primary fuel for incinerate waste. In principle, the HHO gas generated through photovoltaic (PV) integrated water electrolysis system would be feed from the bottom to provide heat energy to the waste. Theoretical design of fluidized bed type incinerator has been presented with water electrolyzer system. It was calculated that 150 lph of hydrogen is required for this proposed incinerator system which can handle 5 kg of waste.

Comparison of Fault Tolerant Capability of Three-phase Induction Motor Drives for Automotive Applications

Abstract: With the increase proliferation of electric vehicles in the world, the demand for more reliable power electronics drive train is also on the rise. While theoretically the use of multiphase (more than three-phase) motors can increase the reliability of electrical drive train for EV, they are generally not commercially ready and available in the market. Hence, three-phase drive train are still the main stream in current EV technology and the fault-tolerant control of these motor drives remain an interesting and important topic. In this presentation, the existing fault tolerant three-phase motor drive topologies and control methods are reviewed. In particular, the post-fault controls of three-phase motor using 4 legs inverters are discussed and the opportunity for voltage utilization improvement with this configuration is demonstrated.

Feasibility Analysis of Solar Power Generation System for Office Building in Academic Institution

Abstract: This paper study the potential of energy-saving through lighting located at the office building in an academic institution known as Politeknik Sultan Azlan Shah (PSAS). Exercise through energy audit has been conducted at 3 main academic building to identify energy usage of lighting. 3 academic building involved is Mechanical Engineering Department (MED), Civil Engineering Department (CED), and the Electrical Engineering Department (EED). This study analysis 5 types of lighting to identify which types of lighting use the highest amount of energy in academic buildings. The 5 types of lighting involved in this study are Fluorescent T8 36W, Fluorescent T8 18W, Compact Fluorescent (CFL) 24W, Metal halide (MH) 400W and Ttube 18W. Energy savings are calculated based on the installation of hybrid solar in 3 related buildings. From an energy audit, the energy-saving at-least 5% from previous data has been estimated through the installation of a solar photovoltaic (PV) system. Through feasibility analysis, it is found that energy-saving potential obtained in the year 2019 for MED, CED and EED are about 4299 kWh, 2,319 kWh and 3,269 kWh respectively. Besides, the energy bill saving obtained is about RM 1,569, RM 846 and RM 3,269 respectively for MED, CED, and EED.

Layered and spinel structures as lithium-intercalated compounds for cathode materials

Abstract: Two intercalation-type compounds—layered and spinel—have been widely studied for decades. Structural, morphological, and chemical properties, electrochemical performance, structure stability, and the mechanism of drawback issues have been discussed comprehensively, and are still being debated today. On the basis of these studies, one consensus is that electrochemical performance can be highly improved by doping, coating layers, optimizing morphology, particle sizes, and crystallite sizes. Thus compressive studies of layered and spinel structures are summarized with extensive reports.

Introduction to solar energy and its conversion into electrical energy by using dye-sensitized solar cells

Abstract: This chapter is fundamental to applications of materials and discusses the latest approaches to materials and synthesis procedures being adopted for dye-sensitized solar cell (DSSC) electrodes. This review chapter has been divided into seven main topics: an introduction, solar cells, DSSCs, working principle of DSSCs, anatomy of DSSCs, materials used as electrodes for DSSCs, and a few detailed synthesis procedures for electrode materials of DSSCs. Basically, the idea of this chapter is to understand materials and synthesis procedures fundamental to DSSC applications in depth. As mentioned, a photoanode can be divided into two main materials: semiconductor-based and carbon-based materials to form optimum photoanodes for DSSCs. However, for counter electrodes, platinum (Pt) is still the best-known material to be deposited on transparent conductive glass. However, Pt-based material is expensive, which leads some researchers to look for other Pt-free alternative materials. Examples of Pt-free alternative materials are carbon materials, conducting polymers, composite materials, inorganic materials, and organic materials. The development of new innovative procedures from the well-known synthesis method of both electrodes to optimize and enhance DSSC performance is also needed.

Investigation on wind energy for grid connection in Bangladesh: Case study

Abstract: The increasing demand for energy in Bangladesh as well as all over the world is continuously growing unabated because of the increase of the world population and the countries’ fast-developing industrialization programs. In this critical stage of energy crisis, renewable energy is a highly welcome reliable energy source wherein wind energy is the cheapest replenishable and available energy source of the time. Regarding this particular energy source, a feasibility study of the wind energy in Chittagong has been done by analyzing the wind speed data. It is estimated that the maximum practical power output generated can be 124.53 MW at Parky beach. The number of wind turbines, operation and maintenance cost and pay-back period of those sites are also calculated.

Effect of concentration of MoS2 on the TCO-Pt free polyaniline nano-rod based counter electrode for dye sensitised solar cell application

Abstract: The concentration effect of molybdenum disulphide (MoS2) on the catalytic activity of polyaniline (PANi)-based counter electrode (CE) was investigated for cost-effective replacement of both transpa...

PV integrated on-demand water electrolysis system for HHO generation and it application as primary fuel in combustion

Abstract: The brown’s gas also known as HHO gas has been produced using dye cell alkaline water electrolyser using 316L stainless plates. The electrolyzer has been integrated with solar panel using battery bank and charge controller to develop on-demand HHO generation system. The produced gas has been employed as primary fuel for combustion and its effectiveness has been investigated. Preliminary observations revealed that the photovoltaic (PV) integrated alkaline water electrolysis system exhibits smooth operation and provides proper control over the production process. On the other hand, the utilization of HHO gas as primary fuel displayed highly satisfying results. The developed system has the capacity to generate HHO on the order of 3L/min at 15Amps and it almost instantly burn paper and acrylic sheet.