Journal of Renewable Energy The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Dynamic Modeling, Control, and Analysis of a Solar Water Pumping System for Libya Mon, 24 Apr 2017 00:00:00 +0000 In recent years, one of the suitable solar photovoltaic (PV) applications is a water pumping system. The simplest solar PV pumping system consists of PV array, DC-DC converter, DC motor, and water pump. In this paper, water pumping system sizing for Libya is evaluated based on a daily demand using HOMER software, and dynamic modeling of a solar PV water pumping system using a Permanent Magnet DC (PMDC) motor is presented in Matlab/Simulink environment. The system performance with maximum power point tracking (MPPT) based on Fractional Open Circuit Voltage (FOCV) is evaluated with and without a battery storage system. In some applications, a rated voltage is needed to connect a PMDC motor to a PV array through a DC-DC converter and in other applications the input voltage can vary. The evaluation of the system is based on the performance during a change in solar irradiation. Using Matlab/Simulink, simulation results are assessed to see the efficiency of the system when it is operating at a specific speed or at the MPPT. The results show that an improvement in the system efficiency can be achieved when the PMDC motor is running at a specific speed rather than at the peak PV power point. Muamer M. Shebani and Tariq Iqbal Copyright © 2017 Muamer M. Shebani and Tariq Iqbal. All rights reserved. Simulation Based Investigation of the Impact of Information Sharing on the Offshore Wind Farm Installation Process Tue, 21 Mar 2017 00:00:00 +0000 In the recent decades, the introduction of a sustainable and green energy infrastructure, and, by this, the reduction of emissions caused by fossil energy generation, has been focused on by industry-oriented nations worldwide. Among the technologies of renewable energy generation, wind energy has the highest deployment rate, due to the high wind resource availability and the high technology maturity reached mainly by the onshore installation of wind turbines. However, the planning and the installation of offshore wind farms are a challenging task, because of harsh weather conditions and limited resource availability. Due to the current practice of decentralised information acquisition by the supply chain partners, we investigate the impact of sharing information on the installation process of offshore wind farms by means of a simulation model. Therefore, relevant information items will be identified in order to improve the installation process. Moritz Quandt, Thies Beinke, Abderrahim Ait-Alla, and Michael Freitag Copyright © 2017 Moritz Quandt et al. All rights reserved. On the Wind Energy Resource and Its Trend in the East China Sea Mon, 20 Feb 2017 00:00:00 +0000 This study utilizes a 30-year (1980–2009) 10 m wind field dataset obtained from the European Center for Medium Range Weather Forecast to investigate the wind energy potential in the East China Sea (ECS) by using Weibull shape and scale parameters. The region generally showed good wind characteristics. The calculated annual mean of the wind power resource revealed the potential of the region for large-scale grid-connected wind turbine applications. Furthermore, the spatiotemporal variations showed strong trends in wind power in regions surrounding Taiwan Island. These regions were evaluated with high wind potential and were rated as excellent locations for installation of large wind turbines for electrical energy generation. Nonsignificant and negative trends dominated the ECS and the rest of the regions; therefore, these locations were found to be suitable for small wind applications. The wind power density exhibited an insignificant trend in the ECS throughout the study period. The trend was strongest during spring and weakest during autumn. Adekunle Ayodotun Osinowo, Xiaopei Lin, Dongliang Zhao, and Kaiwen Zheng Copyright © 2017 Adekunle Ayodotun Osinowo et al. All rights reserved. Piezoelectric Energy Generation from Vehicle Traffic with Technoeconomic Analysis Mon, 13 Feb 2017 00:00:00 +0000 This paper presents a technical simulation based system to support the concept of generating energy from road traffic using piezoelectric materials. The simulation based system design replicates a real life system implementation. It investigates practicality and feasibility using a real-time simulation platform known as MATLAB-Simulink. The system design structure was proposed considering factors involved with the field of material sciences for piezoelectric generator modeling and field of power electronics for additional components in producing a realist outcome. It also ensures ease of vehicle performance, as this system utilizes energy source derived as kinetic energy released from vehicles into electrical power output, that is, obtained by harnessing kinetic energy due to strain of vehicles over asphalt road surface. Due to the real-time simulation platform, the system simulation predicts the effective global carbon footprint. In addition to evaluating technical viability, a technoeconomical business analysis provides a strategic perspective. By using the simulation based power generation results, an estimation of implementation cost and payback time in real life (for United Arab Emirates) was derived, hence validating and predicting real-time economic outcome. This is followed by a comparative study with other sources of renewable energy based on levelized energy cost factor that justifies the performance of the proposed system over other renewable energy sources, in support of providing an economical solution on reducing global carbon footprint. Hiba Najini and Senthil Arumugam Muthukumaraswamy Copyright © 2017 Hiba Najini and Senthil Arumugam Muthukumaraswamy. All rights reserved. Geoffroea decorticans for Biofuels: A Promising Feedstock Thu, 09 Feb 2017 00:00:00 +0000 In this work, chañar (Geoffroea decorticans) fruit is evaluated as a potential feedstock for biodiesel and biomass pellets production with reference to some relevant properties. The fatty acid profile of this oil (83% unsaturated acids) is found to be comparable to similar seed oils which have been attempted for biodiesel production. As a result, the methyl esters (biodiesel) obtained from this oil exhibits high quality properties. Chañar biodiesel quality meets all other biodiesel international standards (ASTM D6751 and EN 14214). Moreover, the husk that surrounds the kernel showed a high potential for usage as densified solid fuels. The results demonstrate that chañar husks pellets have a higher calorific value when compared with other biomass pellets, typically, approximately 21 MJ kg−1 with 1.8% of ashes (which is equivalent to that obtained from the combustion of pellets produced from forest wastes). This study indicates that chañar can be used as a multipurpose energy crop in semiarid regions for biodiesel and densified solid fuels (pellets) production. Claudia Santibáñez and Marcela Vargas Copyright © 2017 Claudia Santibáñez and Marcela Vargas. All rights reserved. Institutional and Policy Assessment of Renewable Energy Sector in Afghanistan Sun, 15 Jan 2017 00:00:00 +0000 Renewable energy resources could play a vital role in the sustainable economic, social, and environmental development of Afghanistan. Heavy reliance of rural households on firewood, rising costs of fossil fuels, outdoor and indoor air pollution, and climate change are some of the challenges that can be addressed by diversifying our power production fuel inputs and adopting renewable energy technologies. In order to deploy and scale up renewable energy technologies and improve access to sustainable energy, clear policies and targets and dedicated institutions are crucial. Fortunately, Afghan government with the support of international community is setting ambitious targets for the renewable energy sector and is encouraging national and international investors to take part in the generation, transmission, and distribution of renewable energy especially electricity through Power Purchase Agreements or very cheap land leases. Thus, the objectives of this report are (I) to review the existing institutions in the field of renewable energy, (II) to review renewable energy policies and targets in Afghanistan, and (III) to identify institutional and policy gaps and recommend solutions. Ahmad Murtaza Ershad Copyright © 2017 Ahmad Murtaza Ershad. All rights reserved. Wind Energy Development in India and a Methodology for Evaluating Performance of Wind Farm Clusters Thu, 10 Nov 2016 14:33:23 +0000 With maturity of advanced technologies and urgent requirement for maintaining a healthy environment with reasonable price, India is moving towards a trend of generating electricity from renewable resources. Wind energy production, with its relatively safer and positive environmental characteristics, has evolved from a marginal activity into a multibillion dollar industry today. Wind energy power plants, also known as wind farms, comprise multiple wind turbines. Though there are several wind-mill clusters producing energy in different geographical locations across the world, evaluating their performance is a complex task and is an important focus for stakeholders. In this work an attempt is made to estimate the performance of wind clusters employing a multicriteria approach. Multiple factors that affect wind farm operations are analyzed by taking experts opinions, and a performance ranking of the wind farms is generated. The weights of the selection criteria are determined by pairwise comparison matrices of the Analytic Hierarchy Process (AHP). The proposed methodology evaluates wind farm performance based on technical, economic, environmental, and sociological indicators. Both qualitative and quantitative parameters were considered. Empirical data were collected through questionnaire from the selected wind farms of Belagavi district in the Indian State of Karnataka. This proposed methodology is a useful tool for cluster analysis. Sanjeev H. Kulkarni, Tumkur Ramakrishnarao Anil, and Rajakumar Dyamenally Gowdar Copyright © 2016 Sanjeev H. Kulkarni et al. All rights reserved. Generalized Extreme Value Distribution Models for the Assessment of Seasonal Wind Energy Potential of Debuncha, Cameroon Tue, 25 Oct 2016 06:42:05 +0000 The method of generalized extreme value family of distributions (Weibull, Gumbel, and Frechet) is employed for the first time to assess the wind energy potential of Debuncha, South-West Cameroon, and to study the variation of energy over the seasons on this site. The 29-year (1983–2013) average daily wind speed data over Debuncha due to missing values in the years 1992 and 1994 is gotten from NASA satellite data through the RETScreen software tool provided by CANMET Canada. The data is partitioned into min-monthly, mean-monthly, and max-monthly data and fitted using maximum likelihood method to the two-parameter Weibull, Gumbel, and Frechet distributions for the purpose of determining the best fit to be used for assessing the wind energy potential on this site. The respective shape and scale parameters are estimated. By making use of the values of the Kolmogorov-Smirnov statistic (K-S) and the standard error (s.e) analysis, the results show that the Frechet distribution best fits the min-monthly, mean-monthly, and max-monthly data compared to the Weibull and Gumbel distributions. Wind speed distributions and wind power densities of both the wet and dry seasons are compared. The results show that the wind power density of the wet season was higher than in the dry season. The wind speeds at this site seem quite low; maximum wind speeds are listed as between 3.1 and 4.2 m/s, which is below the cut-in wind speed of many modern turbines (6–10 m/s). However, we recommend the installation of low cut-in wind turbines like the Savonius or Aircon (10 KW) for stand-alone low energy need. Nkongho Ayuketang Arreyndip and Ebobenow Joseph Copyright © 2016 Nkongho Ayuketang Arreyndip and Ebobenow Joseph. All rights reserved. Investigation of the Unsteady Flow Behaviour on a Wind Turbine Using a BEM and a RANSE Method Wed, 19 Oct 2016 14:08:25 +0000 Analyses of the unsteady flow behaviour of a 5 MW horizontal-axis wind turbine (HAWT) rotor (Case I) and a rotor with tower (Case II) are carried out using a panel method and a RANSE method. The panel method calculations are obtained by applying the in-house boundary element method (BEM) panMARE code, which is based on the potential flow theory. The BEM is a three-dimensional first-order panel method which can be used for investigating various steady and unsteady flow problems. Viscous flow simulations are carried out by using the RANSE solver ANSYS CFX 14.5. The results of Case I allow for the calculation of the global integral values of the torque and the thrust and include detailed information on the local flow field, such as the pressure distribution on the blade sections and the streamlines. The calculated pressure distribution by the BEM is compared with the corresponding values obtained by the RANSE solver. The tower geometry is considered in the simulation in Case II, so the unsteady forces due to the interaction between the tower and the rotor blades can be calculated. The application of viscous and inviscid flow methods to predict the forces on the HAWT allows for the evaluation of the viscous effects on the calculated HAWT flows. Israa Alesbe, Moustafa Abdel-Maksoud, and Sattar Aljabair Copyright © 2016 Israa Alesbe et al. All rights reserved. Municipal Solid Waste to Energy Generation in Bangladesh: Possible Scenarios to Generate Renewable Electricity in Dhaka and Chittagong City Thu, 29 Sep 2016 11:34:22 +0000 Increased generation of methane (CH4) from municipal solid wastes (MSW) alarms the world to take proper initiative for the sustainable management of MSW, because it is 34 times stronger than carbon dioxide (CO2). Mounting land scarcity issue around the world brands the waste to energy (WtE) strategy for MSW management in urban areas as a promising option, because WtE not only reduces the land pressure problem, but also generates electricity, heat, and green jobs. The goal of this study is to evaluate the renewable electricity generation potential and associated carbon reduction of MSW management in Bangladesh using WtE strategies. The study is conducted in two major cities of Bangladesh: Dhaka and Chittagong. Six different WtE scenarios are evaluated consisting of mixed MSW incineration and landfill gas (LFG) recovery system. Energy potential of different WtE strategy is assessed using standard energy conversion model and subsequent GHGs emissions models. Scenario A1 results in highest economic and energy potential and net negative GHGs emission. Sensitivity analysis by varying MSW moisture content reveals higher energy potential and less GHGs emissions from MSW possessing low moisture content. The study proposes mixed MSW incineration that could be a potential WtE strategy for renewable electricity generation in Bangladesh. K. M. Nazmul Islam Copyright © 2016 K. M. Nazmul Islam. All rights reserved. Improvement of Waste Tire Pyrolysis Oil and Performance Test with Diesel in CI Engine Mon, 29 Aug 2016 14:11:39 +0000 The standard of living, quality of life, and development of a nation depend on its per capita energy consumption. Global energy supply that mainly depends on fossil fuel is decreasing day by day. It is estimated that the energy demand will be increased five times by the year 2021 from present scenario. Due to the fossil fuel crisis, the development of alternative fuel technologies has drawn more attraction to deliver the replacement of fossil fuel. Pyrolysis is one of the promising alternative fuel technologies which produces valuable oil, char, and gas product from organic waste. Early investigations report that tire pyrolysis oil extracted from vacuum pyrolysis method seemed to have properties similar to diesel fuel. The main concern of this paper is to produce and improve the properties of crude tire pyrolysis oil by desulfurizing, distilling, and utilizing it with diesel in CI engine to analyze the efficiency for various compositions. M. N. Islam and M. R. Nahian Copyright © 2016 M. N. Islam and M. R. Nahian. All rights reserved. Corrigendum to “Propagation of Shock on NREL Phase VI Wind Turbine Airfoil under Compressible Flow” Tue, 24 May 2016 11:52:12 +0000 Mohammad A. Hossain, Ziaul Huque, and Raghava R. Kommalapati Copyright © 2016 Mohammad A. Hossain et al. All rights reserved. Biodiesel Production from Castor Oil by Using Calcium Oxide Derived from Mud Clam Shell Wed, 04 May 2016 09:10:10 +0000 The catalytic potential of calcium oxide synthesized from mud clam shell as a heterogeneous catalyst for biodiesel production was studied. The mud clam shell calcium oxide was characterized using particle size analyzer, Fourier transform infrared spectroscopy, scanning electron microscopy, and BET gas sorption analyzer. The catalyst performance of mud clam shell calcium oxide was studied in the transesterification of castor oil as biodiesel. Catalyst characterization and transesterification study results of synthesized catalyst proved the efficiency of the natural derived catalyst for biodiesel production. A highest biodiesel yield of 96.7% was obtained at optimal parameters such as 1 : 14 oil-to-methanol molar ratio, 3% w/w catalyst concentration, 60°C reaction temperature, and 2-hour reaction time. Catalyst reusability test shows that the synthesized calcium oxide from mud clam shell is reusable up to 5 times. S. Ismail, A. S. Ahmed, Reddy Anr, and S. Hamdan Copyright © 2016 S. Ismail et al. All rights reserved. Techno-Economic Feasibility of Small Scale Hydropower in Ethiopia: The Case of the Kulfo River, in Southern Ethiopia Wed, 02 Mar 2016 11:07:14 +0000 This paper presents the technical and economic feasibility of grid connected small scale hydropower construction in selected site of the Kulfo River in southern Ethiopia. In doing so the paper presents the general overview of Ethiopia electric power situation; small scale hydropower situation and barriers and drivers for its development; site assessment and cost estimation methods and at the end presents techno-economic analysis of small scale hydropower development on the Kulfo River in southern Ethiopia. The technical and economic feasibility of the site have been studied by using HOMER, RETscreen, and SMART Mini-IDRO software. The result of simulation shows that the construction of small scale hydropower in the Kulfo River is technically and economically feasible with total net present cost of 13,345,150, cost of energy 0.028/kWh, simple payback period of 12.4 year, and internal rate of return 12.9%. The result also shows that construction of hydropower curtails greenhouse gas emissions such as carbon dioxide by 96,685,45 kg/year, sulfur dioxide by 4,1917 kg/year, and nitrogen dioxide by 20,500 kg/year. Zelalem Girma Copyright © 2016 Zelalem Girma. All rights reserved. Performance Analysis of Savonius Rotor Based Hydropower Generation Scheme with Electronic Load Controller Mon, 08 Feb 2016 14:27:32 +0000 This paper describes the performance of electronic load controller (ELC) of asynchronous generator (AG) coupled to an uncontrolled Savonius turbine and variable water velocity. An AC-DC-AC converter with a dc link capacitor is employed to maintain the required frequency. The ELC which is feeding a resistive dump load is connected in parallel with the generating system and the power consumption is varied through the duty cycle of the chopper. Gate triggering of ELC is accomplished through sinusoidal pulse width modulation (SPWM) by sensing the load current. A MATLAB/Simulink model of Savonius rotor, asynchronous generator, ELC, and three-phase load is presented. The proposed scheme is tested under various load conditions under varying water velocities and the performances are observed to be satisfactory. Rajen Pudur and Sarsing Gao Copyright © 2016 Rajen Pudur and Sarsing Gao. All rights reserved. Dynamic Stability Improvement of Grid Connected DFIG Using Enhanced Field Oriented Control Technique for High Voltage Ride Through Sun, 13 Dec 2015 11:05:20 +0000 Doubly fed induction generator (DFIG) is a better alternative to increased power demand. Modern grid regulations force DFIG to operate without losing synchronism during overvoltages called high voltage ride through (HVRT) during grid faults. Enhanced field oriented control technique (EFOC) was proposed in Rotor Side Control of DFIG converter to improve power flow transfer and to improve dynamic and transient stability. Further electromagnetic oscillations are damped, improved voltage mitigation and limit surge currents for sustained operation of DFIG during voltage swells. The proposed strategy has advantages such as improved reactive power control, better damping of electromagnetic torque oscillations, and improved continuity of voltage and current from stator and rotor to grid during disturbance. In EFOC technique, rotor flux reference changes its value from synchronous speed to zero during fault for injecting current at the rotor slip frequency. In this process, DC-Offset component of stator flux is controlled so that decomposition during overvoltage faults can be minimized. The offset decomposition of flux will be oscillatory in a conventional FOC, whereas in EFOC it is aimed to be quick damping. The system performance with overvoltage of 1.3 times, 1.62 times, and 2 times the rated voltage occurring is analyzed by using simulation studies. V. N. Ananth Duggirala and V. Nagesh Kumar Gundavarapu Copyright © 2015 V. N. Ananth Duggirala and V. Nagesh Kumar Gundavarapu. All rights reserved. Assessment of Stand-Alone Residential Solar Photovoltaic Application in Sub-Saharan Africa: A Case Study of Gambia Mon, 23 Nov 2015 09:39:49 +0000 The focus of this paper is the design and implementation of solar PV deployment option, which is economical and easy to maintain for remote locations in less developed countries in Sub-Saharan Africa. The feasibility of stand-alone solar PV systems as a solution to the unstable electricity supply and as an alternative to the conventional resource, “diesel generators,” is presented. Moreover, a design of a system is carried out, such that the electrical demand and site meteorological data of a typical household in the capital, Banjul, is simulated. Likewise, the life cycle cost analysis to assess the economic viability of the system, along with the solar home performance, is also presented. Such system will be beneficial to the inhabitants of Gambia by ensuring savings in fuel costs and by reducing carbon emissions produced by generators. The selection of appropriate-sized components is crucial, as they affect the lifetime, reliability, and initial costs. The design presented in this study represents a solution for domestic houses to adopt the system according to the location and environment, in order to meet electricity demand. Sambu Kanteh Sakiliba, Abubakar Sani Hassan, Jianzhong Wu, Edward Saja Sanneh, and Sul Ademi Copyright © 2015 Sambu Kanteh Sakiliba et al. All rights reserved. A Pedestrian Approach to Indoor Temperature Distribution Prediction of a Passive Solar Energy Efficient House Mon, 16 Nov 2015 07:21:00 +0000 With the increase in energy consumption by buildings in keeping the indoor environment within the comfort levels and the ever increase of energy price there is need to design buildings that require minimal energy to keep the indoor environment within the comfort levels. There is need to predict the indoor temperature during the design stage. In this paper a statistical indoor temperature prediction model was developed. A passive solar house was constructed; thermal behaviour was simulated using ECOTECT and DOE computer software. The thermal behaviour of the house was monitored for a year. The indoor temperature was observed to be in the comfort level for 85% of the total time monitored. The simulation results were compared with the measured results and those from the prediction model. The statistical prediction model was found to agree (95%) with the measured results. Simulation results were observed to agree (96%) with the statistical prediction model. Modeled indoor temperature was most sensitive to the outdoor temperatures variations. The daily mean peak ones were found to be more pronounced in summer (5%) than in winter (4%). The developed model can be used to predict the instantaneous indoor temperature for a specific house design. Golden Makaka Copyright © 2015 Golden Makaka. All rights reserved. Optimal Operation Conditions for a Methane Fuelled SOFC and Microturbine Hybrid System Tue, 10 Nov 2015 13:04:37 +0000 The study of a hybrid system obtained coupling a methane fuelled gas microturbine (MTG) and a solid oxide fuel cell (SOFC) was performed. The objective of this study is to evaluate the operation conditions as a function of the independent variables of the system, which are the current density and fuel utilization factor. Numerical simulations were carried out in developing a C++ computer code, in order to identify the preferable plant configuration and both the optimal methane flow and the current density. Operation conditions are able to ensure elasticity and the most suitable fuel utilization factor. To confirm the reliability of the models, results of the simulations were compared with reference results found in literature. Vincenzo De Marco, Gaetano Florio, and Petronilla Fragiacomo Copyright © 2015 Vincenzo De Marco et al. All rights reserved. Improved Cat Swarm Optimization for Simultaneous Allocation of DSTATCOM and DGs in Distribution Systems Tue, 03 Nov 2015 07:27:21 +0000 This paper addresses a new methodology for the simultaneous optimal allocation of DSTATCOM and DG in radial distribution systems to maximize power loss reduction while maintaining better node voltage profiles under multilevel load profile. Cat Swarm Optimization (CSO) is one of the recently developed powerful swarm intelligence-based optimization techniques that mimics the natural behavior of cats but usually suffers from poor convergence and accuracy while subjected to large dimension problem. Therefore, an Improved CSO (ICSO) technique is proposed to efficiently solve the problem where the seeking mode of CSO is modified to enhance its exploitation potential. In addition, the problem search space is virtually squeezed by suggesting an intelligent search approach which smartly scans the problem search space. Further, the effect of network reconfiguration has also been investigated after optimally placing DSTATCOMs and DGs in the distribution network. The suggested measures enhance the convergence and accuracy of the algorithm without loss of diversity. The proposed method is investigated on 69-bus test distribution system and the application results are very promising for the operation of smart distribution systems. Neeraj Kanwar, Nikhil Gupta, K. R. Niazi, and Anil Swarnkar Copyright © 2015 Neeraj Kanwar et al. All rights reserved. Alkali Pretreatment and Enzymatic Hydrolysis of Australian Timber Mill Sawdust for Biofuel Production Thu, 22 Oct 2015 13:58:35 +0000 This study investigated the potential use of alkali pretreatment of sawdust from Australian timber mills to produce bioethanol. Sawdust was treated using 3–10% w/w NaOH at temperatures of 60, 121, and −20°C. Two pathways of production were trialled to see the impact on the bioethanol potential, enzymatic hydrolysis for glucose production, and simultaneous saccharification and fermentation (SSF) for ethanol production. The maximum yields obtained were at 121°C and −20°C using 7% NaOH, with 29.3% and 30.6% ethanol yields after 0.5 and 24 hr, respectively, these treatments yielded 233% and 137% increase from the 60°C counter parts. A notable trend of increased ethanol yields with increased NaOH concentration was observed for samples treated at 60°C; for example, samples treated using 10% NaOH produced 1.92–2.07 times more than those treated using 3% NaOH. FTIR analysis showed reduction in crystallinity correlating with increased ethanol yields with the largest reduction in crystallinity in the sample treated at −20°C for 24 hr with 7% NaOH. Raymond Martin Trevorah and Maazuza Z. Othman Copyright © 2015 Raymond Martin Trevorah and Maazuza Z. Othman. All rights reserved. Decentralized Autonomous Hybrid Renewable Power Generation Sun, 04 Oct 2015 13:00:56 +0000 Power extension of grid to isolated regions is associated with technical and economical issues. It has encouraged exploration and exploitation of decentralized power generation using renewable energy sources (RES). RES based power generation involves uncertain availability of power source round the clock. This problem has been overcome to certain extent by installing appropriate integrated energy storage unit (ESU). This paper presents technical review of hybrid wind and photovoltaic (PV) generation in standalone mode. Associated components like converters, storage unit, controllers, and optimization techniques affect overall generation. Wind and PV energy are readily available, omnipresent, and expected to contribute major future energy market. It can serve to overcome global warming problem arising due to emissions in fossil fuel based thermal generation units. This paper includes the study of progressive development of standalone renewable generation units based on wind and PV microgrids. Prakash Kumar and Dheeraj Kumar Palwalia Copyright © 2015 Prakash Kumar and Dheeraj Kumar Palwalia. All rights reserved. Load Mitigation and Optimal Power Capture for Variable Speed Wind Turbine in Region 2 Sun, 27 Sep 2015 14:15:07 +0000 This paper proposes the two nonlinear controllers for variable speed wind turbine (VSWT) operating at below rated wind speed. The objective of the controller is to maximize the energy capture from the wind with reduced oscillation on the drive train. The conventional controllers such as aerodynamic torque feedforward (ATF) and indirect speed control (ISC) are adapted initially, which introduce more power loss, and the dynamic aspects of WT are not considered. In order to overcome the above drawbacks, modified nonlinear static state with feedback estimator (MNSSFE) and terminal sliding mode controller (TSMC) based on Modified Newton Raphson (MNR) wind speed estimator are proposed. The proposed controllers are simulated with nonlinear FAST (fatigue, aerodynamics, structures, and turbulence) WT dynamic simulation for different mean wind speeds at below rated wind speed. The frequency analysis of the drive train torque is done by taking the power spectral density (PSD) of low speed shaft torque. From the result, it is found that a trade-off is to be maintained between the transient load on the drive train and maximum power capture. Saravanakumar Rajendran and Debashisha Jena Copyright © 2015 Saravanakumar Rajendran and Debashisha Jena. All rights reserved. Optimal Location, Sizing, and Appropriate Technology Selection of Distributed Generators for Minimizing Power Loss Using Genetic Algorithm Wed, 16 Sep 2015 11:50:30 +0000 Genetic algorithm (GA) is utilized to select most suitable Distributed Generator (DG) technology for optimal operation of power system as well as determine the optimal location and size of the DG to minimize power loss on the network. Three classes of DG technologies, synchronous generators, asynchronous generators, and induction generators, are considered and included as part of the variables for the optimization problem. IEEE 14-bus network is used to test the applicability of the algorithm. The result reveals that the developed algorithm is able to successfully select the most suitable DG technology and optimally size and place the DGs to minimize power loss in the network. Furthermore, optimum multiple placement of DG is considered to see the possible impact on power loss in the network. The result reveals that multiple placements can further reduce the power loss in the network. T. R. Ayodele, A. S. O. Ogunjuyigbe, and O. O. Akinola Copyright © 2015 T. R. Ayodele et al. All rights reserved. The Study of Kinetic Properties and Analytical Pyrolysis of Coconut Shells Wed, 26 Aug 2015 07:18:54 +0000 The kinetic properties of coconut shells during pyrolysis were studied to determine its reactivity in ground form. The kinetic parameters were determined by using thermogravimetric analyser. The activation energy was 122.780 kJ/mol. The pyrolysis products were analyzed using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effects of pyrolysis temperature on the distribution of the pyrolytic products were assessed in a temperature range between 673 K and 1073 K. The set time for pyrolysis was 2 s. Several compounds were observed; they were grouped into alkanes, acids, ethers and alcohols, esters, aldehydes and ketones, furans and pyrans, aromatic compounds, and nitrogen containing compounds. The product compositions varied with temperature in that range. The highest gas proportion was observed at high temperature while the acid proportion was observed to be highest in coconut shells, thus lowering the quality of bio-oil. It has been concluded that higher pyrolysis temperature increases the amount of pyrolysis products to a maximum value. It has been recommended to use coconut shell for production of gas, instead of production of bio-oil due to its high proportion of acetic acid. Mahir Said, Geoffrey John, Cuthbert Mhilu, and Samwel Manyele Copyright © 2015 Mahir Said et al. All rights reserved. The Technical and Economic Study of Solar-Wind Hybrid Energy System in Coastal Area of Chittagong, Bangladesh Thu, 09 Jul 2015 12:04:33 +0000 The size optimization and economic evaluation of the solar-wind hybrid renewable energy system (RES) to meet the electricity demand of 276 kWh/day with 40 kW peak load have been determined in this study. The load data has been collected from the motels situated in the coastal areas of Patenga, Chittagong. RES in standalone as well as grid connected mode have been considered. The optimal system configurations have been determined based on systems net present cost (NPC) and cost of per unit energy (COE). A standalone solar-wind-battery hybrid system is feasible and economically comparable to the present cost of diesel based power plant if 8% annual capacity shortage is allowed. Grid tied solar-wind hybrid system, where more than 70% electricity contribution is from RES, is economically comparable to present grid electricity price. Moreover, grid tied RES results in more than 60% reduction in greenhouse gases emission compared to the conventional grid. Sensitivity analysis has been performed in this study to determine the effect of capital cost variation or renewable resources variation on the system economy. Simulation result of sensitivity analysis has showed that 20% reduction of installation cost results in nearly 9%–12% reductions in cost of per unit energy. Shuvankar Podder, Raihan Sayeed Khan, and Shah Md Ashraful Alam Mohon Copyright © 2015 Shuvankar Podder et al. All rights reserved. Effect of Operating Conditions on Pollutants Concentration Emitted from a Spark Ignition Engine Fueled with Gasoline Bioethanol Blends Thu, 14 May 2015 07:35:54 +0000 This study is an experimental investigation of the effect of bioethanol gasoline blending on exhaust emissions in terms of carbon dioxide CO2, carbon monoxide CO, unburnt hydrocarbons UHC, and nitric oxide NOx of a spark ignition engine. Tests are conducted at controlled throttle and variable speed condition over the range of 1200 to 2000 rpm with intervals 400 rpm. Different compression ratios are tested for each speed, namely (7,8,10, and 11). Pure gasoline and bioethanol gasoline blends are used. The bioethanol used is produced from Iraqi date crop (Zehdi). Blending is done on energy replacement bases. Ethanol energy ratio (EER) used is 5%, 10%, and 15%. At each of the three designated engine speeds, the torque is set as 0, 3, 7, 10, and 14 N·m. It is found that ethanol blending reduces CO and UHC concentration in the exhaust gases by about 45% and 40.15%, respectively, and increases NOx and CO2 concentrations in the exhaust gases by about 16.18% and 7.5%, respectively. It is found also that load and speed increase causes an increase in CO2 and NOx concentrations and reduces CO and UHC concentrations. It is also found that increasing the compression ratio causes the emissions of CO2 and NOx to decrease and those of CO and UHC to increase. Haroun A. K. Shahad and Saad K. Wabdan Copyright © 2015 Haroun A. K. Shahad and Saad K. Wabdan. All rights reserved. Biodiesel Production Process Optimization from Sugar Apple Seed Oil (Annona squamosa) and Its Characterization Thu, 08 Jan 2015 13:28:07 +0000 This paper presents the production of biodiesel from nonedible, renewable sugar apple seed oil and its characterization. The studies were carried out on transesterification of oil with methanol and sodium hydroxide as catalyst for the production of biodiesel. The process parameters such as catalyst concentration, reaction time, and reaction temperature were optimized for the production of sugar apple biodiesel (SABD). The biodiesel yield of 95.15% was noticed at optimal process parameters. The fuel properties of biodiesel produced were found to be close to that of diesel fuel and also they meet the specifications of ASTM standards. Siddalingappa R. Hotti and Omprakash D. Hebbal Copyright © 2015 Siddalingappa R. Hotti and Omprakash D. Hebbal. All rights reserved. Prospect of Pongamia pinnata (Karanja) in Bangladesh: A Sustainable Source of Liquid Fuel Thu, 18 Dec 2014 09:34:02 +0000 Energy is the basic requirement for the existence of human being in today’s digital world. Indigenous energy of Bangladesh (especially natural gas and diesel) is basically used in power generation and depleting hastily to meet the increasing power demand. Therefore, special emphasis has been given to produce alternative liquid fuel worldwide to overcome the crisis of diesel. Pongamia pinnata (karanja) may be an emerging option for providing biooil for biodiesel production. Although karanja biooil has been used as a source of traditional medicines in Bangladesh, it can also be used for rural illumination. This paper outlines the medical and energy aspects of Pongamia pinnata. It has been assessed that Bangladesh can utilize about 128.95 PJ through Pongamia cultivation in unused lands. The paper reviews the potentiality of Pongamia pinnata as a source of biodiesel and its benefits in Bangladesh. The paper also revives that, about 0.52 million tons of biodiesel can be produced only utilizing the unused lands per year in sustainable basis as it reduces CO2, CO, HC, and NOx emission compared to pure diesel. P. K. Halder, N. Paul, and M. R. A. Beg Copyright © 2014 P. K. Halder et al. All rights reserved. Sustainable Design of a Nearly Zero Energy Building Facilitated by a Smart Microgrid Wed, 10 Dec 2014 12:43:40 +0000 One of the emerging milestones in building construction is the development of nearly zero energy buildings (NZEBs). This complex concept is defined as buildings that on a yearly average consume as much energy as they generate using renewable energy sources. Realization of NZEBs requires a wide range of technologies, systems, and solutions with varying degrees of complexity and sophistication, depending upon the location and surrounding environmental conditions. This paper will address the role of the above technologies and solutions and discusses the challenges being faced. The objective is to maximize energy efficiency, optimize occupant comfort, and reduce dependency on both the grid and the municipal potable water supply by implementing sustainable strategies in designing a research and sports facility. Creative solutions by the architectural and engineering team capitalize on the design of a unique glazing system; energy efficient technologies; water use reduction techniques; and a combined cooling, heating, and power (CCHP) microgrid (MG) with integrated control aspects and renewable energy sources. Gandhi Habash, Daniel Chapotchkine, Peter Fisher, Alec Rancourt, Riadh Habash, and Will Norris Copyright © 2014 Gandhi Habash et al. All rights reserved.