ISRN Renewable Energy http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Energy and Exergy Analysis of a Plane Reflector Integrated Photovoltaic-Thermal Water Heating System Mon, 14 Apr 2014 00:00:00 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/180618/ A photovoltaic-thermal water heating system is a hybrid energy conversion device transforming the incident solar radiation to yield electrical energy and thermal energy. Plane reflectors are found to be a convenient option for enhancing the solar radiation incident on the collector plane. The present work investigates the performance of a photovoltaic-thermal water heater integrated with a plane reflector mounted on the top edge of the collector for the tropical climate of Calicut (11.25°N, 75.78°E). Performance testing of the system has been carried out for the winter season of the location. The variations in thermal and electrical output are studied for various inclination angles of the reflector. The system performance is evaluated on the basis of system energy efficiency and exergetic efficiency. It is observed that there is a significant enhancement in the thermal and electrical output of the system with the integration of the reflector as compared to the system without the reflector. For the present system, the reflector tilt angle in the range of 85–100° has been found to be suitable in terms of enhanced system output and exergetic efficiency for the winter conditions of Calicut. Prem Sagar Naik and Arun Palatel Copyright © 2014 Prem Sagar Naik and Arun Palatel. All rights reserved. Efficient Maximum Power Point Tracking Algorithm for PV Application under Rapid Changing Weather Condition Thu, 27 Mar 2014 09:45:12 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/673840/ This study presents a novel search algorithm of maximum power point tracking for photovoltaic power generation systems. The I-V characteristics and the P-V power output under specific irradiation and temperature conditions are simulated. The performance of the algorithm under fully shaded and sudden partially shaded conditions as well as variable insulations levels is investigated. The developed algorithm performs a wide-range search in order to detect rapidly changing weather conditions, and keeps the simulated stand-alone or grid-connected systems continuously operating close to the maximum power point. The performance of the developed algorithm, under extremely changing environmental conditions, is found to be superior compared to that of other conventional algorithms. The results of this study show that, under uniform radiations conditions, the developed algorithm takes only half of the time required by the Perturbation and Observe algorithms to reach maximum power point MMP. Furthermore, when PV is subjected to sudden partial shading conditions, the algorithm rapidly detects these changes and reaches the new MMP in less than a second. Khaled M. Bataineh and Amr Hamzeh Copyright © 2014 Khaled M. Bataineh and Amr Hamzeh. All rights reserved. Survey on Microgrid: Power Quality Improvement Techniques Sun, 16 Mar 2014 11:18:00 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/342019/ Microgrid became one of the key spot in research on distributed energy systems. Since the definition of the microgrid is paradigm of the first time, investigation in this area is growing continuously and there are numerous research projects in this moment all over the world. The increased infiltration of nonlinear loads and power electronic interfaced distribution generation system creates power quality issues in the distributed power system. In this paper, a comprehensive survey on microgrid to improve the power quality parameters is taken as the main objective. Furthermore, the detailed investigations are explored in this paper for the enhancement of power quality issues with the help of an optimization technique, filters, controllers, FACTS devices, compensators, and battery storage. Chitra Natesan, Senthil Kumar Ajithan, Priyadharshini Palani, and Prabaakaran Kandhasamy Copyright © 2014 Chitra Natesan et al. All rights reserved. Production of Biodiesel from Lipid of Porphyridium cruentum through Ultrasonic Method Mon, 10 Mar 2014 14:02:24 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/107278/ A research on production of biodiesel from lipid of phytoplankton Porphyridium cruentum through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extraction method using ethanol 96%, while biodiesel synthesis was carried out by transesterification reaction using methanol and KOH catalyst under sonication. Weight of biodiesel yield per biomass Porphyridium cruentum is 40,27%. Characterization of biodiesel was well carried out in terms of physical properties which are density and viscosity and chemical properties which are FFA content, saponification value, and iodine value. These values meet the American Society for Testing and Materials (ASTM D6751) standard levels, except for the density value which was 0.9461 g·cm−3 and the FFA content which was 4.6671%. Raymond Kwangdinata, Indah Raya, and Muhammad Zakir Copyright © 2014 Raymond Kwangdinata et al. All rights reserved. Using the SWEPT Methodology for a Preliminary Wind Potential Estimation Sun, 09 Mar 2014 15:52:31 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/516964/ The implantation of wind turbines generally follows a wind potential study which is made using specific numerical tools; the generated expenses are only acceptable for great projects. The purpose of the present paper is to propose a simplified methodology for the evaluation of the wind potential, following three successive steps for the determination of (i) the mean velocity, either directly or by the use of the most occurrence velocity (MOV); (ii) the velocity distribution coming from the single knowledge of the mean velocity by the use of a Rayleigh distribution and a Davenport-Harris law; (iii) an appropriate approximation of the characteristic curve of the turbine, coming from only two technical data. These last two steps allow calculating directly the electric delivered energy for the considered wind turbine. This methodology, called the SWEPT approach, can be easily implemented in a single worksheet. The results returned by the SWEPT tool are of the same order of magnitude than those given by the classical commercial tools. Moreover, everybody, even a “neophyte,” can use this methodology to obtain a first estimation of the wind potential of a site considering a given wind turbine, on the basis of very few general data. Jean-Luc Menet Copyright © 2014 Jean-Luc Menet. All rights reserved. MPPT Algorithm for Photovoltaic Panel Based on Augmented Takagi-Sugeno Fuzzy Model Mon, 17 Feb 2014 11:46:11 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/253146/ This paper deals with the Maximum Power Point Tracking (MPPT) for photovoltaic energy system. It includes photovoltaic array panel, DC/DC converter, and load. The operating point for photovoltaic energy system depends on climatic parameters and load. For each temperature and irradiation pair, there exists only one optimal operating point which corresponds to the maximum power transmitted to the load. The photovoltaic energy system is described by nonlinear equations. It is transformed into an augmented system which is described with a Takagi-Sugeno (T-S) fuzzy model. The proposed MPPT algorithm which permits transfering the maximum power from the panel to the load is based on Parallel Distributed Compensation method (PDC). The control parameters have been computed based on Linear Matrix Inequalities tools (LMI). The Lyapunov approach has been used to prove the stability of the system. Some reliable simulation results are provided to check the efficiency of the proposed algorithm. Hafedh Abid, Ahmed Toumi, and Mohamed Chaabane Copyright © 2014 Hafedh Abid et al. All rights reserved. Numerical Study of Natural Convection Heat Loss from Cylindrical Solar Cavity Receivers Thu, 23 Jan 2014 08:50:56 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/104686/ The numerical study of the natural convection loss occurring from cylindrical solar cavity receivers is reported in this communication. These cavity receivers can be used with solar dish concentrators for process heat applications at medium temperature levels. Three cylindrical cavity receivers of diameter 0.2, 0.3, and 0.4 m with aspect ratio equal to one and opening ratios of 1 and 0.5 are used for the analysis. Fluent CFD software is used for the analysis of the three-dimensional (3D) receiver models. In this study the receiver tubes within the cylindrical cavity are modeled as a helical coil similar to those existing in actual systems. The flow of the working fluid within the helical coil is also modeled. The simulations are performed for fluid inlet temperatures of 150°C and 250°C and for receiver inclination angles of 0 (sideways-facing cavity), 30, 45, 60, and 90 degree (vertically downward-facing receiver). It is found that the convective loss increases with increasing mean fluid temperature and decreases with, increase in receiver inclination. The convective loss is found to increase with, opening ratio. These observations are true for all cavity receivers analysed here. A Nusselt number correlation involving Rayleigh numbers, receiver inclinations, and opening ratios is proposed for the convective loss. M. Prakash Copyright © 2014 M. Prakash. All rights reserved. The Effect of PCM Capsule Material on the Thermal Energy Storage System Performance Tue, 21 Jan 2014 13:54:20 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/529280/ Phase change material (PCM) based thermal energy storage (TES) systems are gaining increasing importance in recent years in order to reduce the gap between energy supply and demand in solar thermal applications. The present work investigates the effect of PCM capsule material on the performance of TES system during charging and discharging processes. The TES unit contains paraffin as PCM filled in spherical capsules and is integrated with flat plate solar collector. Water is used as sensible heat material as well as heat transfer fluid (HTF). The PCM capsules are of 68 mm diameter and are made using three different materials, namely, (i) high density polyethylene (HDPE), (ii) aluminum (Al), and (iii) mild steel (MS). The experimental investigation showed that the charging and recovery of stored energy are less affected by the spherical capsules material. The variables, like charging time and discharging quantity, are varied around 5% for the different capsule materials. Even though aluminum thermal conductivity is much higher than HDPE and mild steel, its influence on the performance of TES system is very low due to the very high internal heat resistance of PCM material stored in the spherical capsules. R. Meenakshi Reddy, N. Nallusamy, and K. Hemachandra Reddy Copyright © 2014 R. Meenakshi Reddy et al. All rights reserved. Potential Cellulosic Ethanol Production from Organic Residues of Agro-Based Industries in Nepal Mon, 20 Jan 2014 12:56:30 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2014/305695/ With the objective of exploring the potential of bioethanol production from lignocellulosic wastes from major agro-based industries in Nepal, four types of major industries using raw materials from agriculture are selected as sources of lignocellulosic residues. They include a sugar industry, a paper industry, a tobacco industry, and a beer industry. Data from secondary/primary sources were used to record organic residues from these industries and estimates were made of potential production of bioethanol from them. About 494892.263 tons of dry bagasse could be produced if the total production of sugarcane in Nepal is taken to the sugar industry which means that about 138569.833 KL of bioethanol could be produced (in the year 2011/12). Similarly, the dry biomass residue produced from the paper mill is 86.668 ton/year that could produce 24.267 KL of bioethanol. The lignocellulosic residue from tobacco field in Nepal is approximately 18.826 ton/year that has potential to produce 5.836 KL of bioethanol. The dry biomass residue produced in beer industry amounts to 155.0596 ton/year that can yield about 63.5744 KL of bioethanol. It is estimated that about 57,841.3754 KL of bioethanol could be produced when these residues are fully utilized in producing bioethanol. If E10 is used in total import of petrol, about 20246.7 KL of bioethanol could be utilized, and the rest 37,594.6754 KL of bioethanol could be utilized for many other purposes. Ram Kailash P. Yadav, Arbindra Timilsina, Rupesh K. Yadawa, and Chandra P. Pokhrel Copyright © 2014 Ram Kailash P. Yadav et al. All rights reserved. Thermal with Mass Spectroscopic Analysis of Wood and Cereal Biomass Torrefaction Tue, 24 Dec 2013 11:30:51 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/508965/ Torrefaction is a mild form of pyrolysis that, when applied to biomass, has the effect of improving the energy density of biomass-derived solid fuels. In this study, thermogravimetric analysis (coupled with mass spectrometry) was applied to two biomass fuels (pine wood and white maize ear) to investigate a potential representative torrefaction thermal treatment process. The mass loss from the torrefaction process was indicative of emission of aliphatic hydrocarbons, evidenced by mass spectroscopic data and it is evident that optimal torrefaction conditions are determined by the type of biomass to which torrefaction processing is applied. René Laryea-Goldsmith and Chris Woolard Copyright © 2013 René Laryea-Goldsmith and Chris Woolard. All rights reserved. Wind Speed Estimation: Incorporating Seasonal Data Using Markov Chain Models Wed, 18 Dec 2013 17:18:58 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/657437/ This paper presents a novel approach for accurately modeling and ultimately predicting wind speed for selected sites when incomplete data sets are available. The application of a seasonal simulation for the synthetic generation of wind speed data is achieved using the Markov chain Monte Carlo technique with only one month of data from each season. This limited data model was used to produce synthesized data that sufficiently captured the seasonal variations of wind characteristics. The model was validated by comparing wind characteristics obtained from time series wind tower data from two countries with Markov chain Monte Carlo simulations, demonstrating that one month of wind speed data from each season was sufficient to generate synthetic wind speed data for the related season. Selin Karatepe and Kenneth W. Corscadden Copyright © 2013 Selin Karatepe and Kenneth W. Corscadden. All rights reserved. Sunflower Methyl Ester as an Engine Fuel: Performance Evaluation and Emissions Analysis Sun, 17 Nov 2013 11:46:19 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/352024/ Biodiesel from sunflower oil offers a potential as an alternative to petroleum-based diesel fuel and must be evaluated in terms of the resulting engine performance and exhaust emissions. Two diesel engines rated at 14.2 kW (small) and 60 kW (large) were operated on pure sunflower methyl ester (SFME) and its blends with a reference diesel (REFDIESEL). Results showed that less power and torque were delivered by both the small and large engines when ran on pure SFME than on REFDIESEL, while brake-specific fuel consumption (BSFC) was found to be higher in pure SFME. Blends of SFME with REFDIESEL (B5 and B20) showed negligible power loss and similar BSFC with the REFDIESEL. Higher concentrations of nitrogen oxides (), carbon dioxide (CO2), and total hydrocarbons (THC) in the exhaust emissions were observed for both pure SFME and SFME-REFDIESEL fuel blends. Comparison with soybean methyl ester indicates similar engine performance. Thus, blends of SFME with diesel may be used as a supplemental fuel for steady-state nonroad diesel engines to take advantage of the lubricity of biodiesel as well as contributing to the goal of lowering the dependence to petroleum diesel. Bjorn S. Santos, Sergio C. Capareda, and Jewel A. Capunitan Copyright © 2013 Bjorn S. Santos et al. All rights reserved. Retracted: Cashew Nut Shell Waste: Availability in Small-Scale Cashew Processing Industries and Its Fuel Properties for Gasification Wed, 30 Oct 2013 17:43:37 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/147365/ ISRN Renewable Energy Copyright © 2013 ISRN Renewable Energy. All rights reserved. Modeling Solar Energy Transfer through Roof Material in Africa Sub-Saharan Regions Mon, 21 Oct 2013 15:23:30 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/480137/ As a result of the global warming, the atmospheric temperature in sub-Saharan regions of Africa may drastically increase, thus worsening the poor living conditions already experienced by people in those regions. Roof’s thermal insulation capacity may play key role in reducing indoor thermal comfort cost. In the present study, effort is put to model heat transfer through roofs in south Saharan regions. Validation of the model was achieved using the slightly sloppy galvanized aluminum-iron sheet roof. Atmospheric data were hourly measured during April and June in Ouagadougou, Burkina Faso. Solar energy values increase from  W/m2 in the morning to a maximum of  W/m2 in the early afternoon. Ambient temperature follows the same trend as solar radiation with a maximum at °C. Wind speed varies from 0.5 to  m/s. The measured roof inner wall temperatures agreed excellently with the developed model with a Nash-Sutcliffe Coefficient of Efficiency of 0.988. Energy flux entering the room through the roof varies from  W/m2 earlier in the morning to a maximum of  W/m2 in the earlier afternoon. These results shall help to better design human habitat under changing climate conditions in the sub-Saharan regions. Julien G. Adounkpe, A. Emmanuel Lawin, Clément Ahouannou, Rufin Offin Lié Akiyo, and Brice A. Sinsin Copyright © 2013 Julien G. Adounkpe et al. All rights reserved. Air Density Climate of Two Caribbean Tropical Islands and Relevance to Wind Power Thu, 26 Sep 2013 09:04:33 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/378027/ The standard air density of 1.225 kg m−3 is often used in determining the energy output of a wind turbine although the energy output is dependent on a site's air density. By using measurements of temperature, dew-point temperature, and pressure, we calculate the monthly air density of moist tropical climates at two sites in the small-island state of Trinidad and Tobago. In addition, we calculate the energy output of a BOREAS 30 kW small wind turbine using the 10 m level wind speed distribution extrapolated to hub height. The average air densities at Crown Point and Piarco were 1.156 kg m−3 and 1.159 kg m−3, respectively, and monthly air densities at both sites were at most 6% less than standard air density. The difference in energy output of the BOREAS 30 kW calculated using standard air density over that using the local site's air density could provide electrical energy for the continuous monthly operation of 6 light bulbs rated at 50 W at Crown Point and 4 light bulbs at Piarco. Thus, communities interested in implementing wind turbine technologies must use the local air density of the site when sizing a wind turbine system for its needs. Xsitaaz Twinkle Chadee and Ricardo Marcus Clarke Copyright © 2013 Xsitaaz Twinkle Chadee and Ricardo Marcus Clarke. All rights reserved. Performance and Emission Analysis of a CI Engine in Dual Mode with LPG and Karanja Oil Methyl Ester Wed, 18 Sep 2013 09:55:04 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/540589/ The use of liquefied petroleum gas (LPG) is experimented with to improve the performance of a dual fuel compression ignition (CI) engine running on Karanja oil methyl ester (KOME) blends. Diesel is used as a reference fuel for the dual fuel engine results. During the experimentation, the engine performance is measured in terms of brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), and exhaust emission is measured in terms of carbon monoxide (CO), hydrocarbon (HC), and oxides of nitrogen (). Dual fuel engine with LPG showed a reduction in and smoke emission; however, it suffers from high HC and CO emission, particularly, at lower loads due to poor ignition. Comparison of performance and emissions is done for diesel and blends of KOME. Results showed that using KOME blends (10% and 20%) has improved the CI engine performance with a reduction in HC and CO emissions. S. K. Acharya and S. P. Jena Copyright © 2013 S. K. Acharya and S. P. Jena. All rights reserved. Carbon Based PV: n-Si(100)/DLC Structure for Photovoltaic Application Sun, 08 Sep 2013 14:50:49 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/851876/ Diamond-like carbon films were electrodeposited on n-Si substrate to realize an n-Si/DLC PV structure. The films thus obtained were characterized by FESEM, XPS, FTIR, and Raman studies. Solar cell characteristics were also investigated critically. Maximum efficiency of 3.7% was obtained for the best n-Si(100)/DLC structure. Carrier life time was obtained from decay measurement. It was observed that photoinduced charge separation in n-Si(100)/DLC structure was associated with an increase in the dielectric constant and a decrease in the device resistance. The process, being reproducible, cheap, and scalable, involving significantly less process steps, is likely to usher a new hope to the current competitive scenario of PV technology. D. Ghosh, B. Ghosh, Anindita Ghosh, S. Hussain, R. Bhar, and A. K. Pal Copyright © 2013 D. Ghosh et al. All rights reserved. Performance Analysis of Flat and Rippled Wick-Inverted V-Type Solar Still Integrated with Drip System in Kerala Climatic Conditions Sun, 08 Sep 2013 10:46:35 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/126234/ Thermal aspect of solar energy is widely used in the desalination plants. Experimental investigation and mathematical modeling of inverted V-type solar still integrated with drip system are presented in this paper. The experiment is performed in the Kerala climatic conditions (10.8439°N, 76.0328°E), March 2012 at M E S College of Engineering, Kuttippuram. A two segment still of 2 m2 is constructed. Experimental investigations on productivity and internal heat transfer are analyzed. The results indicate that the mean standard deviations between theoretical and experimental values are less than 7% (temperature of rippled wick), 8% (temperature of glass in rippled system), 11% (temperature of flat wick), and 7% (temperature of glass in flat system), an average for the working hours of the day. T. Namshad, K. R. Ayush, K. C. Salih, Athul James, Suficker Ahammed, Hashim Vayalilakath, and P. U. Suneesh Copyright © 2013 T. Namshad et al. All rights reserved. A New Low-Cost Plastic Solar Collector Mon, 02 Sep 2013 09:00:03 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/102947/ An innovative solar collector based on a long plastic hose that is connected directly in series from the district water grid to consumption is presented. It takes advantage of plastic tubing to develop a simple self-construction collector that costs about 70 dollars for a one-family unit. In addition, due to its solar-pond configuration, it could achieve a good thermal performance, as it was demonstrated by modeling. Luis E. Juanicó and Nicolás Di Lalla Copyright © 2013 Luis E. Juanicó and Nicolás Di Lalla. All rights reserved. Estimating Angstrom-Prescott Coefficients for India and Developing a Correlation between Sunshine Hours and Global Solar Radiation for India Mon, 12 Aug 2013 14:56:38 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/403742/ The amount of solar energy that reaches the earth in one hour is sufficient to supply the world's energy needs for one year. Harvesting this energy efficiently is a huge challenge. In most countries including India, the number of observing stations is inadequate. Therefore, it is essential that some reliable mathematical models be developed to estimate the solar radiation for places where measurements are not carried out and for places where measurement records are not available. In this paper, Angstrom-Prescott model parameters are estimated for seven different sites in India, and a correlation is developed for India, which is found to be a good fit. Also a correlation is developed for predicting the solar radiation using only sunshine hour data. R. C. Srivastava and Harsha Pandey Copyright © 2013 R. C. Srivastava and Harsha Pandey. All rights reserved. A High-Performance Stand-Alone Solar PV Power System for LED Lighting Sun, 14 Jul 2013 07:56:29 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/573919/ This paper presents new improvements and real result of a stand-alone photovoltaic power system for LED lighting that was developed previously. The actual system, during day, charges a lead acid battery using MPPT algorithm for power transfer optimization, and, during night, it supervises battery discharge and controls the current in the power LED array. The improvements are in hardware and software. The hardware was simplified using only one DC/DC converter and only one microcontroller making it more efficient. The system board uses an ATMEL ATTINY861V microcontroller, a single-ended primary inductance converter (SEPIC), and sensors to read input and output voltages and currents to control all system. The software improvements are made in the battery charging algorithm, battery discharging algorithm, and in current control of the power LED array adjusting the light intensity. Moreover, results are presented showing the balance of energy in a period of 24 hours: first results of the MPPT algorithm in bulk battery charge phase and then the over battery charge phase, both in a sunny day. The power LED current control results are also presented showing a very small error. It turns off at 00 : 00 at each day to reduce the waste of energy. Finally, the balance of energy is studied and presented to help the right projection of the PV power panel needed and the necessary battery capacity. José António Barros Vieira and Alexandre Manuel Mota Copyright © 2013 José António Barros Vieira and Alexandre Manuel Mota. All rights reserved. Mismatch Loss Reduction in Photovoltaic Arrays as a Result of Sorting Photovoltaic Modules by Max-Power Parameters Mon, 17 Jun 2013 10:58:13 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/327835/ Variations in photovoltaic (PV) module current-voltage curves result in a power loss in PV arrays often referred to as mismatch loss (MML). As a means of reducing MML, newly fabricated PV modules are sorted to meet a set tolerance for variation in overall maximum power output with respect to a given module’s rated power. Starting with flash test data sets for two different polycrystalline PV modules and a simulated sorting procedure, Monte Carlo techniques were used to generate a large number of artificial PV arrays. The MMLs for each of these arrays were then calculated to assess the sorting procedure’s ability to reduce MML. Overall MMLs were quite small (0.001–0.01%). Sorting by resulted in the most consistent MML reductions. Sorting by yielded insignificant results. Sorting by yielded significant MML reduction in only one of the two PV module data sets. Analysis was conducted to quantify if additional sorting on top of what both manufacturers had already done would make economic sense. Based on high level economic analysis, it appears that additional sorting yields little economic gain; however, this is highly dependent upon manufacturer sorting cost. J. Webber and E. Riley Copyright © 2013 J. Webber and E. Riley. All rights reserved. State of the Art and Perspectives of Inorganic Photovoltaics Tue, 11 Jun 2013 12:03:57 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/830731/ In the last decade, the fast increase of the global energy consumption, mainly related to the strong economic growth in the Far East, and the progressive depletion of the fossil fuels induced a run-up in the world oil price. Both these economic concerns and the growing global pollution pointed out that a transition toward renewable energies is mandatory. Among renewables, the conversion of sunlight into electricity by photovoltaic (PV) devices is a reliable choice to cope the growing energy consumption, due to the huge potentially extractable power (up to 120000 TW). The most important classes of inorganic PV devices developed in the last sixty years will be reviewed in this paper, in order to depict the state of the art of the technologies which dominate the PV market. Some novel concepts which could have an important role in the future of PV will be also described. A. Le Donne, A. Scaccabarozzi, S. Tombolato, S. Marchionna, P. Garattini, B. Vodopivec, M. Acciarri, and S. Binetti Copyright © 2013 A. Le Donne et al. All rights reserved. Photovoltaic and Thermal Hybridized Solar Cooker Thu, 06 Jun 2013 18:12:16 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/746189/ The objective of the present research work is to design user friendly solar cooker which can be commercialized too. This cooker is designed, developed, and tested in our laboratory. The basic principle is to incorporate heating into material by photovoltaic effect and thermal treatment. Different temperatures inside the solar cooker were measured and profile of solar cooker was studied for several days during April, May, and June 2012. It is observed that the designed cooker needs the boosting of only 30 watt power which is generated by a small solar panel connected with it. Heater connected with it can be powered by a solar panel of 75 watt. This boosting can reduce the cooking time. Different recipes were prepared to test its actual performance. Smita B. Joshi and A. R. Jani Copyright © 2013 Smita B. Joshi and A. R. Jani. All rights reserved. A Comparative Study of Some Regression Models to Estimate the Global Solar Radiation on a Horizontal Surface from Sunshine Duration and Meteorological Parameters for Ghardaïa Site, Algeria Tue, 04 Jun 2013 15:06:26 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/754956/ A comparison between some regression correlations for predicting the global solar radiation received on a horizontal plane has been processed. Seven models for estimating the global solar radiation from sunshine duration and two meteorological parameters (air temperature and relative humidity) are presented. The root mean square error (RMSE), mean bias error (MBE), correlation coefficient (CC), and percentage error () have been also computed to test the accuracy of the proposed models. Comparisons between the measured and the calculated values have been made. The results obtained show that the linear and quadratic models are the most suitable for estimating the global solar radiation from sunshine duration, and for the models based on meteorological parameters, Abdalla and Ojosu's models give the best performance with a CC of 0.898 and 0.892, respectively. Kacem Gairaa and Yahia Bakelli Copyright © 2013 Kacem Gairaa and Yahia Bakelli. All rights reserved. Alternate Strategies for Conversion of Waste Plastic to Fuels Mon, 20 May 2013 13:17:59 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/902053/ The present rate of economic growth is unsustainable without saving of fossil energy like crude oil, natural gas, or coal. There are many alternatives to fossil energy such as biomass, hydropower, and wind energy. Also, suitable waste management strategy is another important aspect. Development and modernization have brought about a huge increase in the production of all kinds of commodities, which indirectly generate waste. Plastics have been one of the materials because of their wide range of applications due to versatility and relatively low cost. The paper presents the current scenario of the plastic consumption. The aim is to provide the reader with an in depth analysis regarding the recycling techniques of plastic solid waste (PSW). Recycling can be divided into four categories: primary, secondary, tertiary, and quaternary. As calorific value of the plastics is comparable to that of fuel, so production of fuel would be a better alternative. So the methods of converting plastic into fuel, specially pyrolysis and catalytic degradation, are discussed in detail and a brief idea about the gasification is also included. Thus, we attempt to address the problem of plastic waste disposal and shortage of conventional fuel and thereby help in promotion of sustainable environment. Neha Patni, Pallav Shah, Shruti Agarwal, and Piyush Singhal Copyright © 2013 Neha Patni et al. All rights reserved. The Production of Bioethanol from Cashew Apple Juice by Batch Fermentation Using Saccharomyces cerevisiae Y2084 and Vin13 Mon, 13 May 2013 11:04:49 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/107851/ Bioethanol as a fossil fuel additive to decrease environmental pollution and reduce the stress of the decline in crude oil availability is becoming increasingly popular. This study aimed to evaluate the concentration of bioethanol obtainable from fermenting cashew apple juice by the microorganism Saccharomyces cerevisiae Y2084 and Vin13. The fermentation conditions were as follows: initial sugar = 100 g/L, pH = 4.50, agitation = 150 rpm, temperatures = 30°C (Y2084) and 20°C (Vin13), oxygen saturation = 0% or 50%, and yeast inoculum concentration = ~8.00 Log CFU/mL. The maximum ethanol concentration achieved by Y2084 was 65.00 g/L. At 50% oxygen the fermentation time was 5 days, whilst at 0% oxygen the fermentation time was 11 days for Y2084. The maximum ethanol concentration achieved by Vin13 was 68.00 g/L. This concentration was obtained at 50% oxygen, and the fermentation time was 2 days. At 0% oxygen, Vin13 produced 31.00 g/L of ethanol within 2 days. Both yeast strains produced a higher glycerol concentration at 0% oxygen. Yeast viability counts showed a decrease at 0% oxygen and an increase at 50% oxygen of both yeast stains. Other analyses included measurement of carbon dioxide and oxygen gases, process monitoring of the fermentation conditions, and total organic carbon. Gas analysis showed that carbon dioxide increased in conjunction with ethanol production and oxygen decreased. Process monitoring depicted changes and stability of fermentation parameters during the process. Total organic carbon analysis revealed that aerobic fermentation (50% oxygen) was a more efficient process as a higher carbon recovery (95%) was achieved. Evanie Devi Deenanath, Karl Rumbold, and Sunny Iyuke Copyright © 2013 Evanie Devi Deenanath et al. All rights reserved. Hydrogen Production Using Reduced-Iron Nanoparticles by Laser Ablation in Liquids Mon, 04 Mar 2013 13:24:33 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/827681/ A recyclable energy cycle using a pulsed laser and base-metal nanoparticles is proposed. In this energy cycle, iron nanoparticles reduced from iron oxides by laser ablation in liquid are used for hydrogen generation. The laser energy can be stored in the base-metal nanoparticles as the difference between the chemical energies of iron oxide and iron. According to the results of an experiment on hydrogen production using the reduced iron nanoparticles, the reaction efficiency of the hydrogen generation at a temperature of 673 K was more than 94% for the ideal amount of generated hydrogen. Takehiro Okada, Taku Saiki, Seiji Taniguchi, Tsuyoshi Ueda, Kazuhiro Nakamura, Yusuke Nishikawa, and Yukio Iida Copyright © 2013 Takehiro Okada et al. All rights reserved. Large-Area Crystalline Silicon Solar Cell Using Novel Antireflective Nanoabsorber Texturing Surface by Multihollow Cathode Plasma System and Spin-On Doping Thu, 28 Feb 2013 13:19:58 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/738326/ We present 11.7% efficient p-type crystalline silicon solar cells with a nanoscale textured surface and no dielectric antireflection coating. We propose nanocrystalline-like textured surface consisting of nanocrystalline columnar structures of diameters from 50 to 100 nm and depth of about 500 nm formed by reactive-ion etching (RIE) in multihollow cathode system. This novel nano textured surface acts as an antireflective absorbing surface of c-Si abbreviate as ARNAB (antireflective nanoabsorber). Light shining on the surface of RIE-etched silicon bounces back and forth between the spikes in such a way that most of it never comes back. Radio frequency (RF) hollow cathode discharge allows an improvement of plasma density by an order of magnitude in comparison to standard RF parallel-plate discharge. Desirable black silicon layer has been achieved when RF power of about 20 Watt per one hollow cathode glow is applied for our multihollow cathode system. The RF power frequency was 13.56 MHz. The antireflection property of ARNAB textured surface has been investigated and compared with wet-textured and PECVD coated silicon samples. Solar cell using low-cost spin-on coating technique has been demonstrated in this paper. We have successfully achieved 11.7% efficient large area (98 cm2) ARNAB textured crystalline silicon solar cell using low-cost spin-on coating (SOD) doping. Utpal Gangopadhyay, Sukhendu Jana, and Sayan Das Copyright © 2013 Utpal Gangopadhyay et al. All rights reserved. Analysis of a Three-Phase Grid-Connected PV Power System Using a Modified Dual-Stage Inverter Thu, 31 Jan 2013 08:24:27 +0000 http://www.hindawi.com/journals/isrn.renewable.energy/2013/406312/ This paper presents a grid-connected PV system in a centralized configuration constructed through a three-phase dual-stage inverter. For the DC-DC stage the three-phase series resonant converter is chosen thanks to the advantages that it exhibits. However, it is inadequate for the accomplishment of MPPT, due to its efficiency strongly depending on the implemented deadtime and switching frequency. Then, this paper proposes a conceptual modification, that is, a modified dual-stage inverter in which the inverter stage is responsible for both the MPPT and the grid-current control. In addition, the DC-DC converter operates with constant duty cycle and frequency. Such configuration requires a new concept, introduced as Behavior Matching. It serves as a fundamental feature for the DC-DC converter to reproduce the PV array I–V characteristic when they are connected, without control action. The maximum power operating point is found by maximizing the direct axis current, obtained by Park's transformation from the inverter, through the perturbation and observation algorithm. Any specific measurement to realize the MPPT is needed. The galvanic isolation is achieved by using a high-frequency transformer. The structure is appropriate for high power applications, above 10 kW. Denizar Cruz Martins Copyright © 2013 Denizar Cruz Martins. All rights reserved.