Showing papers in "Smart Grid and Renewable Energy in 2011"
TL;DR: In this article, the authors briefly discuss evolution of smart grid development and the importance of Smart Grid is discussed as it will take us towards energy independence and environmentally sustainable economic growth, which will slowly but surely take us toward fulfilling the dreams of former President Dr. A.P.J. Abdul Kalam, "Energy for all and Energy forever".
Abstract: This paper briefly discusses evolution of Smart Grid development. Smart Grid is important as it will take us towards energy independence and environmentally sustainable economic growth. Growth of Smart Power Grid in India will slowly but surely take us towards fulfilling the dreams of former President Dr. A.P.J. Abdul Kalam, “Energy for all and Energy forever”.
69 citations
TL;DR: In this article, a model to estimate global solar radiation using temperature and sunshine hour data has been developed (Chandel et al. [1]) which is used to calculate the hourly solar radiation Data.
Abstract: The hourly solar radiation data required for solar energy system design evaluation and performance studies is gener-ally not available for a number of sites especially in remote locations. As such accurate determination of hourly solar radiation data, is important both at horizontal; surfaces and inclined surfaces. A model to estimate global solar radiation using temperature and sunshine hour data has been developed (Chandel et al. [1]) which is used to calculate the hourly solar radiation Data. The hourly solar radiation has also been calculated using Gueymard [2] daily integration approach from the measured daily solar radiation data. These two predicted hourly solar radiation data values are compared with measured hourly values to test the accuracy of the models. The total solar radiation on the inclined surfaces and vertical surfaces for different orientations, have also been estimated. The estimated values are found to be in close agreement with measured values. The method presented can be used to estimate hourly, global, diffuse solar radiation for horizontal surfaces and total solar radiation on inclined and vertical surfaces at different orientations with greater accuracy for any location.
64 citations
TL;DR: In this article, the authors proposed a new methodology that uses hourly daily loads to predict the next year hourly loads, and hence predict the peak loads expected to be reached in the next coming year.
Abstract: Medium-term forecasting is an important category of electric load forecasting that covers a time span of up to one year ahead. It suits outage and maintenance planning, as well as load switching operation. We propose a new methodol-ogy that uses hourly daily loads to predict the next year hourly loads, and hence predict the peak loads expected to be reached in the next coming year. The technique is based on implementing multivariable regression on previous year's hourly loads. Three regression models are investigated in this research: the linear, the polynomial, and the exponential power. The proposed models are applied to real loads of the Jordanian power system. Results obtained using the pro-posed methods showed that their performance is close and they outperform results obtained using the widely used ex-ponential regression technique. Moreover, peak load prediction has about 90% accuracy using the proposed method-ology. The methods are generic and simple and can be implemented to hourly loads of any power system. No extra in-formation other than the hourly loads is required.
53 citations
TL;DR: Pongamia Pinnata trees are normally planted along the highways, roads, canals to stop soil erosion as mentioned in this paper and they can survive in 1.5 meters deep water submergence / inunda-tion for five to six months duration at a stretch.
Abstract: Pongamia Pinnata trees are normally planted along the highways, roads, canals to stop soil erosion. Billions of trees exist all over India. If the seeds fallen along road side are collected, and oil is extracted at village level expellers, few million tons of oil will be available for Lighting the Lamps in rural area. It is the best substitute for Kerosene. Since these are spread over a large area, collection of seeds for Biodiesel manufacture is not viable. (A compact plantation can support a Biodiesel plant. The seedlings of Pongamia can survive in 1.5 meters deep water submergence / inunda-tion for five to six months duration at a stretch. There are nearly 30,000 square km of water reservoirs in India. This tree can be cultivated in our water storage reservoirs up to 1.5 meters depth and reap additional economic value from unused reservoir lands. The estimated annual production of oil from its seeds is about 50,000 t. The oil has not yet found any significant commercial application. But due to increase in awareness and growth in research in this area the Pongamia it can be developed as the alternative source of fuel by replacing diesel. In the present study attempt has been made to study the scope of Pongamia in India.
52 citations
TL;DR: In this paper, the authors present a state of the art of several studies dealing with the environmental impact assessment of fuel cell (FC) vehicles and the comparison with their conventional fossil-fuelled counterparts, by means of the Life Cycle As-sessment (LCA) methodology.
Abstract: This study presents a state of the art of several studies dealing with the environmental impact assessment of fuel cell (FC) vehicles and the comparison with their conventional fossil-fuelled counterparts, by means of the Life Cycle As-sessment (LCA) methodology. Results declare that, depending on the systems characteristics, there are numerous envi-ronmental advantages, but also some disadvantages can be expected. In addition, the significance of the manufac-turing process of the FC, more specifically the Polymer Electrolyte Membrane Fuel Cell (PEMFC) type, in terms of environmental impact is presented. Finally, CIEMAT’s role in HYCHAIN European project, consisting of supporting early adopters for hydrogen FCs in the transport sector, is highlighted
47 citations
TL;DR: In this paper, a procedure is established for solving the Probabilistic Load Flow in an electrical power network, considering correlation between power generated by power plants, loads demanded on each bus and power injected by wind farms.
Abstract: In this paper a procedure is established for solving the Probabilistic Load Flow in an electrical power network, considering correlation between power generated by power plants, loads demanded on each bus and power injected by wind farms. The method proposed is based on the generation of correlated series of power values, which can be used in a MonteCarlo simulation, to obtain the probability density function of the power through branches of an electrical network.
44 citations
TL;DR: In this paper, the authors compared three earthing systems (TT, IT, and IT) for MG protection against various fault types during the connected mode, including the models of all the micro sources which interfaced to the MG by power electronic inverters.
Abstract: This paper presents, tests and compares three earthing systems (TT, TN and IT) for Micro-Grid (MG) protection against various fault types during the connected mode. The main contribution of this work is including the models of all the micro sources which interfaced to the MG by power electronic inverters. Inverters in turns are provided with current limiters and this also included in the inverter models to exactly simulate the real situation in the MG during fault times. Results proved that the most suitable earthing system for MG protection during the connecting mode is the TN earthing system. That system leads to a suitable amount of fault current sufficient to activate over current protection relays. With using TN system, Touch voltages at the faulted bus and all other consumer’s buses are less than the safety limited value if current limiter is included with the transformer of the main grid which connects MG. For the two others earthing systems (TT and IT), fault current is small and nearly equal to the over load current which make over current protection relay can not differentiate between fault current and overload current. All models of micro sources, earthing systems, inverters, main grid and control schemes are built using Matlab(R)/Simulink(R) environment.
41 citations
TL;DR: In this paper, the authors explore smart grid technologies, distributed generation systems, R&D efforts across Europe and the United States, and technical, economical and regulatory barriers facing modern utilities.
Abstract: The global Electricity Sector and its customers are faced with a number of challenges that are unparalleled since the advent of widespread electrification. Challenges including climate change, escalating energy prices, energy security and energy efficiency are converging to drive fundamental change in the way energy is produced, delivered and utilized. The electricity system of the future must produce and distribute electricity that is reliable, affordable and clean. To accomplish these goals, both the electricity grid and the existing regulatory system must be smarter. This paper explores smart grid technologies, distributed generation systems, R & D efforts across Europe and the United States, and technical, economical and regulatory barriers facing modern utilities.
39 citations
TL;DR: In this paper, an investigation of the performance and device parameters of photovoltaic single crystalline silicon (Si) solar cell of the construction n+pp++ PESC at different conditions of solar irradiance, title angle and mirror boosting effects had been studied.
Abstract: The electrical performance of a photovoltaic (PV) silicon solar cell is described by its current–voltage (I–V) character-istic curve, which is in turn determined by device and material properties. In this study, an investigation of the performance and device parameters of photovoltaic single crystalline silicon (Si.) solar cell of the construction n+pp++ PESC(Passivatted Emitter Solar Cell) at different conditions of solar irradiance, title angle and mirror boosting effects had been studied. Also the paper reports on the performance data of the Si. cell, using standard I–V characteristic curves to obtain output parameters and to show that there are possible performance degrading defects presents.
31 citations
TL;DR: In this article, a multi-agent based scheme for fault diagnosis in power distribution networks with distributed generators is proposed, where relay agents measure the bus currents at which they are located such that it can detect and classify the fault, and determine the fault location.
Abstract: The penetration of distributed generation (DG) in distribution power system would affect the traditional fault current level and characteristics. Consequently, the traditional protection arrangements developed in distribution utilities are difficult in coordination. Also, the reclosing scheme would be affected. With the rapid developments in distribution system automation and communication technology, the protection coordination and reclosing scheme based on information exchange for distribution power system can be realized flexibly. This paper proposes a multi-agent based scheme for fault diagnosis in power distribution networks with distributed generators. The relay agents are located such that the distribution network is divided into several sections. The relay agents measure the bus currents at which they are located such that it can detect and classify the fault, and determine the fault location. The proposed technique uses the entropy of wavelet coefficients of the measured bus currents. The performance of the proposed protection scheme is tested through simulation of two systems. The first system is a benchmark medium voltage (MV) distribution system and the second system is practical 66 kV system of the city of Alexandria.
31 citations
TL;DR: In this article, the effect of temperature and radiation intensity on the parameters of a copper indium diselenide (CIS) photovoltaic module was investigated by using an Orthogonal distance regression (ODR) algorithm.
Abstract: This work investigates the effects of temperature and radiation intensity on the parameters of a copper indium diselenide (CIS) photovoltaic module. The module performance parameters are determined from calculated module parameters. An outdoor experimental setup is installed to carryout a series of I-V curve measurements under different irradiance and temperature conditions for the module. A numerical model which considers the effect of series and shunt resistances is developed to evaluate the different parameters of PV modules. Orthogonal distance regression (ODR) algorithm is adapted for fitting I-V measurements and extracting module parameters from I-V measurements. The values of module parameters, series resistance Rs, shunt resistance Rsh, diode ideality factor n and reverse saturation current Io determined from I-V measurements at different irradiation intensity and temperature range are in good agreement with the corresponding parameters obtained from the developed numerical model. The module parameters extracted from I-V measurements are employed to calculate the module performance parameters, i.e. open circuit voltage Voc, fill factor FF and module efficiency η at different irradiation intensity and temperature range. Present results indicate that the largest drop in open circuit voltage Voc due to about 20℃ increase in temperature is approximately 8.8% which is not compensated for by the relatively small increase in short circuit current, (2.9% in Isc), resulting in a reduction in maximum power of about 6.3%. Results let us conclude that the shunt resistance RSh increases with radiation at low radiation values (2). As radiation increases at high radiation values (> 400 W/m2), RSh begins to decease sharply and dramatically. Also, as the light intensity incident on the solar module increases, the series resistance and the output voltage decrease. When the irradiance intensity increases, the series resistance decreases but with a very low rate at the two studied temperatures ranges. The low rate decrease of Rs is found to have little effect on module performance in comparison with the significant change of other module parameters. The ideality factor n and saturation current Io decrease first sharply in the low range of radiation intensity (2) and this decrease becomes smaller for irradiance values greater than 400 W/m2. The previous observations and conclusions regarding the module parameters RSh, RS, n and Io obtained at 20℃ observed again at 40℃ but there is a great difference between the peak values of RSh at both temperature levels. Present results also show that module efficiency decreases with increasing irradiance intensity due to the combined effect of both Voc and FF.
TL;DR: In this article, the influence of the temperature on yield and product composition was studied at the temperature range of 700 PoPC-900 PoPC, and the results showed that higher temperature resulted in more HR2R and COR2R production, and dry gas yield.
Abstract: In the present study the catalytic steam gasification of biomass to produce hydrogen-rich gas with calcined dolomite as catalyst in an externally heated fixed bed reactor was investigated. The influence of the reactor temperature on yield and product composition was studied at the temperature range of 700 PoPC-900 PoPC. Over the ranges of experimental con-ditions examined, tar was completely decomposed as temperature increases from 800P oPC to 900 PoPC. Higher temperature resulted in more HR2R and COR2R production, and dry gas yield. The highest H2 content of 51.02 V%, and the highest HR2 Ryield of 1.66 mP3P/kg biomass were observed at the highest temperature level of 900P oPC.
TL;DR: Two solar water heaters of 100 liter and 200 liter were installed on the roof-top of electronics laboratory at Old Academic Building (OAB) of Electrical and Electronics Engineering Department of BUET as discussed by the authors.
Abstract: Two solar water heaters of 100 liter and 200 liter were installed on the roof-top of electronics laboratory at Old Academic Building (OAB) of Electrical and Electronics Engineering Department of BUET. The data of 12 months have been collected and analyzed in this paper. It is found that the incoming hot tap water is about 30℃ higher than the room temperature during day time during winter months. This is about 25℃ in afternoon hours.
TL;DR: In this paper, the potential of switched reluctance generator (SRG) in wind energy application is analyzed, which consists of a generator, a power converter and a controller, and the generator can operate over a wide speed range.
Abstract: The aim of this paper is to analyze the potential of switched reluctance generator (SRG) in wind energy application. The machine comprises of switched reluctance generator, power converter and controller. In this paper the main ele-ments that form the generator system is discussed. It also highlights the common type of converter and structure used for SRG in wind energy application and types of control strategy available. Using power converter for switching the generator can operate over a wide speed range. Its applications in high speed area such as starter/generator for air-craft and gas turbine has been established, however the low/medium speed operation is still at an early stage of re-search. In order to subject the machine to various parameters, offline modeling is being investigated to produce the best optimum design.
TL;DR: In this article, the impact of distributed generation on Smart Grid, particularly its system stability after installing distributed generation in the Smart Grid was examined by examining the system stability during interconnection and faults on the system and validated with Dig-SILENT Power Factory Software V 13.2.
Abstract: In the 21st century Smart Grid and Renewable Energy technologies are an important issue with regards to global climate change problem and energy security. The evolution of current conventional or centralized generation in form of distributed generation and Smart Power Grid (SPG) has great opportunity and potentially can eradicate several issues associated with energy efficiency, energy security and the drawback of aging power system infrastructures. In order to meet the rising electrical power demand and increasing service quality as well as reducing pollution, the existing power grid infrastructure should be developed into Smart Grid (SG) that is flexible for interconnectivity with the distributed generation. However, integrating distributed generation to power system causes several technical issues especially system stability. To make the power grid become “smarter”, particularly in terms of stability, Flexible AC Transmission System (FACTS) device especially Static VAR Compensator (SVC) is used. This paper explores Smart Grid technologies and distributed generation systems. Furthermore, it discusses the impact of distributed generation on Smart Grid, particularly its system stability after installing distributed generation in the Smart Grid. This was done by examining the system stability during interconnection and faults on the system and validated with Dig-SILENT Power Factory Software V 13.2.
TL;DR: In this paper, a multilevel line commutated inverter topology has been proposed and analyzed which improves the wave shape and hence reduces the total harmonic distortion (THD) of the line current in a grid-tie line-committed inverter.
Abstract: There has been a noticeable increase in use of Solar PV based systems for power generation, given its renewable nature. A solar PV based grid tie inverters are used for dc-ac conversion. The conventional line commutated ac-to-dc inverters have square-shaped line current which contains higher-order harmonics. The line current with the high harmonic contents generates EMI and moreover it causes more heating of the core of distribution/power transformers. Alternatively, PWM based inverters using MOSFET/IGBT switches are also used for the same purpose. However, apart from higher switching losses, the power handling capability and reliability of these devices are quite low in comparison to thyristors/SCR. Nevertheless, the conventional thyristor based forced commutated inverters are not suitable for PWM applications due to the problems of commutation circuits. A pure sinusoidal line current or waveform with low har- monic contents is the most desirable. In the present work, a multilevel line commutated inverter topology has been proposed and analyzed which improves the wave shape and hence reduces the total harmonic distortion (THD) of the line current in a grid tie line commutated inverter. The scheme has successfully been implemented and tested. Moreover, the performance of the proposed topology is far better than the conventional line-commutated inverter. It reduces THD, losses, switching stress and EMI.
TL;DR: In this article, the design modification of a single basin solar still has been discussed to improve the solar still performance through increasing the production rate of distilled water in Tamilnadu.
Abstract: Water is essential to life. The origin and continuation of mankind is based on water. The supply of drinking water is an important problem for the developing countries. Among the non-conventional methods to desalinate brackish water or seawater, is solar distillation. The solar still is the most economical way to accomplish this objective. Tamilnadu lies in the high solar radiation band and the vast solar potential can be utilized to convert saline water to potable water. The sun’s energy heats water to the point of evaporation. When water evaporates, water vapour rises leaving the impurities like salts, heavy metals and condensate on the underside of the glass cover. Sunlight has the advantage of zero fuel cost but it requires more space and generally more equipment. Solar distillation has low yield, but safe and pure supplies of water in remote areas. In this context, the design modification of a single basin solar still has been discussed to improve the solar still performance through increasing the production rate of distilled water. The attempts are also made to increase the productivity of water by using different absorbing materials, depths of water, heat storage medium and also by providing low pressure inside the still basin. They greatly improve the rate of evaporation and hence the rate of condensation on the cooler surface. The theoretical results agree well with the experimental ones.
TL;DR: In this article, an energy and exergy analysis of a GT Brayton cycle coupled with a refrigeration air cooling unit shows a promise for increasing the output power with a little decrease in thermal efficiency.
Abstract: Gas turbine (GT) power plants operating in arid climates suffer a decrease in output power during the hot summer months because of the high specific volume of air drawn by the compressor. Cooling the air intake to the compressor has been widely used to mitigate this shortcoming. Energy and exergy analysis of a GT Brayton cycle coupled to a refrigeration air cooling unit shows a promise for increasing the output power with a little decrease in thermal efficiency. A thermo-economics algorithm is developed to estimate the economic feasibility of the cooling system. The analysis is applied to an open cycle, HITACHI-FS7001B GT plant at the industrial city of Yanbu (Latitude 24o 05” N and longitude 38o E) by the Red Sea in the Kingdom of Saudi Arabia. Result show that the enhancement in output power depends on the degree of chilling the air intake to the compressor (a 12 - 22 K decrease is achieved). For this case study, maximum power gain ratio (PGR) is 15.46% (average of 12.25%), at an insignificant decrease in thermal efficiency. The second law analysis show that the exergetic power gain ratio drops to an average 8.5%. The cost of adding the air cooling system is also investigated and a cost function is derived that incorporates time-dependent meteorological data, operation characteristics of the GT and the air intake cooling system and other relevant parameters such as interest rate, lifetime, and operation and maintenance costs. The profit of adding the air cooling system is calculated for different electricity tariff.
TL;DR: In this article, the authors presented a total solution for EV charging service platform (EVAMI) based on power line and internet communication, which can not only reduce the peak consumption but also relocates the energy demand effectively.
Abstract: The widely adoption of Electric Vehicle (EV) has been identified as a major challenge for future development of smart grids. The ever increasing electric vehicle charging further increases the energy demand. This paper reports the development of an Advanced Metering Infrastructure (AMI) as an effective tool to reshape the load profile of EV charging by adopting appropriate demand side management strategy. This paper presents a total solution for EV charging service platform (EVAMI) based on power line and internet communication. It must be stressed that the development of Third Party Customer Service Platform in this investigation facilitates a single bill to be issued to EV owners. Hence, EV owners understand their energy usage and thus may perform energy saving activity efficiently. Experiment and evaluation of the proposed system show that the throughput achieved is about 5 Mbps at 10 ms end to end delay in Power line Communication. By introducing two dimensional dynamic pricing and charging schedule, the proposed EVAMI successfully reduces 36% peak consumption and increases the “off peak” consumption by 54%. Therefore the EVAMI does not only reduce the peak consumption but also relocates the energy demand effectively.
TL;DR: In this paper, a new fast charging method named decreased charging current based on SOC is proposed to apply into micro-grid photovoltaic systems, which combines batteries' SOC with the maximum charging voltage to determine the charging rate without strictly selecting reduction coefficient.
Abstract: In the micro-grid photovoltaic systems, the random changes of solar radiation enable lead-acid batteries to experience low SOC (State of Charge) or overcharged for periods of time if directly charged with such traditional methods as decreased charging current, which will reduce lifetime of batteries. What’s more, it’s difficult to find a proper reduction coefficient in decreasing charging current. To adapt to the random changes of circumstance and avoid selecting the reduction coefficient, a new fast charging method named decreased charging current based on SOC is proposed to apply into micro-grid photovoltaic systems. It combines batteries’ SOC with the maximum charging voltage to determine the charging rate without strictly selecting reduction coefficient. By close-loop current control strategy and related scheme, the experiment proves the new method is feasible and verifies that, comparing with decreased charging current, the improved method make batteries’ SOC reach 100% in shorter time as well as the temperature of batteries raise more slowly.
TL;DR: In this article, a SEIG-IM system using a self excited induction generator driven by wind turbine and supplying an induction motor which is coupled to a centrifugal pump is presented, and a method to describe the steady state performance based on nodal analysis is presented.
Abstract: This paper presents a SEIG-IM system using a self excited induction generator driven by wind turbine and supplying an induction motor which is coupled to a centrifugal pump. A method to describe the steady state performance based on nodal analysis is presented. Furthermore, a dynamic analysis and performance characteristics are examined. The pro-posed methodology is discussed in order to optimize the quantity of the pumped water. Therefore an optimal excitation capacitor for a given wind rotor speed is determined and a suitable operation mode of the system is established.
TL;DR: In this article, the authors compare mainstream network technologies applicable to home appliance control and propose a solution combining Power Line Communication (PLC) with wireless communication in smart homes for the purpose of energy saving.
Abstract: Integrating the power grid technology with renewable power generation technologies, Demand Response (DR) programs enabled by the Advanced Metering Infrastructure (AMI) were introduced into the power grid in the interest of both utilities and residents. They help to achieve load balance and increase the grid reliability by encouraging residents to reduce their power usage during peak load periods in return for incentives. To automate this process, appliances, in-house sensors, and the AMI controller need to be networked together. In this paper, we compare mainstream network technologies applicable to home appliance control and propose a solution combining Power Line Communication (PLC) with wireless communication in smart homes for the purpose of energy saving. We extended NS-2, a popular network simulator, to model such combined network scenarios. Using a number of different routing strategies, we then model and evaluate the network performance of DR programs in smart homes in such a combined network.
TL;DR: In this paper, a self-organizing hierarchical particle swarm optimization technique with time-varying acceleration coefficients (SOHPSO_TVAC) was proposed for solving short-term economic generation scheduling of hydrothermal systems to avoid premature convergence.
Abstract: Optimum scheduling of hydrothermal plants generation is of great importance to electric utilities. Many evolutionary techniques such as particle swarm optimization, differential evolution have been applied to solve these problems and found to perform in a better way in comparison with conventional optimization methods. But often these methods converge to a sub-optimal solution prematurely. This paper presents a new improved particle swarm optimization technique called self-organizing hierarchical particle swarm optimization technique with time-varying acceleration coefficients (SOHPSO_TVAC) for solving short-term economic generation scheduling of hydrothermal systems to avoid premature convergence. A multi-reservoir cascaded hydrothermal system with nonlinear relationship between water discharge rate, power generation and net head is considered here. The performance of the proposed method is demonstrated on two test systems comprising of hydro and thermal units. The results obtained by the proposed methods are compared with other methods. The results show that the proposed technique is capable of producing better results.
TL;DR: In this article, a 2D analytical model for direct ethanol fuel cell (DEFC) performance is presented, which includes equations inside diffusion layer, catalyst layer, and ethanol cross-over through membrane.
Abstract: Analytical models provide useful information for researchers to study fuel cell function. In this paper, it’s aimed to present a 2D analytical model for direct ethanol fuel cell (DEFC) performance. The model included equations inside diffusion layer, catalyst layer, and Ethanol cross-over through membrane, which all have been solved. Analytical model has been validated by some experimental trials. The results showed that there is proper agreement between experimental and analytical curves. Furthermore, by increasing current density, cathodic over potential will remain zero but anodic over potential will increase up to certain value. The model showed that Ethanol concentration changes almost linearly inside anode channel.
TL;DR: In this paper, the operation of the Double Fed Induction Generator (DFIG) in the range from synchronous speed down to sub-synchronous speeds is analyzed using the power-flow approach.
Abstract: In this paper, the operation of the Double Fed Induction Generator (DFIG) in the range from synchronous speed down to sub-synchronous speeds is analyzed using the power-flow approach. The objective of this analysis is to determine a ceiling for the rating of the converter interfacing the rotor of the wind driven double fed induction generator (DFIG) to the grid. Sizing the converter is an important issue in determining the economic viability of using the DFIM as a generator at synchronous and sub-synchronous speeds in wind energy conversion systems. The size of the converter is proved to be less than 10% of the rated power of the DFIG, which is 40% to 67% lower than that estimated in previous publications.
TL;DR: In this article, a simple method to calculate global, diffuse and direct irradiance on vertical and tilted surfaces for all uniform sky conditions (clear sky and overcast sky), developed in Constantine (Algeria) and Louvain-la-neuve (Belgium), has been compared with experimental data obtained at Ghardaia, and can be proposed as a simpli?ed tool for design purposes.
Abstract: The meteorological data concerning solar radiation are generally not sufficient to allow quantifying all the phenomena which occur when a photovoltaic panel receives solar light. It is therefore, necessary to supplement these data by using astronomical calculation for the sun position and modelling the atmosphere. A simple method to calculate global, diffuse and direct irradiance on vertical and tilted surfaces for all uniform sky conditions (clear sky and overcast sky), developed in Constantine (Algeria) and Louvain-la-neuve (Belgium), has been compared with experimental data obtained at Ghardaia (Algeria). In spite of its simplicity, the method furnishes reasonably good predictions, in comparison with experimental data, and can be proposed as a simpli?ed tool for design purposes. This method relies on the fact that we can calculate the irradiance on a plane with arbitrary orientation and inclination, based on the measurement of a single irradiance value on a reference plane.
TL;DR: In this paper, the I-V measurements of two different structures: ITO/PEDOT: PSS/(CuPc:C60 or CuPc :PCBM)/BCP/Al.
Abstract: Organic photovoltaic cells have been fabricated using copper phthalocyanine CuPc as electron donor and C60 or PCBM as electron acceptor. We have investigated the I-V measurements of two different structures: ITO/PEDOT: PSS/(CuPc:C60 or CuPc:PCBM)/BCP/Al. We have observed that the substitution of PCBM by C60 scales up the photocurrent and the efficiency of the devices. As for the open-circuit voltage and the fill factor, we have seen that Voc and FF depend on the energy difference between the highest occupied molecular orbital (HOMO) of CuPc and the lowest unoccupied molecular orbital (LUMO)of C60 or PCBM.
TL;DR: In this article, the authors developed a correlation to determine the cost based on the cost influencing parameters as power and head using three different methods, namely; sigma plot method, linest method and logest method.
Abstract: Electricity is one of the most widely used forms of energy. Being a renewable source of energy small hydropower is considered as an environment—friendly and cheap source of electricity. The installation cost of the small hydropower project depends mainly on two parts—civil works and electromechanical equipment. One of the most important element on the recovery of a small hydro-power plant is the electromechanical equipment (turbine-alternator). The present paper intends to develop a correlation to determine the cost based on the cost influencing parameters as power and head using three different methods, namely; sigma plot method, linest method and logest method. An attempt has also been made to identify the best correlation among the three models closer to the actual cost of electro-mechanical equipment as collected from recently developed projects.
TL;DR: In this paper, a method based on marginal cost theory is presented for locational marginal prices calculation for real and reactive power considering different reactive power cost models of generators' reactive support.
Abstract: In a competitive environment reactive power management is an essential service provided by independent system operator taking into account the voltage security and transmission losses. The system operator adopts a transparent and non-dis-criminatory procedure to procure the reactive power supply for optimal deployment in the system. Since generators’ are the main source of reactive power generation and the cost of the reactive power should be considered for their noticeable impact on both real and reactive power marginal prices. In this paper, a method based on marginal cost theory is presented for locational marginal prices calculation for real and reactive power considering different reactive power cost models of generators’ reactive support. With the presence of FACTS controllers in the system for more flexible operation, their impact on nodal prices can not be ignored for wheeling cost determination and has also to be considered taking their cost function into account. The results have been obtained for hybrid electricity market model and results have also been computed for pool model for comparison. Mixed Integer Non-linear programming (MINLP) approach has been formulated for solving the complex problem with MATLAB and GAMS interfacing. The proposed approach has been tested on IEEE 24-bus Reliability Test System (RTS).
TL;DR: In this paper, the spectral dependence of the relevant radiation properties of glass (i.e. specular reflectivity, refraction angle and absorption coefficient) is taken into account.
Abstract: Accurate prediction of thermal radiation by applying rigorous model for the radiative heat transfer combined with the conduction and the convection has been performed for a single and double window glazing subjected to solar and thermal irradiation. The glass window is analysed as a non-gray plane-parallel medium disctritized to thin layer as-suming the glass material as participating media in one-dimensional case, using the Radiation Element Method by Ray Emission Model (REM2). The model allows the calculation of the steady-state heat flux and the temperature distribution within the glass cover. The spectral dependence of the relevant radiation properties of glass (i.e. specular reflectivity, refraction angle and absorption coefficient) is taken into account. Both solar and thermal incident irradiations are applied at the boundary surfaces using the spectral solar model proposed by Bird and Riordan. The optical constant of a commercial clear glass material have been used. The calculation has been performed during winter period and the effect of the thickness of the glass for a single glazing and of the air layer between the two panels for double glazing has been studied. The result shows that increasing the air layer, the steady heat flux decreases and the temperature distribution within the glass changes.