Search results for: solar generator
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1951

Search results for: solar generator

1561 Flux-Linkage Performance of DFIG Under Different Types of Faults and Locations

Authors: Mohamed Moustafa Mahmoud Sedky

Abstract:

The double-fed induction generator wind turbine has recently received a great attention. The steady state performance and response of double fed induction generator (DFIG) based wind turbine are now well understood. This paper presents the analysis of stator and rotor flux linkage dq models operation of DFIG under different faults and at different locations.

Keywords: double fed induction motor, wind energy, flux linkage, short circuit

Procedia PDF Downloads 504
1560 Integration of Icf Walls as Diurnal Solar Thermal Storage with Microchannel Solar Assisted Heat Pump for Space Heating and Domestic Hot Water Production

Authors: Mohammad Emamjome Kashan, Alan S. Fung

Abstract:

In Canada, more than 32% of the total energy demand is related to the building sector. Therefore, there is a great opportunity for Greenhouse Gases (GHG) reduction by integrating solar collectors to provide building heating load and domestic hot water (DHW). Despite the cold winter weather, Canada has a good number of sunny and clear days that can be considered for diurnal solar thermal energy storage. Due to the energy mismatch between building heating load and solar irradiation availability, relatively big storage tanks are usually needed to store solar thermal energy during the daytime and then use it at night. On the other hand, water tanks occupy huge space, especially in big cities, space is relatively expensive. This project investigates the possibility of using a specific building construction material (ICF – Insulated Concrete Form) as diurnal solar thermal energy storage that is integrated with a heat pump and microchannel solar thermal collector (MCST). Not much literature has studied the application of building pre-existing walls as active solar thermal energy storage as a feasible and industrialized solution for the solar thermal mismatch. By using ICF walls that are integrated into the building envelope, instead of big storage tanks, excess solar energy can be stored in the concrete of the ICF wall that consists of EPS insulation layers on both sides to store the thermal energy. In this study, two solar-based systems are designed and simulated inTransient Systems Simulation Program(TRNSYS)to compare ICF wall thermal storage benefits over the system without ICF walls. In this study, the heating load and DHW of a Canadian single-family house located in London, Ontario, are provided by solar-based systems. The proposed system integrates the MCST collector, a water-to-water HP, a preheat tank, the main tank, fan coils (to deliver the building heating load), and ICF walls. During the day, excess solar energy is stored in the ICF walls (charging cycle). Thermal energy can be restored from the ICF walls when the preheat tank temperature drops below the ICF wall (discharging process) to increase the COP of the heat pump. The evaporator of the heat pump is taking is coupled with the preheat tank. The provided warm water by the heat pump is stored in the second tank. Fan coil units are in contact with the tank to provide a building heating load. DHW is also delivered is provided from the main tank. It is investigated that the system with ICF walls with an average solar fraction of 82%- 88% can cover the whole heating demand+DHW of nine months and has a 10-15% higher average solar fraction than the system without ICF walls. Sensitivity analysis for different parameters influencing the solar fraction is discussed in detail.

Keywords: net-zero building, renewable energy, solar thermal storage, microchannel solar thermal collector

Procedia PDF Downloads 115
1559 Effects of Concentrator and Encapsulated Phase Change Material for Desalination: An Experimental Study

Authors: Arunkumar Thirugnanasambantham, Velraj Ramalingam

Abstract:

An experimental attempt has been made to study the effect of system integration by two different concentrator assisted desalting systems. The compound parabolic concentrator (CPC) and compound conical concentrator (CCC) are used in this research work. Two solar desalination systems, the single slope solar still (SSSS) and pyramid solar still (PSS), have been integrated with a CCC and compound parabolic concentrator-concentric circular tubular solar still (CPC-CCTSS). To study the effect of system integration, a thick cloth prevents the entry of sunlight into the solar still top. Additionally, the concentrator assisted desalting systems are equipped with phase change material (PCM) for enhancement. In CCC-SSSS, PCM has been filled inside copper balls and placed on the SSSS basin. The PCM is loaded in the specially designed circular trough of the tubular solar still. Here, the used concentrators and distillers are not the same. Two methodologies are followed here to produce the fresh water even while the distillers are blocked from the sunlight. They are (1) thermosyphon effect in CCC-SSSS and (2) waste heat recovery from CPC-CCTSS. The results showed that the productivity of CCC-SSSS, CCC-SSSS with PCM and CCC-SSSS (PCM) top cover shaded were found as 2680 ml / m² / day, 3240 ml / m² / day, and 1646 ml / m² / day. Similarly, the productivity of the CPC-CCTSS-PSS, CPC-CCTSS (PCM)-PSS and CPC-CCTSS (PCM)-PSS top cover shaded were found as 7160 ml / m² / day, 7346 ml / m² / day, and ml / m² / day. The productivity of the CCC-SSSS and CPC-CCTSS-PSS is examined, and conclusions are drawn such as the solar radiation blocked distillers productivity did not drop to zero.

Keywords: compound conical concentrator, compound parabolic concentrator, desalination, system integration

Procedia PDF Downloads 251
1558 Adsorption Cooling Using Hybrid Energy Resources

Authors: R. Benelmir, M. El Kadri, A. Donnot, D. Descieux

Abstract:

HVAC represents a significant part of energy needs in buildings. Integrating renewable energy in cooling processes contributes to reducing primary energy consumption. Sorption refrigeration allows cold production through the use of solar/biomass/geothermal energy or even valuation of waste heat. This work presents an analysis of an experimental bench incorporating an adsorption chiller driven by hybrid energy resources associating solar thermal collectors with a cogeneration gas engine and a geothermal heat pump.

Keywords: solar cooling, cogeneration, geothermal heat pump, hybrid energy resources

Procedia PDF Downloads 345
1557 Photocapacitor Integrating Solar Energy Conversion and Energy Storage

Authors: Jihuai Wu, Zeyu Song, Zhang Lan, Liuxue Sun

Abstract:

Solar energy is clean, open, and infinite, but solar radiation on the earth is fluctuating, intermittent, and unstable. So, the sustainable utilization of solar energy requires a combination of high-efficient energy conversion and low-loss energy storage technologies. Hence, a photo capacitor integrated with photo-electrical conversion and electric-chemical storage functions in single device is a cost-effective, volume-effective and functional-effective optimal choice. However, owing to the multiple components, multi-dimensional structure and multiple functions in one device, especially the mismatch of the functional modules, the overall conversion and storage efficiency of the photocapacitors is less than 13%, which seriously limits the development of the integrated system of solar conversion and energy storage. To this end, two typical photocapacitors were studied. A three-terminal photocapacitor was integrated by using perovskite solar cell as solar conversion module and symmetrical supercapacitor as energy storage module. A function portfolio management concept was proposed the relationship among various efficiencies during photovoltaic conversion and energy storage process were clarified. By harmonizing the energy matching between conversion and storage modules and seeking the maximum power points coincide and the maximum efficiency points synchronize, the overall efficiency of the photocapacitor surpassed 18 %, and Joule efficiency was closed to 90%. A voltage adjustable hybrid supercapacitor (VAHSC) was designed as energy storage module, and two Si wafers in series as solar conversion module, a three-terminal photocapacitor was fabricated. The VAHSC effectively harmonizes the energy harvest and storage modules, resulting in the current, voltage, power, and energy match between both modules. The optimal photocapacitor achieved an overall efficiency of 15.49% and Joule efficiency of 86.01%, along with excellent charge/discharge cycle stability. In addition, the Joule efficiency (ηJoule) was defined as the energy ratio of discharge/charge of the devices for the first time.

Keywords: joule efficiency, perovskite solar cell, photocapacitor, silicon solar cell, supercapacitor

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1556 Sustainable Development of Adsorption Solar Cooling Machine

Authors: N. Allouache, W. Elgahri, A. Gahfif, M. Belmedani

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. The energy available from the sun is greater than about 5200 times the global world’s need in 2006. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world in the 21st century. One of these important technologies is the solar cooling systems that make use of either absorption or adsorption technologies. The solar adsorption cooling systems are a good alternative since they operate with environmentally benign refrigerants that are natural, free from CFCs, and therefore they have a zero ozone depleting potential (ODP). A numerical analysis of thermal and solar performances of an adsorption solar refrigerating system using different adsorbent/adsorbate pairs, such as activated carbon AC35 and activated carbon BPL/Ammoniac; is undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber, that is the most important component of the machine. The Wilson and Dubinin- Astakhov models of the solid-adsorbat equilibrium are used to calculate the adsorbed quantity. The porous medium is contained in the annular space, and the adsorber is heated by solar energy. Effect of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The performances of the system that depends on the incident global irradiance during a whole day depends on the weather conditions: the condenser temperature and the evaporator temperature. The AC35/methanol pair is the best pair comparing to the BPL/Ammoniac in terms of system performances.

Keywords: activated carbon-methanol pair, activated carbon-ammoniac pair, adsorption, performance coefficients, numerical analysis, solar cooling system

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1555 Control Power in Doubly Fed Induction Generator Wind Turbine with SVM Control Inverter

Authors: Zerzouri Nora, Benalia Nadia, Bensiali Nadia

Abstract:

This paper presents a grid-connected wind power generation scheme using Doubly Fed Induction Generator (DFIG). This can supply power at constant voltage and constant frequency with the rotor speed varying. This makes it suitable for variable speed wind energy application. The DFIG system consists of wind turbine, asynchronous wound rotor induction generator, and inverter with Space Vector Modulation (SVM) controller. In which the stator is connected directly to the grid and the rotor winding is in interface with rotor converter and grid converter. The use of back-to-back SVM converter in the rotor circuit results in low distortion current, reactive power control and operate at variable speed. Mathematical modeling of the DFIG is done in order to analyze the performance of the systems and they are simulated using MATLAB. The simulation results for the system are obtained and hence it shows that the system can operate at variable speed with low harmonic current distortion. The objective is to track and extract maximum power from the wind energy system and transfer it to the grid for useful work.

Keywords: Doubly Fed Induction Generator, Wind Energy Conversion Systems, Space Vector Modulation, distortion harmonics

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1554 Assessment of the Thermal Performance of a Solar Heating System on an Agricultural Greenhouse Microclimate

Authors: Nora Arbaoui, Rachid Tadili

Abstract:

The substantial increase of areas cultivated under glasshouses compels the use of other natural heating and cooling procedures to make a profit as well as avoid both exorbitant fuel consumption and CO₂ emissions. This experimental study is designed to examine the functioning of a solar heating system that will increase positive consequences in terms of both quantity and quality while successfully enhancing greenhouse microclimate during wintertime. Those configurations have been tested in a miniaturized greenhouse simply after having optimized the operating parameters. These were noteworthy results when compared to an unheated witness greenhouse.

Keywords: solar system, agricultural greenhouse, heating, cooling, storage, drying

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1553 Feasibility on Introducing an Alternative Solar Powered Propelling Mechanism for Multiday Fishing Boats in Sri Lanka

Authors: Oshada Gamage, Chamal Wimalasooriya, Chrismal Boteju, W. K. Wimalsiri

Abstract:

This paper presents a study on the feasibility of introducing a solar powered propelling mechanism to multi-day fishing boats as an alternative energy source. Since solar energy is readily available on the sea throughout the year, this free energy could be utilized to power multi-day fishing vessels. Multi-day boats have a large deck area where solar panels can be mounted above without much effort. This project involves studying the amount of power that can be generated using onboard solar panels and implementing an independent propelling system to run the boat. A chain drive system was designed to propel the boat, when the batteries are fully charged, from an electric motor using the same propeller. A 60 feet multi-day fishing boat built by a local boat manufacturer was chosen for the study. The service speed of the boat was around 6 knots with the electric motor, and the duration of cruising is 1 hour per day with around 11 hours of charging. 350-watt Mono-crystalline PV module, 75 kW HVH type motor, and 10 kWh lithium-ion battery packs were chosen for the study. From the calculations, it was obtained that the boat has 30 PV modules (10.5 kW), 5 batteries (47 kWh), The boat dimensions are 20 meter length of water line, 5.51 meter of beam, 1.8 meter of draught, and 77 ton of total displacement with the PV system net present value of USD 12445 for 20 years of operation and a payback period of around 8.2 years.

Keywords: multiday fishing boats, photovoltaic cells, solar energy, solar powered boat

Procedia PDF Downloads 138
1552 High Thrust Upper Stage Solar Hydrogen Rocket Design

Authors: Maged Assem Soliman Mossallam

Abstract:

The conversion of solar thruster model to an upper stage hydrogen rocket is considered. Solar thruster categorization limits its capabilities to low and moderate thrust system with high specific impulse. The current study proposes a different concept for such systems by increasing the thrust which enables using as an upper stage rocket and for future launching purposes. A computational model for the thruster is discussed for solar thruster subsystems. The first module depends on ray tracing technique to determine the intercepted solar power by the hydrogen combustion chamber. The cavity receiver is modeled using finite volume technique. The final module imports the heated hydrogen properties to the nozzle using quasi one dimensional simulation. The probability of shock waves formulation inside the nozzle is almost diminished as the outlet pressure in space environment tends to zero. The computational model relates the high thrust hydrogen rocket conversion to the design parameters and operating conditions of the thruster. Three different designs for solar thruster systems are discussed. The first design is a low thrust high specific impulse design that produces about 10 Newton of thrust .The second one output thrust is about 250 Newton and the third design produces about 1000 Newton.

Keywords: space propulsion, hydrogen rocket, thrust, specific impulse

Procedia PDF Downloads 155
1551 The Impact of a Sustainable Solar System on the Growth of Strawberry Plants in an Agricultural Greenhouse

Authors: Ilham Ihoume, Rachid Tadili, Nora Arbaoui

Abstract:

This study examines the effects of a solar-based heating system, in a north-‎south oriented agricultural greenhouse on the development of strawberry ‎plants during winter. This system relies on the circulation of water as a heat ‎transfer fluid in a closed circuit installed on the greenhouse roof to store heat ‎during the day and release it inside at night. A comparative experimental ‎study was conducted in two greenhouses, one experimental with the solar ‎heating system and the other for control without any heating system. Both ‎greenhouses are located on the terrace of the Solar Energy and Environment ‎Laboratory of the Mohammed V University in Rabat, Morocco. The devel-‎oped heating system consists of a copper coil inserted in double glazing and ‎placed on the roof of the greenhouse, a water pump circulator, a battery, and ‎a photovoltaic solar panel to power the electrical components. This inexpen-‎sive and environmentally friendly system allows the greenhouse to be heated ‎during the winter and improves its microclimate system. This improvement ‎resulted in an increase in the air temperature inside the experimental green-‎house by 6 °C and 8 °C, and a reduction in its relative humidity by 23% and ‎‎35% compared to the control greenhouse and the ambient air, respectively, ‎throughout the winter. For the agronomic performance, it was observed that ‎the production was 17 days earlier than in the control greenhouse.‎

Keywords: sustainability, solar energy, thermal energy storage.‎, greenhouse heating

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1550 Water Irrigation in the Chlef Region Using Photovoltaic Solar Energy

Authors: T. Tahri, H. Zahloul, K. E. Meddah, H. Lazergue

Abstract:

This paper presents a theoretical study that leads to the design of a photovoltaic pumping system to irrigate six hectares of oranges in the valley of Chlef using the software "PVSYST". It was shown that the site of Chlef presents a favorable climate to this type of energy with an irradiation of over 5 kWh/m2/day, and significant resources underground water. Another very important coincidence still promotes the use of this type of energy for pumping water in Chlef is that the demand for water, especially in agriculture, peaked in hot and dry where it is precisely when one has access to the maximum of solar energy.

Keywords: solar energy, irradiation, water pumping, design, Valley of Chlef

Procedia PDF Downloads 243
1549 Study of Some Factors Effecting on Productivity of Solar Distillers

Authors: Keshek M.H, Mohamed M.A, El-Shafey M.A

Abstract:

The aim of this research was increasing the productivity of solar distillation. In order to reach this aim, a solar distiller was created with three glass sides sloping 30o at the horizontal level, and the experiments were carried out on the solar distillation unit during the period from 24th August, 2016 till 24th May, 2017 at the Agricultural Engineering and Bio Systems Department, Faculty of Agriculture, Menoufia University. Three gap lengths were used between the water level and the inner glass cover, those were 3, 6, and 9 cm. As the result of change the gap length between the water level and the inner glass cover the total volume of basins were changed from 15.5, 13, and 11 L, respectively. The total basin volume was divided to three sections, to investigate the effect of water volume. The three water volumes were 100%, 75%, and 50%. Every section was supplied with one, two, or three heaters. The one heater power was 15 W. The results showed that, by increasing the distance between the basins edge and the inner edge of the glass cover, an increase occurs in the percentage of temperature difference with maximum value was 52% at distance 9 cm from each edge, an increase occurs in the productivity with maximum productivity was 3.3 L/m2 at distance 9 cm from each edge and an increase occurs in the efficiency with maximum efficiency was 70% at distance 9 cm from each edge.

Keywords: distillation, solar energy, still productivity, efficiency

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1548 Experimental Study for the Development of a Wireless Communication System in a Solar Central Tower Facility

Authors: Victor H. Benitez, Ramon V. Armas-Flores, Jesus H. Pacheco-Ramirez

Abstract:

Systems transforming solar energy into electrical power have emerged as a viable source of clean, renewable energy. Solar power tower technology is a good example of this type of system, which consists of several mobile mirrors, called heliostats, which reflect the sun's radiation to the same point, located on top of a tower at the center of heliostat field, for collection or transformation into another type of energy. The so-called Hermosillo’s Solar Platform (Plataforma Solar de Hermosillo, PSH, in Spanish) is a facility constituted with several heliostats, its aim and scope is for research purposes. In this paper, the implementation of a wireless communication system based on intelligent nodes is proposed in order to allow the communication and control of the heliostats in PSH. Intelligent nodes transmit information from one point to another, and can perform other actions that allow them to adapt to the conditions and limitations of a field of heliostats, thus achieving effective communication system. After deployment of the nodes in the heliostats, tests were conducted to measure the effectiveness of the communication, and determine the feasibility of using the proposed technologies. The test results were always positive, exceeding expectations held for its operation in the field of heliostats. Therefore, it was possible to validate the efficiency of the wireless communication system to be implemented in PSH, allowing communication and control of the heliostats.

Keywords: heliostat, intelligent node, solar energy, wireless communication

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1547 Further Development of Offshore Floating Solar and Its Design Requirements

Authors: Madjid Karimirad

Abstract:

Floating solar was not very well-known in the renewable energy field a decade ago; however, there has been tremendous growth internationally with a Compound Annual Growth Rate (CAGR) of nearly 30% in recent years. To reach the goal of global net-zero emission by 2050, all renewable energy sources including solar should be used. Considering that 40% of the world’s population lives within 100 kilometres of the coasts, floating solar in coastal waters is an obvious energy solution. However, this requires more robust floating solar solutions. This paper tries to enlighten the fundamental requirements in the design of floating solar for offshore installations from the hydrodynamic and offshore engineering points of view. In this regard, a closer look at dynamic characteristics, stochastic behaviour and nonlinear phenomena appearing in this kind of structure is a major focus of the current article. Floating solar structures are alternative and very attractive green energy installations with (a) Less strain on land usage for densely populated areas; (b) Natural cooling effect with efficiency gain; and (c) Increased irradiance from the reflectivity of water. Also, floating solar in conjunction with the hydroelectric plants can optimise energy efficiency and improve system reliability. The co-locating of floating solar units with other types such as offshore wind, wave energy, tidal turbines as well as aquaculture (fish farming) can result in better ocean space usage and increase the synergies. Floating solar technology has seen considerable developments in installed capacities in the past decade. Development of design standards and codes of practice for floating solar technologies deployed on both inland water-bodies and offshore is required to ensure robust and reliable systems that do not have detrimental impacts on the hosting water body. Floating solar will account for 17% of all PV energy produced worldwide by 2030. To enhance the development, further research in this area is needed. This paper aims to discuss the main critical design aspects in light of the load and load effects that the floating solar platforms are subjected to. The key considerations in hydrodynamics, aerodynamics and simultaneous effects from the wind and wave load actions will be discussed. The link of dynamic nonlinear loading, limit states and design space considering the environmental conditions is set to enable a better understanding of the design requirements of fast-evolving floating solar technology.

Keywords: floating solar, offshore renewable energy, wind and wave loading, design space

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1546 Power Angle Control Strategy of Virtual Synchronous Machine: A Novel Approach to Control Virtual Synchronous Machine

Authors: Shishir Lamichhane, Saurav Dulal, Bibek Gautam, Madan Thapa Magar, Indraman Tamrakar

Abstract:

Renewable energies such as wind turbines and solar photovoltaic have gained significance as a result of global environmental pollution and energy crises. These sources of energy are converted into electrical energy and delivered to end-users through the utility system. As a result of the widespread use of power electronics-based grid-interfacing technologies to accommodate renewable sources of energy, the prevalence of converters has expanded as well. As a result, the power system's rotating inertia is decreasing, endangering the utility grid's stability. The use of Virtual Synchronous Machine (VSM) technology has been proposed to overcome the grid stability problem due to low rotating inertia. The grid-connected inverter used in VSM can be controlled to emulate inertia, which replicates the external features of a synchronous generator. As a result, the rotating inertia is increased to support the power system's stability. A power angle control strategy is proposed in this paper and its model is simulated in MATLAB/Simulink to study the effects of parameter disturbances on the active power and frequency for a VSM. The system consists of a synchronous generator, which is modeled in such a way that the frequency drops to an unacceptable region during transient conditions due to a lack of inertia when VSM is not used. Then, the suggested model incorporating VSM emulates rotating inertia, injecting a controllable amount of energy into the grid during frequency transients to enhance transient stability.

Keywords: damping constant, inertia–constant, ROCOF, transient stability, distributed sources

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1545 Numerical Simulation of a Solar Photovoltaic Panel Cooled by a Forced Air System

Authors: Djamila Nebbali, Rezki Nebbali, Ahmed Ouibrahim

Abstract:

This study focuses on the cooling of a photovoltaic panel (PV). Indeed, the cooling improves the conversion capacity of this one and maintains, under extreme conditions of air temperature, the panel temperature at an appreciable level which avoids the altering. To do this, a fan provides forced circulation of air. Because the fan is supplied by the panel, it is necessary to determine the optimum operating point that unites efficiency of the PV with the consumption of the fan. For this matter, numerical simulations are performed at varying mass flow rates of air, under two extreme air temperatures (50°C, 25°C) and a fixed solar radiation (1000 W.m2) in a case of no wind.

Keywords: energy conversion, efficiency, balance energy, solar cell

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1544 Fabrication of Graphene Oxide Based Planar Hetero-Junction Perovskite Solar Cells

Authors: Khursheed Ahmad, Shaikh M. Mobin

Abstract:

In this work, we have developed a highly stable planar heterojunction perovskite solar cells (PSCs) with a architecture (ITO/GO/PEDOT:PSS/MAPbI3/PCBM/Carbon tape). The PSCs was fabricated under air using GO/PEDOT:PSS as hole transport layer while the carbon tape used as a back contact to complete the device. The fabricated PSCs device exhibited good stability and performance in terms of power conversion efficiency of 5.2%. The PSCs devices were exposed to ambient condition for 4 days which shows excellent stability confirmed by XRD analysis. We believed that the stability of the planar heterojunction perovskite solar cell may be due the presence of GO which inhibits the direct contact between PEDOT:PSS and MAPbI3.

Keywords: graphene oxide, perovskite solar cells, hole transport layer, PEDOT:PSS

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1543 Charge Carrier Mobility Dependent Open-Circuit Voltage in Organic and Hybrid Solar Cells

Authors: David Ompong, Jai Singh

Abstract:

A better understanding of the open-circuit voltage (Voc) related losses in organic solar cells (OSCs) is desirable in order to assess the photovoltaic performance of these devices. We have derived Voc as a function of charge carrier mobilities (μe and μh) for organic and hybrid solar cells by optimizing the drift-diffusion current density. The optimum Voc thus obtained depends on the energy difference between the highest occupied molecular orbital (HOMO) level and the quasi-Fermi level of holes of the donor material. We have found that the Voc depends on the ratio of the electron (μe) and hole (μh) mobilities and when μh > μe the Voc increases. The most important loss term in the Voc arises from the energetics of the donor and acceptor materials, which will be discussed in detail in this paper.

Keywords: charge carrier mobility, open-circuit voltage, organic solar cells, quasi-fermi levels

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1542 Validation of Solar PV Inverter Harmonics Behaviour at Different Power Levels in a Test Network

Authors: Wilfred Fritz

Abstract:

Grid connected solar PV inverters need to be compliant to standard regulations regarding unwanted harmonic generation. This paper gives an introduction to harmonics, solar PV inverter voltage regulation and balancing through compensation and investigates the behaviour of harmonic generation at different power levels. Practical measurements of harmonics and power levels with a power quality data logger were made, on a test network at a university in Germany. The test setup and test results are discussed. The major finding was that between the morning and afternoon load peak windows when the PV inverters operate under low solar insolation and low power levels, more unwanted harmonics are generated. This has a huge impact on the power quality of the grid as well as capital and maintenance costs. The design of a single-tuned harmonic filter towards harmonic mitigation is presented.

Keywords: harmonics, power quality, pulse width modulation, total harmonic distortion

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1541 Optimization Techniques of Doubly-Fed Induction Generator Controller Design for Reliability Enhancement of Wind Energy Conversion Systems

Authors: Om Prakash Bharti, Aanchal Verma, R. K. Saket

Abstract:

The Doubly-Fed Induction Generator (DFIG) is suggested for Wind Energy Conversion System (WECS) to extract wind power. DFIG is preferably employed due to its robustness towards variable wind and rotor speed. DFIG has the adaptable property because the system parameters are smoothly dealt with, including real power, reactive power, DC-link voltage, and the transient and dynamic responses, which are needed to analyze constantly. The analysis becomes more prominent during any unusual condition in the electrical power system. Hence, the study and improvement in the system parameters and transient response performance of DFIG are required to be accomplished using some controlling techniques. For fulfilling the task, the present work implements and compares the optimization methods for the design of the DFIG controller for WECS. The bio-inspired optimization techniques are applied to get the optimal controller design parameters for DFIG-based WECS. The optimized DFIG controllers are then used to retrieve the transient response performance of the six-order DFIG model with a step input. The results using MATLAB/Simulink show the betterment of the Firefly algorithm (FFA) over other control techniques when compared with the other controller design methods.

Keywords: doubly-fed induction generator, wind turbine, wind energy conversion system, induction generator, transfer function, proportional, integral, derivatives

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1540 Wind Turbines Optimization: Shield Structure for a High Wind Speed Conditions

Authors: Daniyar Seitenov, Nazim Mir-Nasiri

Abstract:

Optimization of horizontal axis semi-exposed wind turbine has been performed using a shield protection that automatically protects the generator shaft at extreme wind speeds from over speeding, mechanical damage and continues generating electricity during the high wind speed conditions. A semi-exposed to wind generator has been designed and its structure has been described in this paper. The simplified point-force dynamic load model on the blades has been derived for normal and extreme wind conditions with and without shield involvement. Numerical simulation has been conducted at different values of wind speed to study the efficiency of shield application. The obtained results show that the maximum power generated by the wind turbine with shield does not exceed approximately the rated value of the generator, where shield serves as an automatic break for extreme wind speed values of 15 m/sec and above. Meantime the wind turbine without shield produced a power that is much larger than the rated value. The optimized horizontal axis semi-exposed wind turbine with shield protection is suitable for low and medium power generation when installed on the roofs of high rise buildings for harvesting wind energy. Wind shield works automatically with no power consumption. The structure of the generator with the protection, math simulation of kinematics and dynamics of power generation has been described in details in this paper.

Keywords: renewable energy, wind turbine, wind turbine optimization, high wind speed

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1539 Analysis of Electricity Demand at Household Level Using Leap Model in Balochistan, Pakistan

Authors: Sheikh Saeed Ahmad

Abstract:

Electricity is vital for any state’s development that needs policy for planning the power network extension. This study is about simulation modeling for electricity in Balochistan province. Baseline data of electricity consumption was used of year 2004 and projected with the help of LEAP model up to subsequent 30 years. Three scenarios were created to run software. One scenario was baseline and other two were alternative or green scenarios i.e. solar and wind energy scenarios. Present study revealed that Balochistan has much greater potential for solar and wind energy for electricity production. By adopting these alternative energy forms, Balochistan can save energy in future nearly 23 and 48% by incorporating solar and wind power respectively. Thus, the study suggests to government planners, an aspect of integrating renewable sources in power system for ensuring sustainable development and growth.

Keywords: demand and supply, LEAP, solar energy, wind energy, households

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1538 Study on the Integration Schemes and Performance Comparisons of Different Integrated Solar Combined Cycle-Direct Steam Generation Systems

Authors: Liqiang Duan, Ma Jingkai, Lv Zhipeng, Haifan Cai

Abstract:

The integrated solar combined cycle (ISCC) system has a series of advantages such as increasing the system power generation, reducing the cost of solar power generation, less pollutant and CO2 emission. In this paper, the parabolic trough collectors with direct steam generation (DSG) technology are considered to replace the heat load of heating surfaces in heat regenerator steam generation (HRSG) of a conventional natural gas combined cycle (NGCC) system containing a PG9351FA gas turbine and a triple pressure HRSG with reheat. The detailed model of the NGCC system is built in ASPEN PLUS software and the parabolic trough collectors with DSG technology is modeled in EBSILON software. ISCC-DSG systems with the replacement of single, two, three and four heating surfaces are studied in this paper. Results show that: (1) the ISCC-DSG systems with the replacement heat load of HPB, HPB+LPE, HPE2+HPB+HPS, HPE1+HPE2+ HPB+HPS are the best integration schemes when single, two, three and four stages of heating surfaces are partly replaced by the parabolic trough solar energy collectors with DSG technology. (2) Both the changes of feed water flow and the heat load of the heating surfaces in ISCC-DSG systems with the replacement of multi-stage heating surfaces are smaller than those in ISCC-DSG systems with the replacement of single heating surface. (3) ISCC-DSG systems with the replacement of HPB+LPE heating surfaces can increase the solar power output significantly. (4) The ISCC-DSG systems with the replacement of HPB heating surfaces has the highest solar-thermal-to-electricity efficiency (47.45%) and the solar radiation energy-to-electricity efficiency (30.37%), as well as the highest exergy efficiency of solar field (33.61%).

Keywords: HRSG, integration scheme, parabolic trough collectors with DSG technology, solar power generation

Procedia PDF Downloads 246
1537 A Study on Cleaning Mirror Technology with Reduced Water Consumption in a Solar Thermal Power Plant

Authors: Bayarjargal Enkhtaivan, Gao Wei, Zhang Yanping, He Guo Qiang

Abstract:

In our study, traditional cleaning mirror technology with reduced consumption of water in solar thermal power plants is investigated. In developed countries, a significant increase of growth and innovation in solar thermal power sector is evident since over the last decade. These power plants required higher water consumption, however, there are some complications to construct and operate such power plants under severe drought-inflicted areas like deserts where high water-deficit can be seen but sufficient solar energy is available. Designing new experimental equipments is the most important advantage of this study. These equipments can estimate various types of measurements at the mean time. In this study, Glasses were placed for 10 and 20 days at certain positions to deposit dusts on glass surface by using a common method. Dust deposited on glass surface was washed by experimental equipment and measured dust deposition on each glass. After that, experimental results were analyzed and concluded.

Keywords: concentrated solar power (CSP) plant, high-pressure water, test equipment of clean mirror, cleaning technology of glass and mirror

Procedia PDF Downloads 163
1536 A Three-Dimensional TLM Simulation Method for Thermal Effect in PV-Solar Cells

Authors: R. Hocine, A. Boudjemai, A. Amrani, K. Belkacemi

Abstract:

Temperature rising is a negative factor in almost all systems. It could cause by self heating or ambient temperature. In solar photovoltaic cells this temperature rising affects on the behavior of cells. The ability of a PV module to withstand the effects of periodic hot-spot heating that occurs when cells are operated under reverse biased conditions is closely related to the properties of the cell semi-conductor material. In addition, the thermal effect also influences the estimation of the maximum power point (MPP) and electrical parameters for the PV modules, such as maximum output power, maximum conversion efficiency, internal efficiency, reliability, and lifetime. The cells junction temperature is a critical parameter that significantly affects the electrical characteristics of PV modules. For practical applications of PV modules, it is very important to accurately estimate the junction temperature of PV modules and analyze the thermal characteristics of the PV modules. Once the temperature variation is taken into account, we can then acquire a more accurate MPP for the PV modules, and the maximum utilization efficiency of the PV modules can also be further achieved. In this paper, the three-Dimensional Transmission Line Matrix (3D-TLM) method was used to map the surface temperature distribution of solar cells while in the reverse bias mode. It was observed that some cells exhibited an inhomogeneity of the surface temperature resulting in localized heating (hot-spot). This hot-spot heating causes irreversible destruction of the solar cell structure. Hot spots can have a deleterious impact on the total solar modules if individual solar cells are heated. So, the results show clearly that the solar cells are capable of self-generating considerable amounts of heat that should be dissipated very quickly to increase PV module's lifetime.

Keywords: thermal effect, conduction, heat dissipation, thermal conductivity, solar cell, PV module, nodes, 3D-TLM

Procedia PDF Downloads 376
1535 Mass Transfer in Reactor with Magnetic Field Generator

Authors: Tomasz Borowski, Dawid Sołoducha, Rafał Rakoczy, Marian Kordas

Abstract:

The growing interest in magnetic fields applications is visible due to the increased number of articles on this topic published in the last few years. In this study, the influence of various magnetic fields (MF) on the mass transfer process was examined. To carry out the prototype set-up equipped with an MF generator that is able to generate a pulsed magnetic field (PMF), oscillating magnetic field (OMF), rotating magnetic field (RMF) and static magnetic field (SMF) was used. To demonstrate the effect of MF’s on mass transfer, the calcium carbonate precipitation process was selected. To the vessel with attached conductometric probes and placed inside the generator, specific doses of calcium chloride and sodium carbonate were added. Electrical conductivity changes of the mixture inside the vessel were measured over time until equilibrium was established. Measurements were conducted for various MF strengths and concentrations of added chemical compounds. Obtained results were analyzed, which allowed to creation of mathematical correlation models showing the influence of MF’s on the studied process.

Keywords: mass transfer, oscillating magnetic field, rotating magnetic field, static magnetic field

Procedia PDF Downloads 191
1534 Optimal Tuning of RST Controller Using PSO Optimization for Synchronous Generator Based Wind Turbine under Three-Phase Voltage Dips

Authors: K. Tahir, C. Belfedal, T. Allaoui, C. Gerard, M. Doumi

Abstract:

In this paper, we presented an optimized RST controller using Particle Swarm Optimization (PSO) meta-heuristic technique of the active and reactive power regulation of a grid connected wind turbine based on a wound field synchronous generator. This regulation is achieved below the synchronous speed, by means of a maximum power point tracking algorithm. The control of our system is tested under typical wind variations and parameters variation, fault grid condition by simulation. Some results are presented and discussed to prove simplicity and efficiency of the WRSG control for WECS. On the other hand, according to simulation results, variable speed driven WRSG is not significantly impacted in fault conditions.

Keywords: wind energy, particle swarm optimization, wound rotor synchronous generator, power control, RST controller, maximum power point tracking

Procedia PDF Downloads 439
1533 Analysis of Flux-Linkage Performance of DFIG by Using Simulink under Different Types of Faults and Locations

Authors: Mohamed Moustafa Mahmoud Sedky

Abstract:

The double-fed induction generator wind turbine has recently received a great attention. The steady state performance and response of double fed induction generator (DFIG) based wind turbine are now well understood. This paper presents the analysis of stator and rotor flux linkage dq models operation of DFIG under different faults and at different locations.

Keywords: double fed induction motor, wind energy, flux linkage, short circuit

Procedia PDF Downloads 578
1532 Validation and Projections for Solar Radiation up to 2100: HadGEM2-AO Global Circulation Model

Authors: Elison Eduardo Jardim Bierhals, Claudineia Brazil, Deivid Pires, Rafael Haag, Elton Gimenez Rossini

Abstract:

The objective of this work is to evaluate the results of solar radiation projections between 2006 and 2013 for the state of Rio Grande do Sul, Brazil. The projections are provided by the General Circulation Models (MCGs) belonging to the Coupled Model Intercomparison Phase 5 (CMIP5). In all, the results of the simulation of six models are evaluated, compared to monthly data, measured by a network of thirteen meteorological stations of the National Meteorological Institute (INMET). The performance of the models is evaluated by the Nash coefficient and the Bias. The results are presented in the form of tables, graphs and spatialization maps. The ACCESS1-0 RCP 4.5 model presented the best results for the solar radiation simulations, for the most optimistic scenario, in much of the state. The efficiency coefficients (CEF) were between 0.95 and 0.98. In the most pessimistic scenario, HADGen2-AO RCP 8.5 had the best accuracy among the analyzed models, presenting coefficients of efficiency between 0.94 and 0.98. From this validation, solar radiation projection maps were elaborated, indicating a seasonal increase of this climatic variable in some regions of the Brazilian territory, mainly in the spring.

Keywords: climate change, projections, solar radiation, validation

Procedia PDF Downloads 183