Showing papers on "Photovoltaic system published in 2003"
TL;DR: In this article, the authors present the history, the present status and possible future developments of photovoltaic (PV) materials for terrestrial applications and discuss the physical and technical limitations of this material.
Abstract: This paper reviews the history, the present status and possible future developments of photovoltaic (PV) materials for terrestrial applications. After a brief history and introduction of the photovoltaic effect theoretical requirements for the optimal performance of materials for pn-junction solar cells are discussed. Most important are efficiency, long-term stability and, not to be neglected, lowest possible cost. Today the market is dominated by crystalline silicon in its multicrystalline and monocrystalline form. The physical and technical limitations of this material are discussed. Although crystalline silicon is not the optimal material from a solid state physics point of view it dominates the market and will continue to do this for the next 5–10 years. Because of its importance a considerable part of this review deals with materials aspects of crystalline silicon. For reasons of cost only multicrystalline silicon and monocrystalline Czochralski (Cz) crystals are used in practical cells. Light induced instability in this Cz-material has recently been investigated and ways to eliminate this effect have been devised. For future large scale production of crystalline silicon solar cells development of a special solar grade silicon appears necessary. Ribbon growth is a possibility to avoid the costly sawing process. A very vivid R&D area is thin-film crystalline silicon (about 5–30 μm active layer thickness) which would avoid the crystal growing and sawing processes. The problems arising for this material are: assuring adequate light absorption, assuring good crystal quality and purity of the films, and finding a substrate that fulfills all requirements. Three approaches have emerged: high-temperature, low-temperature and transfer technique. Genuine thin-film materials are characterized by a direct band structure which gives them very high light absorption. Therefore, these materials have a thickness of only one micron or less. The oldest such material is amorphous silicon which is the second most important material today. It is mainly used in consumer products but is on the verge to also penetrate the power market. Other strong contenders are chalcogenides like copper indium diselenide (CIS) and cadmium telluride. The interest has expanded from CuInSe 2 , to CuGaSe 2 , CuInS 2 and their multinary alloys Cu(In,Ga)(S,Se) 2 . The two deposition techniques are either separate deposition of the components followed by annealing on one hand or coevaporation. Laboratory efficiencies for small area devices are approaching 19% and large area modules have reached 12%. Pilot production of CIS-modules has started in the US and Germany. Cadmium telluride solar cells also offer great promise. They have only slightly lower efficiency and are also at the start of production. In the future other materials and concepts can be expected to come into play. Some of these are: dye sensitized cells, organic solar cells and various concentrating systems including III/V-tandem cells. Theoretical materials that have not yet been realized are Auger generation material and intermediate metallic band material.
919 citations
TL;DR: It is found that the P&O method, when properly optimized, can have MPPT efficiencies well in excess of 97%, and is highly competitive against other MPPT algorithms.
Abstract: Maximum power point trackers (MPPTs) play an important role in photovoltaic (PV) power systems because they maximize the power output from a PV system for a given set of conditions, and therefore maximize the array efficiency. Thus, an MPPT can minimize the overall system cost. MPPTs find and maintain operation at the maximum power point, using an MPPT algorithm. Many such algorithms have been proposed. However, one particular algorithm, the perturb-and-observe (P&O) method, claimed by many in the literature to be inferior to others, continues to be by far the most widely used method in commercial PV MPPTs. Part of the reason for this is that the published comparisons between methods do not include an experimental comparison between multiple algorithms with all algorithms optimized and a standardized MPPT hardware. This paper provides such a comparison. MPPT algorithm performance is quantified through the MPPT efficiency. In this work, results are obtained for three optimized algorithms, using a microprocessor-controlled MPPT operating from a PV array and also a PV array simulator. It is found that the P&O method, when properly optimized, can have MPPT efficiencies well in excess of 97%, and is highly competitive against other MPPT algorithms. Copyright © 2002 John Wiley & Sons, Ltd.
866 citations
TL;DR: In this article, the authors distinguish between conventional solar cells and excitonic solar cells (XSCs) by showing that charge carriers are generated and simultaneously separated across a heterointerface.
Abstract: Existing types of solar cells may be divided into two distinct classes: conventional solar cells, such as silicon p−n junctions, and excitonic solar cells, XSCs. Most organic-based solar cells, including dye-sensitized solar cells, DSSCs, fall into the category of XSCs. In these cells, excitons are generated upon light absorption, and if not created directly at the heterointerface as in DSSCs, they must diffuse to it in order to photogenerate charge carriers. The distinguishing characteristic of XSCs is that charge carriers are generated and simultaneously separated across a heterointerface. In contrast, photogeneration of free electron−hole pairs occurs throughout the bulk semiconductor in conventional cells, and carrier separation upon their arrival at the junction is a subsequent process. This apparently minor mechanistic distinction results in fundamental differences in photovoltaic behavior. For example, the open circuit photovoltage Voc in conventional cells is limited to less than the magnitude of...
812 citations
TL;DR: In this paper, the optical and electronic properties of the In1−xGaxN alloys have been investigated and shown to exhibit a much higher resistance to high energy (2 MeV) proton irradiation than the standard currently used photovoltaic materials such as GaAs and GaInP, and therefore offer great potential for radiation-hard high-efficiency solar cells for space applications.
Abstract: High-efficiency multijunction or tandem solar cells based on group III–V semiconductor alloys are applied in a rapidly expanding range of space and terrestrial programs. Resistance to high-energy radiation damage is an essential feature of such cells as they power most satellites, including those used for communications, defense, and scientific research. Recently we have shown that the energy gap of In1−xGaxN alloys potentially can be continuously varied from 0.7 to 3.4 eV, providing a full-solar-spectrum material system for multijunction solar cells. We find that the optical and electronic properties of these alloys exhibit a much higher resistance to high-energy (2 MeV) proton irradiation than the standard currently used photovoltaic materials such as GaAs and GaInP, and therefore offer great potential for radiation-hard high-efficiency solar cells for space applications. The observed insensitivity of the semiconductor characteristics to the radiation damage is explained by the location of the band edge...
598 citations
Book•
01 Jan 2003
TL;DR: The Handbook of Photovoltaics as mentioned in this paper is a "benchmark" publication for those involved in the design, manufacture and use of photovoltaic devices, which covers the principles of solar cell function, the raw materials, photvoltaic systems, standards, calibration, testing, economics and case studies.
Abstract: As part of the growing sustainable and renewable energy movement, the design, manufacture and use of photovoltaic devices is increasing in pace and frequency. The Handbook of Photovoltaics will be a 'benchmark' publication for those involved in the design, manufacture and use of these devices.
The Handbook covers the principles of solar cell function, the raw materials, photovoltaic systems, standards, calibration, testing, economics and case studies.
The editors have assembled a cast of internationally-respected contributors from industry and academia.
The report is essential reading for: Physicists, electronic engineers, designers of systems, installers, architects, policy-makers relating to photovoltaics.
569 citations
TL;DR: In this paper, a feedforward MP-point tracking scheme is developed for the coupled-inductor interleaved-boost-converter-fed PV system using a fuzzy controller that results in better tracking performance.
Abstract: The photovoltaic (PV) generator exhibits a nonlinear V-I characteristic and its maximum power (MP) point varies with solar insolation. In this paper, a feedforward MP-point tracking scheme is developed for the coupled-inductor interleaved-boost-converter-fed PV system using a fuzzy controller. The proposed converter has lower switch current stress and improved efficiency over the noncoupled converter system. For a given solar insolation, the tracking algorithm changes the duty ratio of the converter such that the solar cell array voltage equals the voltage corresponding to the MP point. This is done by the feedforward loop, which generates an error signal by comparing the instantaneous array voltage and reference voltage corresponding to the MP point. Depending on the error and change of error signals, the fuzzy controller generates a control signal for the pulsewidth-modulation generator which in turn adjusts the duty ratio of the converter. The reference voltage corresponding to the MP point for the feedforward loop is obtained by an offline trained neural network. Experimental data are used for offline training of the neural network, which employs a backpropagation algorithm. The proposed peak power tracking effectiveness is demonstrated through simulation and experimental results. Tracking performance of the proposed controller is also compared with the conventional proportional-plus-integral-controller-based system. These studies reveal that the fuzzy controller results in better tracking performance.
477 citations
TL;DR: In this article, an explicit dynamic model was developed for a single-glazed flat-plate water-heating photovoltaic-thermal (PV/T) collector.
466 citations
23 Jun 2003
TL;DR: In this paper, the authors present an overview on recent developments and a summary of the state-of-the-art in inverter technology for single-phase grid connected photovoltaic (PV) systems.
Abstract: This work presents an overview on recent developments and a summary of the state-of-the-art in inverter technology for single-phase grid connected photovoltaic (PV) systems. The information provided includes details on commercially available European string and module integrated PV inverters, their efficiency, price trends and market share. This review is given for inverters for a power level up to 6 kW. Furthermore, the paper deals with the recent developments of new inverter topologies and PV system concepts and discusses possible future trends.
447 citations
TL;DR: The results indicate that with obstacles of irregular shape being close to the photovoltaic array, simulation estimates the shadowing losses rather imprecise, but at array positions mainly suffering from a reduction of the visible horizon by obstacles far away from the photvoltaic arrays, a simulation returns good results.
439 citations
TL;DR: A multilayer photovoltaic device structure in which photon absorption instead occurs in photoreceptors deposited on the surface of an ultrathin metal–semiconductor junction Schottky diode is reported, which might provide the basis for durable low-cost solar cells using a variety of materials.
Abstract: There has been an active search for cost-effective photovoltaic devices since the development of the first solar cells in the 1950s (refs 1-3). In conventional solid-state solar cells, electron-hole pairs are created by light absorption in a semiconductor, with charge separation and collection accomplished under the influence of electric fields within the semiconductor. Here we report a multilayer photovoltaic device structure in which photon absorption instead occurs in photoreceptors deposited on the surface of an ultrathin metal-semiconductor junction Schottky diode. Photoexcited electrons are transferred to the metal and travel ballistically to--and over--the Schottky barrier, so providing the photocurrent output. Low-energy (approximately 1 eV) electrons have surprisingly long ballistic path lengths in noble metals, allowing a large fraction of the electrons to be collected. Unlike conventional cells, the semiconductor in this device serves only for majority charge transport and separation. Devices fabricated using a fluorescein photoreceptor on an Au/TiO2/Ti multilayer structure had typical open-circuit photovoltages of 600-800 mV and short-circuit photocurrents of 10-18 micro A cm(-2) under 100 mW cm(-2) visible band illumination: the internal quantum efficiency (electrons measured per photon absorbed) was 10 per cent. This alternative approach to photovoltaic energy conversion might provide the basis for durable low-cost solar cells using a variety of materials.
394 citations
TL;DR: In this article, the HELIOSAT method applied to derive surface solar irradiance from satellite images is described and shown examples of applications: the use of daylight in buildings, the generation of correlated time series of solar irradiances and temperature as input data for simulations of solar energy systems and a short-term forecast of sun irradiance which can be used in intelligent building control techniques.
TL;DR: In this article, the authors proposed a photovoltaic inverter system composed of a half-bridge inverter at the utility interface and a novel generation control circuit which compensates for reductions in the output power of the system that are attributable to variations in the generation conditions of respective PV modules.
Abstract: This paper presents a novel photovoltaic inverter that cannot only synchronize a sinusoidal AC output current with a utility line voltage, but also control the power generation of each photovoltaic module in an array. The proposed inverter system is composed of a half-bridge inverter at the utility interface and a novel generation control circuit which compensates for reductions in the output power of the system that are attributable to variations in the generation conditions of respective photovoltaic modules. The generation control circuit allows each photovoltaic module to operate independently at peak capacity, simply by detecting the output power of the system. Furthermore, the generation control circuit attenuates low-frequency ripple voltage, which is caused by the half-bridge inverter, across the photovoltaic modules. Consequently, the output power of the system is increased due to the increase in average power generated by the photovoltaic modules. The effectiveness of the proposed inverter system is confirmed experimentally and by means of simulation.
TL;DR: A complete set of match calculation method for optimum sizing of a PV/wind hybrid system is presented in this paper, where more accurate mathematic models for characterizing components as well as models for estimating the available natural resources are adopted.
13 Jul 2003
TL;DR: In this paper, a two-stage MPPT control method is proposed to realize a relatively simple control system which can track the real maximum power point even under nonuniform insolation conditions.
Abstract: A photovoltaic (PV) array shows relatively low output power density, and has a greatly drooping current-voltage (I-V) characteristic. Therefore, maximum power point tracking (MPPT) control is used to maximize the output power of the PV array. Many papers have been reported in relation to MPPT. However, the current-power (I-P) curve sometimes shows multilocal maximum points mode under nonuniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under nonuniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and Lab VIEW.
TL;DR: In this article, a simulation model for analyzing the probability of power supply failure in hybrid photovoltaic-wind power generation systems incorporating a storage battery bank, and also analyzes the reliability of the systems.
15 Jun 2003
TL;DR: In this paper, a new control method and proportional PWM modulation of the cascaded H-bridge multilevel converter for grid-connected photovoltaic systems is introduced.
Abstract: This paper introduces a new control method and proportional PWM modulation of the cascaded H-bridge multilevel converter for grid-connected photovoltaic systems. This control makes each H-bridge module supply different power levels, allowing therefore for each module an independent maximum power point tracking of the corresponding photovoltaic array.
TL;DR: In this paper, a solution-processed hybrid solar cells consisting of a nanocrystalline inorganic semiconductor, CuInS2, and organic materials was used to form flat-interface donor-acceptor heterojunction solar cells.
Abstract: We report on solution-processed hybrid solar cells consisting of a nanocrystalline inorganic semiconductor, CuInS2, and organic materials. Synthesis of quantized CuInS2 nanoparticles was performed using a colloidal route, where the particle surface was shielded by an organic surfactant. First attempts were made to use nanocrystalline CuInS2 with fullerene derivatives to form flat-interface donor–acceptor heterojunction solar cells. We investigated also bulk heterojunctions by replacing the CuInS2 single layer by a blend of CuInS2 and p-type polymer (PEDOT:PSS; poly(3,4-ethylenedioxythiophene:poly(styrene sulfonic acid) in the same cell configuration. Bulk heterojunction solar cells show better photovoltaic response with external quantum efficiencies up to 20 %.
Book•
01 Jan 2003
TL;DR: In this paper, the authors present a thermal model of building-integrated photovoltaics (BIPV) components (U- and g-values) and evaluate their performance.
Abstract: Preface. Abbreviations in the Text. 1. Solar energy use in buildings. Energy consumption of buildings. Meeting requirements by active and passive solar energy use. 2. Solar irradiance. Extraterrestrial solar irradiance. The passage of rays through the atmosphere. Statistical production of hourly irradiance data records. Global irradiance and irradiance on inclined surfaces. Shading. 3. Solar thermal energy. Solar-thermal water collectors. Solar air collectors. 4. Solar cooling. Open cycle desiccant cooling. Closed cycle adsorption cooling. Absorption cooling technology. 5. Grid connected photovoltaic systems. Structure of grid connected systems. Solar cell technologies. Module technology. Building integration and costs. Energy production and the performance ratio of PV systems. Physical fundamentals of solar electricity production. Current-voltage characteristics. PV performance with shading. Simple temperature model for PV models. System engineering. 6. Thermal analysis of building-integrated solar components. Empirical thermal model of building-integrated photovoltaics. Energy balance and stationary thermal model of ventilated double facades. Building-integrated solar components (U- and g-values). Warm-air generation by photovoltaic facades. 7. Passive solar energy. Passive solar use by glazings. Transparent themal insulation. Heat storage by interior building elements. 8. Lighting technology and daylight use. Introduction to lighting and daylighting technology. Solar irradiance and light flux. Luminance and illuminance. Sky luminance intensity models. Light measurements. Daylight distribution in interior spaces. References. Index.
15 Jun 2003
TL;DR: In this paper, a modified version of the inverter proposed by Shimizu et al. solves a major problem within the original topology; regeneration of transformer leakage energy, and a decomposition of the currents and voltages inside the inverters is used to derive the stress and power losses.
Abstract: The objective for this paper is to present a novel inverter topology for photovoltaic (PV) applications, in particular for the AC-module. A modified version of the inverter proposed by Shimizu et al. solves a major problem within the original topology; regeneration of transformer leakage energy. Also presented is a decomposition of the currents and voltages inside the inverter. The decomposition is used to derive the stress and power losses, and hereby developing a tool for optimizing the inverter in terms of efficiency and ratings. Finally, the developed tool is used to design an inverter. The annual European efficiency is calculated to 81.8% for a 160 W inverter, which is regarded as high for an inverter for AC-module applications, as long the cost can be kept low.
TL;DR: In this paper, a novel technique for efficiently extracting the maximum output power from a solar panel under varying meteorological conditions is presented, which is based on connecting a pulsewidth-modulated (PWM) DC/DC SEPIC or Cuk converter between the solar panel and a load or battery bus.
Abstract: A novel technique for efficiently extracting the maximum output power from a solar panel under varying meteorological conditions is presented. The methodology is based on connecting a pulse-width-modulated (PWM) DC/DC SEPIC or Cuk converter between a solar panel and a load or battery bus. The converter operates in discontinuous capacitor voltage mode whilst its input current is continuous. By modulating a small-signal sinusoidal perturbation into the duty cycle of the main switch and comparing the maximum variation in the input voltage and the voltage stress of the main switch, the maximum power point (MPP) of the panel can be located. The nominal duty cycle of the main switch in the converter is adjusted to a value, so that the input resistance of the converter is equal to the equivalent output resistance of the solar panel at the MPP. This approach ensures maximum power transfer under all conditions without using microprocessors for calculation. Detailed mathematical derivations of the MPP tracking technique are included. The tracking capability of the proposed technique has been verified experimentally with a 10-W solar panel at different insolation (incident solar radiation) levels and under large-signal insolation level changes.
TL;DR: In this article, the authors investigated the relation between the output lowering due to shaded PV cells and the change of I-V characteristics, utilizing the computer simulation and proved that I-v characteristics are changed by the condition of the shadow, which covered the module.
TL;DR: In this article, the authors present an overview of the current state-of-the-art of photovoltaic electricity technology, and address its potential for cost reductions over the first few decades of the 21st century.
ENEA1
TL;DR: In this article, an attempt has been made to estimate the water production cost for two different seawater desalination systems: reverse osmosis and multiple effect, powered by a solar thermal and a photovoltaic field.
TL;DR: In this paper, a mini-hybrid solar power plant integrating a field of solar concentrators, two superposed organic Rankine cycles (ORC) and a (bio-)Diesel engine is introduced.
19 Feb 2003
TL;DR: In this article, a DSP-based improved maximum power point tracking (MPPT) approach for multiple solar array application is presented, which incorporates a "shared bus" current sharing method that can regulate many paralleled current mode DC/DC converters.
Abstract: A DSP-based improved maximum power point tracking (MPPT) approach for multiple solar array application is presented. It incorporates a "shared bus" current sharing method that can regulate many paralleled current mode DC/DC converters. The modular architecture eases the expansion of system power. The current sharing and MPPT performance of the proposed system is validated and evaluated by a 500 W prototype with two solar arrays.
TL;DR: In this article, an efficient cost-effective batteryless photovoltaic-powered seawater reverse-osmosis desalination system is described, which employs standard industrial inverters, motors and pumps, which offer excellent energy and cost efficiency.
01 Sep 2003
TL;DR: In this paper, Marti et al. discuss the importance of very high concentration in 3rd generation photovoltaic cells and discuss multi-interface novel devices with a continuous substructure.
Abstract: Non-conventional photovoltaic technology: a need to reach goals A. Luque and A. Marti Trends in development of solar photovoltaics Zh. I. Alferov and V.D. Rumyantsev Thermodynamics of solar converters P. Wurfel Tandem cells for very high concentration A.W. Bett Quantum wells in photovoltaic cells C. Rohr The importance of very high concentration in 3rd generation solar cells C. Algora Intermediate band solar cells A. Marti et. al Multi-interface novel devices: Models with a continuous substructure Z.T. Kuznicki Quantum dot solar cells A.J. Nozik Progress in thermophotovoltaic converters B. Bitnar et. al Solar cells for TPV converters V.M. Andreev Wafer bonding and film transfer for advanced PV cells C. Jaussaud, E. Jalaguier, and D. Mencaraglia Concentrator optics for the next generation photovoltaics P. Benitez and J.C. Minano Conclusions of the third generation PV workshop for high efficiency through full spectrum utilization
TL;DR: In this paper, a comparative study of three different options in applying large-scale building-integrated PV technology in a coastal city at the South China Sea is presented, based on a 260 m2 mono-crystalline silicon PV wall on a 30-storey hotel building.
Patent•
19 May 2003
TL;DR: In this article, the authors proposed a circuit arrangement for controlling/regulating photovoltaic systems (10b), which comprises a plurality of solar generators (14b) which are serially connected or/and connected in parallel.
Abstract: The invention relates to a circuit arrangement for controlling/regulating photovoltaic systems (10b) which comprise a plurality of solar generators (14b) which are serially connected or/and connected in parallel. In order to reduce power loss of solar generators which is based on the fact that not all solar generators are operated in the MPP thereof, each solar generator is associated with a variable energy-bypass (68b) which is controlled/ regulated in such a manner that each solar generator (14b) is operated in a continuous manner with the current, specific MPP thereof.
Proceedings Article•
01 May 2003
TL;DR: In this work, the performance of a PV-powered dc permanent-magnet (PM) motor coupled with a centrifugal pump has been analyzed at different solar intensities and corresponding cell temperature and it is observed that this system has a good match between the PV array and the electromechanical system characteristics.