Solar powered airport lit. review

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solar cell powered airport
"solar cell" visible spectrum absorbance
solar cell to power grid
solar cell anti-glare

Lit. reivew

1.Chen, D. Anti-reflection (AR) coatings made by sol–gel processes: A review. Solar Energy Materials and Solar Cells 68, 313–336 (2001).

Traditionally, various vacuum-based processes, depending on material systems and properties, and chemical etching process have been used for producing different types of anti-reflection (AR) coating on different substrate materials. In this paper, the development of sol–gel derived AR coating on different substrates for various applications in the past 40 years are reviewed. These coatings possess good uniformity in thickness and properties which have met requirements for various applications. The major approaches to fabricate AR coating and their characteristics have been discussed. This paper outlines the major solution coating processes and design principles of AR coatings. Major fabrication processes used in AR coating technologies have been compared. Different solution chemistries developed for producing different materials for AR coating preparation have been extensively reviewed. The optical performance of different types of sol–gel-derived AR coatings have been summarized and comparison to the commercial AR coating produced by traditional technologies have been discussed. The sol–gel AR coating has been shown to possess comparable or superior performance to those produced by vacuum-based processes.

Notes:

Described how to use sol-gel technology to derive AR coating
Compared sol-gel derived AR coating to other commercial coating
Sol-gel derived AR coating fabrication methods, include dip coating, spin coating and meniscus coating.
Described coating on different substrates, like glass or plastic.

Potential contribution to project: Focused on low-cost AR coating may could apply on solar cells in airport to prevent glare.

2.Raut, H. K., Ganesh, V. A., Nair, A. S. & Ramakrishna, S. Anti-reflective coatings: A critical, in-depth review. Energy & Environmental Science 4, 3779 (2011).

Anti-reflective coatings (ARCs) have evolved into highly effective reflectance and glare reducing components for various optical and opto-electrical equipments. Extensive research in optical and biological reflectance minimization as well as the emergence of nanotechnology over the years has contributed to the enhancement of ARCs in a major way. In this study the prime objective is to give a comprehensive idea of the ARCs right from their inception, as they were originally conceptualized by the pioneers and lay down the basic concepts and strategies adopted to minimize reflectance. The different types of ARCs are also described in greater detail and the state-of-the-art fabrication techniques have been fully illustrated. The inspiration that ARCs derive from nature (‘biomimetics’) has been an area of major research and is discussed at length. The various materials that have been reportedly used in fabricating the ARCs have also been brought into sharp focus. An account of application of ARCs on solar cells and modules, contemporary research and associated challenges are presented in the end to facilitate a universal understanding of the ARCs and encourage future research.

Notes:

Described how the AR coating works.
State-of-the-art fabrication of AR coating.

Potential contribution to project: develop a suitable AR coating which could apply on solar cells in airport to prevent glare.

3.Park, S. H. et al. Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nat Photon 3, 297–302 (2009).

We report the fabrication and measurement of solar cells with 6% power conversion efficiency using the alternating co-polymer, poly[N-9-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole) (PCDTBT) in bulk heterojunction composites with the fullerene derivative [6,6]-phenyl C70-butyric acid methyl ester (PC70BM). The PCDTBT/PC70BM solar cells exhibit the best performance of any bulk heterojunction system studied to date, with JSC = 10.6 mA cm-2, VOC = 0.88 V, FF = 0.66 and e = 6.1% under air mass 1.5 global (AM 1.5 G) irradiation of 100 mW cm-2. The internal quantum efficiency is close to 100%, implying that essentially every absorbed photon results in a separated pair of charge carriers and that all photogenerated carriers are collected at the electrodes.

Notes:

A successful demonstration that using certain co-polymer could achieve close to 100% internal quantum efficiency in heterojunction solar cells

Potential contribution to project: a better design to solar cell which could apply to the airport.

4.Liu, K. & Makaran, J. Design of a solar powered battery charger. in 2009 IEEE Electrical Power Energy Conference (EPEC) 1–5 (2009). doi:10.1109/EPEC.2009.5420817

A solar powered battery charger is presented, where a photovoltaic (PV) panel is used to convert solar power into electricity and a DC/DC converter is used to control the output power of the PV panel and the charging current for the battery. In the software, an optimal control algorithm is applied to obtain the maximum available power from the sunshine. The simulation and experimental results are presented and compared. The applications of this technique can be light electrical vehicles such as golf carts, scooters, airport utility vehicles, as well as other renewable power stations where batteries are used for energy storage.

Notes

Presented how the energy stored from solar cell could be transferred to battery.
Shown that how the control and conversion works.

Potential contribution to project: give idea that how to convert energy from solar cell to battery, and provide energy to utilities in airport.

5.Raturi, A., Singh, A. & Prasad, R. D. Grid-connected PV systems in the Pacific Island Countries. Renewable and Sustainable Energy Reviews 58, 419–428 (2016).

Grid connected solar photovoltaic (GCPV) systems are fast becoming a regular feature of electricity power networks in urban and peri-urban areas within most Pacific Island Countries. A number of systems have been installed with many in the pipeline. This relatively new technology, utilizing the intermittent solar energy resource has presented new challenges to small island utilities that were hitherto almost completely dependent on diesel generators and hydropower. The present paper describes the current status of GCPV systems in the Pacific region and reviews some of the issues that arise in the deployment of this technology. It also reports a case study involving a 45 kWp GCPV system located at the University of the South Pacific (USP) marine campus in Fiji. One of the first two GCPV systems established in Fiji, this system has an annual production of ~54,000 kW h and supplies about 10% of the electricity requirements of the campus. The actual system performance agreed well with the simulated results. This system also reduces USP׳s annual carbon footprint by more than 27,000 kg CO2e.

Notes:

Described how the energy stored by solar cell converted to grid power system

Potential contribution to project: overcome the technical issue and give the idea how to power the airport by solar panels

6.Kim, I.-S., Kim, M.-B. & Youn, M.-J. New Maximum Power Point Tracker Using Sliding-Mode Observer for Estimation of Solar Array Current in the Grid-Connected Photovoltaic System. IEEE Transactions on Industrial Electronics 53, 1027–1035 (2006).

A new maximum power point tracker (MPPT) for a grid-connected photovoltaic system without solar array current sensor is proposed. The solar array current information is obtained from the sliding-mode observer and fed into the MPPT to generate the reference voltage. The parameter values such as capacitances can be changed up to 50% from their nominal values, and the linear observer cannot estimate the correct state values under the parameter variations and noisy environments. The structure of a sliding-mode observer is simple, but it shows the robust tracking property against modeling uncertainties and parameter variations. In this paper, the sliding-mode observer for the solar array current has been proposed to compensate for the parameter variations. The mathematical modeling and the experimental results verify the validity of the proposed method.

Notes:

Using sliding-mode observer to obtain the current information from solar system
Replacing the more expensive sensors by the proposed observers

Potential contribution to project: Lower the budget, makes the whole project easier to be achieve

7.Borowy, B. S. & Salameh, Z. M. Optimum photovoltaic array size for a hybrid wind/PV system. IEEE Transactions on Energy Conversion 9, 482–488 (1994).

A methodology for calculation of the optimum size of a PV array for a stand-alone hybrid wind/PV power system is developed. Long term data of wind speed and irradiance recorded for every hour of the day for 30 years were used. These data were used to calculate the probability density functions of the wind speed and the irradiance for each hour of a typical day in a month. The wind speed and irradiance probability density functions and manufacturer's specification on a wind turbine and a PV module were used to calculate the average power generated by the wind turbine and the PV module for each hour of a typical day in a month. The least square method is used to determine the best fit of the PV array and wind turbine to a given load. On the basis of the energy concept an algorithm was developed to find the optimum size of the PV array in the system.

Notes:

Proposed a methodology which is how to calculate the optimized size of wind/PV hybrid system

Potential contribution to project: Use similar methodology to find the size we needed in airport project

8.Sharma, S. K., Samuel, K. B., Srinivasamurthy, N. & Agrawal, B. L. Overcoming the problems in determination of solar cell series resistance and diode factor. J. Phys. D: Appl. Phys. 23, 1256 (1990).

A theory has been developed to determine solar cell design parameters in the conventional solar cell equation using measured cell I sc , I mp , V mp and V oc . The theory overcomes the problem of series resistance becoming negative. It is shown that the diode factor a indeed depends upon cell temperature. The theoretical predictions are in good agreement with experimental observations.

Notes:

Proposed the theory to determine the resistance and diode factor in solar cell series
Demonstrated by experimental data

Potential contribution to project: Determine the properties of the system we designed for airport

9.Green, M. A., Emery, K., Hishikawa, Y., Warta, W. & Dunlop, E. D. Solar cell efficiency tables (Version 45). Prog. Photovolt: Res. Appl. 23, 1–9 (2015).

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2014 are reviewed. Copyright © 2014 John Wiley & Sons, Ltd.

Notes:

Collected data for solar cell efficiency table

Potential contribution to project: Have a reference to suitable solar cell we choose for airport

10.Nann, S. & Riordan, C. Solar spectral irradiance under overcast skies [solar cell performance effects]. in , Conference Record of the Twenty First IEEE Photovoltaic Specialists Conference, 1990 1110–1115 vol.2 (1990). doi:10.1109/PVSC.1990.111789

The authors examine a particular aspect of cloudy-sky conditions that affects PV (photovoltaic) device performance, i.e. the solar spectral distribution under an overcast sky with respect to the spectral response of PV devices. The approach is to analyze several thousand measured spectral irradiance data that illustrate spectral shifts under cloud cover. The questions raised are how the transmission of clouds deviates from an assumed neutral density filter and whether the standard reference spectrum applied by the PV community to design and performance prediction is applicable for cloudy climates. Comparing the measurements with clear-sky simulations, the authors established a correlation between cloud thickness and alterations in the relative spectral transmission. Because of the approach used, these observed effects are true only for the statistical mean of a sufficiently large number of measurements.

Notes:

Provided how the solar cell will be effected by the relatively cloudy sky
Comparison the data under cloudy sky with the clear sky

Potential contribution to project: Give a better felling to the solar panel selection based on the location of the airport

11.Ro, K. & Rahman, S. Two-loop controller for maximizing performance of a grid-connected photovoltaic-fuel cell hybrid power plant. IEEE Transactions on Energy Conversion 13, 276–281 (1998).

Maximizing performance of a grid-connected photovoltaic (PV)-fuel cell hybrid system by use of a two-loop controller is discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC achieves the system's requirements for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. Results of time-domain simulations prove not only the effectiveness of the proposed computer models of the two-loop controller but also its applicability for use in stability analysis of the hybrid power plant.

Notes:

Two-loop controller is proposed, one loop for controlling solar panel side and extracting maximum available solar power, other is for fuel.

Potential contribution to project: We could use the similar idea to have a tracker for solar cell system in airport

12.Broderick, L. Z., Albert, B. R., Pearson, B. S., Kimerling, L. C. & Michel, J. Design for energy: Modeling of spectrum, temperature and device structure dependences of solar cell energy production. Solar Energy Materials and Solar Cells 136, 48–63 (2015).

Solar photovoltaic energy generation can benefit from high efficiency, environment specific design. In this work, a model is developed to assess the electrical energy produced by concentrator solar cells during specific time frames with varying realistic weather conditions and cell temperatures. The model is applied to a comparative study of the spectral and temperature sensitivities of efficiency and energy production for tandem junction and spectrally split parallel junction solar cell structures. Direct normal solar spectra in a representative sunny site, Tucson, Arizona are calculated using the SPCTRAL2 model at 15-minute intervals throughout a year with real-time meteorological data input. The corresponding efficiencies of the two devices under 500 times concentration at cell temperatures deduced from thermal modeling with real-time ambient temperatures are computed. Both device structures comprise the same materials, InGaP, GaAs and Ge, and each device design is optimized to standard operating conditions (AM1.5D spectrum and a cell temperature of 25 °C). The two devices are compared for their efficiencies and power/energy output at (i) 15 min intervals (instantaneous values), (ii) daily and (iii) yearly time spans. Despite efficiency loss due to series resistance that is three times as high as that for the tandem junction, the parallel junction has a higher daily averaged efficiency every single day, and its yearly averaged efficiency is 1.2% absolute higher, meaning an additional annual energy production of 19.2 MWh per m2 cell area. Besides energy forecast and assessment, the developed method can be used to obtain optimum solar cell designs for maximum energy production under varying geographical and climatic conditions.

Potential contribution to project: We could figure out how the weather will affect efficiency of solar cell based on the location of airport.

13.Spitzer, M. B. Development of a large area space solar cell assembly. (1982). at <http://ntrs.nasa.gov/search.jsp?R=19820022830>

The development of a large area high efficiency solar cell assembly is described. The assembly consists of an ion implanted silicon solar cell and glass cover. The important attributes of fabrication are the use of a back surface field which is compatible with a back surface reflector, and integration of coverglass application and cell fabrications. Cell development experiments concerned optimization of ion implantation processing of 2 ohm-cm boron-doped silicon. Process parameters were selected based on these experiments and cells with area of 34.3 sq cm wre fabricated. The average AMO efficiency of the twenty-five best cells was 13.9% and the best bell had an efficiency of 14.4%. An important innovation in cell encapsulation was also developed. In this technique, the coverglass is applied before the cell is sawed to final size. The coverglass and cell are then sawed as a unit. In this way, the cost of the coverglass is reduced, since the tolerance on glass size is relaxed, and costly coverglass/cell alignment procedures are eliminated. Adhesive investigated were EVA, FEP-Teflon sheet and DC 93-500. Details of processing and results are reported.

Potential contribution to project: Get some idea from large area space solar cell assembly and apply them to the airport.

14.Taguchi, M. et al. 24.7 #x0025; Record Efficiency HIT Solar Cell on Thin Silicon Wafer. IEEE Journal of Photovoltaics 4, 96–99 (2014).

A new record conversion efficiency of 24.7% was attained at the research level by using a heterojunction with intrinsic thin-layer structure of practical size (101.8 cm2, total area) at a 98-μm thickness. This is a world height record for any crystalline silicon-based solar cell of practical size (100 cm2 and above). Since we announced our former record of 23.7%, we have continued to reduce recombination losses at the hetero interface between a-Si and c-Si along with cutting down resistive losses by improving the silver paste with lower resistivity and optimization of the thicknesses in a-Si layers. Using a new technology that enables the formation of a-Si layer of even higher quality on the c-Si substrate, while limiting damage to the surface of the substrate, the Voc has been improved from 0.745 to 0.750 V. We also succeeded in improving the fill factor from 0.809 to 0.832.

Notes:

The designed HIT solar cell on thin silicon wafer achieved new record of conversion efficiency.

Potential contribution to project: Maybe could use this type of solar cell into airport project.

15.Alajmi, B. N., Ahmed, K. H., Finney, S. J. & Williams, B. W. A Maximum Power Point Tracking Technique for Partially Shaded Photovoltaic Systems in Microgrids. IEEE Transactions on Industrial Electronics 60, 1596–1606 (2013).

A modified fuzzy-logic controller for maximum power point (MPP) tracking is proposed to increase photovoltaic (PV) system performance during partially shaded conditions. Instead of perturbing and observing the PV system MPP, the controller scans and stores the maximum power during the perturbing and observing procedures. The controller offers accurate convergence to the global maximum operating point under different partial shadowing conditions. A mathematical model of the PV system under partial shadowing conditions is derived. To validate the proposed modified fuzzy-logic-based controller, simulation and experimentation results are provided.

Notes:

The paper proposed a controller for MPP tracking to increase performance when PV system is partially shaded.

Potential contribution to project: We could based on the airport location, determine the possibility that solar panel in shaded condition

16.Lohner, A., Meyer, T. & Nagel, A. A new panel-integratable inverter concept for grid-connected photovoltaic systems. in , Proceedings of the IEEE International Symposium on Industrial Electronics, 1996. ISIE ’96 2, 827–831 vol.2 (1996).

This paper describes the problems of conventional inverter concepts for photovoltaic power systems and presents a new, panel-integratable inverter concept as a solution. This concept is advantageous regarding safety (no DC-lines), flexibility (modular concept), converted energy per year (no mismatch losses due to individual MPP tracking of each panel) and costs (no reinforced isolation due to AC distribution). Furthermore a 250 W DC to AC inverter is developed, which consists of a series resonant DC-DC power converter and a line inverter. The inverter has a high efficiency and consumes little power itself. Meeting international standards, sinusoidal line current with low distortion is achieved. The inverter has a built-in controller to operate the panel in the maximum power point. Above this, the concept allows the flexible use with many different combinations of solar panels. To realize an inexpensive system, the controller is built up using standard low-cost components

Notes:

Overcome the problems of conventional inverter by presenting a panel-integratable inverter.

Potential contribution to project: For grid-connected PV system, we could apply the new model into the airport project.

17.Kadri, R., Gaubert, J.-P. & Champenois, G. An Improved Maximum Power Point Tracking for Photovoltaic Grid-Connected Inverter Based on Voltage-Oriented Control. IEEE Transactions on Industrial Electronics 58, 66–75 (2011).

In this paper, an improved maximum power point (MPP) tracking (MPPT) with better performance based on voltage-oriented control (VOC) is proposed to solve a fast-changing irradiation problem. In VOC, a cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous orthogonal d,q frame using a decoupled feedback control. The reference current of proportional-integral (PI) d-axis controller is extracted from the dc-side voltage regulator by applying the energy-balancing control. Furthermore, in order to achieve a unity power factor, the q-axis reference is set to zero. The MPPT controller is applied to the reference of the outer loop control dc voltage photovoltaic (PV). Without PV array power measurement, the proposed MPPT identifies the correct direction of the MPP by processing the d-axis current reflecting the power grid side and the signal error of the PI outer loop designed to only represent the change in power due to the changing atmospheric conditions. The robust tracking capability under rapidly increasing and decreasing irradiance is verified experimentally with a PV array emulator. Simulations and experimental results demonstrate that the proposed method provides effective, fast, and perfect tracking.

18.Das, D., Esmaili, R., Xu, L. & Nichols, D. An optimal design of a grid connected hybrid wind/photovoltaic/fuel cell system for distributed energy production. in 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005 6 pp.– (2005). doi:10.1109/IECON.2005.1569298

This paper proposes a hybrid energy system consisting of wind, photovoltaic and fuel cell designed to supply continuous power to the load. A simple and economic control with DC-DC converter is used for maximum power point tracking and hence maximum power extraction from the wind turbine and photovoltaic array. Due to the intermittent nature of both the wind and photovoltaic energy sources, a fuel cell is added to the system for the purpose of ensuring continuous power flow. The fuel cell is thus controlled to provide the deficit power when the combined wind and photovoltaic sources cannot meet the net power demand. In worst environmental conditions, when there is no output power from the wind or photovoltaic sources, the fuel cell will operate at its rated power of 10 kW. Hence this system under any operating condition will ensure a minimum power flow of 10 kW to the load. This hybrid system allows maximum utilization of freely available renewable energy sources like wind and photovoltaic and demand-based utilization of hydrogen-based fuel cell. The proposed system is attractive owing to its simplicity, ease of control and low cost. Also it can be easily adjusted to accommodate different and any number of energy sources. A complete description of this system is presented along with its simulation results which ascertain its feasibility.

19.Ma, W. W., Rasul, M. G., Liu, G., Li, M. & Tan, X. H. Climate change impacts on techno-economic performance of roof PV solar system in Australia. Renewable Energy 88, 430–438 (2016).

The techno-economic performance of roof PV solar system depends on local climatic conditions. The energy conversion behavior of PV system will change as a result of the new solar irradiation data caused by climate change. This study aims to investigate the quantified impacts of climate change on the future performance of PV roof system with a general electricity load and legal maximum size of solar array. In this study, the morphing method is employed to predict the future hourly mean global solar irradiation data for the year 2030, 2050 and 2070. By using the current and future solar irradiation data as the inputs, a simulation model of PV system is built to simulate the long-term implementation of the systems in the capital cities of Australian states. The solutions of the model given by computer programme, includes the system's electricity generation, greenhouse gas emissions, and cost of energy are analysed, and all the solutions are compared between different climatic conditions of all the capital cities. It is shown that there is a nearly linear correlation between the increase of average external air temperature and the increase of solar irradiation from 2030 to 2070. For the PV system in the majority of cities, a 10–20% increase of economic costs between the 2030 and 2050 climate scenario would be required. It is also found that the Hoba system has the best techno-economic performance with the lowest economic costs and higher renewable fraction, at both current climate and future climate.

20.Meier, D. L. & Schroder, D. K. Contact resistance: Its measurement and relative importance to power loss in a solar cell. IEEE Transactions on Electron Devices 31, 647–653 (1984).

The concept of contact resistivity is discussed briefly and a technique for its measurement is presented. This technique allows for resistive contact material and for the possibility that the semiconductor sheet resistance beneath the contact differs from the semiconductor sheet resistance beside the contact. The test pattern is unique in that the effects of contact resistance are accumulated over the pattern, nearly unencumbered by voltage and current probes which might otherwise influence the current flow. Measurements of contact resistivities for typical solar cell metallizations using this technique are reported to be in the mid 10-6Ω-cm2range. The relative importance of contact resistance compared to other sources of power loss in a solar cell is determined for a typical contact system. Expressions derived in order to make this comparison are useful for evaluating and optimizing a solar cell contact system. Values of series resistance calculated using these expressions are compared with measured values.

21.Barbosa, P. G., Rolim, L. G. B., Watanabe, E. H. & Hanitsch, R. Control strategy for grid-connected DC-AC converters with load power factor correction. Generation, Transmission and Distribution, IEE Proceedings- 145, 487–491 (1998).

The paper presents the modelling, analysis and design of a pulse width modulation voltage source inverter (PWM-VSI) to be connected between a DC source, which is supplied from a photovoltaic (PV) array and the AC grid. The control algorithm of the PWM-VSI applies the concepts of the instantaneous p-q (real-imaginary) power theory. The objective is to show that, with adequate control, the power converter can transfer the DC energy from a PV array and improve the power factor (and the power quality) of the electrical system. Some design considerations are also discussed. A digital simulation and measurements on a small prototype model verified the feasibility of the proposed control method.

22.Kandatsu, Y. DC/AC inverter controller for solar cell, including maximum power point tracking function. (1993). at <http://www.google.com/patents/US5268832>

A DC/AC inverter controlling system controls a DC/AC inverter so as to continuously output maximum AC power thereof, taking account of solar energy generated from a solar cell. The DC/AC inverter controlling system comprises: a DC/AC inverter unit for inverting DC (direct current) power derived from the solar cell power source into AC (alternating current) power to be supplied to an AC power line; a power variation judging unit for judging whether or not a variation measured during a predetermined time period and occurring in the AC power outputted from the DC/AC inverter unit, exceeds a predetermined value, thereby producing a power variation judging signal; and a power controlling unit for controlling the DC/AC inverter unit so as to reduce the power variation to substantially zero in response to the power variation judging signal, while the power variation does not exceed the predetermined value. As a result, the AC power outputted from the DC/AC inverter unit becomes a maximum value thereof.

23.Ito, Y., Zhongqing, Y. & Akagi, H. DC microgrid based distribution power generation system. in Power Electronics and Motion Control Conference, 2004. IPEMC 2004. The 4th International 3, 1740–1745 Vol.3 (2004).

This paper describes an autonomous-control method for a DC microgrid system having distribution power generators. This system consists of following five generation and control units; a solar-cell generation unit, a wind-turbine generation unit, a battery energy-storage unit, a flywheel power-leveling unit, and an AC grid-connected power control unit. The proposed control method intended for suppression of circulating current detects only the DC grid voltage. Each unit could be controlled autonomously without communicating each other. This method brings high reliability, high-flexibility and maintenance-free operation to the system. Experimental results from a 10 kW-prototype system verify the validity and effectiveness of the proposed control method.

24.Chuah, D. G. S. in Solar Energy Applications in the Tropics (ed. M.S.I.P, B. B. P. L. P. D. B. A. S. Dip T. C. P. Syd , F. R. A. I. A. , M. R. I. B. A. , M. S. I. A.) 165–185 (Springer Netherlands, 1983). at <http://link.springer.com/chapter/10.1007/978-94-009-7936-9_13>

A photovoltaic system converts sunlight into electricity. The elements of such a system are briefly described. Performance characteristics of these systems under local atmospheric conditions are presented. Urban applications of photovoltaic solar cells and cost goals are indicated.

25.Hassaine, L., Olias, E., Quintero, J. & Haddadi, M. Digital power factor control and reactive power regulation for grid-connected photovoltaic inverter. Renewable Energy 34, 315–321 (2009).

The overall efficiency of photovoltaic (PV) systems connected to the grid depends on the efficiency of direct current (DC) of the solar modules to alternate current (AC) inverter conversion. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, high power factor and low total harmonic distortion of the currents injected into the grid. An approach to power factor control and reactive power regulation for PV systems connected to the grid using field programmable gate array (FPGA) is proposed. According to the grid demands; both the injected active and reactive powers are controlled.

In this paper, a new digital control strategy for a single-phase inverter is carried out. This control strategy is based on the phase shift between the inverter output voltage and the grid voltage, and the digital sinusoidal pulse width modulation (DSPWM) patterns, in order to control the power factor for a wide range of the inverter output current and consequently the control and the regulation of the reactive power will be achieved. The advantage of the proposed control strategy is its implementation around simple digital circuits.

In this work, a simulation study of this strategy has been realized using Matlab/Simulink and PSIM. In order to validate its performance, this control has been implemented in a FPGA. Experimental tests have been carried out demonstrating the viability of this control in order to control the power factor and the injected power into the grid.

26.Ackermann, T., Andersson, G. & Söder, L. Distributed generation: a definition1. Electric Power Systems Research 57, 195–204 (2001).

Distributed generation (DG) is expected to become more important in the future generation system. The current literature, however, does not use a consistent definition of DG. This paper discusses the relevant issues and aims at providing a general definition for distributed power generation in competitive electricity markets. In general, DG can be defined as electric power generation within distribution networks or on the customer side of the network. In addition, the terms distributed resources, distributed capacity and distributed utility are discussed. Network and connection issues of distributed generation are presented, too.