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4 pages, 190 KiB

Open AccessEditorial

Photovoltaic Power

by Jesus C. Hernández and Carlos R. Baier

Sustainability 2021, 13(4), 2123; https://doi.org/10.3390/su13042123 - 17 Feb 2021

Viewed by 1831

Abstract

Renewable energies increase their participation in the electricity markets year by year [...] Full article

(This article belongs to the Special Issue Photovoltaic Power)

Research

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16 pages, 12581 KiB

Open AccessArticle

The Analysis Performance of a Grid-Connected 8.2 kWp Photovoltaic System in the Patagonia Region

by Humberto Vidal, Marco Rivera, Patrick Wheeler and Nicolás Vicencio

Sustainability 2020, 12(21), 9227; https://doi.org/10.3390/su12219227 - 6 Nov 2020

Cited by 20 | Viewed by 3695

Abstract

Solar PV structures for locations at high latitudes in the Northern and Southern Hemispheres are increasingly in the spotlight. The work reported in this paper analyses the behaviour of a grid-connected 8.2 kWp photovoltaic system to either feed on-site electrical loads (a public [...] Read more.

Solar PV structures for locations at high latitudes in the Northern and Southern Hemispheres are increasingly in the spotlight. The work reported in this paper analyses the behaviour of a grid-connected 8.2 kWp photovoltaic system to either feed on-site electrical loads (a public institution, Corporación Nacional Forestal (CONAF), located 5.5 km south of Punta Arenas, lat. 53° S) or to feed into the electrical grid when the photovoltaic system generation is higher than the on-site load demand. The system simulation uses the PVSyst software with Meteonorm derived and measured climate information sets (ambient temperature, solar irradiation and wind speed). The agreement between the simulated and measured energy yield is analysed including the evaluation of the optimal generation energy of the PV array, the energy that is fed into the network, the performance ratio, and the normalised energy generation per installed kWp. The PV system considered in this work generates 7005.3 kWh/year, out of which only 6778 kWh/year are injected into the grid. The measured annual performance ratio is around 89%. The normalised productions of the inverter output or final system yield, i.e., useful energy, is 3.6 kWh/kWp/day. The measured annual average capacity factor obtained from this study is 15.1%. These performance parameters will encourage greater use of photovoltaic technology in the Chilean Patagonia region. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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18 pages, 1669 KiB

Open AccessArticle

Seasonality Effect Analysis and Recognition of Charging Behaviors of Electric Vehicles: A Data Science Approach

by Juan A. Dominguez-Jimenez, Javier E. Campillo, Oscar Danilo Montoya, Enrique Delahoz and Jesus C. Hernández

Sustainability 2020, 12(18), 7769; https://doi.org/10.3390/su12187769 - 20 Sep 2020

Cited by 16 | Viewed by 3511

Abstract

Electric vehicles (EVs) presence in the power grid can bring about pivotal concerns regarding their energy requirements. EVs charging behaviors can be affected by several aspects including socio-economics, psychological, seasonal among others. This work proposes a case study to analyze seasonal effects on [...] Read more.

Electric vehicles (EVs) presence in the power grid can bring about pivotal concerns regarding their energy requirements. EVs charging behaviors can be affected by several aspects including socio-economics, psychological, seasonal among others. This work proposes a case study to analyze seasonal effects on charging patterns, using a public real-world based dataset that contains information from the aggregated load of the total charging stations of Boulder, Colorado. Our approach targets to forecast and recognize EVs demand considering seasonal factors. Principal component analysis (PCA) was used to provide a visual representation of the variables and their contribution and the correlation among them. Then, twelve classification models were trained and tested to discriminate among seasons the charging load of electric vehicles. Later, a benchmark stage is presented for regression as well as for classification results. For regression models, examined through Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE), the random Forest provides better prediction than quasi-Poisson model widely. However, it was observed that for large variations in electric vehicles’ charging load, quasi-Poisson fits better than random forest. For the classification models, evaluated through Accuracy and the Area under the Curve, the Lasso and elastic-net regularized generalized linear (GLMNET) model provided the best global performance with accuracy up to 100% when evaluated on the test dataset. The results of this work offer great insights for enhancing demand response strategies that involve PEV charging regarding charging habits across seasons. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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29 pages, 6623 KiB

Open AccessArticle

A Techno-Economic Optimization and Performance Assessment of a 10 kW_P Photovoltaic Grid-Connected System

by Abraham Alem Kebede, Maitane Berecibar, Thierry Coosemans, Maarten Messagie, Towfik Jemal, Henok Ayele Behabtu and Joeri Van Mierlo

Sustainability 2020, 12(18), 7648; https://doi.org/10.3390/su12187648 - 16 Sep 2020

Cited by 15 | Viewed by 3586

Abstract

The system under consideration in this paper consists of a photovoltaic (PV) array, described as having a 10 kWp capacity, battery storage, and connection to the grid via a university grid network. It is stated that the system meets a local load of [...] Read more.

The system under consideration in this paper consists of a photovoltaic (PV) array, described as having a 10 kWp capacity, battery storage, and connection to the grid via a university grid network. It is stated that the system meets a local load of 4–5 kVA. The system is in Ethiopia, and the authors give details of the location and solar resource to provide information to assess its performance. However, the performance assessment will be specific to the details of the installation and the operational rules, including the variable nature of the load profile, charging and discharging the battery storage, and importing from and exporting to the university grid. The nearby load is mostly supplied from PV and grid sources, and hence the battery installed is found to be idle, showing that the PV together with storage battery system was not utilized in an efficient and optimized way. This in turn resulted in inefficient utilization of sources, increased dependency of the load on the grid, and hence unnecessary operational expenses. Therefore, to alleviate these problems, this paper proposes a means for techno-economic optimization and performance analysis of an existing photovoltaic grid-connected system (PVGCS) by using collected data from a plant data logger for one year (2018) with a model-based Matlab/Simulink simulation and a hybrid optimization model for electric renewables (HOMER) software. According to the simulation result, the PVGCS with 5 kWp PV array optimized system was recommended, which provides a net present cost (NPC) of 5770 (€/kWh), and a cost of energy (COE) of 0.087 (€/kWh) compared to an existing 10 kWp PV system, which results in a NPC value of 6047 (€/kWh) and COE of 0.098 (€/kWh). Therefore, the resulting 5 kWp PV system connected with a storage battery was found to be more efficient and techno-economically viable as compared to the existing 10 kWp PVGCS plant. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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33 pages, 3174 KiB

Open AccessArticle

Impacts Generated by a Large-Scale Solar Photovoltaic Power Plant Can Lead to Conflicts between Sustainable Development Goals: A Review of Key Lessons Learned in Madagascar

by Carole Brunet, Oumarou Savadogo, Pierre Baptiste, Michel A Bouchard, Jean Chrysostome Rakotoary, Andry Ravoninjatovo, Céline Cholez, Corinne Gendron and Nicolas Merveille

Sustainability 2020, 12(18), 7471; https://doi.org/10.3390/su12187471 - 10 Sep 2020

Cited by 27 | Viewed by 6469

Abstract

In a context of energy transition towards renewable energies, this case study situated in Madagascar allows us to verify the extent to which an on-grid photovoltaic solar power plant represents a vector for sustainable development. The article proposes a model for assessing sustainability [...] Read more.

In a context of energy transition towards renewable energies, this case study situated in Madagascar allows us to verify the extent to which an on-grid photovoltaic solar power plant represents a vector for sustainable development. The article proposes a model for assessing sustainability from a qualitative multi-criteria perspective. This analysis fits into the theoretical question of the science of sustainability by challenging the theory of endogenous development. The innovation of this research is based on the use of a qualitative approach to a technological issue filling a literature gap in the major issue of the effective sustainability of renewable energy (particularly in the context of an island state). The study emphasizes that the plant can only represent a vector for sustainable development with the collaboration of the concerned parties, which implies considering the electrification needs at the local level. The article confirms that the impacts generated by the power plant can lead to conflicts between different sustainable development goals. Theoretically, the study emphasizes that the evaluation of the sustainability of solar power plants should follow a process that: (i) uses a preferably qualitative methodology likely to understand the local conditions of the communities in which they are established; (ii) identifies dissociated indicators while taking into account the context; and (iii) analyzes the possible negative interactions between the impact areas by highlighting the key areas linked to land management and the well-being of women within a poverty reduction approach. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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16 pages, 6227 KiB

Open AccessArticle

Active Power Management of Virtual Power Plant under Penetration of Central Receiver Solar Thermal-Wind Using Butterfly Optimization Technique

by Partha Pratim Dey, Dulal Chandra Das, Abdul Latif, S. M. Suhail Hussain and Taha Selim Ustun

Sustainability 2020, 12(17), 6979; https://doi.org/10.3390/su12176979 - 27 Aug 2020

Cited by 49 | Viewed by 3603

Abstract

Striving for the suppression of greenhouse emissions, the modern power network is facing fundamental changes with the utilization of renewable energies (REs) for the future carbon-free society. The utilization of intermittent renewable-green power needs a better power management system and virtual power plant [...] Read more.

Striving for the suppression of greenhouse emissions, the modern power network is facing fundamental changes with the utilization of renewable energies (REs) for the future carbon-free society. The utilization of intermittent renewable-green power needs a better power management system and virtual power plant (VPP) can be a vital candidate that meets this demand. This study investigates a coordinated control grid integrated virtual power plant (VPP) in the presence of Central Receiver Solar Thermal System (CRSTS), Wind Turbine Generator (WTG), and Electric Vehicle (EV). To this end, CRSTS employed with thermal storage acts as a dispatchable renewable generating unit and coordinated control of the system units are achieved using the available control strategy on interconnected microgrids in the modified form, employing communication time delay. The proposed control strategy employs the proportional-integral (PI) and PI-derivative (PID) controller. Coordinated power control with real-time communication delay in grid integrated VPP in presence of CRSTS, WTG, and EV is a novel approach. Genetic algorithm (GA), Particle Swarm Optimization (PSO), Slap Swarm Algorithm (SSA), and recent Butterfly Optimization Algorithm (BOA) are used for tuning the necessary control parameters. The results establish the superiority of the BOA over SSA and PSO in suppressing system frequency deviations and tie line power deviation. The analysis of the dynamic response reveals that the consideration of the communication delay in the system expressively impedes the stable operation of the power system. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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22 pages, 1011 KiB

Open AccessArticle

Improved Predictive Control for an Asymmetric Multilevel Converter for Photovoltaic Energy

by Patricio Gaisse, Javier Muñoz, Ariel Villalón and Rodrigo Aliaga

Sustainability 2020, 12(15), 6204; https://doi.org/10.3390/su12156204 - 1 Aug 2020

Cited by 8 | Viewed by 2793

Abstract

This article proposes a 27-level asymmetric cascade H-bridge multilevel topology for photovoltaic applications, which considers a predictive control strategy that allows minimization of the commutations of the converter. This proposal ensures a highly sinusoidal and stable photovoltaic injection when there are solar irradiance [...] Read more.

This article proposes a 27-level asymmetric cascade H-bridge multilevel topology for photovoltaic applications, which considers a predictive control strategy that allows minimization of the commutations of the converter. This proposal ensures a highly sinusoidal and stable photovoltaic injection when there are solar irradiance disturbances, generating a low distortion in the current waveform and low switching losses. To validate the performance of the control and the proposed topology, the dynamic model of the alternating current (AC) and direct current (DC) side system is first obtained, which is checked by computational simulations. Subsequently, the implementation of a master–slave control is carried out, focused on the control of DC voltage and AC current. The proposal is simulated, and the total harmonic distortion (THD) is obtained in the voltage and current waveforms. Undesired commutations, typical of the predictive control, are eliminated in the AC voltage waveform, and a proper DC voltage tracking is achieved for the high-power cell. In order to demonstrate the performance of the proposed control strategy, a low-power proof-of-concept prototype is implemented, in which the energy is injected to the grid, under the event of solar irradiance disturbances (with DC control).Then, the undesired switching in the main cell is eliminated, generating THDs in the voltage and current signal of 7.76% and 2.65%, respectively. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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15 pages, 2994 KiB

Open AccessArticle

Researches of the Impact of the Nominal Power Ratio and Environmental Conditions on the Efficiency of the Photovoltaic System: A Case Study for Poland in Central Europe

by Mariusz T. Sarniak

Sustainability 2020, 12(15), 6162; https://doi.org/10.3390/su12156162 - 30 Jul 2020

Cited by 13 | Viewed by 3983

Abstract

The paper analyzes a case study of the impact of changing the nominal power ratio (NPR) on the efficiency of a PV (photovoltaic) system located in Poland. In the first stage of the research, the acceptable range of variability for NPR [...] Read more.

The paper analyzes a case study of the impact of changing the nominal power ratio (NPR) on the efficiency of a PV (photovoltaic) system located in Poland. In the first stage of the research, the acceptable range of variability for NPR was determined based on simulation calculations, taking into account the parameters of PV modules, inverter, and climatic conditions. The second stage was verification tests for two acceptable extreme cases, carried out based on the analysis of detailed data from the monitoring of PV installations. The results of the verification tests for the two considered periods of operation of the PV system with the change of the NPR coefficient from 82% to 98% resulted in an increase in the annual energy yield by 446.2 kWh. On the other hand, higher relative values of generated energy were obtained only for the months with the lowest insolation in December and in January by 8.2 and 6.04 kWh/kW_p, respectively. Higher oversizing of the PV generator (for NPR = 82%) also resulted in an increase by 6.4% in the frequency of operation of the PV inverter in the largest power range (2250–2500 W) and a decrease by 3.7% in the frequency in the lowest power range (0–250 W) for the whole year. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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15 pages, 3566 KiB

Open AccessArticle

A Novel Fixed-Time-Convergent Sliding Mode Technology Using Improved Quantum Particle Swarm Optimization for Renewable Energy Inverters

by En-Chih Chang

Sustainability 2020, 12(3), 1102; https://doi.org/10.3390/su12031102 - 4 Feb 2020

Viewed by 2216

Abstract

This paper describes a robust feedback technique involving novel fixed-time-convergent sliding mode technology (NFTCSMT) using improved quantum particle swarm optimization (QPSO) to obtain high-performance renewable energy inverters. Customary SMT encounters long time convergence towards the origin and the influence of the dithering. The [...] Read more.

This paper describes a robust feedback technique involving novel fixed-time-convergent sliding mode technology (NFTCSMT) using improved quantum particle swarm optimization (QPSO) to obtain high-performance renewable energy inverters. Customary SMT encounters long time convergence towards the origin and the influence of the dithering. The NFTCSMT can rapidly impel system-following movement to approach the sliding manifold and effectively accelerate the convergence speed to equilibrium states. However, the NFTCSMT cannot easily select the global optimum of the controller parameters subject to large parameter changes and nonlinear interventions, leading to the dither phenomenon/steady-state error still being caused. The dither inflicts decreased control accuracy, high voltage harmonics, major harm in relation to switching components, and great thermal losses in power electronic converters. The improved QPSO including the unique property of a random compression/expansion factor is used to find optimal parameters of the NFTCSMT in practical applications, for the reason that it importantly mitigates the dither and amends convergent speed as well as guaranteeing global convergence. The presented alliance amid NFTCSMT and improved QPSO achieves faster response time and singularityless, and also yields high-accuracy tracking and dither attenuation. The robust stability using Lyapunov theorem of the suggested system has provided precise mathematical derivations. Simulations show that the suggested controller offers less than 0.1% voltage THD (total harmonic distortion) which exceeds IEEE standard 519 under heavily distorted rectifier loads, and less than 10% voltage dip which surpasses IEEE standard 1159 during step load transients. Experimental tests of an algorithmically controlled laboratory prototype (1 kW, 110 Vrms/60 Hz) of a renewable energy inverter (REI) based on digital signal processing manifest less than 0.05% voltage THD in the face of great inductor-capacitor alterations, and less than 10% voltage dip in the face of transient load scenarios. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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20 pages, 2037 KiB

Open AccessArticle

Standalone Photovoltaic Direct Pumping in Urban Water Pressurized Networks with Energy Storage in Tanks or Batteries

by Miguel Ángel Pardo, Ricardo Cobacho and Luis Bañón

Sustainability 2020, 12(2), 738; https://doi.org/10.3390/su12020738 - 20 Jan 2020

Cited by 19 | Viewed by 3519

Abstract

Photovoltaic energy production is nowadays one of the hottest topics in the water industry as this green energy source is becoming more and more workable in countries like Spain, with high values of irradiance. In water pressurized systems supplying urban areas, they distribute [...] Read more.

Photovoltaic energy production is nowadays one of the hottest topics in the water industry as this green energy source is becoming more and more workable in countries like Spain, with high values of irradiance. In water pressurized systems supplying urban areas, they distribute energy consumption in pumps throughout the day, and it is not possible to supply electromechanical devices without energy storages such as batteries. Additionally, it is not possible to manage energy demand for water consumption. Researchers and practitioners have proven batteries to be reliable energy storage systems, and are undertaking many efforts to increase their performance, capacity, and useful life. Water pressurized networks incorporate tanks as devices used for accumulating water during low consumption hours while releasing it in peak hours. The compensation tanks work here as a mass and energy source in water pressurized networks supplied with photovoltaic arrays (not electricity grids). This work intends to compare which of these two energy storage systems are better and how to choose between them considering that these two systems involve running the network as a standalone pumping system without being connected to electricity grids. This work also calculates the intermediate results, considering both photovoltaic arrays and electricity grids for supplying electricity to pumping systems. We then analyzed these three cases in a synthetic network (used in earlier research) considering the effect of irradiation and water consumption, as we did not state which should be the most unfavorable month given that higher irradiance coincides with higher water consumption (i.e., during summer). Results show that there is no universal solution as energy consumption depends on the network features and that energy production depends very much on latitude. We based the portfolio of alternatives on investments for purchasing different equipment at present (batteries, pipelines, etc.) based on economic criteria so that the payback period is the indicator used for finding the best alternative, which is the one with the lowest value. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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31 pages, 15681 KiB

Open AccessArticle

The Conducted Emission Attenuation of Micro-Inverters for Nanogrid Systems

by Chaiyan Jettanasen and Atthapol Ngaopitakkul

Sustainability 2020, 12(1), 151; https://doi.org/10.3390/su12010151 - 23 Dec 2019

Cited by 7 | Viewed by 5086

Abstract

Road lighting systems require a significant amount of electric energy. To compensate for the utilized energy, the concept of a nanogrid road lighting system is presented. A solar panel is installed on the top of a lighting pole to generate electric power. In [...] Read more.

Road lighting systems require a significant amount of electric energy. To compensate for the utilized energy, the concept of a nanogrid road lighting system is presented. A solar panel is installed on the top of a lighting pole to generate electric power. In this research, a photovoltaic simulator (PV simulator), which is used to simulate solar behavior such as current, voltage, and power based on temperature and solar irradiance levels, is employed to replace a solar panel. In the nanogrid system, grid-connected and stand-alone micro-inverters are employed to convert the electric power. The inverters comprise switching devices that can generate electromagnetic interference (EMI) when operating, which is harmful to the grid system and the electrical equipment. In general, EMI has been studied and reduced in electrical appliances, which only receive electric power. However, for the nanogrid system, which supplies electricity to the grid system, there is less study on the EMI topic because the usage is still not widespread. In the future, the nanogrid system will be widely used delivering high power directly into the electrical grid system. Therefore, the study and attenuation of EMI in the nanogrid system are very promising. Conducted emission (CE) is one form of EMI that flows through a cable connecting several appliances in the frequency range of 150 kHz to 30 MHz. CE of grid-connected and stand-alone micro-inverters have high levels in the low-frequency range between 150 kHz–5 MHz and then decreases steadily. CE attenuation is important for this inverter in a solar power system. This research studies the effect of CE mitigation on the nanogrid system. The result is compared with the Comité International Spécial des Perturbations Radio (CISPR) 14-1 standard. Finally, the passive EMI filter can reduce CE and meets the CISPR 14-1 standard. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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29 pages, 5953 KiB

Open AccessArticle

Solar Energy Production for a Decarbonization Scenario in Spain

by Rafael Sánchez-Durán, Julio Barbancho and Joaquín Luque

Sustainability 2019, 11(24), 7112; https://doi.org/10.3390/su11247112 - 12 Dec 2019

Cited by 10 | Viewed by 3801

Abstract

Solar energy is one of the most promising sources of energy that could be used to address distributed supply problems. Global warming and decarbonization are significant global concerns, particularly for countries that are not fossil fuel providers. This paper presents a study focused [...] Read more.

Solar energy is one of the most promising sources of energy that could be used to address distributed supply problems. Global warming and decarbonization are significant global concerns, particularly for countries that are not fossil fuel providers. This paper presents a study focused on Spain, a country with a favorable location with respect to horizontal irradiance. The study addresses the future energy demand forecast and how photovoltaic energy could supply an important part of electricity needs. Our approach focuses on two analyses. First, several traditional statistical techniques are discussed in order to obtain a model that best suits Spanish energy demand forecasts for the future years. Different algorithms are compared in order to determine which is the most appropriate for the considered purpose. Second, the evolution of solar photovoltaic technology in Spain is analyzed. The latitude of Spanish cities makes them suitable for utilizing this kind of technology. In this sense, seasonal and monthly trends are identified with high levels of detail, considering a large historical dataset. The increase of the capacity of electricity generation based on this procedure is evaluated. Finally, a discussion about matching electricity demand forecasts and photovoltaic production is offered. Considering the selected model for the photovoltaic power of Spain, from

5

to

42

GW in 2030, the Spanish production is determined as

81

TWh. The obtained results suggest that a possible energy transition is feasible. However, some challenges have to be considered, such us the design of an effective strategy to store excess energy produced when generation is higher than electricity demand. In this way, the electrical distribution system could be fed by the stored energy when solar energy production is deficient. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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21 pages, 2236 KiB

Open AccessArticle

Optimum Tilt Angle and Orientation of Photovoltaic Thermal System for Application in Greater Toronto Area, Canada

by Getu Hailu and Alan S. Fung

Sustainability 2019, 11(22), 6443; https://doi.org/10.3390/su11226443 - 15 Nov 2019

Cited by 57 | Viewed by 13041

Abstract

We present a study conducted to obtain optimum tilt angle and orientation of a solar panel for the collection of maximum solar irradiation. The optimum tilt angle and orientation were determined using isotropic and anisotropic diffuse sky radiation models (isotropic and anisotropic models). [...] Read more.

We present a study conducted to obtain optimum tilt angle and orientation of a solar panel for the collection of maximum solar irradiation. The optimum tilt angle and orientation were determined using isotropic and anisotropic diffuse sky radiation models (isotropic and anisotropic models). The four isotropic models giving varying optimum tilt angles in the range of 37 to 44°. On the other hand, results of the four anisotropic models were more consistent, with optimum tilt angles ranging between 46–47°. Both types of models indicated that the collector tilt should be changed four times a year to receive more solar radiation. The results also indicate that the solar panel should be installed with orientation west or east of due south with a flatter tilt angle. A 15° change in orientation west or east of due south results in less than 1% reduction of the total solar radiation received. For a given optimum tilt angle, the effect of photovoltaic/thermal (PV/T) orientation west or east of due south on the outlet temperature was determined using a one-dimensional steady state heat transfer model. It was found that there is less than 1.5% decrease in outlet temperature for a PV/T panel oriented up to 15° east or west of due south from March to December. This result indicates that existing roofs with orientations angles up to 15° east or west of due south can be retrofitted with a PV/T system without changing the roof shape. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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10 pages, 2801 KiB

Open AccessArticle

Outdoor Performance Test of Bifacial n-Type Silicon Photovoltaic Modules

by Hyeonwook Park, Sungho Chang, Sanghwan Park and Woo Kyoung Kim

Sustainability 2019, 11(22), 6234; https://doi.org/10.3390/su11226234 - 7 Nov 2019

Cited by 26 | Viewed by 4641

Abstract

The outdoor performance of n-type bifacial Si photovoltaic (PV) modules and string systems was evaluated for two different albedo (ground reflection) conditions, i.e., 21% and 79%. Both monofacial and bifacial silicon PV modules were prepared using n-type bifacial Si passivated emitter rear totally [...] Read more.

The outdoor performance of n-type bifacial Si photovoltaic (PV) modules and string systems was evaluated for two different albedo (ground reflection) conditions, i.e., 21% and 79%. Both monofacial and bifacial silicon PV modules were prepared using n-type bifacial Si passivated emitter rear totally diffused cells with multi-wire busbar incorporated with a white and transparent back-sheet, respectively. In the first set of tests, the power production of the bifacial PV string system was compared with the monofacial PV string system installed on a grey concrete floor with an albedo of ~21% for approximately one year (June 2016–May 2017). In the second test, the gain of the bifacial PV string system installed on the white membrane floor with an albedo of ~79% was evaluated for approximately ten months (November 2016–August 2017). During the second test, the power production by an equivalent monofacial module installed on a horizontal solar tracker was also monitored. The gain was estimated by comparing the energy yield of the bifacial PV module with that of the monofacial module. For the 1.5 kW PV string systems with a 30° tilt angle to the south and 21% ground albedo, the year-wide average bifacial gain was determined to be 10.5%. An increase of the ground albedo to 79% improved the bifacial gain to 33.3%. During the same period, the horizontal single-axis tracker yielded an energy gain of 15.8%. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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15 pages, 9989 KiB

Open AccessArticle

Multi-Objective Sizing of Hybrid Energy Storage System for Large-Scale Photovoltaic Power Generation System

by Chao Ma, Sen Dong, Jijian Lian and Xiulan Pang

Sustainability 2019, 11(19), 5441; https://doi.org/10.3390/su11195441 - 1 Oct 2019

Cited by 23 | Viewed by 3257

Abstract

Hybrid energy storage systems (HESS) are an effective way to improve the output stability for a large-scale photovoltaic (PV) power generation systems. This paper presents a sizing method for HESS-equipped large-scale centralized PV power stations. The method consists of two parts: determining the [...] Read more.

Hybrid energy storage systems (HESS) are an effective way to improve the output stability for a large-scale photovoltaic (PV) power generation systems. This paper presents a sizing method for HESS-equipped large-scale centralized PV power stations. The method consists of two parts: determining the power capacity by a statistical method considering the effects of multiple weather conditions and calculating the optimal energy capacity by employing a mathematical model. The method fully considers the characteristics of PV output and multiple kinds of energy storage combinations. Additionally, a pre-storage strategy that can further improve stability of output is proposed. All of the above methods were verified through a case study application to an 850 MW centralized PV power station in the upstream of the Yellow river. The optimal hybrid energy storage combination and its optimization results were obtained by this method. The results show that the optimal capacity configuration can significantly improve the stability of PV output and the pre-storage strategy can further improve the target output satisfaction rate by 8.28%. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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15 pages, 1491 KiB

Open AccessEditor’s ChoiceArticle

An Improved Method for Obtaining Solar Irradiation Data at Temporal High-Resolution

by Leocadio Hontoria, Catalina Rus-Casas, Juan Domingo Aguilar and Jesús C. Hernandez

Sustainability 2019, 11(19), 5233; https://doi.org/10.3390/su11195233 - 24 Sep 2019

Cited by 14 | Viewed by 3281

Abstract

Solar irradiation that is received on a terrestrial surface at minor scale of an hour does not have many records, since the current solar irradiation databases generally only have data recorded on a daily (most) and hourly (some less) scale. For places where [...] Read more.

Solar irradiation that is received on a terrestrial surface at minor scale of an hour does not have many records, since the current solar irradiation databases generally only have data recorded on a daily (most) and hourly (some less) scale. For places where there are no records of solar irradiation, there are a lot of methods that are used to synthetically or artificially generate these data, and again they are usually methods that generate data on a daily or hourly scale. Currently, for all types of applications, especially in the field of photovoltaic solar energy, irradiation data are needed at minor scale of an hour. In this case, there are very few methods to generate such data. For this purpose, a new methodology to generate series of solar irradiation at temporal high-resolution. In this paper, it is presented on a 10-min basis. A comparative study with real data has been done and the conclusion, as it will be explained is that the proposed methodology provides very good results. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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8 pages, 1801 KiB

Open AccessArticle

Optimal Orientation and Tilt Angle for Maximizing in-Plane Solar Irradiation for PV Applications in Japan

by Cao Yu, Yong Sheng Khoo, Jing Chai, Shuwei Han and Jianxi Yao

Sustainability 2019, 11(7), 2016; https://doi.org/10.3390/su11072016 - 4 Apr 2019

Cited by 17 | Viewed by 4978

Abstract

To maximize the direct insolation received by flat-plate photovoltaic (PV) modules, the tilt angle is usually the site’s latitude and the modules are oriented towards the equator. However, this may not be the optimal placement, as the local climatic conditions will influence the [...] Read more.

To maximize the direct insolation received by flat-plate photovoltaic (PV) modules, the tilt angle is usually the site’s latitude and the modules are oriented towards the equator. However, this may not be the optimal placement, as the local climatic conditions will influence the optimal orientation and tilt angle. Transposition models can be used to simulate the insolation on planes with various tilts and azimuths, using a single set of (horizontal) global and diffuse irradiance measurements. Following this method, five maps including optimal orientations, tilt angles, maximum annual tilted irradiations, percentage improvements of the optimally-tilted PV installation versus the conventional latitude-tilted PV installation, and annual diffuse fraction were plotted over the geographical area of Japan. Spatial patterns in these maps were observed and analyzed. The key contribution of this work is to establish a database of optimal PV installations in Japan. Compared to the conventional rule of thumb of tilting the module at latitude facing south, it is shown that the optimally tilted surface receives up to 2% additional annual solar irradiation. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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Review

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21 pages, 4005 KiB

Open AccessReview

A Review of Control Techniques in Photovoltaic Systems

by Duberney Murillo-Yarce, José Alarcón-Alarcón, Marco Rivera, Carlos Restrepo, Javier Muñoz, Carlos Baier and Patrick Wheeler

Sustainability 2020, 12(24), 10598; https://doi.org/10.3390/su122410598 - 18 Dec 2020

Cited by 24 | Viewed by 7709

Abstract

Complex control structures are required for the operation of photovoltaic electrical energy systems. In this paper, a general review of the controllers used for photovoltaic systems is presented. This review is based on the most recent papers presented in the literature. The control [...] Read more.

Complex control structures are required for the operation of photovoltaic electrical energy systems. In this paper, a general review of the controllers used for photovoltaic systems is presented. This review is based on the most recent papers presented in the literature. The control architectures considered are complex hybrid systems that combine classical and modern techniques, such as artificial intelligence and statistical models. The main contribution of this paper is the synthesis of a generalized control structure and the identification of the latest trends. The main findings are summarized in the development of increasingly robust controllers for operation with improved efficiency, power quality, stability, safety, and economics. Full article

(This article belongs to the Special Issue Photovoltaic Power)

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