scholarly journals Experimental Application of Methods to Compute Solar Irradiance and Cell Temperature of Photovoltaic Modules

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2490
Author(s):  
Caio Felippe Abe ◽  
João Batista Dias ◽  
Gilles Notton ◽  
Ghjuvan Antone Faggianelli

Solar irradiance and cell temperature are the most significant aspects when assessing the production of a photovoltaic system. To avoid the need of specific sensors for quantifying such parameters, recent literature presents methods to estimate them through electrical measurements, using the photovoltaic module itself as a sensor. This work presents an application of such methods to data recorded using a research platform at University of Corsica, in France. The methods and the platform are briefly presented and the results are shown and discussed in terms of normalized mean absolute errors (nMAE) and root mean square errors (nRMSE) for various irradiance and cell temperature levels. The nMAE (and nRMSE) for solar irradiance are respectively between 3.5% and 3.9% (4.2% and 4.7%). Such errors on computed irradiance are in the same order of magnitude as those found in the literature, with a simple implementation. For cell temperatures estimation, the nMAE and nRMSE were found to be in the range 3.4%–8.2% and 4.3%–10.7%. These results show that using such methods could provide an estimation for the values of irradiance and cell temperature, even if the modules are not new and are not regularly cleaned, but of course not partially shaded.

2016 ◽  
Vol 27 (1) ◽  
pp. 28 ◽  
Author(s):  
N. Marc-Alain Mutombo ◽  
Freddie Inambao ◽  
Glen Bright

The conversion of solar irradiance into electricity by a photovoltaic module (PV) is 6– 7% of the incoming energy from the sun depending on the type of technology and the environmental parameters. More than 80% of incoming energy from the sun is reflected or absorbed by the solar module. The fraction of energy absorbed increases with solar cell temperature and the cells’ efficiency drops as a consequence. The efficiency of a PV module is improved by combining a PV module and a thermal collector in one unit, resulting in a hybrid photovoltaic and thermal collector (PV/T). The purpose of this paper is to present the behavior a thermosyphon hybrid PV/T when exposed to variations of environmental parameters and to demonstrate the advantage of cooling photovoltaic modules with water using a rectangular channel profile for the thermal collector. A single glazed flat-box absorber PV/T module was designed, its behavior for different environmental parameters tested, the numerical model developed, and the simulation for particular days for Durban weather run. The simulation result showed that the overall efficiency of the PV/T module was 38.7% against 14.6% for a standard PV module while the water temperature in the storage tank reached 37.1 °C. This is a great encouragement to the marketing of the PV/T technology in South Africa particularly during summer, and specifically in areas where the average annual solar irradiance is more than 4.70 kWh/m²/day.


Author(s):  
Allison Gray ◽  
Robert Boehm ◽  
Kenneth W. Stone

Cooling of photovoltaic cells under high intensity solar irradiance is a major concern when designing concentrating photovoltaic systems. The cell temperature will increase if the waste heat is not removed and the cell voltage/power will decrease with increasing cell temperature. This paper presents an analysis of the passive cooling system on the Amonix high concentration photovoltaic system (HCPV). The concentrator geometry is described. A model of the HCPV passive cooling system was made using Gambit. Assumptions are discussed that were made to create the numerical model based on the actual system, the methods for drawing the model is discussed, and images of the model are shown. Fluent was used to compute the numerical results. In addition to the theoretical results that were computed, measurements were made on a system in the field. These data are compared to the theoretical data and differences are calculated. Theoretical conditions that were studied included uniform cell temperatures and worst case weather scenarios, i.e., no wind, high ambient conditions, and high solar irradiance. The performance of the Amonix high concentrating system could be improved if more waste heat were removed from the cell. Now that a theoretical model has been developed and verified, it will be used to investigate different designs and material for increasing the cooling of the system.


2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Ty W. Neises ◽  
Sanford A. Klein ◽  
Douglas T. Reindl

The temperature of a photovoltaic module is typically required as an input to models that predict the module’s performance. Some common models use the nominal operating cell temperature (NOCT), as by the manufacturer. This paper develops a thermal model and uses it to analyze NOCT testing standards. Specifically, the standard correction factor charts found in the ASTM E1036 and IEC 61215 standards are evaluated. Results show that the correction charts were likely created assuming laminar flow correlations, while validation efforts and the fact that wind is often characterized by turbulence even at low wind speeds suggest that turbulent flow models may be more appropriate. In addition, the results presented in this paper show that the standard NOCT charts do not account for the backside insulation of photovoltaic (PV) arrays. These results suggest that the standard correction charts are inaccurate for any mounting types that differ from the open rack configuration. The paper concludes with recommendations to improve the usefulness of the NOCT.


2019 ◽  
pp. 199-208
Author(s):  
Caio Felippe Abe ◽  
João Batista Dias

Resumo Este trabalho apresenta uma avaliação do efeito de sombreamentos parciais em um módulo fotovoltaico por meio de simulação e análise experimental, considerando um sistema conectado à rede elétrica da concessionária com topologia de microinversor. Para as simulações, considerou-se um modelo elétrico da célula fotovoltaica, assim como métodos para identificação e translação de seus parâmetros, de acordo com as condições de irradiância solar e temperatura das células. Por sua vez, a avaliação experimental foi realizada através de medições de variáveis elétricas em um módulo fotovoltaico, o que foi feito empregando um traçador de curvas. Os resultados mostram que o sombreamento, além de reduzir a potência disponibilizada pelo módulo fotovoltaico, pode levar a tensão do ponto de máxima potência do módulo para valores fora da faixa de operação do microinversor, causando perdas adicionais no sistema. Palavras-chave: Sistemas fotovoltaicos. Microinversor. Sombreamentos parciais. Abstract This paper presents an evaluation of partial shading effect in a photovoltaic module through simulation and experimental analysis, considering a system connected to the utility grid with microinverter topology. For the simulations, an electric model of the photovoltaic cell has been considered, as well as methods for identification and translation of its parameters, according to the solar irradiance and cell temperature conditions. On the other hand, the experimental evaluation has been carried out by performing electrical measurements in a photovoltaic module, which was done using a curve tracer. The results show that shading, in addition to reducing the power provided by the photovoltaic module, can take the maximum power point voltage to values outside the microinverter operating range, causing additional system losses. Keywords: Photovoltaic systems. Microinverter. Partial shadings.


Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2082
Author(s):  
Guoqian Lin ◽  
Samuel Bimenyimana ◽  
Ming-Lang Tseng ◽  
Ching-Hsin Wang ◽  
Yuwei Liu ◽  
...  

This study aims to provide photovoltaic module selection with better performance in the shading condition for improving production efficiency and reducing photovoltaic system investment cost through the symmetry concept, combining both solar energy mathematical and engineering principles. The study builds a symmetrical photovoltaic model and uses the series-parallel circuit theory, piecewise function and Matlab simulation. The voltage and current output characteristics of commercial photovoltaic modules made of different materials and structures are analyzed and their shading effects are evaluated. The results show that for each photovoltaic module, the output power is directly proportional to the irradiance. The output voltage of the photovoltaic module slightly increases and the output current greatly decreases from no shading to shading. The rate of output power reduction varies for each photovoltaic module type when the irradiance changes. The thin film modules show a lower output power reduction rate than crystalline photovoltaic modules from no shading to shading and they have good adaptability to shading. The use of thin film photovoltaic modules is recommended when the shading condition cannot be avoided.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Anser Bashir ◽  
Hafiz Muhammad Ali ◽  
Shahid Khalil ◽  
Muzaffar Ali ◽  
Aysha Maryam Siddiqui

This paper presents the comparative performance evaluation of three commercially available photovoltaic modules (monocrystalline, polycrystalline, and single junction amorphous silicon) in Taxila, Pakistan. The experimentation was carried out at outdoor conditions for winter months. Power output, module efficiency, and performance ratio were calculated for each module and the effect of module temperature and solar irradiance on these parameters was investigated. Module parameters showed strong dependence on the solar irradiance and module temperature. Monocrystalline and polycrystalline modules showed better performance in high irradiance condition whereas it decreased suddenly with decrease in irradiance. Amorphous solar module also showed good performance in low irradiance due to its better light absorbing characteristics and thus showed higher average performance ratio. Monocrystalline photovoltaic module showed higher monthly average module efficiency and was found to be more efficient at this site. Module efficiency and performance ratio showed a decreasing trend with increase of irradiance and photovoltaic module back surface temperature.


2016 ◽  
Vol 6 (5) ◽  
pp. 1115-1118
Author(s):  
F. Mavromatakis ◽  
Y. Franghiadakis ◽  
F. Vignola

A robust and reliable model describing the power produced by a photovoltaic system is needed in order to be able to detect module failures, inverter malfunction, shadowing effects and other factors that may result to energy losses. In addition, a reliable model enables an investor to perform accurate estimates of the system energy production, payback times etc. The model utilizes the global irradiance reaching the plane of the photovoltaic modules since in almost all Photovoltaic (PV) facilities the beam and the diffuse solar irradiances are not recorded. The airmass, the angle of incidence and the efficiency drop due to low values of solar irradiance are taken into account. Currently, the model is validated through the use of high quality data available from the National Renewable Energy Laboratory (USA). The data were acquired with IV tracers while the meteorological conditions were also recorded. Several modules of different technologies were deployed but here we present results from a single crystalline module. The performance of the model is acceptable at a level of 5% despite the assumptions made. The dependence of the residuals upon solar irradiance temperature, airmass and angle of incidence is also explored and future work is described.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Sakaros Bogning Dongue ◽  
Donatien Njomo ◽  
Lessly Ebengai

This paper presents an improved nonlinear five-point model capable of analytically describing the electrical behaviors of a photovoltaic module for each generic operating condition of temperature and solar irradiance. The models used to replicate the electrical behaviors of operating PV modules are usually based on some simplified assumptions which provide convenient mathematical model which can be used in conventional simulation tools. Unfortunately, these assumptions cause some inaccuracies, and hence unrealistic economic returns are predicted. As an alternative, we used the advantages of a nonlinear analytical five-point model to take into account the nonideal diode effects and nonlinear effects generally ignored, which PV modules operation depends on. To verify the capability of our method to fit PV panel characteristics, the procedure was tested on three different panels. Results were compared with the data issued by manufacturers and with the results obtained using the five-parameter model proposed by other authors.


Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1860 ◽  
Author(s):  
J. Teo ◽  
Rodney Tan ◽  
V. Mok ◽  
Vigna Ramachandaramurthy ◽  
ChiaKwang Tan

A photovoltaic system is highly susceptible to partial shading. Based on the functionality of a photovoltaic system that relies on solar irradiance to generate electrical power, it is tacitly assumed that the maximum power of a partially shaded photovoltaic system always decreases as the shading heaviness increases. However, the literature has reported that this might not be the case. The maximum power of a partially shaded photovoltaic system under a fixed configuration and partial shading pattern can be highly insusceptible to shading heaviness when a certain critical point is met. This paper presents an investigation of the impact of partial shading and the critical point that reduce the susceptibility of shading heaviness. Photovoltaic string formed by series-connected photovoltaic modules is used in this research. The investigation of the P-V characteristic curve under different numbers of shaded modules and shading heaviness suggests that the photovoltaic string becomes insusceptible to shading heaviness when the shaded modules irradiance reaches a certain critical point. The critical point can vary based on the number of the shaded modules. The formulated equation in this research contributes to determining the critical point for different photovoltaic string sizes and numbers of shaded modules in the photovoltaic string.


Author(s):  
D. I. Zalizny

A new Simulink model of a photovoltaic cell has been proposed. The model is focused on the use of a standard SimPowerSystems library with power engineering elements from the MatLab/Simulink software package. The model allows altering the values of solar irradiance, photovoltaic cell temperature and load resistance. The results of the model application are the calculated values of voltages and currents at the photovoltaic cell output. The Simulink model that has been developed implements the known dependence of the photovoltaic cell volt-ampere characteristic by using both standard MatLab/Simulink blocks and special electric SimPowerSystems library blocks. The model is characterized by the fact that the series and parallel resistance of the photovoltaic cell are made in the form of resistors from the SimPowerSystems library. The main calculation algorithm is implemented programmatically by using the “C” programming language. To increase the algorithm stability to algebraic cycles the restrictions parameters are introduced. A new technique of calculating the photovoltaic cell model parameters based on experimental data has been proposed. The technique includes the preparation of a system of equations with experimental values of the photovoltaic cell voltages and currents. Experimental tests have been carried out for the photovoltaic module OSP XTP 250 under different solar irradiance values. The tests showed that the relative error of the Simulink model that has been developed does not exceed 12 %. The Simulink model makes it possible to build photovoltaic modules and then to build schemes of photovoltaic power plants as a part of power supply systems. Due to the latter it is possible to simulate the electricity consumers’ work, weather conditions, and the presence of shadows or pollution on the surface of photovoltaic modules. Also, one can carry out a simulation of increasing failures in power plant photovoltaic modules, e.g. simulating of modules efficiency reducing because of their degradation, or simulating of modules series resistance increasing because of the photovoltaic cell internal contacts deterioration. The Simulink model that has been developed can be used both at the design stage and at the stage of photoelectric power plants operation.


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