Polycrystalline Modules Research Articles

Effect of Tilt and Azimuth Angle on the Performance of PV Rooftop System

This paper focuses on to evaluate technical performance of PV roof top system. This system totally consists of 168 polycrystalline modules in which 14 are connected in series and 12 are connected in parallel. The total capacity of the system is 50 kWp, in which each module has the rated power capacity of 305 Watt. This system is connected to three 20kW inverters and which intern is connected to grid. Tilt angle and orientation is obtained by MATLAB 7.10 and PVsyst software for each 150 change in tilt angle, the variation in solar irradiance absorbed by the PV modules, variation in energy produced by the modules and the variation in the final yield are observed. MATLAB software is also used to find the curve fitting by using surface fitting tool. The result showed that at 150 tilt and 450 azimuth angles, the maximum yield and effective energy were obtained as 4.65 h/day and 1394 kWh/kWp/year respectively.

Energy performance of different silicon photovoltaic technologies under hot and harsh climate

This paper presents a performance comparison study performed on four photovoltaic modules. Three silicon technologies are concerned: one monocrystalline module, two polycrystalline modules and one module of tandem structure (amorphous/microcrystalline) also known as micromorph module. The modules I–V data and meteorological data have been measured during one year using an outdoor monitoring test facility named “IV bench”. This set up is installed at Ouagadougou (Latitude 12.45° North, Longitude 1.56° West) in Sudano Sahelian climate. The actual maximum power, the average performance ratios, the series resistances and the maximum power temperature coefficient of tested modules are determined from the outdoor measurements and used for comparison study. The power of all the modules has been stabilized in outdoor conditions before the performance analysis. The results show that the micromorph module presents the best performance on the selected site, with an average performance ratio of 92%. The monocrystalline and polycrystalline modules from the same manufacturer, have both an average performance ratio of 84%. The second polycrystalline module from another manufacturer, strangely presents the lowest average performance ratio (80%) due to both its large series resistance and the high maximum power temperature coefficient in operating conditions.

Effect of Temperature on the I-V Characteristics of a Polycrystalline Solar Cell

<p>The present paper reports the temperature dependencies of full-spectrum photovoltaic parameters for poly-crystalline PV module. The measurements were performed under outdoor environment conditions. The most interesting feature that was observed for these devices was that above a cell temperature of 20°C the positive temperature coefficient observed for the short-circuit current exceeds in magnitude the negative temperature coefficient that was found for the open-circuit voltage. This means that, unlike the situation for conventional PV devices, these cells actually exhibit decrease in efficiency with increasing temperature (reaching a value of 0.05 % at 60°C).</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 35-40</p>

Comparison of Two PV Modules Technologies Using Analytical and Experimental Methods

Based on actual operating conditions, this paper focuses on the I-V characteristics of the two common types of silicon photovoltaic (PV) modules i.e. the polycrystalline and monocrystalline silicon modules using, for analysis the PV module behaviors, two mathematical models: the implicit model and the explicit model. In the implicit model, five coefficients are calculated analytically whereas in the explicit model, two coefficients are calculated from experimental measurements. These two models allow obtaining the I-V characteristics evaluating the marketed PV module quality and predicting its life and so its behavior according to environmental parameters changes. In the experimental part of this work, I-V characterizations of polycrystalline and monocrystalline silicon PV modules were performed to establish their explicit models. In real environmental conditions, considering illumination and temperature, and in addition to data provided by manufacturers, I-V characteristics are plotted and compared for the two models using codes developed under Matlab software environment. The results show a strong agreement between the implicit model and the experimental characteristics.

Comparison of different physical models for PV power output prediction

The electricity produced from renewable energy, in particular from wind and photovoltaic plants, has seen exponential rise in the last decade. Consequently, the prediction of power produced from these plants is fundamental for the reliability, safety and stability of the grid. This paper compares three physical models describing the PV cell (corresponding to three-, four- and five-parameter equivalent electric circuit) and two thermal models for the cell temperature estimation (NOCT and Sandia). The models were calibrated and tested towards ten monocrystalline and eight polycrystalline modules installed at SolarTechLab at Politecnico di Milano. The hourly error of the forecasted power output is usually lower than 15Wh, while NMAE% and WMAE% are in the range of 0.5% and 10%. Low errors, calculated with actual weather conditions, suggest that the implemented models are accurate, but they cannot be directly compared with other approaches which adopt weather forecasts. Results show that there is no clear advantage of using complex models, but the data used for the model calibration mostly affect the model accuracy. It was found that forecasted power output are more accurate using experimental data and Sandia’s thermal model in monocrystalline cells type, while for the polycrystalline the data from the manufacturer and NOCT have lower errors.

An experimental investigation of performance of photovoltaic modules in Pakistan

An outdoor experimental study was carried out to investigate and compare the performance of three commercially available photovoltaic modules (monocrystalline, polycrystalline and single junction amorphous silicon) under the weather of Pakistan for the month of January. Power output efficiency, module efficiency, and performance ratio are calculated for each module and comparison is presented. Results have shown that mono-crystalline and poly-crystalline modules perform better at high irradiance and show poor performance in low irradiance conditions. Amorphous solar module has shown better light absorption characteristic and performs better in low irradiance i.e. in cloudy and diffuse sunshine conditions. Monocrystalline photovoltaic module is found to be more efficient, having module efficiency of 13.5% which is higher than the other two modules. Furthermore the power output of mono-crystalline and poly-crystalline modules has shown a higher decrement at higher module temperatures compared to the amorphous solar module. Because of better performance in low solar irradiance, amorphous solar module has shown monthly average performance ratio of 1.07 which is higher than other photovoltaic modules under study.

Real Time Data Acquisition System for Performance Analysis of Modified PV Module and Derivation of Cooling Coefficients of Electrical Parameters

Abstract Photovoltaic module working temperature significantly reduces the electrical efficiency, increases degradation rates and thermal stresses. In solar module operation temperature is an important issue. As with appropriate cooling system, electrical output can be increased, a special pass reverse flow absorber collector is designed and developed. And a commercial polycrystalline module is modified by gluing this heat extraction unit by thermally conducted epoxy at back surface of module through which water is flowing by gravity at preset flow rate and no pump is used. Electrical and thermal performance of modified system has been evaluated for climatic condition of Dehradun in comparison with reference module. From collected real time data cooling coefficients of electrical parameters of modified proposed module with respect to reference are derived by mathematical modelling and programming in MATLAB at optimized flow rate for minimum operating temperature. It is found that there is significant increase in electrical efficiency. The effect of environmental parameters on cooling coefficients is also analyzed. RS232 logic and MATLAB GUI are used to log the real time electrical and environmental parameters.

Issues in Modeling Amorphous Silicon Photovoltaic Modules by Single-Diode Equivalent Circuit

In this paper, the applicability of the well-known single-diode equivalent circuit to modeling amorphous silicon photovoltaic modules is questioned. It is shown that, unlike in mono- and polycrystalline modules, all of the equivalent circuit parameters are irradiation dependent. This dependence may be derived from either manufacturer-provided or measured I-V curves for different irradiation levels. In order to extract the equivalent circuit parameters, the suggested approach combines numerical solution of two transcendental and two regular algebraic equation systems with single-parameter fitting procedure. Two additional parameters are introduced to describe temperature dependence of photocurrent and diode reverse saturation current. As result, a set of seven parameters is obtained, comprehensively describing the panel performance for arbitrary ambient conditions. It is shown that characteristic curves obtained using the proposed approach match well the manufacturer-provided data for various values of temperature and irradiation.

The Application of Novel Platinum-Reinforced Tin-Silver-Copper Solder to Bifacial Photovoltaic Module for Improvement of Yield and Reliability

The characteristics of solder joints between the busbars of solar cells and copper ribbons can affect the performance of a photovoltaic (PV) module significantly. The resistivity of the joints and the intermetallic compound structures within the joints are the two main characteristics that impose a substantial impact on the yield and the reliability of the PV module. In this paper, we aim to present and analyze a novel platinum-reinforced tin-silver-copper (Sn-3.8Ag-0.7Cu-0.2Pt) as the lead-free solder material to connect copper ribbons to the metallization of bifacial solar cells. The performance of the PV module using platinum-reinforced solder is investigated by constructing two bifacial PV modules using the popular lead-free Sn-3.8Ag-0.7Cu solder and Sn-3.8Ag-0.7Cu-0.2Pt solder, respectively. Micrographs of the joints are obtained to show that the platinum-reinforced solder joint has fewer voids and a more evenly distributed and thinner intermetallic layer than that of a conventional SnAgCu solder joint. As a result, the physical attachment between the busbars and the ribbon using SnAgCuPt solder is stronger than that using SnAgCu solder. The power outputs of both PV modules are measured together with two commercial PV modules under the sun using an IV plotter. The results show that the total energy yield of the bifacial PV module with the new solder is about 6–10% higher than that with the conventional SnAgCu solder. The energy yield of the bifacial PV module using SnAgCuPt solder is 35.8% and 0.2% higher than that of the commercially available monofacial polycrystalline and monocrystalline PV modules, respectively.

Degradation evaluation of crystalline-silicon photovoltaic modules after a few operation years in a tropical environment

This paper presents an evaluation of the performance degradation of Photovoltaic modules after few operation years in a tropical environment. To this end, the International Center for Research and Training in solar energy at Dakar University and the Lasquo-ISTIA laboratory of Angers University have put in place a research project in order to investigate the impact of the tropical climatic conditions on the PV modules characteristics. Accordingly, two monocrystalline-silicon (mc-Si) PV modules and two polycrystalline- silicon (pc-Si) PV modules are installed at Dakar in Senegal and monitored during a few operation years: Module A (16 months), Module B (41 months), Module C (48 months) and Module D (48 months). After few operation years under tropical environment, the global degradation and the degradation rate of electrical characteristics such as I-V and P-V curves, open-circuit voltage (Voc), short-circuit current (Isc), maximum ouput current (Imax), maximum output voltage (Vmax), maximum power output (Pmax) and fill factor (FF) are evaluate at standard test conditions (STC). This study reports on data collected from 4 distinct mono- and poly-crystalline modules deployed at Dakar University in Senegal. The study has shown that Pmax, Imax, Isc and FF are the most degraded performance characteristics for all PV modules. The maximum power output (Pmax) presents the highest loss that can be from 0.22%/year to 2.96%/year. However, the open-circuit voltage (Voc) is not degraded after these few exposition years for all studied PV modules.

The Effect of Average Photon Energy and Module Temperature on Performance of Photovoltaic Module under Thailand's Climate Condition

This article present the effect of average photon energy and module temperature on performance of amorphous silicon (a-Si), polycrystalline (p-Si) and hetero-junction intrinsic thin layer (HIT) photovoltaic (PV) modules under Thailand climatic condition which located at the equator zone. The outdoor solar irradiance distribution measurements on the PV array installed at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Thailand revealed that the field output factor of the poly-Si and HIT PV modules depended almost only on a module temperature, while that of the a-Si ones mainly depended on APE. The behaviors were reasonable considering from the operating mechanisms of the PV modules. These results demonstrate that APE is a reasonable and useful index to describe the spectral irradiance distribution for evaluating the performance of PV modules.

Comparison of Performance Measurements of Photovoltaic Modules during Winter Months in Taxila, Pakistan

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.

공공건물 옥상녹화와 설치태양광(PV)의 효율향상 상관관계 연구

This study aims to investigate advantages of complex installation of green roof and PV system in a public building, to analyze the impact of green roof on the efficiency of PV power generation, and to consider the correlation between green roof and PV power generation. When the temperature and power generation of the modules installed in the green roof and non-green roof of the public building were measured for 3 days, the average temperature of the green roof was 23.6 degrees, and it was 36.1 degrees in the non-green roof which increased by nearly 53%. Overall, the module temperature in the green roof was lower. On the other hand, in relation to the PV generation depending on temperature reduction during the same period, the mono-crystalline module and the poly-crystalline module in the green roof showed an increase in generation at nearly 222.2W and 341.6W, and the efficiency rose by 5.5% and 6.2%, respectively, compared to the modules in the non-green roof. Therefore, it is analyzed that green roof has a positive influence on PV power generation. Finally shows the efficiency of the installed on the Green Roof PV system (complex Installation) higher than on the concrete roof PV system. Thus, the complex PV systems as well as the usual benefits of green roofs will provide greater synergies.

Comparative Analysis of Crystalline and Double-Junction Amorphous Silicon Modules Performance in Outdoor Conditions

The paper deals with an extensive photovoltaic (PV) modules monitoring activity carried out at the outdoor station ESTER (Solar Energy TEst and Research) of the University of Rome Tor Vergata, Italy. The purpose of the work was to evaluate and compare the performance of PV silicon modules of polycrystalline (poli-Si) and amorphous (a-Si) technologies during a medium-term outdoor exposure at optimized tilt angle, facing south. Two PV modules, one polycrystalline silicon and one double-junction amorphous silicon, have been exposed since May 2009 until Oct. 2010. A complete characterization of the weather conditions at the site during the test has been performed, and the most relevant parameters for the performance comparison of the two technologies have been derived. In order to compare different technologies and power productions, the energy yield (Y) and performance ratio (PR) for the two modules have been evaluated on a monthly and yearly basis. The typical seasonal trend of PR has been observed for the polycrystalline module, essentially due to the temperature influence on the module performance. For the a-Si module, instead, a degradation trend has been observed for the first months of operation. Subsequently, a significant recovery in the PR and energy production has been registered.

Experimental investigation of partial shading scenarios on PV (photovoltaic) modules

The power generation of photovoltaic systems is significantly affected by partial or complete shading of its cells and it depends of the PV array configuration, shading characteristics, and presence of bypass diode. The paper deals with the investigation of the impact of partial shading on poly-crystalline and mono-crystalline PV modules operation. Several experiments consisting of measuring the current–voltage and power–voltage curves of photovoltaic modules of a real PV plant, both unshaded and applying shading profiles, have been carried out in clear sunny days. The experimental analysis can be applied to derive mathematical models for evaluating the power losses under shading conditions influencing PV modules operation.

Thin-film-based CdTe photovoltaic module characterization: Measurements and energy prediction improvement

Photovoltaic characterization is a topic of major interest in the field of renewable energy. Monocrystalline and polycrystalline modules are mostly used and, hence characterized since many laboratories have data of them. Conversely, cadmium telluride (CdTe), as thin-film module are, in some circumstances, difficult to be used for energy prediction. This work covers outdoor testing of photovoltaic modules, in particular that regarding CdTe ones. The scope is to obtain temperature coefficients that best predict the energy production. A First Solar (K-275) module has been used for the purposes of this research. Outdoor characterizations were performed at Department of Innovation Engineering, University of Salento, Lecce, Italy. The location of Lecce city represents a typical site in the South Italy. The module was exposed outdoor and tested under clear sky conditions as well as under cloudy sky ones. During testing, the global-inclined irradiance varied between 0 and 1500 W/m(2). About 37,000 I-V characteristics were acquired, allowing to process temperature coefficients as a function of irradiance and ambient temperature. The module was characterized by measuring the full temperature-irradiance matrix in the range from 50 to 1300 W/m(2) and from -1 to 40 W/m(2) from October 2011 to February 2012. Afterwards, the module energy output, under real conditions, was calculated with the "matrix method" of SUPSI-ISAAC and the results were compared with the five months energy output data of the same module measured with the outdoor energy yield facility in Lecce.

The Effect of Photon Flux Density and Module Temperature on Power Output of Photovoltaic Array

This article presents the effects of photon flux density and module temperature on power output of amorphous silicon (a-Si), polycrystalline (p-Si) and hetero-junction intrinsic thin layer (HIT) photovoltaic (PV) modules under Thailand climatic condition which located at the equator zone. The outdoor solar irradiance distribution measurements on the PV array installed at Energy Park, School of Renewable Energy Technology (SERT), Naresuan University, Thailand revealed that the solar irradiance is directly proportional with photon flux density which the wavelength is influence of photon flux density. The increasing of power output under real working of a-Si and p-Si depends on both photon flux density and module temperature. But the increasing of power output of HIT mainly depends on both photon flux density.

The Performance of Three Different Solar Panels for Solar Electricity Applying Solar Tracking Device under the Malaysian Climate Condition

The main objective of this study was to measure and determine the efficiency of poly-crystalline, mono-crystalline and amorphous silicon solar module by applying single-axis time/date solar tracker to the installation of photovoltaic panel (dynamic system) as a strategy to increase the performance of the modules under hot-humid climate of Malaysia. The dynamic system in this experiment was designed to support the three types of PV panels which allowed it to move with single degree of freedom (horizontally) according to the sun’s orientation (sunrise to sunset) from east to west. Studies on sun movement in equator countries have been conducted to locate the sun‘s position on site (azimuth and altitude angle) using the Stereographic Diagram and Tabulate Daily Solar Data. It was found that poly-crystalline solar module have shown better performance ratio and average module efficiency compare to the others tested PV module under Malaysian climate.

옥상녹화가 PV모듈 발전량에 미치는 영향 고찰

This study aims to examine the effect of the combined application of green roof and PV system on the PV efficiency by measuring the temperature and performance of PV module in order to reduce the temperature on the roof using roof planting system and determine the potential of efficient increase in solar-light power generation. In the experimental methodology, either monocrystalline or polycrystalline PV module was installed in green roof or non-green roof, and then the surface temperature of PV was measured by TR-71U thermometer and again the performance, module body temperature, and conversion efficiency were measured by MP-160, TC selector MI-540, and PV selector MI-520, respectively. As a result, the average body temperature of monocrystalline module was lower by in green roof than in non-green roof; that of polycrystalline module was lower by in green roof than in non-green roof. In the difference of generation, the electricity generation of monocrystalline module in green roof was 46.13W, but that of polycrystalline module was 68.82 W, which indicated that the latter produced 22.69W more than the former.

Thermal and Optical Properties of Semi-Transparent Amorphous Silicon BIPV for Building Application

A new type of poly-crystalline amorphous thin film photovoltaic module with high visible light transmittance was developed for use in a building. The method of PECVD (Plasma-enhanced chemical vapor deposition) was applied to produce satisfactory high color rendering index (HCRI) BIPV module of good quality with visible light transmittance as high as 26.9%, solar radiation absorptance below 60% and shading coefficient equal to 54%. The thermal and optical properties of HCRI BIPV module are studied in some detail and the results reported. The thermal conductivity and diffusivity of HCRI BIPV module are less than that of Si-based BIPV. The HCRI-BIPV module appeared to be effective in improving the visible transmittance and reducing the absorptance, but the value of SC of HCRI-BIPV module was higher than that of Si-based BIPV. This indicates that there is still a trade-off between day lighting and thermal insulation for designing an optimal BIPV module. Further thermal performance work conducted by a small-sized hot-box with a solar simulator lamp revealed that heat is mostly absorbed by the HCRI-BIPV and a small amount of heat is conducted into building. The surface temperature on both sides of Si-based BIPV reached a steady state is faster than that of HCRI-BIPV due to the higher thermal diffusivity. This can have important practical implications on the fabrication of low-cost, high visible light transmittance of BIPV module.