Performance Of Photovoltaic Panels Research Articles

Can movable PCM-filled TES units be used to improve the performance of PV panels? Overview and experimental case-study

This paper provides an overview on how phase change materials (PCMs) can be used for the thermal regulation of photovoltaic (PV) devices, and describes an experimental apparatus to assess whether the performance of 250 W STC-rated commercial polycrystalline silicon PV panels can be improved by placing movable thermal energy storage (TES) units filled with the free-form PCM RT 22 HC on the panels' back. The outdoor apparatus is located at Coimbra, Portugal. Three identical PV panels were separately installed and individually monitored: one panel was taken as reference; the other two were considered together with a TES unit each with horizontally and vertically oriented cavities, PV/PCM1 and PV/PCM2 systems, respectively. The time evolutions of the temperature of the PV panels were compared with each other to analyse the possible thermal regulation potential of the TES units. The time evolution of the power output was also assessed to compare the efficiency of the different systems. Finally, the energy produced per day by each system was evaluated. The results showed that the PV operating temperature has increased ca. 16–21 °C and 14–18 °C in the PV/PCM1 and PV/PCM2 systems, respectively, in comparison with the reference PV panel (at peak time). Moreover, the daily energy produced by the PV panel of the PV/PCM1 and PV/PCM2 systems was, respectively, 3.3–6.5% and 3.3–6.0% lower than that produced by the reference PV panel during the measured short-term summer operation period. Therefore, it was concluded that the movable TES units have a negative impact on the performance of the PV/PCM systems, and that a PCM with a higher phase change temperature must be chosen for Mediterranean climate.

Optimum location and influence of tilt angle on performance of solar PV panels

With the growing demand of economically feasible, clean, and renewable energy, the use of solar photovoltaic (PV) systems is increasing. The PV panel performance to generate electrical energy depends on many factors among which tilt angle is also a crucial one. Among hundreds of research work performed pertinent to solar PV panels performance, this work critically reviews the role of tilt angles and particularly locating the optimum tilt angle using different methods. The past data collected for analysis can be categorized mainly into mathematical model based, experimental based, simulation based, or combination of any of these. Single-axis tracking, dual-axis tracking, simple glass cover, hydrophobic glass cover, soiled glass, clean glass, partial shadow, use of phase-change material, computational fluid dynamic analysis, etc., are the novel methods found in the literature for analysis and locating the optimum tilt angle. For illustration purpose, few figures are provided in which the optimum tilt angle obtained on monthly, seasonally, and annual basis is shown. Research works are growing in the field of computations and simulations using online software and codes. Pure mathematical-based calculations are also reported but the trend is to combine this method with the simulation method. As the PV panel performance is found to be affected by number of parameters, their consideration in any single study is not reported. In future, work is required to carry out the experiment or simulation considering the effect of soiling, glass material, temperature, and surrounding ambience on the location of optimum tilt angle. As a whole, the optimum tilt angles reported for locations exactly on the equator line, i.e., 0° latitude, ranges between − 2.5° and 2.5°, for locations just above the equator line, i.e., latitude 2.6°–30° N ranges between 5° and 28°, for 40°–70° N, it is 29°–40°, and for 71°–90° N, it is 41°–45°. For locations at 2.6°–30° S, optimum tilt angles range between − 4° and − 32°, 30°–46° S, it is − 33° to − 36°, 47°–65° S, it is − 34° to − 50°, and for 66°–90° S it is − 51° to − 62°.

Influence of shading to the output power of photovoltaic in Indonesia

Indonesia, being a tropical country, has a high photovoltaic (PV) energy generation potential that can help meet demand due to the impending shortage of power supplies in the coming years. The shading effect is a negative effect that causes the Photovoltaic power output to drop from its normal state. The performance of Photovoltaic Panels (PV) is a shared module surface exposed to sunlight. Shading effects usually occur from the influence of clouds, but the influence of these clouds often causes a lack of uniform illumination of sunlight received by the photovoltaic. This is also often called Partial Shaded. Partially shaded PV systems cannot operate at maximum efficiency because of shadows cast by surrounding structures, foliage and cloud cover. This is done to see the effect of partial shading pattern effect on solar cell PV. Characteristics of I-V can be influenced by pattern shading effect. The voltage and current of PV solar cells will drop from partial shading effect experiment which consists of 20%, 40%, 60%, 80% and 100% shading area.

Performance evaluation and degradation assessment of crystalline silicon based photovoltaic rooftop technologies under outdoor conditions

Keeping track of field performance and degradation rate of photovoltaic panels in regions with diverse environmental exposures is critical. The objective of this paper is to determine two and half year performance characteristics and degradation rate of poly-crystalline and heterojunction with intrinsic thin layer roof-top photovoltaic units under prevailing weather conditions in the Central Anatolia region. Degradation rates of the photovoltaic units were determined through analysing the effective peak power, and the temperature corrected performance ratio of each technology. Processing of the measured data covering the test period reveals that the thin film technology offers lower degradation rate with nearly −0.1% than the poly-crystalline based technology within the range of −0.67% to −0.83%, respectively. The study allows a better understanding of variations in performance and behaviour of the output power of poly-crystalline and heterojunction with intrinsic thin layer roof-top photovoltaic units after 2.5 years of outdoor exposure.

Thermal regulation of photovoltaic panel installed in Upper Egyptian conditions in Qena

High ambient temperature and excessive solar radiation, especially in Upper Egypt, are essential factors in photovoltaic (PV) panel overheating, which in turn reduce its efficiency in such regions. Therefore, this study aims to develop a cooling system for the proposed thin-film PV panel installed in a harsh climate region in Qena City in Upper Egypt to obtain practically reasonable electrical efficiency. To achieve this target, three different cooling systems and operating modes were investigated: open-loop water-based cooling system, closed-loop water-based cooling system with free-convection air-cooled heat exchanger, and closed-loop water-based cooling system with forced-convection air-cooled heat exchanger using a DC fan. All these systems were supplemented with a fourth operating mode without cooling, i.e., normal conditions. The PV panel efficiency was experimentally investigated using the proposed cooling systems, and the experimental results demonstrated that without cooling, the daily average efficiency reached only approximately 6.2%, whereas it increased to 11.3% when the open-loop system was used. However, the daily average efficiency reached 8.5% using the closed-loop free-convection cooling system, and it reached 10.5% when the closed-loop forced-convection cooling system was used. Therefore, these cooling systems are highly recommended for application as effective techniques to increase the PV panel performance. The entire experimental data were obtained during a 10-h period from 7:00 a.m. to 5:00p.m.

Performance and design optimization of single-axis multi-position sun-tracking PV panels

In this article, the photovoltaic (PV) and sun-tracking performance of single-axis multiposition sun-tracking PV panels (MP-PV) is investigated based on solar geometry and dependence of PV conversion efficiency on the incident angle of solar rays on PV panels. For such PV systems, the azimuth angle of the PV panels is adjusted daily M times from an eastward direction in the morning to a westward direction in the afternoon by rotating the PV panels about the inclined north–south axis (INSA) to ensure that the projected incident angle (PIA) of solar rays on the plane perpendicular to the INSA is always less than the angle θa, the specified maximum PIA. Results show that the annual average sun-tracking efficiency (ηst) and the annual electricity generation (AEG) of the MP-PV system increase as M increases, but this increase is less than 1% when M > 5. The optimal θa of the MP-PV system for maximizing AEG and the ratio (Cp,MP-0) of AEG of the optimized MP-PV system to that of a similar fixed PV system are highly dependent on the annual average atmospheric clearness index (Kt) but only slightly dependent on the site latitude (λ). For an MP-PV with a tilt angle (β) of the INSA that is fixed yearly, the AEG of 3P-, 5P-, and 7P-PV systems is about 92%, 94%, and 95%, respectively, of that obtained from a similar dual-axis tracking PV panel (2A-PV). However, for an MP-PV whose β is adjusted four times a year at three tilts, the AEG of 3P-, 5P-, and 7P-PV systems is about 96%, 98%, and 99%, respectively, of that of a similar 2A-PV system. Empirical correlations for quick estimation of the optimal θa and Cp,MP-0 of the MP-PV optimized for maximizing AEG are suggested and examined based on monthly global radiation on the horizon at 30 sites around China.

Performance of Solar Photovoltaic panel using Forced convection of water-based CuO nanofluid: An Understanding

Most of the conventional Solar Photovoltaic module consists of a Silicon cell that converts sunlight into electric energy. The process of conversion into electricity is exothermic and all photons are not able to produce electricity due to insufficient energy. Depending upon efficiency to convert it into electricity only the small amount of radiations are used and rest all are involved in increasing the temperature of the module. Study shows that 80% of incident solar radiation are absorbed by a solar photovoltaic cell. This increases the temperature of the module, reduces its electrical efficiency. This increase in temperature affects the power output and lifespan of the PV module. So to maintain the temperature of the module various cooling methods such as air cooling, hydraulic cooling, heat pipe cooling, cooling with phase change materials and cooling with nanofluids have been reported in the literature. The use of suitable nanofluids is one of the effective methods to increase thermal capacitance and control the temperature rise of the PV module. To increase the performance of the system thermal properties of working fluid must be improved which is achieved by using suitable additives with the base fluid which are referred to as nanofluids. Using Copper oxide/water as a working fluid analysis was performed. It was concluded that performance can be improved significantly if we integrate the system with a good heat exchanger. In this paper, the effect of CuO based nanofluids as a cooling medium for a PV module has been reported.

Effects of Coal and Fly Ash Dust Deposition of Photovoltaic Panel Performance: A Photovoltaic System at Coal-Fired Power Plant Case Study

Malaysia is aiming to increase its renewable energy generation capacity from 2% to 20% by 2030. Solar photovoltaic (PV) system will play a huge role in getting this target achieve as it is considered a maturing technology in Malaysia and the nation is blessed with ample amount of solar irradiation throughout the year. However, in Malaysia, this technology faces various implementation challenges such as the PV performance degradation due to dust deposition on the PV panels. Generally, coal-fired power plants have an abundant area of coal ash pond that is suitable for installing floating PV systems. However, this area is prone to dust deposition resulting from pulverized coal particles and fly ashes. This paper aims to evaluate the effects of dust deposition on PV panels’ performance, specifically for PV systems that will be installed near coal-fired power plants in Malaysia. In this study, PV panels were exposed to four different types of dust deposit conditions, which are coal particles, fly ashes, normal environmental dust as well as control PV panel that was clean on daily basis. The tests were carried out outdoor under natural sunlight. Performance of the PV panels were measured based on the power generated by the panels. The average power drop based on the types of dust deposition on PV panels are; natural dust (2.72%), fly ash (13.16 %) and coal ash (15.82 %).

Effect of dust concentration, wind speed, and relative humidity on the performance of photovoltaic panels in Tehran

ABSTRACT Impact of dust concentration and weather conditions – wind speed and relative humidity – on power generation of photovoltaic (PV) panels investigated experimentally in Tehran, Iran, for the period of April 10–September 22, 2018. Two Photovoltaic panels together with data-logging equipment were applied in this experiment. One panel was cleaned every day, while the other was remained unclean after 45 days. A performance ratio called “cleanness index” (CI) which is a temperature-corrected performance ratio of a soiled PV panel to that of a clean one was also used to indicate the dust deposition effect on PV panel performance. The uncertainty range of experimental results was between 5.27% and 5.55%. The results show that cleanness index had positive correlation with wind speed and negative correlations with relative humidity and dust concentration. Thus, in comparison to the clean PV panel, the output-power of the soiled panel reduced, approximately 8–12% per month. Furthermore, in order to numerically predict daily change of cleanness index (ΔCIPre ), a linear regression model was developed and the outcome revealed that dust concentration had the most impact, with 21.56%.

Rapid evaluation of micro-scale photovoltaic solar energy systems using empirical methods combined with deep learning neural networks to support systems’ manufacturers

Abstract Solar energy is becoming one of the most attractive renewable sources. In many cases, due to a wide range of financial or installation limitations, off-grid small scale micro power panels are favoured as modular systems to power lighting in gardens or to be integrated together to power small devices such as mobile phone chargers and distributed smart city facilities and services. Manufacturers and systems’ integrators have a wide range of options of micro-scale photo voltaic panels to choose from. This makes the selection of the right panel a challenging task and risky investment. To address this and to help manufacturers, this paper suggests and evaluates a novel approach based on integrating empirical lab-testing with short-term real data and neural networks to assess the performance of micro-scale photovoltaic panels and their suitability for a specific application in specific environment. The paper outlines the combination of lab testing power output under seasonal and hourly conditions during the year combined with environmental and operating conditions such as temperature, dust accumulation and tilt angle performance. Based on the lab results, a short in-situ experimental work is implemented and the performance over the year in the selected location in Kuwait is evaluated using deep learning neural networks. The findings of this approach are compared with simulation and long-term real data. The results show a maximum error of 23% of the neural network output when compared with the actual data, and a correlation values with previous work within 87.3% and 91.9% which indicate that the proposed approach could provide an experimental rapid and accurate assessment of the expected power output. Hence, supporting the rapid decision-making process for manufacturers and reducing investment risks.

Photovoltaic performance of one axis multiple-position sun-tracked PV panels

In this article, the photovoltaic performance of one-axis multiple-positions sun-tracked photovoltaic panels (MP-PV) is investigated based on solar geometry and dependence of photovoltaic conversion efficiency on the incident angle (IA) of solar rays on PV panels. For such PV system, the azimuth angle (AZA) of PV panels is daily adjusted several times (M) from eastward in the morning to westward in the afternoon by rotating PV panels about inclined north-south axis (INSA) to ensure the projected incident angle (PIA) of solar rays on the plane perpendicular to INSA is always less than the specified angle θa. Results show that, the annual electricity generation (AEG) of MP-PV increases with the increase of M, but such increase is not noticeable when M>5. For MP-PV with the tilt-angle (β) of INSA being yearly fixed (1T-MP-PV), the optimal θa of 3P-,5P- and 7P-PV for maximizing AEG are respectively 24°, 15° and 11.5°, and their AEGs are respectively about 92%, 94% and 95% of that from similar 2-axis tracked PV panels (2A-PV). Whereas for MP-PV with the β being yearly adjusted four times at three tilts (3T-MP-PV), the optimal θa of 3P-, 5P- and 7P-PV are respectively about 22.5°, 14.5° and 11°, and the Pa are respectively about 96%, 98% and 99% of that of similar 2A-PV systems.

Investigation of Operating Parameters and Degradation of Photovoltaic Panels in a Photovoltaic Power Plant

Recently, the use of photovoltaic (PV) cells and the increase in the number of photovoltaic power plants has led to a detailed examination of their operating parameters. In this article, we discuss material and operating parameter influences on the performance and efficiency of photovoltaic panels in a photovoltaic power plant. The plant consisted of 3600 pieces of polycrystalline PV panels from Renewable Energy Corporation (REC) Solar (type REC 230AE) with a maximum power of 230 Wp. Parameter measurements were made three years after the power plant was started. The measured and computed data were statistically processed using multidimensional statistical methods where the relationships between input and output variables were examined, which was subsequently quantified by regression analysis. Using the ANOVA, the variability of the measured efficiency of the panels and the performance for individual years was examined. Efficiency has been found to increase significantly over the years. The reason for this is the statistically proven prevailing operating time of the PV power plant in conditions with lower temperature than standard operating conditions (25 °C). Ageing was not confirmed in optimal conditions and calculated efficiency was constant.

Analysis of an Integrated Photovoltaic Thermal System by Top Surface Natural Circulation of Water

The performance of photovoltaic (PV) panel is extremely sensitive to its operating temperature. Most of the energy absorbed by the panel is wasted in the form of heat and provides no value. Integrated photovoltaic thermal system can be a great solution to this problem. In this study, a numerical and experimental work is conducted on hybrid photovoltaic – thermal water heating system with front surface water cooling. First, a numerical analysis is conducted which is capable of describing various thermal parameters affecting the performance of photovoltaic panel and collector. The effect of supplying different mass flow rates of water over the individual photovoltaic and collector system and the overall system are examined thoroughly by experiment. The results of the numerical analysis are found in good agreement with the experimental analysis. Due to active cooling, it was also observed that the overall efficiency of the whole system is approximately five times higher than the efficiency of PV panel alone. Top surface cooling method significantly dropped the panel temperature and increased the panel efficiency by almost 1.5% with an overall system efficiency of around 80% where, PV and collector efficiencies are approximately 16% and 64% respectively.

Improved Photovoltaic Panel Performance Using a Cylindrical Pin Fins as a Heat Sink

In this work, the photovoltaic panel performance has been investigated theoretically and experimentally where using an array of pin fins as a cooling system. Trying to satisfy the ideal operation conditions of the solar panel, heat sink was fixated on the back of the PV panel to use as a passive technique. An Analytical thermal model based on the steady state and one dimension analysis condition was built to transfer the excess heat from PV panel with the heat sink existing to predict the operation temperature of PV panel. Theoretical results were compared with experimental results of solar panels cooled by heat sink, in order to validate the suggested thermal model. Also, the effect of the solar cells temperature on the panel performance has been studied experimentally. The results displays that using pin fins array as a cooling technique led to drop in the average panel's temperature nearly 5.9°C and an enhancement of the average output power nearly 13.5%.

Effect of Temperature on Solar Photovoltaic Panel Efficiency

Solar energy is the important energy source for future. Lot of devices are used for capture the energy from solar radiation and convert into useful form of energy. Solar PV (Photovoltaic) Panels are the promising devices convert the solar radiation into electrical form of energy. The partial portion of solar energy may be converted into electricity remaining in the form heat energy. Solar PV panel performance varies with temperature increase. The PV panel temperature has effect on power and voltage. Due to increase of temperature, the photovoltaic solar cells efficiency may be decreased. The life of the panel also will be decreased. In this paper how the heat energy received from solar radiation in the form of temperature affect the solar panel efficiency was analysed by experiment conducted with solar PV panel of 50W in the real outdoor environmental condition.

Influence of the Parasitic External Electromagnetic Field on the Efficiency of a Photovoltaic System

The aim of this work is to study the effect electromagnetic disturbances issued from high voltage–power stations of a given power on the performance of photovoltaic panels placed at different distances from sources emitting electromagnetic radiation the tests were carried out under real conditions in the region of Annaba for a power line 400 kV high voltage connecting to Ramdane Djamel to Cheffia, the obtained results allowed analyzing the current–voltage, power–voltage characteristics in the presence of the electromagnetic field. For a better characterization of the photovoltaic generators, we study the electrical power delivers by the photovoltaic generators to an external charge and we deduce the conversion efficiency of the photovoltaic system with a maximum power point tracking command for 09 h depending on the intensity of the electromagnetic field. The experimental results make it possible to check the influence of parasitic radiation on the photovoltaic system with the proposed controller.

Using CaCl2·6H2O as a phase change material for thermo-regulation and enhancing photovoltaic panels’ conversion efficiency: Experimental study and TRNSYS validation

This study aims to investigate how Calcium Chloride Hexahydrate (CaCl2·6H2O) as a phase change material (PCM) can regulate the PV cells temperature and improve the electrical performance of photovoltaic panels in a completely cold environment in Tehran, Iran. Moreover, TRNSYS simulation software was employed to validate the experimental Results. Also, a novel kind of facile and cost-effective system design and data acquisition were introduced. A general analysis for all the experiments’ days and an investigation on a particular day at the end of November for having a closer look was done. Then, a comparison between experimental and simulation results was performed. In this regard, experimental outcomes showed a maximum temperature drop by 26.3∘C (38% of reduction) for the PV-PCM panel compared to the conventional PV module. Furthermore, PV-PCM panel benefited from a power output increase by 1.16 W (24.68% of increase) during November and December. Finally, modeling outcomes followed the experimental data perfectly with very low errors. With this in mind, the minimum and the maximum difference between experimental and simulation results were 0.96% and 8.25% respectively, which demonstrated a great agreement between these data.

Influence of wind speed on the performance of photovoltaic panel

The aim of this project is to investigate the performance of photovoltaic (PV) panel influence by wind speed in Kangar, Perlis, Malaysia. A low conversion energy efficiency of the PV panel is the major problem of a PV application system. The PV panel is absorbed solar irradiance minor converted into electrical energy, and the rest is converted into heat energy. Therefore, the heat energy generated by the PV panel is increased in its operating temperature. However, PV panel is necessary to operate them at the low operating temperatures to keep the PV panel electrical efficiency at an acceptable level. In this experiment, one unit of the PV panel was limited wind flow over its surface and the other one PV panel was operated in the normal condition. The operating temperature of the PV panel with wind speed is less than the PV panel without wind speed. This is due to wind flow over the surface of the PV panel can enhance heat extraction from the PV panel. Hence, PV panel with wind speed can generate a higher output power than that without wind speed. This improvement output performance of PV panel will have an important contribution to PV application systems.

Study on Lighting -Heating-Electricity Coupled Energy Saving Potential for STPV Window in Southwest China

Building integrated photovoltaic (BIPV) is an important application of solar cells. In this paper, the experiments were conducted to test the performance of photovoltaic panels installed in buildings. The experiments were carried out in Chengdu, Southwest China which located in climate zone of hot summer and cold winter. The real-time power generation, the simultaneous generation of heat and the impact on indoor lighting are important factors for building energy consumption. Two identical rooms were built up as experimental units, and one of which was fitted with amorphous silicon PV windows, and another was fitted with conventical window. According to the test results, it can be seen that, the PV film windows could save the 30% building load on typical sunny days, and provide additional 0.41 kWh/per day.

Experimental study of PV strings affected by cracks

Crack is one critical factor that degrades the performance of photovoltaic (PV) panels. To gain a better understanding of the impacts of cracks appeared on PVs and also to mitigate it, its failure mechanism, detrimental effects, criticality, and potential risks on independent PV panels are firstly reviewed in this study. An experimental study which investigates the degree of series connected and parallel connected PV strings which are affected by cracked cells are presented. A comparison of impacts of the partially shaded PV panel string and cracked cells happened to the PV panel string is given to evaluate their criticality levels. The experimental results show that the series connected PV panel string is strongly affected once the cell is seriously cracked, as the current generation capability is clamped. Partial shading, however, shows better performance. In addition, though the overall power the parallel connected PV string is reduced, it is less affected by the cracked cells compared to the series connected one. Lastly, a bypass diode is added to a series connected PV panel string with cracked cells, and the experimental results show that it can be an effective way to minimise the negative impacts of cracks.