Conversion Efficiency Of Photovoltaic Modules Research Articles

State-of-the-art review of MPPT techniques for hybrid PV-TEG systems: Modeling, methodologies, and perspectives

The development of alternative renewable energy technologies is crucial for alleviating climate change and promoting energy transformation. Of the currently available technologies, solar energy has promising application prospects owing to its merits of being clean, safe, and sustainable. Solar energy is converted into electricity through photovoltaic (PV) cells; however, the overall conversion efficiency of PV modules is relatively low, and most of the captured solar energy is dissipated in the form of heat. This not only reduces the power generation efficiency of solar cells but may also have a negative impact on the electrical parameters of PV modules and the service life of PV cells. To overcome the shortcomings, an efficient approach involves combining a PV cell with a thermoelectric generator (TEG) to form hybrid PV-TEG systems, which simultaneously improve the energy conversion efficiency of the PV system by reducing the operating temperature of the PV modules and increasing the power output by utilizing the waste heat generated from the PV system to generate electricity via the TEGs. Based on a thorough examination of the literature, this study comprehensively reviews 14 maximum power point tracking (MPPT) algorithms currently applied to hybrid PV-TEG systems and classifies them into five major categories for further discussion, namely conventional, mathematics-based, metaheuristic, artificial intelligence, and other algorithms. This review aims to inspire advanced ideas and research on MPPT algorithms for hybrid PV-TEG systems.

Thermal analysis of radiative cooling coating on the rear surface of photovoltaic tile

Temperature is one of the key factors to limit the conversion efficiency of photovoltaic modules. Passive radiative cooling (PRC) technology commonly used in the energy-saving applications is hopeful to improve this situation. In this paper, photovoltaic tile covered with PRC coating was studied to evaluate the feasibility of PRC technology. A thermal model was proposed to theoretically calculating the temperature distribution of PV tile module along the thickness direction. Two kinds of PRC coatings with different ideal infrared spectrums applied on the front and rear surface of PV tile was compared to assess the thermal and electrical performances. Then the optimum infrared spectrum and coating location of PRC coating for PV tile were determined, which means that the PRC coating with ideal broadband emittance applied on the rear surface of PV tile would be the best choice. A commercial radiative coating (CRC) with broadband emittance was applied on the rear surface of PV tile to ensure the cooling effect. The results indicated that the CRC on the rear surface could cool PV tile module down by 3.6 °C, and increase the efficiency by ∼ 0.33% under the average irradiance of 930 W/m2. Environmental parametric investigations demonstrated that the ground emissivity had a significant impact on the cooling effect of the optimal radiative coating (ORC) on the rear surface of PV tile. Moreover, the cooling capacity of the ORC was proved to be immune to the impact of humidity.

Photovoltaic fault diagnosis model based on dynamic switching

PV module fault diagnosis is mostly based on the prediction of photovoltaic module's power generation in the short term, and the fault of the module can be judged by comparing the difference between the actual power generation and the predicted power generation. However, the photoelectric conversion efficiency of photovoltaic modules varies significantly with seasons and weather, single prediction model is lack of stability, the season in a significant and a change in the weather forecast results will appear large deviation, this will lead to frequent false alarms of fault diagnosis, make power plant maintenance and repair costs unnecessarily. According to the characteristics that the photoelectric conversion efficiency of photovoltaic modules is greatly affected by weather and season, a fault diagnosis method for photovoltaic power generation based on dynamic model switching is proposed. when meet preset conditions, using the different quarters of historical data, combined with recent data to update the model, improved the fitness of model for the current weather and season. Compared with a single fixed model, the results show that the proposed method has better adaptability to different seasons and different weather.

The effect of flight state parameters on the performance of photovoltaic modules in solar aircraft

Based on the power generation model of photovoltaic modules, the effects of flight speed, altitude, time and area in solar aircraft on the performance of photovoltaic modules have been studied. As the flight speed increases, the power generated by the module increases but tends to saturate. When the conversion efficiency of photovoltaic modules is improved, the required power of the solar aircraft and the power generated by the photovoltaic modules are balanced at a faster flight speed. The power generated by the modules increases with the flight altitude but tends to saturate due to the drop of air temperature and the surface temperature of the module. The higher the altitude, the smaller is the atmospheric density, and atmospheric permeability, and the greater is the solar radiation intensity, and thus the power generated by the module increases. The power generated by the components is the strongest at noon. Battery performance is the strongest in summer and the weakest in winter, as the module’s performance is mainly determined by the intensity of solar radiation. Finally, the energy distribution of solar aircraft and long-time space flight has been discussed.
 J. Bangladesh Acad. Sci. 45(1); 73-83: June 2021

Study of the influence of dust deposits on photovoltaic solar panels: Case of Nouakchott

Degradation performance of photovoltaic (PV) modules by real weather conditions has become increasingly problematic. In the desert climate, dust accumulation is one of the main concerns that may cause a significant deterioration of PV efficiency. In the present work, experimental investigations were carried out to understand the effect of dust on the electrical performance of PV modules under Toujounine, Nouakchott, Mauritania weather conditions. The measurements were performed with an I-V tracer ftv200. The measured parameters were I-V and P-V curves, open-circuit voltage (Voc), short-circuit current (Isc), current and voltage at maximum power (Imp and Vmp) and maximum power (Pmax); as well as the measurement of temperature of panels and Irradiation. The study was carried out according to the following cleaning scenarios: panels cleaned before each measurement (Clean panels 01), panels undergoing systematic cleaning with the central unit (Clean panels 02) and chains undergoing no cleaning (Dusty panels 03). Then, the modeling of reliability as a function of maximum power by Weibull's law, for clean and dusty panels is evaluated. According to the experimental results, disturbances in I-V and P-V curves for dusty panels were noticed. Also, a decrease in the Isc and the Imp for dusty panels compared to clean panels was found. These results are explained by the effect of dust accumulation on the module's surface, which blocks the solar radiation and thus reduces the conversion efficiency of PV modules. Again, dust reduces the output power of photovoltaic modules by 21.57% for dusty panels per clean panels. Finally, a low reliability for dusty panels compared to clean panels was found, due to the loss in the output power under the dust effect. These results clearly show the importance of properly maintaining and servicing the photovoltaic modules to avoid their degradation by dust deposits.

Comparison of maximum power point tracking techniques used in photovoltaic system

Among the various renewable energy sources, photovoltaic (PV) systems are experiencing a great expansion, due to their low polluting levels, the abundance of solar energy and the cost decreasing of PV technologies, attracting research and investments in the field. The maximum power generated in a PV panel varies according to irradiation and temperature. Since the conversion efficiency of photovoltaic modules is low, it is necessary to implement sophisticated control techniques for monitoring the maximum power point (MPPT). Maximum power point tracking techniques are automatic control algorithms that adjust power interfaces to achieve the maximum power generation, during variations in irradiation, temperature, and characteristics of the photovoltaic module. The purpose of the MPPT is to adjust the solar panel operating voltage near the maximum power point (MPP) according to environmental conditions. This technique has become an essential component in photovoltaic power system designs. This article presents comparison of the performance of various MPPT tracking methods in photovoltaic systems using the MATLAB/Simulink software and a comparative approach.

Performance analysis of passive cooling for photovoltaic modules and estimation of energy-saving potential

Photovoltaic (PV) cooling techniques focus on the conversion efficiency of PV modules. Unlike active cooling techniques, which consume more energy, selective spectral cooling and passive radiative cooling are based on the principle of suppressing heating by the PV module itself. In this study, a thermal-electric coupled model is established for evaluating the cooling effect of selective spectral and passive radiative cooling under variable conditions. Compared with referenced PV modules, under conditions of AM1.5, v = 2 m/s, Ta = 309.15 K, selective spectral, passive radiative, and combined cooling could promote the efficiency by 0.98%, 2.40%, and 4.55%, respectively. Based on the proposed model, the potentials of passive radiative cooling are theoretically estimated by considering differences in relative humidity for different locations around China, and potential improvements of efficiency by 2–2.5% in the northwest and northeast could be estimated. In addition, the levelized cost of electricity (LCOE) was used to clear the economic viability of the proposed passive cooling methods, and the integrated energy-saving efficiency (IESE) was proposed to quantify the gains of power generation and the shading performance.

Implementation of Maximum Power Point Tracking (MPPT) Technique on Solar Tracking System Based on Adaptive Neuro-Fuzzy Inference System (ANFIS)

Characteristic I-V of photovoltaic is depended on solar irradiation and operating temperature. Solar irradiation particularly affects the output current where the increasing solar irradiation will tend to increase the output current. Meanwhile, the operating temperature of photovoltaic module affects the output voltage where increasing temperature will reduce the output voltage. There is a point on the I-V curve where photovoltaic modules produce maximum possible output power that is called Maximum Power Point (MPP). A technique to track MPP on the I-V curve is known as Maximum Power Point Tracking (MPPT). In this study, the MPPT has been successfully designed based on Adaptive Neuro-Fuzzy Inference System (ANFIS) and integrated with solar tracking system to improve the conversion efficiency of photovoltaic modules. The designed ANFIS MPPT system consists of current and voltage sensors, buck-boost converter, and Arduino MEGA 2560 microcontroller as a controller. Varying amounts of lamp with 12V 10W rating arranged in series is used as load. Solar tracking system that is equipped with MPPT ANFIS able to increase the output power of photovoltaic modules by 46.198% relative to the fixed system when 3 lamps is used as load.

Comprehensive Analysis of Effect of Accumulation of Dust on a Solar Panel

In the pursuit of a cleaner and sustainable environment, solar photovoltaic (PV) power has been established as the fastest growing alternative energy source in the world. This extremely fast growth is brought about, mainly, by government policies and support mechanisms world-wide. Solar PV technology that was once limited to specialized applications and considered very expensive is becoming more efficient and affordable. Solar PV promises to be a major contributor of the future global energy mix due to its minimal running costs, zero emissions and steadily declining module and inverter costs. Deposition of airborne dust on outdoor photovoltaic (PV) modules may decrease the transmittance of solar cell glazing and cause a significant degradation of solar conversion efficiency of PV modules. Dust deposition is closely related to the tilt angle of solar collector, exposure period, site climate conditions, wind movement and dust properties. In this practical field study, an experimental-based investigation is conducted. Thus, we conducted a study to gauge the effect of dust on the solar panel over a pre-determined period.

Degradation of electrical performance of a crystalline photovoltaic module due to dust deposition in northern Poland

The reduction in power output caused by the accumulation of dust on the photovoltaic module surface is an important problem and should receive much more attention in the literature. This study was an evaluation of the performance degradation of crystalline photovoltaic modules due to natural and simulated dust deposition. Dust is created from powdered grains of sand and particles of different bodies. Dust originates from different sources, e.g. from the soil and volcanic eruptions. Dust in the air is an aerosol, and in high concentrations can cause climate change. Deposition of airborne dust on photovoltaic modules may decrease the transmittance of solar cell glazing and cause a significant degradation in the solar conversion efficiency of photovoltaic modules. Dust deposition is closely related to the tilt angle of the module, the exposure period, site climate conditions, wind movement and dust properties. In this article, a brief review of the energy yield losses caused by dust deposition on photovoltaic modules and the results of experimental research conducted in Poland are presented. Dust samples were collected after a few years of natural and artificial dust deposition. The reduction in efficiency had a linear relationship with the dust deposition density.

Experimental investigation of the impact of airborne dust deposition on the performance of solar photovoltaic (PV) modules

Abstract Deposition of airborne dust on outdoor photovoltaic (PV) modules may decrease the transmittance of solar cell glazing and cause a significant degradation of solar conversion efficiency of PV modules. Previous studies of this issue indicated that dust deposition is closely related to the tilt angle of solar collector, exposure period, site climate conditions, wind movement and dust properties. However, few studies considered the influence of the properties of PV module itself on dust deposition and efficiency degradation, such as the cell types and surface materials. This experimental work aimed to study the dust accumulation onto different types of solar PV modules and the corresponding efficiency degradation. The experiment was designed and conducted in the laboratory with a sun simulator and a test chamber. The degradation of PV module efficiency caused by dust deposition under various conditions was investigated. The results indicated that dust pollution has a significant impact on PV module output. With dust deposition density increasing from 0 to 22 g m −2 , the corresponding reduction of PV output efficiency grew from 0 to 26%. The reduction of efficiency has a linear relationship with the dust deposition density, and the difference caused by cell types was not obvious. When the dust deposition density was fixed, the reductions of output efficiency at relatively lower or higher solar densities were much more severe. Moreover, the surface material may influence dust deposition and accumulation considerably. The poly-crystalline silicon module packaged with epoxy degraded faster than other modules with glass surface under the same dust concentration.

Experimental natural convection on vertical surfaces for building integrated photovoltaic (BIPV) applications

An experimental study on natural convection in an open channel is carried out in order to investigate the effect of the geometrical configuration of heat sources on the heat transfer behaviour. To this aim, a series of vertical heaters are cooled by natural convection of air flowing between two parallel walls. The objective of the work is to investigate the physical mechanisms which influence the thermal behaviour of a double-skin photovoltaic (PV) facade. This results in a better understanding of the related phenomena and infers useful engineering information for controlling the energy transfers from the environment to the PV surfaces and from the PV surfaces to the building. Furthermore increasing the heat transfer rate from the PV surfaces increases the conversion efficiency of the PV modules since they operate better as their temperature is lower. The test section consists in a double vertical wall, 2 m high, and each wall is constituted by 10 different heating modules 0.2 m high. The heater arrangement simulates, at a reduced scale, the presence of a series of vertical PV modules. The heat flux at the wall ranges from 75 to 200 W/m 2. In this study, the heated section is 1.6 m in height, preceded by an adiabatic of 0.4 m in height. Different heating configurations are analyzed, including the uniform heating mode and two different configurations of non uniform, alternate heating. The experimental procedure allows the wall surface temperature, local heat transfer coefficient and local and average Nusselt numbers to be inferred. The experimental evidences show that the proper selection of the separating distance and heating configuration can noticeably decrease the surface temperatures and hence enhance the conversion efficiency of PV modules.

Effective efficiency of PV modules under field conditions

AbstractThe conversion efficiency of photovoltaic modules varies with irradiance and temperature in a predictable fashion, and hence the effective efficiency averaged over a year under field conditions can be reliably assessed. The suggested procedure is to define the efficiency versus irradiance and temperature for a specific module, collect the local irradiance and temperature data, and combine the two mathematically, resulting in effective efficiency. Reasonable approximations simplify the process. The module performance ratio is defined to be the ratio of effective efficiency to that under standard test conditions. Variations of the order of 10% in this factor among manufacturers, primarily the result of the differences in effective series resistance and leakage conductance, are not unusual. A focus on these parameters that control the effective efficiency should provide a path to PV modules with improved field performance. Copyright © 2006 John Wiley & Sons, Ltd.

Life‐cycle assessment of photovoltaic modules: Comparison of mc‐Si, InGaP and InGaP/mc‐Si solar modules

AbstractA higher conversion efficiency of photovoltaic modules does not automatically imply a lower environmental impact, when the life‐cycle of modules is taken into account. An environmental comparison is carried out between the production and use phase, except maintenance, of an indium–gallium–phosphide (InGaP) on multicrystalline silicon (mc‐Si) tandem module, a thin‐film InGaP cell module and a mc‐Si module. The evaluation of the InGaP systems was made for a very limited industrial production scale. Assuming a fourfold reuse of the GaAs substrates in the production of the thin‐film InGaP (half) modules, the environmental impacts of the tandem module and of the thin‐film InGaP module are estimated to be respectively 50 and 80% higher than the environmental impact of the mc‐Si module. The energy payback times of the tandem module, the thin‐film InGaP module and the mc‐Si module are estimated to be respectively 5.3, 6.3 and 3.5 years. There are several ways to improve the life‐cycle environmental performance of thin‐film InGaP cells, including improved materials efficiency in production and reuse of the GaAs wafer and higher energy efficiency of the metalorganic chemical vapour deposition process. Copyright © 2003 John Wiley & Sons, Ltd.

Transformation du rayonnement solaire par fluorescence: Application a l'encapsulation des cellules

The presence of fluorescent material, associated with a “cascade of light” in the polymethylmethacrylate (PMMA) which coats the silicon solar cells, allows an increase of 25% in the conversion efficiency of photovoltaic modules. This is due to two effects: (1) a better match between the incident radiation and the solar cell spectrum; (2) concentration of the radiation because of the total internal reflections in the PMMA matrix.