Experimental Investigation of the Stability of the Performance Characteristics of a Photovoltaic Module in the Face of Environmental and Meteorological Factors

The explosive technological improvement of photovoltaic systems as well as the necessity of populations to come to less expensive energy sources, that have led to an implosion at the level of solar panel manufacturers. This causes a large flow of these equipments to developing countries where the need is high, without any quality control. That conducted an experimental investigation on the performance characteristics of a 250 wp monocrystalline silicon photovoltaic module in other to check the verification and quality control. Most of these PV panels which often have missing informations are manufactured and tested in places that are inadequate for our environmental and meteorological conditions. Also, their influences on the stability of internal parameters were evaluated in order to optimize their performance. The results obtained at maximum illumination (1000 w/m2) confirmed those produced by the manufacturer. The analysis of these characteristics showed that the illumination and the temperature (meteorological factors) influenced at most the stability of the internal characteristics of the module in the sense that the maximum power increased very rapidly beyond 750 w/m2 but a degradation of performance was accentuated for a temperature of the solar cells exceeding 50°C. The degradation coefficients were evaluated at -0.0864 V/°C for the voltage and at -1.6248 w/°C for the power. The 10° inclination angle of the solar panel proved to be ideal for optimizing overall efficiency in practical situations.

A Study of the Temperature Influence on Different Parameters of Mono-Crystalline Silicon Photovoltaic Module

In this article, the effect of temperature on the photovoltaic parameters of mono-crystalline silicon Photovoltaic Panel is undertaken, using the Matlab environment with varying module temperature in the range 25°C - 60°C at constant solar irradiations 200 - 500 W/m2. The results show that the temperature has a significant impact on the various parameters of the photovoltaic panel and it controls the quality and performance of the solar panel. The photovoltaic parameters are the current of short circuit Isc, the open circuit voltage Vco, the form factor FF, the maximum power Pmax as well as efficiency. The relative change of these photovoltaic parameters with temperature is also evaluated in this article. A DS-100M solar panel has been used as reference model. The results show also that the open circuit voltage, maximum power, fill factor and efficiency decrease with temperature, but the short circuit current increases with temperature. The results are in good agreement with the available literature.

Investigations on the Optimization of Contacts Barrier Height for the Improved Performance of ZnO/CdS/CZTS Solar Cells

The numerical simulations were performed using the AMPS-1D simulator to study the effects of the CZTS as an absorber layer and the contacts’barrier height on the performance of four ZnO/CdS/CZTS solar cells.To obtain the best cell performances,the barrier heights of the back and front contacts were adjusted between 0.01,0.77,0.5,and 1.55 eV,respectively.For simulations,we used the lifetime mode,and the device performances were evaluated under AM1.5 illumination spectra.We found that the efficiency,fill factor,and open-circuit voltage were almost constant at a front contact barrier height of less than 0.31 eV.The short-current density was not affected by the front contact barrier height.The back contact material had a significant impact on the CZTS cells parameters.The best performance was obtained for the CZTS550 cell with JSC=29.53 mA/cm2,VOC=1.07 V,FF=0.88,andη=28.08%at barrier heights of 0.31 and 1.55 eV for front and back contacts,respectively.The conduction band offset at the CZTS550/CdS hetero-junction was found to be spike-like with 0.21 eV.The obtained conversion efficiency is comparable to those previously reported in the literature.

Simulations of the Performance of Maximum Power Point Tracking Algorithms Based on Experimental Data According to the Topologies of DC-DC Converters

Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous performance test under normal weather conditions. This paper proposes an experimental evaluation of MPPT algorithms according to DC-DC converters topologies, under normal operation conditions. Four widely used MPPT algorithms i.e. Perturb and Observe (P & O), Hill Climbing (HC), Fixed step Increment of Conductance (INCF) and Variable step Increment of Conductance (INCV) are implemented using two topologies of DC-DC converters i.e. buck and boost converters. As input variables to the PV systems, recorded irradiance and temperature, and extracted photovoltaic parameters (ideality factor, series resistance and reverse saturation current) were used. The obtained results show that buck converter has a lot of power losses when controlled by each of the four MPPT algorithms. Meanwhile, boost converter presents a stable output power during the whole day. Once more, the results show that INCV algorithm has the best performance.

Effect of temperature on the efficiency of organometallic perovskite solar cells

In recent years perovskite solar cells have attracted an increasing scientific and technological interest in the scientific community. It is important to know that the temperature is one of the factors which have a strong effect on the efficiency of perovskite solar cell. This study communicates a temperature analysis on the pho- tovoltaic parameters of CH3NH3Pbl3-based perovskite solar cell in a broad interval from 80 to 360 K. Strong temperature-dependent photovoltaic effects have been observed in the type of solar cell, which could be mainly attributed to CH3NH3PbI3, showing a ferroelectric-paraelectric phase transition at low temperature （T 〈 160 K）. An increase in temperature over the room temperature decreased the perovskite solar cell performance and reduced its efficiency from 16Z to 9%. The investigation with electronic impedance spectroscopy reveals that at low temperature （T 〈 120 K） the charge transport layer limits the device performance, while at high temperature （T 〉 200 K）, the interfacial charge recombination becomes the dominant factor.

Performance Enhancement in Dye-Sensitized Solar Cells with Composite Mixtures of TiO_2 Nanoparticles and TiO_2 Nanotubes

In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes（TNTs） with TiO_2 nanoparticles（TNPs）.TNPs were synthesized by sol-gel method,and TNTs were prepared through alkali hydrothermal method.Dye-sensitized solar cells（DSSCs） were fabricated with different photoanodes comprising of various ratios of TNTs ＋ TNPs,synthetic indigo dye as photosensitizer,PMII（l-propyl-3-methylimidazolium iodide） as ionic liquid electrolyte and cobalt sulfide as counter electrode.The structures and morphologies of TNPs and TNTs were analyzed through X-ray diffractometer,transmission electron microscope and scanning electron microscopes.The results of the investigation showed that the DSSC-4 made with composite photoanode structure（TNTs/TNPs）（90% of TNPs ＋ 10% of TNTs） had improved photocurrent efficiency（2.11%） than pure TNPs（1.00%） and TNT film（0.78%）.Electrochemical impedance spectra revealed that the composite TNTs/TNPs film-based DSSCs possessed the lowest charge-transfer resistances and longest electron lifetime.Hence,it could be concluded that the composite TNTs/TNPs photoanode facilitates the charge transport rate and enhances the efficiencies of DSSCs.