COMPARISON AND BEHAVIOUR OF PV MODULES

Optics Communications, 1998

Energetic losses, relative to the standard conditions of testing, in photovoltaic modules in outdoor operation, were Ž. analyzed and the role of the optical effects is discussed. The following four loss effects were estimated: a reflection of Ž. Ž. Ž. unpolarized light, b spectrum, c intensity of the light and d temperature of the module. Four independent models were used to describe these four losses. The models were validated by the experimental data of an outdoor measurement campaign performed on 08 tilted modules at 418N latitude in South Italy. Disagreement reaching 5% under clear sky conditions was found between theoretical predictions and experimental data for the instantaneous total loss. As a result of a critical analysis of the literature data on this subject, it could be explained by invoking the presence of a fifth loss mechanism: the polarization of the incident light. Final relative losses, due to the particular state of the incident sunlight, amount to about 7-8% of a total of 14-15%. Of these, 3% is due to the low irradiation level, 1-2% to the polarization of the skylight and Ž. 3% to the reflection of the incident light on the front cover of the module. The spectral effects are negligible less than 1%. The remaining 7% loss is due to temperature effects on the module. All the loss data are reported as a function of the air Ž. mass AM. The maximum operating efficiency is reached at AM f 1.5.

2017

In the present paper, an experimental analysis of the PV modules efficiency of different photovoltaic comprising monocrystalline silicon, polycrystal-line silicon and thin-film silicon technologies has been made. The PV modules were first subjected to thorough indoor evaluation (Sun simulator, Electroluminescence) to check the real characteristics and internal defects that make the effectiveness of these modules lower compared to characteristics declared by the manufacturer under the terms of DIN EN ISO/IEC 17025:2005. Results of the first analysis have been taken as a reference for the second part, which consist of ex-posing the PV modules to various natural factors in outdoor environment (solar radiation, temperature, wind, humidity…) versus time. Then, using the peak power measuring device PVPM, different electrical characteristics of the photovoltaic module during the exposure in operating site were determined. Significant differences in the energy efficiency of PV modules have ...

At the begin of 2009 the ISAAC institute started a new measurement campaign investigating thirteen different modules commercially available on the market. Two modules of each type have been exposed outdoors for energy yield monitoring and a third module has been stored indoors as a reference. The modules covers a large range of different technologies ranging from multi-crystalline silicon (mc-Si) of which two with back-contact cells, 3 single-crystalline silicon (sc-Si), 1 hybrid mono-crystalline technology with amorphous silicon layer (HIT), 1 double junction amorphous silicon (a-Si/a-Si), 1 micromorph (a-Si/µc-Si), 1 Cupper-Indium-Sulfide (CIS) and 1 Cupper-Indium-Gallium-Diselenide (CIGS). The aim of the measurement campaign is to assess the quality of current technologies and the understanding of observed differences between technologies. Outdoor and indoor performance of the modules are analysed over 15 months performing measurements under real operating conditions, regular STC and low irradiance indoor testing with a solar simulator to determine stability of the devices over time and the relation between indoor performance and outdoor yield. The modules are therefore installed on a ventilated rack where each single module is connected to a maximum power point tracker delivering Im, Vm values in minutes intervals. The annual energy output in kWh/Wp is measured and the differences between various module technologies or modules of the same technology is analysed, by quantifying the influence of the temperature coefficient, the low irradiance performance measured indoors, the module temperature as well as all measurement related uncertainties.

2016

The demand of energy is increased due to speedy rise in population and advancement in the technology day-to-day in the entire process of development, growth and continued existence of all living beings. Therefore, countries should have high awareness to utilize alternative sources of energy . The entire world is facing a challenge of energy crisis due to the diminishing deposits of non-renewable energy resources such as coal, natural gas, fossil fuels etc and increasing concerns of its effects on global warming, damage to environment and ecosystem. In order to overcome the growing global energy demand alongside the limitation of the fossil fuels reserves and their negative effects on the environment have results in a great tendency toward renewable energy sources development . Renewable energy sources like wind, geothermal, tidal and solar energy are environmentally friendly, since they have a much lower environmental impact than conventional sources like fossil fuel. Among different kinds of renewable energy sources solar energy is considered as immense source because of its abundance, sustainability and completely free of cost. Solar energy is a renewable that is inexhaustible and if used in a proper way, it has a capacity to fulfill numerous energy needs of the world (Kachhiya, Patel, & Lokhande, 2011). Solar energy is widely accepted as a key energy source for the future around the world with respect to the environmental issues associated with fossil fuels. The information concerning available solar radiation is essential for solar energy devices, such information is also vital for meteorological experts, architects, agriculturalists, air conditioning engineers and energy-conscious designers of buildings . Solar radiant energy is important factors that characterize the energy through the PV (photovoltaic) effect among the renewable energy resources. PVs offer several advantages such as: high reliability, low maintenance cost, no environmental pollution, and absence of noise, photovoltaic cells convert sunlight directly to electricity. The design and analysis of photovoltaic modules require a tool that can predict the behavior of photovoltaic generators under various weather conditions. Manufacturers usually provide electrical specifications of the PV panels at standard test conditions, namely solar radiation of 1000 W/m 2 and cell temperature of 25 0 C. To characterize the performance of a photovoltaic module under varying weather conditions, simulation models of PV modules have been developed . The market for PV systems is growing worldwide. In fact, nowadays, solar PV provides

2015

PV modules are the most reliable component of a photovoltaic (PV) system. This supposed reliability leads the modules to have a warranty of up to 25 years. With the increasing insertion of PV in the energetic matrix, it is necessary to evaluate and guarantee the reliability of this source. This paper presents an evaluation of degradation in PV modules installed 15 years ago on the roof of the Department of Electrical Engineering, Federal University of Ceará, Brazil. This evaluation uses two methods: visual inspection and analysis to measure degradation degree in electrical properties of the modules. Maximum power (P MPP); Current at the maximum power point (I MPP); Voltage at the maximum power point (VMPP); Short circuit current (I SC) and Open circuit voltage (VOC) are measured using a power curve tracer and compared with manufacturers data. Visual analysis show that delamination and discoloration are the degradations found in most of the modules. Considering the electrical paramet...

Global Journal of Energy Technology Research Updates, 2018

Understanding field failure and degradation modes in solar photovoltaic (PV) modules is very important for various reasons especially for this widely used technology. The University of Applied Sciences Ostwestfalen-Lippe in Höxter owns photovoltaic-modules of different cell types, sizes and operation periods in German weather conditions. This paper presents a detailed degradation investigation and performance parameters analysis for chosen samples of polycrystalline, monocrystalline and thin film modules in the laboratory and outdoor test conditions after 10 years of exposure. The obtained measurements were standardized and then compared with the warranted values of the manufacturer's datasheets for each module type. The real outdoor measurements for the larger units show that the maximum power Pmax after 10 years of exposure for polycrystalline, monocrystalline and amorphous thin film modules had declined by: 8.47%, 37.67%, and 19.05% respectively, which translates to an annual linear degradation rates of 0.652%, 3.67%, and 1.465% for each type respectively. While the maximum power output of the smaller units had declined by 19.05%, 19.36%, and 21.75% for polycrystalline, monocrystalline and amorphous thin film modules respectively, which also translated to annual linear degradation rates of 1.48%, 1.67%, and 0.6% for each type respectively. On the other hand, the laboratory tests for these modules show that there is a clear variation with the obtained outdoor results, where the Pmax for the same larger units had declined by 39.6%, 57.4%, and 82.5% for polycrystalline, monocrystalline and thin film modules respectively, While the Pmax output of smaller units had declined by 51.2%, 39.38%, and 9.39% for polycrystalline, monocrystalline and thin film modules respectively, The comparison of the efficiency and fill factor parameters for the obtained results with the manufacturer's data shows that the outdoor measurements introduce close results than the laboratory results. The discoloration of the encapsulant is the most frequently occurring visually observable defects on the modules.

Environmental and Climate Technologies

This article presents an evaluation of the performance of PV modules with the variation of some technical and environmental parameters: The PV module tilt angle, and the impact of soiling on the power output of PV module, and the transmittance of the PV glass surfaces. The experiments were achieved in Helwan City (Egypt) at the premises of the Faculty of Engineering of Helwan University. For the soiling part, it comprises two experiments: Transmittance of PV glass surfaces, and the power output of PV modules. For the transmittance experiment, it has been achieved using a simplified method, where three PV glass surfaces were placed at three different tilt angles (0°, 15°, and 30°) and left exposed to the outdoor environment without cleaning for a period of 25 days during the summer season. For the experiment concerning the impact of soiling on the power output, a set of PV modules connected in series have been exposed for a period of 75 days to the outdoor environment without cleanin...

Photovoltaic modules based on the relatively high efficiency crystalline technology are gaining importance in the photovoltaic market. Improving module performance is driven by a focus on lifetime yields and requirements of spaceconstraints sites. The materials used not only in thin film technologies but also crystalline pose problems in terms of measuring how much power is generated under STC. The fact that the modules power rates vary depends both on the amount of time they have been exposed to the sun and on their history of sunlight exposure in order to know the current state of the module. It is necessary to determine an easily accomplishable testing method that ensures the repeatability of the measurements of the power generated. This is essential because in order to have a reliable sample of the PV module population of a large PV plant, a huge no of modules must be measured. This paper shows different tests performed on different commercial crystalline PV modules both multi and mono, in order to find the best way to obtain measurements. A correlation was tested between sun exposure and power measured. A method for obtaining indoor measurements that takes periods of sunlight exposure into account is proposed. Also, temperature and irradiance coefficients were also determined for different technologies in order to obtain accurate measurements. Tests are operated in outdoor exposure and natural sunlight located in Gurgaon Region of Haryana (India) as specific composite climate environment, characterized by high irradiation and temperature levels.

IntechOpen eBooks, 2020

The present work demonstrates the performance evaluation and economic analysis of different PV module types and brands at the working conditions of Padiham (53.5 N, 2.3 W) in the UK. The total area of PV plant was assumed to be 100 square meters. The simulations were carried out for modules installed on the roof and on the south-facing façade of a residential building. The comparison study is carried out to define the most suitable module type and brands for the considered place in the current study. The energy and economic performance of the gridconnected PV system are analyzed under the meteorological conditions of Padiham. The modules were characterized by evaluating their annual electrical energy generation and different figures of merit of the grid-connected PV systems such as the investment, annual profit, net present value, levelized cost of electricity, and the payback time. The simulations show that in this specific setup, monocrystalline modules have the best energy performance, while thin-film modules have the best economic performance.