Understanding the reliability of photovoltaic (PV) modules under field conditions is one of the primary areas to ensure prolonged operation. This article reported a study on assessing PV modules' reliability under different outdoor environments, using procedures available in the literature. We identified dominant failure modes of PV modules under different climatic conditions of India. Risk priority number (RPN) of different failure modes are estimated by analyzing the consequences of defects in performance and safety. Modules deployed under cold and sunny, hot and dry, warm and humid, and composite climates of India have more varieties of failure modes than those in cold and cloudy and moderate climatic conditions. The frequency of occurrences of benign or cosmetic defects of PV modules varies under different climatic zones. The biggest concerns in old PV systems were hot spots, internal circuitry discoloration, backsheet problems, and grounding wires' corrosion. In the hot zones, primary safety issues were frame grounding corrosion, backsheet problems, hot spots, and nonhot zones were backsheet burn marks, backsheet peeling, and grounding wire corrosion. The defects observed in different climatic zones were analyzed in terms of its possible defect generation route also.

This chapter covers the largest set of projects in SERIIUS that can be viewed overall as having three distinct themes. First is the development of new low-capital thin-film photovoltaic (PV) technologies by high-throughput manufacturing processes with a focus on solution-based roll-to-roll processing. This effort was highly integrated with the development of thin glass substrates and packaging from Corning, and focused on absorbers made from CuInGaSe2, CuZnSnSeS, organic molecules such as fluorinated polymers, perovskite solar cells based on methyl ammonium lead iodide (MAPbI), and silicon. Significant progress, including world-record devices, was achieved in a number of areas, and substantial improvements in lifetime were attained. Second is an assessment of the stability and failure mechanisms of PV in hot/dry and hot/wet climates. This work included assessing PV module stability across the seven climate zones of India and in the United States. The importance of dust and particulates was assessed. New failure mechanisms were identified, in particular to the hot/dry and hot/wet climates, and an international working group was convened. Coupled to developing new PV technology and understanding degradation pathways, an effort was made in multiscale modeling – from atoms to modules – to begin to connect the basic science to the ultimate deployability of the PV devices and modules. Here, the potential importance of bifacial modules was assessed.

Energy rating of PV module as per the site-specific climatic condition is essential for customer's point of view to choose suitable PV technologies. For site and technology-specific energy rating of PV module, it is essential to design standard datasets for it. In this paper, energy ratings of three different technologies with the data sets based on the angle of incidence, spectrum, irradiance, wind and temperature using existing formulae has been reported. The performance surfaces of PV technologies are designed based on the IEC 61853-1 & 2, and IEC 60891. A procedure is reported to including the degradation rate in the energy rating method. Comparisons of energy rating of amorphous silicon, HIT and multi-crystalline silicon using the existing method considering the degradation rate are done with the measured data. It has been observed that all the three technologies at Cold & sunny zone shows the highest energy rating. A procedure, to find out the most frequent conditions in terms of occurrence probability for different PV technologies is also reported.

In this study the comprehensive reliability in terms of clearness index for power production of HIT, amorphous silicon & multi-crystalline silicon (m-cSi) technologies has been analyzed. The energy estimation of these three technologies is done based on regression, and deviation in the measured and estimated values is also reported. It has been found that for winter season, HIT technology module is the most reliable for overcast and partly cloudy conditions between the HIT, amorphous silicon &m-cSitechnologies. For summer season, amorphous Silicon technology shows the highest reliability for clear sky condition, m-cSi has the highest reliability for partly cloudy and HIT technology for overcast condition. HIT technology shows higher reliability both in the post monsoon and autumn season for clear sky and partly cloudy index conditions. The error in the estimations has been reduced by increasing the number of iterations. Keyword:Monte Carlo; SPV Module; Environment Parameter; Simulation; Reliability -------------------------------------------------------------------------------------------------------------------------------------Date of Submission: 13-07-2017 Date of acceptance: 15-07-2017 --------------------------------------------------------------------------------------------------------------------------------------

This paper presents the electrical performance data gathered in the 3 r All India Survey of Photovoltaic Module Reliability conducted in 2016, in which a total of 925 modules were inspected in different climatic zones of India. The average degradation rate of the Group A (‘All’ sites) modules is 1.23%/year and the so-called ‘Good’ sites is 0.63%/year, better than that observed in the 2014 Survey, the reason being partly the inclusion of more large PV power plants, and also discounting of 2% LID in 2016 analysis methodology. The modules in ‘Hot’ climates degrade faster than modules in ‘Non-Hot’ climates, consistent with earlier results. Modules in small systems (capacity <100 kW) degrade at a faster rate than those in large systems (capacity >100 kW). Roof-mounted systems also degrade at a faster rate than ground-mounted systems.

This paper presents a reliable mathematical method to predict the energy generation from grid connected photovoltaic plant of different commercially used technologies in different zones of India. Global horizontal insolation (GHI) and daytime temperature are the two major parameters affecting the output of photovoltaic (PV) plant. Depending on those two major parameters, India is classified into 15 climatic zones. Typical Meteorological Year data were collected from National Renewable Energy Laboratory to classify India in different climatic zones. Energy generation of different commercially used PV technologies in different climatic zones of India is predicted using proposed mathematical method. These results show a decisive study to choose the best PV technology for different climatic zones of India. Results predict that in almost all climatic zones, amorphous silicon (a-Si) is the best suitable PV technology. In very low-temperature zones, irrespective of GHI, the second best suitable PV technology is mono and cadmium telluride (CdTe) as generation from these two technologies is same. Whereas in other climatic zones, after a-Si the best suitable is CdTe PV technology. Predicted energy generation is validated with the 1-year generation of 2014 from 15 working PV plants of different technologies. Predicted generation is in good co-relation with the actual real-time generation from the PV plants.

Potential-induced degradation (PID) is known to have a very severe effect on the reliability of PV modules. PID is caused due to the leakage of current from the cell circuit to the grounded frame under humid conditions of high voltage photovoltaic (PV) systems. There are multiple paths for the current leakage. The most dominant leakage path is from the cell to the frame through encapsulant, glass bulk and glass surface. This dominant path can be prevented by interrupting the electrical conductivity at the glass surface. In our previous works related to this topic, we demonstrated the effectiveness of glass surface conductivity interruption technique using one-cell PV coupons. In this work, we demonstrate the effectiveness of this technique using a full size commercial module susceptible to PID. The interruption of surface conductivity of the commercial module was achieved by attaching a narrow, thin flexible glass strips, from Corning, called Willow Glass (R) on the glass surface along the inner edges of the frame. The flexible glass strip was attached to the module glass surface by heating the glass strip with an ionomer adhesive underneath using a handheld heat gun. The PID stress test was performed at 60 degrees C and 85% RH for 96 hours at -600 V. Pre- and post-PID characterizations including I-V and electroluminescence were carried out to determine the performance loss and affected cell areas. This work demonstrates that the PID issue can be effectively addressed by using this current interruption technique. An important benefit of this approach is that this interruption technique can be applied after manufacturing the modules and after installing the modules in the field as well.

This paper presents comprehensive study on performance comparison of different photovoltaic technologies, when subjected to five distinct proportions of temperature and humidity in a controlled environment under biasing conditions. The study considers five different PV (Photovoltaic) technologies (Mono, Multi, a-Si, CdTe, CIGS) based on their electrical parameters. It is observed that CIGS (Copper Indium Gallium Selenide) performs with best efficiency at 60 degrees C, 60% RH (relative humidity) while CdTe performs with best efficiency at 85 degrees C, 85% RH.The descriptive statistics shows that the largest possible Variance in Maximum Power of a-Si out of all available technologies is about 20.85 whereas the lowest noted in Mono C-Si is 0.917. The variability of data is further checked using Analysis of Variance tool. Finally the study establishes the performance dominance of C-Si (Mono) technology over all the thin film technologies based on stress tests and evaluation through the repeated measurement of maximum Power, module efficiency and cell efficiency. (C) 2016 Elsevier Ltd. All rights reserved.

Temperature is an important factor for efficiency of Photovoltaic (PV) - modules. Variation in temperature over different technologies of same wattages gives the different efficiency. At particular instant temperature is considered for the variation of efficiency in respect to ambient temperature over the technologies. This whole work is performed on Nominal Operating Cell Temperature (NOCT) test bed at National Institute of Solar Energy (NISE), (Gurgaon). Output at NOCT test bed data logger is considered for the determination of suitable technologies for different regions in considering the effect of the temperature. NOCT is the specified test provided in IEC-61215. The output is in terms of efficiency with respect to temperature in suitable form of the graphs. This study considering, two modules of same wattages different technologies multicrystalline (mc-Si) and monocrystalline (M-SI). The whole study finally concludes out the effect over different technologies of temperature that multi is having more temperature at particular ambient temperature hence the efficiency of the monocrystalline is more as that of multi at particular location of test. So multicrystalline is more suitable technologies for high altitude regions like Himalaya's, Andes, etc., and for a particular location at Delhi monocrystalline is more efficient. This whole study provides out most usefully information for plant installation in megawatts, according to technologies as mention for a specific region to provide maximum output.

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 space – constraints 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.

This paper presents results on the field performance degradation of mono-crystalline silicon PV modules from 11PV module manufacturers under identical field conditions. The modules were installed in both fixed tilt and manual tracking modes. The data were monitored using a CR23X Data logger and I–V curves were taken using SPI 240A Sun simulator. The performance parameters analyzed are Voc, Isc, Pmax, Imp, Vmp and the fill factor, as a function of time of field exposure. Qualitative studies are made on physically visible defects such as EVA coloration, cell de-laminations, corrosion of solar cell grid, corrosion of end strip connected in the terminal box, failure of by-pass diode, detachment of the terminal box, tearing of tedlar sheet, etc. The effect of field exposure on the performance parameters indicates that the qualification standard (s) needs to be reviewed and revised if the modules are to perform for ∼20 years under actual field conditions in India.

A high performance white light emitting diode (WLED) based PV lighting system has been developed under a joint project of SEC and ANERT. The system has been analyzed using the test set-ups developed as a part of advanced lighting laboratory (ALL). The results show that the performance is one of the best among the systems developed in the capacity range.