Energy performance results of 240 mw x year of spanish large-scale pv plants

ABSTRACT: large-scale Spanish photovoltaic plants is presented. 20 installations, totalling more than 90 MW, are analysed for a period of up to 4 years. We suggest a procedure to assure the consistency of the data coming from the field and a method of calculating the energy availability rate of the installations, both of them in a way that is independent of the operator of the plant. The operational results are final yields of more than 1,500 kWh/kW for static installations and more than 2,100 kWh/kW for a 2-axis tracking configuration; average performance ratios of 0.8 and energy availabilities of more than 99.5%, with no significant differences between static and tracking systems. Because of the large size and wide location distribution of this sample, we consider these results representative of the performance of large scale PV plants in Spain

Experimental model to estimate shading losses on PV arrays

This paper presents a simple mathematical model to estimate shading losses on PV arrays. The model is applied directly to power calculations, without the need to consider the whole current–voltage curve. This allows the model to be used with common yield estimation software. The model takes into account both the shaded fraction of the array area and the number of blocks (a group of solar cells protected by a bypass diode) affected by shade. The results of an experimental testing campaign on several shaded PV arrays to check the validity of model are also reported

Sala de Artes, Arquitectura y Diseño

La sala de Artes, Arquitectura y Diseño representa un espacio interdisciplinar de divulgación de experiencias de investigación e investigación-creación que se han venido adelantando con orgullo y esfuerzo desde la Institución Universitaria Politécnico Grancolombiano

In-field assessment of batteries and PV modules in a large photovoltaic rural electrification programme

Assuring the sustainability of quality in photovoltaic rural electrification programmes involves enhancing the reliability of the components of solar home systems as well as the characterization of the overall programme cost structure. Batteries and photovoltaic modules have a great impact on both the reliability and the cost assessment, the battery being the weakest component of the solar home system and consequently the most expensive element of the programme. The photovoltaic module, despite being the most reliable component, has a significant impact cost-wise on the initial investment, even at current market prices. This paper focuses on the in-field testing of both batteries and photovoltaic modules working under real operating conditions within a sample of 41 solar home systems belonging to a large photovoltaic rural electrification programme with more than 13,000 installed photovoltaic systems. Different reliability parameters such as lifetime have been evaluated, taking into account different factors, for example energy consumption rates, or the manufacturing quality of batteries. A degradation model has been proposed relating both loss of capacity and time of operation. The user e solar home system binomial is also analysed in order to understand the meaning of battery lifetime in rural electrification

Parenting styles, cyberaggression, and cybervictimization among adolescents

Social concern about the negative effects of cyberbullying in children and adolescents’ psychosocial development is currently increasing. The importance of the family environment and factors in bullying has been highlighted, but little is known about the role of parenting styles in adolescents' engagement in cyberaggression and cybervictimization. The aim of this study was to analyze the relationships of parenting styles (authoritative, indulgent, authoritarian, and neglectful) and cyberbullying (cybervictimization and cyberaggression) in adolescents, also considering sex and age. Participants were 2399 Spanish adolescents, 50.2% boys, aged between 12 and 18 years old (Mage = 14.69, SDage = 1.82). A multivariate analysis of variance (MANOVA, 4 × 2 × 2) was performed, with parenting styles, sex, and age (12–14 years and 15–18 years) as independent variables and cybervictimization and cyberaggression as criteria. Possible interaction effects were also analyzed. Results showed main effects of parenting styles, sex, and age, as well as an interaction effect between sex and parenting styles. Girls suffered more cybervictimization than boys, whereas boys performed higher levels of cyberaggression than girls. Results suggested that authoritarian parenting style was a risk factor for cyberviolence. Girls from authoritarian families scored highest on cybervictimization. Boys from indulgent families were less involved in cybervictimization. These findings highlight the importance of establishing positive and open communication between parents and adolescents. The implications are discussed

Bankable procedures for the technical quality assurance of large scale PV plants

Strict technical quality assurance procedures are essential for PV plant bankability. When large-scale PV plants are concerned, this is typically accomplished in three consecutive phases: an energy yield forecast, that is performed at the beginning of the project and is typically accomplished by means of a simulation exercise performed with dedicated software; a reception test campaign, that is performed at the end of the commissioning and consists of a set of tests for determining the efficiency and the reliability of the PV plant devices; and a performance analysis of the first years of operation, that consists in comparing the real energy production with the one calculated from the recorded operating conditions and taking into account the maintenance records. In the last six years, IES-UPM has offered both indoor and on-site quality control campaigns for more than 60 PV plants, with an accumulated power of more than 300 MW, in close contact with Engineering, Procurement and Construction Contractors and financial entities. This paper presents the lessons learned from such experience

Alternativas de ensayo de potencia sobre grandes generadores fotovoltaicos

Este artículo presenta diferentes alternativas de ensayo para caracterizar en campo grandes generadores fotovoltaicos. Las medidas de curvas I-V con trazadores electrónicos, previa desconexión de la planta, son rápidas y permiten detectar anomalías del generador fotovoltaico como puntos calientes, polarización y sombreados. Sin embargo, la medida de potencia correspondiente engloba demasiada incertidumbre como para ser tomada en cuenta contractualmente. Las medidas de potencia continua usando un vatímetro, tomadas de manera simultánea al funcionamiento normal de la planta, proporcionan mayor precisiónen los resultados, especialmente si se siguen algunas precauciones para disminuir la incertidumbre. Los resultados presentados proceden de los ensayos efectuados en unas 50 centrales fotovoltaicas comerciales, representativas de una potencia cercana a 250 MW

A Tractable Line-of-Sight Product Channel Model: Application to Wireless Powered Communications

We here present a general and tractable fading model for line-of-sight (LOS) scenarios, which is based on the product of two independent and non-identically distributed κ- μ shadowed random variables. Simple closed-form expressions for the probability density function and cumulative distribution function are derived, which are as tractable as the corresponding expressions derived from a product of Nakagami-m random variables. This newly proposed model simplifies the challenging characterization of LOS product channels, as well as combinations of LOS channels with non-LOS ones. Results are used to analyze performance measures of interest in the context of wireless powered communications.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

On the testing of large PV arrays

This paper reports on the IES-UPM experience from 2006 to 2010 in the field of the characterization of PV arrays of commercial large PV plants installed in Spain within the framework of the profitable economic scenarios associated to feed-in tariff laws. This experience has extended to 200 MW and has provided valuable lessons to minimize uncertainty, which plays a key role in quality assurance procedures. The paper deals not only with classic I–V measurements but also with watt-metering-based procedures. Particular attention is paid to the selection of irradiance and cell temperature sensor