Técnicas de aprendizaje computacional aplicadas a la fotovoltaica

[ESP] En este artículo mostramos los resultados de la aplicación de varios métodos de aprendizaje computacional sobre datos procedentes de una instalación fotovoltaica de 222kWp de CdTe. Los datos de uno de los 30 grupos de módulos han sido estudiados en profundidad para predecir el estado en que se encuentra cuando el rendimiento es bajo: afectado por sombra fija, por sombra variable, los módulos están sucios, error ajeno a dichas circunstancias, etc. o bien identificar que está generando electricidad de forma adecuada.Asociación de Jóvenes Investigadores de Cartagena, (AJICT). Universidad Politécnica de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT, (ETSII). Escuela Técnica Superior de Ingeniería Agronónica, (ETSIA), Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos, Canales, y Puertos y de Ingeniería de Minas, (EICM). Fundación Séneca, Agencia Regional de Ciencia y Tecnología. Parque Tecnológico de Fuente Álamo. Grupo Aquiline

Graphene oxide: key to efficient charge extraction and suppression of polaronic transport in hybrids with poly (3-hexylthiophene) nanoparticles

Nanoparticles (NPs) of conjugated polymers in intimate contact with sheets of graphene oxide (GO) constitute a promising class of water-dispersible nanohybrid materials of increased interest for the design of sustainable and improved optoelectronic thin-film devices, revealing properties exclusively pre-established upon their liquid-phase synthesis. In this context, we report for the first time the preparation of a P3HTNPs-GO nanohybrid employing a miniemulsion synthesis approach, whereby GO sheets dispersed in the aqueous phase serve as a surfactant. We show that this process uniquely favors a quinoid-like conformation of the P3HT chains of the resulting NPs well located onto individual GO sheets. The accompanied change in the electronic behavior of these P3HTNPs, consistently confirmed by the photoluminescence and Raman response of the hybrid in the liquid and solid states, respectively, as well as by the properties of the surface potential of isolated individual P3HTNPs-GO nano-objects, facilitates unprecedented charge transfer interactions between the two constituents. While the electrochemical performance of nanohybrid films is featured by fast charge transfer processes, compared to those taking place in pure P3HTNPs films, the loss of electrochromic effects in P3HTNPs-GO films additionally indicates the unusual suppression of polaronic charge transport processes typically encountered in P3HT. Thus, the established interface interactions in the P3HTNPs-GO hybrid enable a direct and highly efficient charge extraction channel via GO sheets. These findings are of relevance for the sustainable design of novel high-performance optoelectronic device structures based on water-dispersible conjugated polymer nanoparticles.This work was funded by Spanish MCIN/AEI/10.13039/501100011033 under projects PID2019-104272RB-C51, PID2019-104272RB-C52, PID2019-104272RB-C55, and PID2019-104739GB-100. Financial support from Gobierno de Aragon (DGA) under project “Grupos Consolidados” T03_20R is acknowledged. E.C. is grateful for PhD grant BES2017-080020 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investingin your future”. M.N.R.’s work was financed by grant PID2019-104272RB-C52/PRE2020-094503 funded by MCIN/AEI/10.13039/501100011033 and by “‘ESF Investingin your future”’. R.A. acknowledge ssupport from EU H2020“ESTEEM3”(Grant number 823717)and Graphene Flagship (881603)

Short vs. long-distance avocado supply chains: Life cycle assessment Impact associated to transport and effect of fruit origin and supply conditions chain on primary and secondary metabolites

Avocado consumption and trade are increasing worldwide, with North America and Europe being the main importing regions. Spain is the major European avocado producer (90% of the production), yet it only supplies 10% of the market. Consequently, more than 90% of the avocados consumed in Europe are imported from overseas, mainly from Chile and Peru. In this work, the Life Cycle Assessment (LCA) impact associated with the transport of two avocado supply chains (short (Spanish) and long (Chilean)) and the effect of the fruit origin and distance of both chains on primary and secondary metabolites from harvest to edible ripeness were evaluated using a gas chromatography-mass spectrometry (GC-MS) and liquid chromatography coupled to diode array detection (LC-DAD) based metabolite analysis. The LCA transport impact of the fresh supply chain from production centers in Chile (Quillota) and Spain (Malaga), and then the distribution to several cities in Europe, suggested road export from Spain to European capitals to have the lowest impact (0.14 to 0.22 kg CO2 eq/kg of avocado). When export from Chile was considered, the option of oceanic freight to European ports closer to final destinations was clearly a better option (0.21 to 0.26 kg CO2 eq/kg) than via the Algeciras port in Spain followed by road transport to final destinations in European capitals (0.34 to 0.43 kg CO2 eq/kg), although the situation could be somewhat different if the avocados are transported from the destination ports in northern Europe to long-distance capitals in other European countries. Fruit origin had a significant impact on avocado primary and secondary metabolites. The conditions of the supply chain itself (10 d in cold storage in regular conditions vs. 30 d cold storage + controlled atmosphere conditions) largely influence the fate of some metabolites that certainly affect the pool of metabolites at edible ripeness. The long-assumed hypothesis that the longer the supply chain the more negative impact on nutritional and functional compounds might not hold in this case, as long as transport conditions are adequate in terms of temperature, atmosphere conditions, and time considering distance from origin to destination.This research was funded by Fondecyt Nº 1180303 and REDBIO0001 PCI from ANID (Chile) and for the RTI2018-099139-B-C21 from Ministry of Science and Innovation (Spain)—National Research Agency (MCIN/AEI/10.13039/501100011033) and by “ERDF A way of making Europe”, of the European Union. R. Pedreschi and E. Aguayo are thankful to the grant of Fundación Séneca (Murcia, Spain) through the “Jiménez de la Espada” Program of Visiting Researchers. This research was partially supported by the grant VRIEA-PUCV Nº 039.436/2020

El efecto hall cuántico y las oscilaciones Shubnikov-de Haas en el gas de electrones bidimensional

Se ha medido experimentalmente el efecto hall cuántico y las oscilaciones shubnikov-de-haas en heteroestructuras de semiconductores. La medida se realiza a altos campos magneticos (hasta 12t) y bajas temperaturas (desde 1.2k) utilizando la técnica de las cuatro puntas. Las muestras son heteroestructuras pseudomorficas en las que el canal es un pozo cuántico de . Se han medido muestras con diferentes tipos de dopaje y anchura del pozo, provistas de puerta y con forma de barra hall. Se miden las componentes diagonal y no-diagonal del tensor de magnetoresistencia transversa (el campo magnético aplicado es perpendicular al gas de electrones bidimensional y a la corriente aplicada). Se obtienen los plateaus del efecto hall cuántico entero para la componente y las oscilaciones shubnikov-de haas para la . A partir de estos resultados se obtiene el ensor de la magnetoconductividad transversa y la densidad de estados del gas de electrones bidimensional en presencia de campo magnético. Se ha desarrollado un modelo teórico que ajusta los resultados experimentales obtenidos, obteniéndose niveles de landau gaussianos para la densidad de estados. La dependencia de la anchura de los niveles respecto el campo magnético resulta ser , para cada caso se obtiene un tiempo de relajación por ajuste con los resultados experimentales. También se ha estudiado la dependencia con la temperatura de la magnetoresistencia transversa, así como el llenado de la segunda subbanda

Measurement of thermal and electrical parameters in photovoltaic systems for predictive and cross-correlated monitorization

Photovoltaic electricity generation is growing at an almost exponential rate worldwide, reaching 400 GW(p) of installed capacity in 2018. Different types of installations, ranging from small building integrated systems to large plants, require different maintenance strategies, including strategies for monitorization and data processing. In this article, we present three case studies at different scales (from hundreds of W-p to a 2.1 MWp plant), where automated parameter monitorization and data analysis has been carried out, aiming to detect failures and provide recommendations for optimum maintenance procedures. For larger systems, the data collected by the inverters provides the best source of information, and the cross-correlated analysis which uses these data is the best strategy to detect failures in module strings and failures in the inverters themselves (an average of 32.2% of inverters with failures was found after ten years of operation). In regards to determining which module is failing, the analysis of thermographic images is reliable and allows the detection of the failed module within the string (up to 1.5% for grave failures and 9.1% of medium failures for the solar plant after eleven years of activity). Photovoltaic (PV) systems at different scales require different methods for monitorization: Medium and large systems depend on inverter automated data acquisition, which can be complemented with thermographic images. Nevertheless, if the purpose of the monitorization is to obtain detailed information about the degradation processes of the solar cells, it becomes necessary to measure the environmental (irradiance and ambient temperature), thermal and electrical parameters (I-V characterization) of the modules and compare the experimental data with the modelling results. This is only achievable in small systems.C.T. is grateful to Fundación Séneca-CARM for grant (Exp. 19768/FPI/15). The authors want to acknowledge Pedro García Trenza (from company Drónica) and Emilio Ballester (from company CRES) for sharing data and for their helpful comments. This research was funded by MINECO-Spain (including FEDER funds): Project ENE2016-79282-C5-5-R and Fundación Séneca (Región de Murcia, Spain): Project 19882-GERM-15

Análisis del ciclo de vida de un generador fotovoltaico de 1kWpy dependencia geográfica de su impacto medioambiental

En este artículo mostramos los resultados de la aplicación de la metodología de Análisis de Ciclo de Vida en una instalación fotovoltaica de 1kWp de capacidad, con módulos fabricados con tecnología de Teluro de Cadmio. Se ha metido su impacto en términos de kilos de CO2 que se podrían evitar emitir a la atmósfera con su funcionamiento, y cómo varían estos valores en función del lugar donde se fabrique y donde finalmente se instale el sistema para su funcionamiento, es decir, la dependencia geográfica del impacto, incluyendo el transporte de los componentes.Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostrum. Estación Experimental Agroalimentaria Tomás Ferro

Aplicaciones del análisis del ciclo de vida en el software SURE

SURE es una herramienta de evaluación de viabilidad de proyectos de desarrollo energético en poblaciones aisladas. Este software implementa algoritmos para evaluar las alternativas tecnológicas que podrían suministrar la electricidad que necesita la comunidad, atendiendo a criterios tanto tecnológicos como socio-económicos y medio ambientales. El resultado del software es un factor numérico aplicado a cinco capitales: natural, físico, humano, social y financiero. En este artículo proponemos un agregado y mejora con respecto a los criterios que inciden en el impacto sobre el capital físico. Se trata de un criterio extraído de la metodología de Análisis de Ciclo de Vida, en concreto el tiempo de retorno energético de la tecnología que se está evaluando en SURE.Escuela Técnica Superior de Ingeniería de Telecomunicación, (ETSIT). Escuela Técnica Superior de Ingeniería Agronómica, (ETSIA). Escuela Técnica Superior de Ingeniería Industrial (ETSII). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Escuela de Ingeniería de Caminos y de Minas, (EICM). Centro Universitario de la Defensa, CUD. Parque Tecnológico de Fuente Álamo Campus Mare Nostrum