Combining offshore wind and solar photovoltaic energy to stabilize energy supply under climate change scenarios: A case study on the western Iberian Peninsula

La expansión de la energía renovable marina es una importante alternativa para la reducción de las emisiones de gases de efecto invernadero. Sin embargo, en Europa, la alta penetración de la energía eólica marina introduce intermitencia y variabilidad de energía en la red eléctrica existente. La energía solar fotovoltaica marina es otra alternativa tecnológica en consideración en los planes de descarbonización. Sin embargo, las futuras variaciones en el viento, la temperatura del aire o la radiación solar debido al cambio climático tendrán un gran impacto en los recursos de energía renovable. En este contexto, este estudio se centra en la evaluación de la energía marina en la costa de la Península Ibérica occidental, una región europea que abarca Portugal y la parte noroccidental de España. Utilizando una amplia fuente de datos de 35 simulaciones de un proyecto de investigación llamado CORDEX, este estudio investiga la complementariedad de las fuentes de energía eólica y solar marina con el objetivo de mejorar la estabilidad del suministro de energía de esta región hasta 2040. Aunque se ha demostrado que el recurso de energía eólica marina es mayor que el recurso fotovoltaico solar a escala anual, ambos recursos renovables mostraron una variabilidad significativa en energía a lo largo de la Península Ibérica occidental. Cuando se combinan ambas fuentes renovables, la estabilidad del recurso energético aumenta considerablemente a lo largo del año. El esquema propuesto de combinación de energía eólica y solar se evalúa mediante un método de clasificación de rendimiento llamado Delphi, teniendo en cuenta la estabilidad, el recurso, el riesgo y los factores económicos. El índice de clasificación total aumenta cuando la estabilidad del recurso se mejora mediante la consideración de la producción híbrida de energía eólica-fotovoltaica solar, especialmente a lo largo de las aguas cercanas a la costa.The expansion of marine renewable power is a major alternative for the reduction of greenhouse gases emissions. In Europe, however, the high penetration of offshore wind brings intermittency and power variability into the existing power grid. Offshore solar photovoltaic power is another technological alternative under consideration in the plans for decarbonization. However, future variations in wind, air temperature or solar radiation due to climate change will have a great impact on both renewable energy resources. In this context, this study focusses on the offshore energy assessment off the coast of Western Iberia, a European region encompassing Portugal and the Northwestern part of Spain. Making use of a vast source of data from 35 simulations of a research project called CORDEX, this study investigates the complementarity of offshore wind and solar energy sources with the aim of improving the energy supply stability of this region up to 2040. Although the offshore wind energy resource has proven to be higher than solar photovoltaic resource at annual scale, both renewable resources showed significant spatiotemporal energy variability throughout the western Iberian Peninsula. When both renewable resources are combined, the stability of the energy resource increased considerably throughout the year. The proposed wind and solar combination scheme is assessed by a performance classification method called Delphi, considering stability, resource, risk, and economic factors. The total index classification increases when resource stability is improved by considering hybrid offshore wind-photovoltaic solar energy production, especially along the nearshore waters.Ministerio de Economía, Industria y Competitividad | Ref. FJCI-2017-32577Agencia Estatal de Investigación | Ref. PID2020-113245RB-I00Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Xunta de Galicia | Ref. ED431C 2021/4

Different approaches to analyze the impact of future climate change on the exploitation of wave energy

The increment of the share of renewable energies in the global mix implies that all renewable energies must be exploited. In this sense, it is necessary to make significant research and investment effort in the particular case of wave energy to reach the degree of maturity of other marine energies in the near future. Apart from the inherent factors that hinder the development of wave energy, such as the non-existence of a market-leading type of capturing device, uncertainties about the available future resource also hamper its growth. In this article, a review of the procedures followed in the literature to deal with the future wave energy resources and their subsequent exploitation is described. These procedures include the evaluation of the best future atmospheric models to drive wave models, the different downscaling techniques to evaluate the resource in large regions with high spatial resolution, and the analysis of the variability of the future energy resource and its future exploitability in a certain region taking into account different types of devices. Additionally, the current state of the art of previous studies dealing with future wave energy resources for different locations worldwide is described. Despite the difficulties involved in studying future wave energy resources, the high technological readiness level of the offshore wind industry, the creation of power generation farms with combined technologies, and the growth of marine aquaculture in the coming years could generate synergies that provide the definitive impulse to achieve the necessary technological development.Agencia Estatal de Investigación | Ref. PID2020‐113245RB‐I00Agencia Estatal de Investigación | Ref. TED2021-129479A-I00Xunta de Galicia | Ref. ED431C 2021/44Agencia Estatal de Investigación | Ref. IJC2020-043745-IAgencia Estatal de Investigación | Ref. PRE2021-097580European Cooperation in Science and TechnologyUniversidade de Vigo/CISU

Detection of the florfenicol resistance gene floR in Chryseobacterium isolates from rainbow trout. Exception to the general rule?

Bacteria from the family Flavobacteriaceae often show low susceptibility to antibiotics. With the exception of two Chryseobacterium spp. isolates that were positive for the florfenicol resistance gene floR, no clinical resistance genes were identified by microarray in 36 Flavobacteriaceae isolates from salmonid fish that could grow in ≥ 4 mg/L florfenicol. Whole genome sequence analysis of the floR positive isolates revealed the presence of a region that contained the antimicrobial resistance genes floR, a tet(X) tetracycline resistance gene, a streptothricin resistance gene and a chloramphenicol acetyltransferase gene. In silico analysis of 377 published genomes for Flavobacteriaceae isolates from a range of sources confirmed that well-characterised resistance gene cassettes were not widely distributed in bacteria from this group. Efflux pump-mediated decreased susceptibility to a range of antimicrobials was confirmed in both floR positive isolates using an efflux pump inhibitor (phenylalanine-arginine β-naphthylamide) assay. The floR isolates possessed putative virulence factors, including production of siderophores and haemolysins, and were mildly pathogenic in rainbow trout. Results support the suggestion that, despite the detection of floR, susceptibility to antimicrobials in Flavobacteriaceae is mostly mediated via intrinsic mechanisms rather than the horizontally acquired resistance genes more normally associated with Gram-negative bacterial pathogens such as Enterobacteriaceae

Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp401524sWe have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of silver chromate (Ag2CrO4) at ambient temperature and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. When the initial orthorhombic Pnma Ag2CrO4 structure (phase I) is compressed up to 4.5 GPa, a previously undetected phase (phase II) has been observed with a 0.95% volume collapse. The structure of phase II can be indexed to a similar orthorhombic cell as phase I, and the transition can be considered to be an isostructural transition. This collapse is mainly due to the drastic contraction of the a axis (1.3%). A second phase transition to phase III occurs at 13 GPa to a structure not yet determined. First-principles calculations have been unable to reproduce the isostructural phase transition, but they propose the stabilization of a spinel-type structure at 11 GPa. This phase is not detected in experiments probably because of the presence of kinetic barriers. Experiments and calculations therefore seem to indicate that a new structural and electronic description is required to model the properties of silver chromate.This study was supported by the Spanish government MEC under grants MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by the Comunidad de Madrid and European Social Fund (S2009/PPQ1551 4161893), by the MALTA Consolider Ingenio 2010 project (CSD2007-00045), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). A.M. and P.R.-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. acknowledges Juan de la Cierva Fellowship Program for its financial support. Diamond and ALBA Synchrotron Light Sources are acknowledged for provisions of beam time. We also thank Drs. Peral, Popescu, and Fauth for technical support.Santamaría Pérez, D.; Bandiello, E.; Errandonea, D.; Ruiz-Fuertes, J.; Gomis Hilario, O.; Sans, JÁ.; Manjón Herrera, FJ.... (2013). Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties. Journal of Physical Chemistry C. 117(23):12239-12248. https://doi.org/10.1021/jp401524sS12239122481172

The OTELO survey: A case study of [O III] lambda 4959,5007 emitters at z=0.83

Context. The OSIRIS Tunable Filter Emission Line Object (OTELO) survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Aims. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. Methods. The selection and analysis procedures of ELS candidates obtained using tunable filter pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF ([O III]), including the main selection biases and uncertainties, are presented. Results. From 541 preliminary emission-line source candidates selected around z = 0.8, a total of 184 sources were confirmed as [O III] emitters. Consistent with simulations, the minimum detectable line flux and equivalent width in this ELS sample are ∼5 × 10−19 erg s−1 cm2 and ∼6 Å, respectively. We are able to constrain the faint-end slope (α = −1.03 ± 0.08) of the observed LF ([O III]) at a mean redshift of z = 0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84%) of the morphologically classified [O III] ELSs are disc-like sources, and 87% of this sample is comprised of galaxies with stellar masses of M⋆ <  1010 M⊙

MAGIC Upper Limits for two Milagro-detected, Bright Fermi Sources in the Region of SNR G65.1+0.6

We report on the observation of the region around supernova remnant G65.1+0.6 with the stand-alone MAGIC-I telescope. This region hosts the two bright GeV gamma-ray sources 1FGL J1954.3+2836 and 1FGL J1958.6+2845. They are identified as GeV pulsars and both have a possible counterpart detected at about 35 TeV by the Milagro observatory. MAGIC collected 25.5 hours of good quality data, and found no significant emission in the range around 1 TeV. We therefore report differential flux upper limits, assuming the emission to be point-like (<0.1 deg) or within a radius of 0.3 deg. In the point-like scenario, the flux limits around 1 TeV are at the level of 3 % and 2 % of the Crab Nebula flux, for the two sources respectively. This implies that the Milagro emission is either extended over a much larger area than our point spread function, or it must be peaked at energies beyond 1 TeV, resulting in a photon index harder than 2.2 in the TeV band.Comment: 8 pages, 3 figures, 1 tabl