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In this work, we have compiled our research on lanthanide-based luminescent materials for use as down-shifter layers in photovoltaic (PV) mini-modules. The complexes we have prepared (C1–17), with formulas [Eu2(phen)2(bz)6] (C1), [Eu2(bphen)2(bz)6] (C2), [Eu(tta)3bphen] (C3), [Eu(bta)3pyz-phen] (C4), [Eu(tta)3pyz-phen] (C5), [Eu(bta)3me-phen] (C6), [Er(bta)3me-phen] (C7), [Yb(bta)3me-phen] (C8), [Gd(bta)3me-phen] (C9), [Yb(bta)3pyz-phen] (C10), [Er(tta)3pyz-phen] (C11), [Eu2(bz)4(tta)2(phen)2] (C12), [Gd2(bz)4(tta)2(phen)2] (C13), [EuTb(bz)4(tta)2(phen)2] (C14), [EuGd(bz)4(tta)2(phen)2] (C15), [Eu1.2Gd0.8(bz)4(tta)2(phen)2] (C16), and [Eu1.6Gd0.4(bz)4(tta)2(phen)2] (C17), can be grouped into three families based on their composition: Complexes C1–6 were synthesized using Eu3+ ions and phenanthroline derivatives as the neutral ligands and fluorinated β-diketonates as the anionic ligands. Complexes C7–11 were prepared with ligands similar to those of complexes C1–6 but were synthesized with Er3+, Yb3+, or Gd3+ ions. Complexes C12–17 have the general formula [M1M2(bz)4(tta)2(phen)2], where M1 and M2 can be Eu3+, Gd3+, or Tb3+ ions, and the ligands were benzoate (bz–), 2-thenoyltrifluoroacetone (tta–), and 1,10–phenanthroline (phen). Most of the complexes were characterized using X-ray techniques, and their photoluminescent properties were studied. We then assessed the impact of complexes in the C1–6 and C12–17 series on the EQE of PV mini-modules and examined the durability of one of the complexes (C6) in a climate chamber when embedded in PMMA and EVA films. This study emphasizes the methodology employed and the key findings, including enhanced mini-module efficiency. Additionally, we present promising results on the application of complex C6 in a bifacial solar cell. [ABSTRACT FROM AUTHOR]

This article provides an extensive examination of the interconnectedness between energy and water in island regions, particularly those heavily reliant on tourism, as exemplified by the present case. This study explores the present state and trends of research in this field with the objective of attaining a sustainable system in future scenarios. Specifically, this analysis delves into the water–energy–CO2 nexus of the Colombian island of San Andrés. Currently, there is no energy generation from the water sector, with 76.18% of water consumption directed towards the cooling of thermal power plants and a mere 1.54% of the energy employed for water extraction, desalination, and purification. In 2019, the island's total energy consumption reached 138 ktoe (kilotons of oil equivalent), and renewable energies have yet to contribute to the system. These findings emphasize the necessity for the island to implement measures that will bolster its sustainability, self-sufficiency, and resilience. This entails mitigating and managing the intensity of resource consumption, particularly in areas experiencing economic growth. According to the Sankey diagram obtained, some political implications and recommendations have been listed. [ABSTRACT FROM AUTHOR]

Groundwater pumping systems using photovoltaic (PV) energy are increasingly being implemented around the world and, to a greater extent, in rural and electrically isolated areas. Over time, the cost of these systems has decreased, providing greater accessibility to freshwater in areas far from urban centers and power grids. This paper proposes a novel sustainability analysis of the groundwater pumping systems in Tenerife Island as an example of a medium-size isolated system, analyzing the current status and the business-as-usual projection to 2030, considering the water reservoirs available and the final use of water. The 2030 projection focused on the PV deployment, evaluation of the levelized cost of electricity (LCOE), and the availability of the groundwater resource. HOMER software was used to analyze the LCOE, and ArcGIS software was used for the visual modeling of water resources. As a result, the average LCOE for a purely PV installation supplying electricity to a pumping system in Tenerife is 0.2430 €/kWh, but the location and characteristic of each pumping system directly affect the performance and costs, mostly due to the solar availability. [ABSTRACT FROM AUTHOR]

Six new mixed-ligand bimetallic complexes [Eu2(bz)4(tta)2(phen)2] (1), [Gd2(bz)4(tta)2(phen)2] (2), [EuTb(bz)4(tta)2(phen)2] (3), [EuGd(bz)4(tta)2(phen)2] (4), [Eu1,2Gd0,8(bz)4(tta)2(phen)2] (5) and [Eu1,6Gd0,4(bz)4(tta)2(phen)2] (6) have been prepared with the Eu3+, Gd3+ and Tb3+ ions and the benzoate (bz−), 2-thenoyltrifluoroacetonate (tta−) and the 1,10-phenanthroline (phen) ligands. The compounds combine highly efficient antennas to obtain highly luminescent complexes to enhance solar cell efficiency. The benzoate ligand has been chosen to take its advantage as a bridging ligand to end up with bimetallic complexes to study the effect of combining two metal ions in the luminescent molecule. The structure of 1 was obtained by single-crystal X-ray diffraction, and 1–6 were found to be isostructural by powder X-ray diffraction analysis. The photophysical properties were studied by the absorbance and emission spectra and emission lifetimes. The magnetic properties of 2 were studied, and we found intramolecular antiferromagnetic interactions between the Gd3+ ions. We prepared luminescent down-shifting layers (LDSL) with the 1, 3–6 complexes embedded in ethylene–vinyl–acetate and studied their effect in the external quantum efficiency (EQE) and intensity–voltage (I–V) plots of a solar mini-module. We found that LDSL containing the bimetallic complexes 3 and 6 enhance the efficiency of the solar mini-module from 11.26(3)% to 11.76(4)% (+0.52%) and to 11.44(2)% (+0.21%), respectively. [ABSTRACT FROM AUTHOR]

Operating distribution grids is increasingly challenging due to the increasing penetration of photovoltaic systems. To address these challenges, modern photovoltaic inverters include features for local control, which sometimes lead to suboptimal results. Improved communication infrastructure and photovoltaic inverters favour global control strategies, which receive information from all the systems in the grid. An estimation of distribution algorithm is used to optimize a global control strategy that minimizes active power curtailment and use of reactive power of the photovoltaic inverters, while maintaining voltage stability. Optimized global control outperforms every other local control evaluated in terms of apparent energy used for control (9.9% less usage compared to the second best alternative in all scenarios studied) and ranks second in terms of voltage stability (with a 0.14% of total time outside the voltage limits). Two new indicators to compare control strategies are proposed, and optimized global control strategy ranks best for both efficiency index (0.98) and average apparent power use (0.48 kVA). [ABSTRACT FROM AUTHOR]

This study tries to provide new solutions to increase the efficiency of conversion of photons in solar cells, using photoluminescent Cu(I) coordination polymers (CPs) as possible alternative materials of lower cost, than those used today, based on lanthanides. The selected CP of chemical formula [Cu(NH2MeIN)I]n (NH2MeIN = methyl, 2-amino isonicotinate) absorbs in the utraviolet and emits in the visible region, being also easily nanoprocessable, by a simple and one-pot bottom-up approach. Nanofibers of this CP can be embedded in organic matrices such as ethyl vinyl acetate (EVA), forming transparent and homogenous films, with a thermal stability of up to approximately 150 °C. These new materials maintain the optical properties of the CP used as a dopant, ([Cu(NH2MeIN)I]n), with emission in yellow (570 nm) at 300 K, which is intensified when the working temperature is lowered. In addition, these materials can be prepared with varying thicknesses, from a few microns to a few hundred nanometers, depending on the deposition method used (drop casting or spin coating respectively). The study of their external quantum efficiency (EQE) found an increase in the UV range, which translates into an increase in the conversion efficiency. The optimal CP concentration is 5% by weight in order to not diminish the transparency of the composite material. The calculated cost on the possible incorporation of this material into solar cells shows a 50% decrease over the cost reported in similar studies based on the use of lanthanides. [ABSTRACT FROM AUTHOR]

Featured Application: Validation of all-sky imager technology at 3 locations: NREL, Joint Base San Antonio, and the Canary Islands, Spain. Increasing photovoltaic (PV) generation in the world's power grid necessitates accurate solar irradiance forecasts to ensure grid stability and reliability. The University of Texas at San Antonio (UTSA) SkyImager was designed as a low cost, edge computing, all-sky imager that provides intra-hour irradiance forecasts. The SkyImager utilizes a single board computer and high-resolution camera with a fisheye lens housed in an all-weather enclosure. General Purpose IO pins allow external sensors to be connected, a unique aspect is the use of only open source software. Code for the SkyImager is written in Python and calls libraries such as OpenCV, Scikit-Learn, SQLite, and Mosquito. The SkyImager was first deployed in 2015 at the National Renewable Energy Laboratory (NREL) as part of the DOE INTEGRATE project. This effort aggregated renewable resources and loads into microgrids which were then controlled by an Energy Management System using the OpenFMB Reference Architecture. In 2016 a second SkyImager was installed at the CPS Energy microgrid at Joint Base San Antonio. As part of a collaborative effort between CPS Energy, UT San Antonio, ENDESA, and Universidad de La Laguna, two SkyImagers have also been deployed in the Canary Islands that utilize stereoscopic images to determine cloud heights. Deployments at three geographically diverse locations not only provided large amounts of image data, but also operational experience under very different climatic conditions. This resulted in improvements/additions to the original design: weatherproofing techniques, environmental sensors, maintenance schedules, optimal deployment locations, OpenFMB protocols, and offloading data to the cloud. Originally, optical flow followed by ray-tracing was used to predict cumulus cloud shadows. The latter problem is ill-posed and was replaced by a machine learning strategy with impressive results. R2 values for the multi-layer perceptron of 0.95 for 5 moderately cloudy days and 1.00 for 5 clear sky days validate using images to determine irradiance. The SkyImager in a distributed environment with cloud-computing will be an integral part of the command and control for today's SmartGrid and Internet of Things. [ABSTRACT FROM AUTHOR]

The objective of this rebuttal letter is to provide a critical analysis of the article entitled “Spatial planning to estimate the offshore wind energy potential in coastal regions and islands. Practical case: The Canary Islands” [Energy 143 (2018) 91–103], mainly in relation to its methodology, suitable marine areas and electricity production costs. The absence of basic considerations about the characteristics of the insular power grids, the composition of the electricity costs in the Canary Islands, and the lack of rigor in some assumptions related to visibility constraints, offshore costs, integration costs, the mixing of data from different time periods and the references used, provides unrealistic and useless results for a necessary debate about the potential of offshore wind energy in the Canary Islands. In this rebuttal letter we will also demonstrate that the potential offshore wind capacity calculated by the authors is much lower. Moreover, the assertion that the electricity cost from offshore wind calculated by the authors is lower than the current electricity cost is wrong and, in fact, the cost of electricity from offshore wind is higher in the time period when the analysis was made, and also at present. [ABSTRACT FROM AUTHOR]

An analysis of the nucleation mechanism of pyramids formed in (100) silicon in Na2CO3/NaHCO3 solution has been carried out. This texturization process of silicon by means of Na2CO3/NaHCO3 solutions is of special interest because it can be applied to the silicon solar cell industry to texture solar cell surfaces to decrease the front reflection and enhance light trapping in the cells. For this purpose, two microscopy techniques—scanning electron microscopy and atomic force microscopy—have been used to study the different stages of pyramidal nucleation and formation. The different aspects and factors involved in the texturization process require different analysis conditions and microscopy resolution. Tracing the transformation of determined surface areas and structures has been achieved, contributing clarification of the mechanism of pyramid nucleation in Na2CO3/NaHCO3 solutions. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, a novel diluted carbonate/bicarbonate solution was applied for texturization of monocrystalline silicon for solar cells. The content of reactants in the solution was decreased 20 times with respect to the previously optimum found by our group and 12 times with respect to the lowest values reported in the literature as optimum. The use of this low-cost and nonhazardous solution, free of additives as isopropyl alcohol, can reduce costs in solar cell processing. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Insular territories face important challenges in achieving effective sustainable development, mainly due to low internal availability of basic resources, which results in a high external dependency. The analysis of the energy–water nexus of islands is a powerful instrument to evaluate the sustainable goals of the region and to identify the key actions to take to fulfill these objectives in future scenarios. The aim of this study is to review the energy–water nexus applied to Tenerife (Canary Islands), considering three scenarios: the base case scenario, corresponding to the current situation, where 1.1% of consumed water is dedicated to energy production and 10.2% of the energy is supplied for water abstraction, depuration, and ocean discharge; and two projections for the year 2050: a maintained trend scenario, and an ecology-aware scenario, where the population growth and the deployment of electrical vehicles are considered. In 2018, the total energy consumed was 1954 ktoe, of which renewable energy made up 2%. In the maintained trend scenario, this amount rises to 2003 ktoe, of which renewable energies represent 29%. However, in the ecology-aware scenario, this amount could be reduced to 1710 ktoe of which 51% of energy is obtained from renewable sources. [ABSTRACT FROM AUTHOR]