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The ubiquity and impact of pharmaceuticals and pesticides, as well as their residues in environmental compartments, particularly in water, have raised human and environmental health concerns. This emphasizes the need of developing sustainable methods for their removal. Solar-driven photocatalytic degradation has emerged as a promising approach for the chemical decontamination of water, sparking intensive scientific research in this field. Advancements in photocatalytic materials have driven the need for solar reactors that efficiently integrate photocatalysts for real-world water treatment. This study reports preliminary results from the development and evaluation of a solar system for TiO2-based photocatalytic degradation of intermittently flowing water contaminated with doxycycline (DXC), sulfamethoxazole (SMX), dexamethasone (DXM), and carbendazim (CBZ). The system consisted of a Fresnel-type UV solar concentrator that focused on the opening and focal point of a parabolic trough concentrator, within which tubular quartz glass reactors were fixed. Concentric springs coated with TiO2, arranged one inside the other, were fixed inside the quartz reactors. The reactors are connected to a raw water tank at the inlet and a check valve at the outlet. Rotating wheels at the collector base enable solar tracking in two axes. The substances (SMX, DXC, and CBZ) were dissolved in dechlorinated tap water at a concentration of 1.0 mg/L, except DXM (0.8 mg/L). The water underwent sequential batch (~ 3 L each, without recirculation) processing with retention times of 15, 30, 60, 90, and 120 min. After 15 min, the degradation rates were as follows: DXC 87%, SMX 35.5%, DXM 32%, and CBZ 31.8%. The system processed 101 L of water daily, simultaneously removing 870, 355, 256, and 318 µg/L of DXC, SMX, DXM, and CBZ, respectively, showcasing its potential for real-world chemical water decontamination application. Further enhancements that enable continuous-flow operation and integrate highly effective adsorbents and photocatalytic materials can significantly enhance system performance.
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Fotoquímica , Energia Solar , Poluentes Químicos da Água , Purificação da Água , Água , Catálise/efeitos da radiação , Água/química , Purificação da Água/instrumentação , Purificação da Água/métodos , Humanos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Doxiciclina/química , Doxiciclina/isolamento & purificação , Sulfametoxazol/química , Sulfametoxazol/isolamento & purificação , Dexametasona/química , Dexametasona/isolamento & purificação , Quartzo , Cromatografia , Temperatura , Fatores de Tempo , Animais , Abastecimento de ÁguaRESUMO
Renewable cooling via absorption chillers being supplied by various green heat technologies such as solar collectors has been widely studied in the literature, but it is still challenging to get positive economic outcomes from such systems due to the large expenses of solar thermal systems. This study offers the use of a new generation of solar collectors, so-called eccentric reflective solar collectors, for driving single-effect absorption chillers and thereby reducing the levelized cost of cooling. This article develops the most optimal design of this system (based on several different scenarios) using multi-objective optimization techniques and employs them for a case study in Brazil to assess its proficiency compared to conventional solar-driven cooling methods. For making the benchmarking analyses fair, the conventional system is also rigorously optimized in terms of design and operation features. The results show that the eccentric solar collector would enhance the cost-effectiveness by 29%. In addition, using optimally sized storage units would be necessary to get acceptable economic performance from the system, no matter which collector type is used. For the case study, at the optimal sizing and operating conditions, the levelized cost of cooling will be 124 USD/MWh and an emission level of 18.97 kgCO2/MWh.
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Energia Solar , Luz Solar , Temperatura Baixa , Temperatura Alta , Transição de FaseRESUMO
Dye-sensitized solar cells (DSSCs) are promising third-generation photovoltaic cell technology owing to their easy fabrication, flexibility and better performance under diffuse light conditions. Natural pigment sensitizers are abundantly available and environmentally friendliness. However, narrow absorption spectra of natural pigments result in low efficiencies of the DSSCs. Therefore, combining two or more pigments with complementary absorption spectra is considered an appropriate method to broaden the absorption band and boost efficiency. This study reports three complex molecules: brazilin-betanidin-oxane (Braz-Bd-oxane), brazilin-betanidin-ether (Braz-Bd-ether) and brazilein-betanidin-ether (Braze-Bd-ether), obtained from the etherification and bi-etherification reactions of brazilin dye and brazilein dye with betanidin dye. The equilibrium geometrical structure properties, frontier molecular orbital, electrostatic surface potential, reorganization energy, chemical reactivities, and non-linear optical properties of the studied dyes were investigated using density functional theory (DFT)/B3LYP methods, with 6-31+G(d,p) basis sets and LANL2DZ for light atom and heavy atoms respectively. The optical-electronic properties were calculated using TD-DFT/B3LYP/6-31+G(d,p) for isolated dye and TD-DFT/CAM-B3LYP/6-31G(d,p)/LANL2DZ for dyes@(TiO2)9H4. The results reveal that spectra for Braz-Bd-oxane and Braze-Bd-ether complexes red-shifted compared to the individually selected dyes. The simulated absorption spectra of the adsorbed dyes on (TiO2)9H4 are red-shifted compared to the free dye. Moreover, Braz-Bd-oxane and Braz-Bd-ether exhibit better charge transfer and photovoltaic properties than the selected natural dyes forming these complexes. Based on the dyes' optoelectronic properties and photovoltaic properties, the designed molecules Braz-Bd-oxane and Braze-Bd-ether are considered better candidates to be used as photosensitizers in dye solar cells.
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Benzopiranos , Corantes , Indenos , Energia Solar , Modelos Moleculares , Corantes/química , Betacianinas , Teoria da Densidade Funcional , ÉteresRESUMO
This study examines the potential for widespread solar photovoltaic panel production in Mexico and emphasizes the country's unique qualities that position it as a strong manufacturing candidate in this field. An advanced model based on artificial neural networks has been developed to predict solar photovoltaic panel plant metrics. This model integrates a state-of-the-art non-linear programming framework using Pyomo as well as an innovative optimization and machine learning toolkit library. This approach creates surrogate models for individual photovoltaic plants including production timelines. While this research, conducted through extensive simulations and meticulous computations, unveiled that Latin America has been significantly underrepresented in the production of silicon, wafers, cells, and modules within the global market; it also demonstrates the substantial potential of scaling up photovoltaic panel production in Mexico, leading to significant economic, social, and environmental benefits. By hyperparameter optimization, an outstanding and competitive artificial neural network model has been developed with a coefficient of determination values above 0.99 for all output variables. It has been found that water and energy consumption during PV panel production is remarkable. However, water consumption (33.16 × 10-4 m3/kWh) and the emissions generated (1.12 × 10-6 TonCO2/kWh) during energy production are significantly lower than those of conventional power plants. Notably, the results highlight a positive economic trend, with module production plants generating the highest profits (35.7%) among all production stages, while polycrystalline silicon production plants yield comparatively lower earnings (13.0%). Furthermore, this study underscores a critical factor in the photovoltaic panel production process which is that cell production plants contribute the most to energy consumption (39.7%) due to their intricate multi-stage processes. The blending of Machine Learning and optimization models heralds a new era in resource allocation for a more sustainable renewable energy sector, offering a brighter, greener future.
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Energia Solar , México , Silício , Centrais Elétricas , Alocação de RecursosRESUMO
Introducción: El tema del cambio climático y sus efectos, en la salud, educación y transporte, es un tema emergente, que pretende la optimización del consumo y la eficiencia energética. Esta investigación se plantea como objetivo,la caracterización del uso y aprovechamiento de energías, en establecimientos de atención médica de la región capital durante el año 2022, considerando la distribución energética, eficiencia y fuentes primarias de energía utilizadas en este país. Métodos: Se trata de una investigación descriptiva, transversal y prospectiva,a través del análisis cuali-cuantitativo, con el uso de informantes clave quienes consideran importante la iluminación natural en los espacios y el mayor aprovechamiento energético en áreas como la quirúrgica y consulta externa. Resultados: Surge el uso de la energía solar, eólica e hidráulica como recursos energéticos aprovechables, así como la sostenibilidad y la mantenibilidad en el diseño y rediseño de infraestructuras hospitalarias. Los tipos de energías utilizados en Venezuela, siguen correspondiendo ala hidráulica y combustibles fósiles, se conoce la tecnología e implementación de paneles solares para la mejoría del cambio climático, la huella del carbono, el uso de energías verdes y reducción de combustibles fósiles. Su aceptación depende de regulaciones y la concientización energética como elementos fundamentales para el cambio.
Introduction: The issue of climate change and itseffects, in health, education and transportation, is an emergingissue, which aims at the optimization of energy consumption andefficiency. îe objective of this research is to characterize the useand exploitation of energy in health care facilities in the capitalregion during the year 2022, considering the energy distribution,efficiency and primary energy sources used in this country.Methods: This is a descriptive, cross-sectional and prospectiveresearch, through qualitative-quantitative analysis, with the useof key informants who consider important the natural lightingin the spaces and the greater use of energy in areas such assurgery and outpatient care. Results: The use of solar, windand hydraulic energy emerged as usable energy resources, aswell as sustainability and maintainability in the design andredesign of hospital infrastructures. The types of energy used inVenezuela continue to correspond to hydraulics and fossil fuels; the technology and implementation of solar panels is known forthe improvement of climate change, the carbon footprint, theuse of green energy and reduction of fossil fuels. Their acceptancedepends on regulations and energy awareness as fundamental elements for change.
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Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto Jovem , Mudança Climática/estatística & dados numéricos , Fontes Geradoras de Energia , Consumo de Energia , Energia Solar , Cuidados Médicos , Política de SaúdeRESUMO
In this work, natural dyes from three different species of the same flower family (Chrysanthemum), which containing anthocyanin were extracted and properly prepared to be used as photosensitizers in DSSCs construction. The cells were fabricated with titanium dioxide nanoparticles (TiO2) for the photoanodes, whereas platinum electrodes were used for the photocathodes. To understand the behavior of light absorption in addition to the coloring components present in the dyes and the molecular functional groups present in the samples, the UV-Vis absorption spectroscopy and FTIR spectroscopy were used respectively. The performance and efficiency of solar cells were evaluated to establish the photovoltaic criteria for each DSSC built. Through electrochemical characterizations, it was possible to notice that the highest photovoltaic conversion efficiency was obtained with the Chrysanthemum Violet (CV) cell, with efficiency (η) of 1.348%, compared to 1.229% and 0.485% for the Chrysanthemum Green (CG) and Chrysanthemum Blue (CB) cells, respectively. The CV cell also has the highest open circuit voltage (VOC) at 0.58 V. The results corroborate to present the organic solar cells as a viable option for the electric energy generation.
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Chrysanthemum , Energia Solar , Antocianinas/química , Corantes/química , Fármacos Fotossensibilizantes , PlatinaRESUMO
A new benzodithiophene and benzotriazole-based terpolymer bearing a fluorescein derivative as a side group was synthesized and studied for organic solar cell (OSC) applications. This side group was covalently bounded to the backbone through an n-hexyl chain to induce the intramolecular Förster Resonance Energy Transfer (FRET) process and thus improve the photovoltaic performance of the polymeric material. The polymer exhibited good solubility in common organic chlorinated solvents as well as thermal stability (TDT10% > 360 °C). Photophysical measurements demonstrated the occurrence of the FRET phenomenon between the lateral group and the terpolymer. The terpolymer exhibited an absorption band centered at 501 nm, an optical bandgap of 2.02 eV, and HOMO and LUMO energy levels of −5.30 eV and −3.28 eV, respectively. A preliminary study on terpolymer-based OSC devices showed a low power-conversion efficiency (PCE) but a higher performance than devices based on an analogous polymer without the fluorescein derivative. These results mean that the design presented here is a promising strategy to improve the performance of polymers used in OSCs.
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Energia Solar , Transferência Ressonante de Energia de Fluorescência , Tiofenos , Fluoresceína , PolímerosAssuntos
Humanos , Energia Solar , Gastos em Saúde , Combustíveis , Fontes Geradoras de Energia , Energia Hidrelétrica , Energia EólicaRESUMO
[Introducción]: El uso de combustibles sólidos para cocinar es un importante problema de salud pública en las Américas y el principal riesgo ambiental, pues afecta a casi 90 millones de personas. La Organización Mundial de la Salud (OMS) ha estimado que en el 2016 la quema de combustibles sólidos para cocinar y calentarse en las Américas causó la muerte de más de 82 000 personas y una pérdida de más de 2,3 millones de años de vida ajustados por discapacidad (AVAD) ... En este informe se presentan los avances, retos y oportunidades para avanzar en la transición energética al uso de combustibles modernos y limpios como el GLP y la electricidad para cocinar, y para cumplir con las directrices de calidad del aire en la vivienda recomendadas por la OMS, contribuyendo a la implementación de la Agenda 2030 de Desarrollo Sostenible.
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Energia Renovável , Saúde Ambiental , Meio Ambiente e Saúde Pública , Eletricidade , Combustíveis , Energia Solar , Fatores Socioeconômicos , Planos e Programas de Saúde , PanamáRESUMO
The obesity worldwide has produced an increase in obesity-related diseases and can be associated with low concentrations of 25-hydroxyvitamin-D. Also obesity and low physical activity can decrease sun exposure, so the aim was to correlate vitamin D intake with serum 25-hydroxyvitamin-D levels and to assess sun exposure habits in schoolchildren with obesity. Materials and methods. A correlational study was performed from January 2017 to January 2018 on 103 children between 6-12 years of age, with a body mass index ≥+2SD for age and sex, according to the World Health Organization. Blood samples were taken to determine the serum concentrations of 25-hydroxyvitamin-D, a nutritional survey to determine the vitamin D intake and a sun exposure questionnaire were applied. A Spearman correlation coefficient analysis was performed. Results. Forty-seven percent of the children were girls. The median years of age was 10. The median serum 25-hydroxyvitamin-D levels were 35.5 ng/mL, 74.8% had sufficient levels, 25.2% had insufficient levels. The median vitamin D intake was 214.7IU in boys and 231.9IU in girls. Regarding sun exposure, most of the children had excessive levels of sun exposure and inadequate sun protection practices. A positive correlation between vitamin D intake and serum 25-hydroxyvitamin-D was identified only in boys (rho=0.276, p=0.041). Conclusion. A positive correlation between vitamin D intake and serum 25-hydroxyvitamin-D levels was found in obese boys and excessive levels of sun exposure with inadequate sun protection practices in boys and girls(AU)
La obesidad se le ha asociado con distintas comorbilidades, bajas concentraciones séricas de 25-hidroxivitamina-D, sedentarismo que a su vez podría comprometer la exposición solar; por tanto, el objetivo fue relacionar la ingesta de vitamina D con los niveles séricos de 25-hidroxivitamina-D y determinar los hábitos de exposición solar en escolares con obesidad. Materiales y métodos. Estudio correlacional realizado de enero 2017 a enero 2018, en 103 niños entre 6 y 12 años, con un índice de masa corporal ≥+2DE para edad y sexo, según la Organización Mundial de la Salud. Se extrajo muestras sanguíneas para determinar las concentraciones séricas de 25-hidroxivitamina-D, se aplicó una encuesta nutricional para determinar la ingesta de vitamina D y un cuestionario de exposición solar. Se realizó un análisis del coeficiente de correlación de Spearman. Resultados. El 47% de los sujetos eran niñas. La mediana de edad fue de 10. La mediana de los niveles séricos de 25-hidroxivitamina-D fue de 35,5 ng/mL, el 74,8% tenía niveles suficientes, el 25,2% tenía niveles insuficientes. La mediana de la ingesta de vitamina D fue de 214,7UI en niños y de 231,9UI en niñas. Con respecto a la exposición solar, la mayoría de los niños presentaban una exposición excesiva y prácticas inadecuadas de protección solar. Se identificó una correlación positiva entre la ingesta de vitamina D y la 25-hidroxivitamina-D sérica en los niños (rho=0,276, p=0,041). Conclusión. Se identificó una correlación positiva entre la ingesta de vitamina D y los niveles séricos de 25-hidroxivitamina-D en niños obesos y exposición excesiva con prácticas inadecuadas de protección solar en niños y niñas(AU)
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Humanos , Masculino , Feminino , Criança , Energia Solar , Vitamina D/administração & dosagem , Comportamento Sedentário , Obesidade/complicações , Estudantes , Exercício Físico , Índice de Massa Corporal , Inquéritos e Questionários , Comportamento Alimentar , MéxicoRESUMO
[Introducción]. El uso de combustibles sólidos para cocinar es un importante problema de salud pública en las Américas y el principal riesgo ambiental, pues afecta a casi 90 millones de personas. La Organización Mundial de la Salud (OMS) estimó que en el 2016 la quema de combustibles contaminantes para cocinar y calentarse en las Américas causó la muerte de más de 82 000 personas, y una pérdida de 2,3 millones de años de vida ajustados por discapacidad (AVAD)... En Honduras, 47% de la población (1 127 000 hogares) depende de la leña y otros residuos orgánicos para cocinar. Según la Encuesta de Hogares para Propósitos Múltiples 2019, 87% de la población rural y 26% de la población urbana usaban leña para cocinar (a menudo en combinación con electricidad o GLP). En el 2011, 66% de los hogares urbanos compraban la leña, frente a 49% en la zona rural; esta diferencia se debe a que en las zonas rurales mayormente la recolectan. En el 2013, únicamente 39% de la población total tenía acceso a GLP, mientras que, en el 2019, 80,82% de la población accedía a la electricidad...
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Meio Ambiente e Saúde Pública , Energia Renovável , Energia Solar , Saúde Ambiental , Eletricidade , Combustíveis , Planos e Programas de Saúde , Fatores Socioeconômicos , HondurasRESUMO
Protected areas and renewable energy generation are critical tools to combat biodiversity loss and climate change, respectively. Over the coming decades, expansion of the protected area network to meet conservation objectives will be occurring alongside rapid deployment of renewable energy infrastructure to meet climate targets, driving potential conflict for a finite land resource. Renewable energy infrastructure can have negative effects on wildlife, and co-occurrence may mean emissions targets are met at the expense of conservation objectives. Here, we assess current and projected overlaps of wind and solar photovoltaic installations and important conservation areas across nine global regions using spatially explicit wind and solar data and methods for predicting future renewable expansion. We show similar levels of co-occurrence as previous studies but demonstrate that once area is accounted for, previous concerns about overlaps in the Northern Hemisphere may be largely unfounded, although they are high in some biodiverse countries (e.g., Brazil). Future projections of overlap between the two land uses presented here are generally dependent on priority threshold and region and suggest the risk of future conflict can be low. We use the best available data on protected area degradation to corroborate this level of risk. Together, our findings indicate that while conflicts between renewables and protected areas inevitably do occur, renewables represent an important option for decarbonization of the energy sector that would not significantly affect area-based conservation targets if deployed with appropriate policy and regulatory controls.
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Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais , Energia Solar , BrasilRESUMO
Photovoltaic panels can be colonized by a highly diverse microbial diversity, despite life-threatening conditions. Although they are distributed worldwide, the microorganisms living on their surfaces have never been profiled in tropical regions using 16S rRNA high-throughput sequencing and PICRUst metagenome prediction of functional content. In this work, we investigated photovoltaic panels from two cities in southeast Brazil, Sorocaba and Itatiba, using these bioinformatics approach. Results showed that, despite significant differences in microbial diversity (p < 0.001), the taxonomic profile was very similar for both photovoltaic panels, dominated mainly by Proteobacteria, Bacteroidota and lower amounts of Cyanobacteria phyla. A predominance of Hymenobacter and Methylobacterium-Methylorubrum was observed at the genus level. We identified a microbial common core composed of Hymenobacter, Deinococcus, Sphingomonas, Methylobacterium-Methylorubrum, Craurococcus-Caldovatus, Massilia, Noviherbaspirillum and 1174-901-12 sharing genera. Predicted metabolisms focused on specific genes associated to radiation and desiccation resistance and pigments, were detected in members of the common core and among the most abundant genera. Our results suggested that taxonomic and functional profiles investigated were consistent with the harsh environment that photovoltaic panels represent. Moreover, the presence of stress genes in the predicted functional content was a preliminary evidence that microbes living there are a possibly source of metabolites with biotechnological interest.
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Cianobactérias , Extremófilos , Microbiota , Energia Solar , Materiais de Construção/microbiologia , Cianobactérias/genética , Extremófilos/classificação , Extremófilos/genética , Metagenoma , Microbiota/genética , RNA Ribossômico 16S/genética , Clima TropicalRESUMO
Reservoirs of hydropower plants (HPP) can amend water, energy, and food security in semi-arid regions. However, during severe droughts, the priority of energy demand leads to critical conditions of water availability. To reduce water use for energy, one possible measure is the adoption of solar power, an abundant energy source in semi-arid regions. This study assessed the influence of adding floating photovoltaic power (PV) in the large-scale reservoir of Sobradinho HPP, located in the São Francisco River (SFR), in Brazil, from 2009 to 2018. The simulated scenarios varied the installed PV power capacity from 50 to 1000 MW. For each scenario, water allocation was modified based on the solar-hydro equivalence that restrained the historical outflow of Sobradinho to maintain water in the reservoir. Besides, a diverse operation rule for the reservoirs in cascade of SFR was adopted to avoid ecological impacts of low streamflow. The scenarios were assessed in water security, solar-hydro electricity output, capacity factor of the powerplant, water and energy losses by evaporation and spilled water. Results show that a PV system starting from 250 MW was necessary to improve water security during the severe drought, reserving 0.7-2.3 of the annual water demand. In addition, the capacity factor was optimized from 29% to 34-47%. However, as the HPPs installed at SFR work as one system, the constrain of the river flow reduced the hydroelectricity by 4.4% for 750 MW. We concluded that PV significantly influenced water security and ecological conditions of SFR, with benefits in the range of 250-750 MW. The research provides assessment on substituting hydro for solar power on the operation of reservoirs in cascade and identifies the correlated benefits in social and ecological aspects. This information can support decisions of water and energy supply system operators and public policies focused on integrated resources management in semi-arid regions.
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Secas , Energia Solar , Brasil , Rios , ÁguaRESUMO
BACKGROUND: Microbes are present in almost every environment on Earth, even in those with extreme environmental conditions such as Antarctica, where rocks may represent the main refuge for life. Lithobiontic communities are composed of microorganisms capable of colonizing rocks and, as it is a not so well studied bacterial community, they may represent a very interesting source of diversity and functional traits with potential for biotechnological applications. In this work we analyzed the ability of Antarctic lithobiontic bacterium to synthesize cadmium sulfide quantum dots (CdS QDs) and their potential application in solar cells. RESULTS: A basaltic andesite rock sample was collected from Fildes Peninsula, King George Island, Antarctica, and processed in order to isolate lithobiontic bacterial strains. Out of the 11 selected isolates, strain UYP1, identified as Pedobacter, was chosen for further characterization and analysis due to its high cadmium tolerance. A protocol for the biosynthesis of CdS QDs was developed and optimized for this strain. After 20 and 80 min of synthesis, yellow-green and orange-red fluorescent emissions were observed under UV light, respectively. QDs were characterized through spectroscopic techniques, dynamic light scattering analysis, high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. Nanostructures of 3.07 nm, composed of 51.1% cadmium and 48.9% sulfide were obtained and further used as photosensitizer material in solar cells. These solar cells were able to conduct electrons and displayed an open circuit voltage of 162 mV, a short circuit current density of 0.0110 mA cm-2, and had an efficiency of conversion up to 0.0016%, which is comparable with data previously reported for solar cells sensitized with biologically produced quantum dots. CONCLUSIONS: We report a cheap, rapid and eco-friendly protocol for the production of CdS QDs by an Antarctic lithobiontic bacterium, Pedobacter, a genus that was not previously reported as a quantum dot producer. The application of the biosynthesized QDs as sensitizer material in solar cells was validated.
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Compostos de Cálcio/química , Pedobacter/química , Pontos Quânticos/química , Energia Solar , Sulfetos/química , Regiões AntárticasRESUMO
The structural and electronic properties were calculated for seventy organic compounds used as dye sensitizers in solar cells, applying the B3LYP exchange-correlation energy functional with the 6-311G∗∗ basis set. Moreover, the present study proposes two new quantitative structure-property relationship (QSPR) models that enable the prediction of the power conversion efficiency (PCE) and maximum absorption wavelength (λmax) of these systems, the two QSPR models were validated using the coefficient of determination (R2) of 0.62 for both models with the leave-one-out cross-validation correlation coefficient (Q2LOO) of 0.55 and 0.57, respectively. Furthermore, applicability domain analysis was conducted in order to identify the related compounds via the extrapolation of the model.
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Energia Solar , Corantes , Compostos Orgânicos , Relação Quantitativa Estrutura-AtividadeRESUMO
The present paper proposes a methodology based on the implementation and assessment of autoregressive (AR) solar radiation models for generating synthetic series and providing guidance on bidding strategies for power purchase agreements. The work considered conventional and periodic AR models with different lag orders, assessing the models against real solar radiation measurements. The synthetic series generation process developed 1000 1-year monthly solar radiation scenarios that were later employed for simulating electric energy production and power purchase agreement models. This application allowed one to evaluate the risk associated with the energy supply security, supporting bidding strategies in energy auctions. A real study case is also illustrated in detail, referring to a spot in the Brazilian best irradiance area.
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Energia Solar , Brasil , EletricidadeRESUMO
Abstract The growth in the use of solar energy has encouraged the development of techniques for short-term prediction of solar photovoltaic energy generation (PSPEG). Machine learning with Artificial Neural Networks (ANNs) is the most widely used technique to solve this problem. However, comparative studies of these networks with distinct structural configurations, input parameters and prediction horizon, have not been observed in the literature. In this context, the aim of this study is to evaluate the prediction accuracy of the Global Horizontal Irradiance (GHI), which is often used in the PSPEG, generated by ANN models with different construction structures, sets of input meteorological variables and in three short-term prediction horizons, considering a unique database. The analyses were performed with controlled environment and experimental configuration. The results suggest that ANNs using the input GHI variable provide better accuracy (approximately 10%), and their absence increases error variability. No significant difference (p>0.05) was identified in the prediction error models trained with distinct meteorological input data sets. The prediction errors were similar for the same ANN model in the different prediction horizons, and ANNs with 30 and 60 neurons with one hidden layer demonstrated similar or higher accuracy than those with two hidden layers.
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Energia Solar , Redes Neurais de Computação , Radiação Solar , Energia FotovoltaicaRESUMO
Abstract The electrical system is becoming more robust with the insertion of distributed energy resources (DERs) and the need for energy autonomy by consumers, given that the current scenario is a growth in demand for electric energy. This paper aims to apply a computational model capable of determining the optimal hourly allocation of controllable loads in residence, as well as studying the optimal dispatch of residential microgrids considering management on the demand side. In addition, this paper presents an economic feasibility analysis of residential microgrids considering distributed generation from wind and solar sources, distributed storage, electric vehicles, and residential controllable loads. Thus, it was possible to conclude that in residence, the insertion of distributed energy generation and storage elements can present a significant reduction in electric energy costs, which can be even greater if these elements are associated with optimized controllable load management.