Desarrollo de un modelo en código R para la estimación en cubiertas del potencial solar fotovoltaico para la cobertura de la demanda eléctrica de edificios residenciales y terciarios en la ciudad de Valencia

[ES] En los últimos años la energía fotovoltaica ha consolidado una madurez tecnológica competitiva frente a otros recursos energéticos, constituyendo una fuente de energía estratégica para promover una transición energética sostenible. En este contexto, la reciente publicación del Real Decreto 244/2019 sobre el autoconsumo fotovoltaico facilita de forma administrativa, legal y técnica la posibilidad de la integración de instalaciones de este tipo en los edificios. El objeto de este trabajo consiste en la estimación, a partir de la radiación solar y datos LIDAR, de la energía eléctrica fotovoltaica que potencialmente se podría generar en los edificios residenciales, comerciales y de servicios de la ciudad de Valencia. Para ello se desarrollará un modelo de cálculo de generación considerando las sombras proyectadas en los tejados por los edificios circundantes mediante código R, que permitirá automatizar las estimaciones y escalar en la cantidad de edificaciones de cada una de las tipologías estudiadas para obtener resultados representativos. Todo ello respaldado con un análisis técnico-económico adaptado a la nueva legislación.[EN] In recent years photovoltaic energy has consolidated a technological maturity to be competitive against other energy resources, constituting a strategic energy source to promote a sustainable energy transition. In this context, the recent publication of Royal Decree 244/2019 on photovoltaic self-consumption facilitates administratively, legally and technically the possibility of integrating this type of facilities into buildings. The purpose of this work is to estimate, based on solar radiation and LIDAR data, the photovoltaic electric energy that could potentially be generated in in residential, commercial and service buildings in the city of Valencia. To this end, a generation calculation model will be developed using R code, taking into account the shadows cast by nearby buildings, that will allow automating the estimations and scaling the number of buildings of each of the typologies studied to obtain representative results. All this backed with a technical-economic analysis adapted to the new legislation.Fuster Palop, E. (2020). Desarrollo de un modelo en código R para la estimación en cubiertas del potencial solar fotovoltaico para la cobertura de la demanda eléctrica de edificios residenciales y terciarios en la ciudad de Valencia. http://hdl.handle.net/10251/137461TFG

Performance analysis and modelling of a 50 MW grid-connected photovoltaic plant in Spain after 12 years of operation

[EN] This study aims to estimate the performance and losses of a 50 MW photovoltaic (PV) utility-scale after 12 years of operation. The PV plant has monocrystalline and polycrystalline silicon modules and is located in the central region of Spain with an annual insolation of 1976 kWh/m2. Monitoring data over the entire year 2020 has been analyzed and filtered to assess the performance results following the IEC 61724 standard guidelines. The annual average reference yield, final yield, performance ratio and capacity utilization factor are of 5.44 h/d, 4.28 h/d, 79.24%, and 19.77%, respectively. Besides the experimental analysis, this work improves the estimation of the daily performance ratio, especially in days with low insolation. Two different modelling approaches have been assessed and compared. In first place, a physical model has been adopted, based on the most common losses, and including an exponential expression to account for low irradiance losses. In second place, statistical models have been used, with either multiple linear regressions or random forest algorithms. In contrast with other published models which require many inputs, the best accuracy has been reached with the random forest model using only the ambient temperature and solar irradiance as predictors, obtaining a RMSE of 1% for the PR and for the energy production.The authors gratefully acknowledge the operation & maintenance staff of the PV Power Plant in Olmedilla de Alarcon ¿ for providing the measured data of the solar PV power plant.Fuster-Palop, E.; Vargas-Salgado, C.; Ferri-Revert, JC.; Payá-Herrero, J. (2022). Performance analysis and modelling of a 50 MW grid-connected photovoltaic plant in Spain after 12 years of operation. Renewable and Sustainable Energy Reviews. 170:1-17. https://doi.org/10.1016/j.rser.2022.11296811717

Innovative regression-based methodology to assess the techno-economic performance of photovoltaic installations in urban areas

[EN] Households present a significant contribution in the national energy consumption, and photovoltaics (PV) has become an economically feasible technology that can play an important role to lower this consumption and the associated emissions. Nevertheless, there is still a gap between too in-depth technical models for detailed studies and what urban energy planners need, which are simpler, yet reliable techno-economical tools to select which roofs of city buildings are the best candidates for PV production. In order to face this gap, a multiple linear regression (MLR) model has been developed to determine the economic payback using dimensionless parameters. The methodology has been adopted in the city of Valencia (Spain) for a large sample of multi-storey buildings, which are the most common typology. The approach has a high replicability since it can be applied for different countries. The MLR model provides a payback root mean squared error (RMSE) of 0.48 years in comparison with a complex techno-economic model which was previously developed and validated with the software System Advisor Model (SAM). The variables which have a bigger weight in the payback are the shadow losses and the power unit cost due to the economy of scale. With the current Spanish regulation, PV installations on multi-storey buildings can reach paybacks of around 7-15 years and the best option is to have large economies of scales together with a low energy surplus.This study was developed owing to the support provided by the Chair of Urban Energy Transition of the Universitat Politecnica de Valencia and the foundation Las Naves. Additionally, this work was supported by The Energy Office of Valencia and the Statistics Office of the Valencia City Council, who collaborated by providing the data of the PV facility for the validation and their recommendations on the statistical analysis.Fuster-Palop, E.; Prades-Gil, C.; Masip, X.; Viana-Fons, JD.; Payá-Herrero, J. (2021). Innovative regression-based methodology to assess the techno-economic performance of photovoltaic installations in urban areas. Renewable and Sustainable Energy Reviews. 149:1-15. https://doi.org/10.1016/j.rser.2021.111357S11514

Modelado energético de una vivienda unifamiliar y diseño de un sistema de ACS solar, con apoyo de caldera de biomasa, para el cumplimiento de la normativa de edificios de balance energético casi nulo

[ES] Como respuesta al actual marco energético europeo y español caracterizado por un elevado consumo de combustibles fósiles, implicando un alto grado de dependencia energética así como un aumento del impacto de las emisiones de los gases de efecto invernadero sobre el clima mundial, se ha puesto en marcha políticas y planes energéticos que garanticen un desarrollo sostenible. El sector de la edificación constituye una de las áreas de mayor consumo energético con un amplio margen mejora. Por ello, la Directiva 2010/31/UE exige a los países miembros la implementación del concepto de los Edificios de Consumo de Energía Casi Nulo (ECCN) promoviendo la eficiencia y el consumo de recursos renovables en las nuevas edificaciones. El presente trabajo abordará los anteriores temas además de especificar una definición de ECCN para España, donde la normativa todavía no está definida. Todo ello orientado al caso de aplicación, que se basará en la conversión de una vivienda unifamiliar de construcción reciente en un ECCN, verificando el cumplimiento de la normativa.[EN] In response to the current European and Spanish energy framework charaterized by a high fossil fuel energy consumption, which involves a high degree of energy dependence as well as an increase in the impact of the greenhouse gas emissions on the global climate, policies and energy plans have been set in order to guarantee sustainable development. The building sector is one of the most energy-intensive areas with a large room for improvement. For this reason, Directive 2010/31 /EU requires member countries to implement the concept of Nearly Zero Energy Buildings (NZEB) by promoting the efficiency and consumption of renewable resources in new buildings. The present project will address the previous issues and also will specify a definition for NZEB for Spain, where the regulations are not defined yet. All this will be focused on the application case, which will be based on the conversion of a newly built single-family housing into a NZEB, verifying the fulfillment of the regulations.Fuster Palop, E. (2017). Modelado energético de una vivienda unifamiliar y diseño de un sistema de ACS solar, con apoyo de caldera de biomasa, para el cumplimiento de la normativa de edificios de balance energético casi nulo. http://hdl.handle.net/10251/84262.TFG

Modeling and Optimization of Photovoltaic Installations at Urban Scale

Tesis por compendio[ES] El sector de la edificación representa el 20% y el 40% de la energía primaria mundial, contribuyendo al 30% de las emisiones de CO2, un desafío amplificado por el crecimiento de la población. Sin embargo, el creciente interés en las fuentes de energía renovables ya maduras, como la energía solar fotovoltaica (PV), ofrece oportunidades para mitigar los anteriores impactos, así como potenciales beneficios económicos, ambientales y sociales. El presente trabajo investiga las posibilidades y limitaciones en el despliegue masivo de sistemas de autoconsumo fotovoltaico (PVSC) en áreas urbanas desde una perspectiva de planificación urbana, considerando las limitaciones técnicas y económicas actuales. Con este fin, esta tesis emplea estrategias basadas en datos para desarrollar modelos físicos y modelos ágiles basados en regresiones como herramientas de evaluación del potencial técnico y económico de los sistemas PVSC en contextos urbanos. En primer lugar, se ha desarrollado y validado un submodelo empírico de producción fotovoltaica con mediciones climáticas y de producción recopiladas de una planta fotovoltaica de 50MW en funcionamiento. Además, se han investigado varias mejoras en el modelado del performance ratio (PR) en entornos de baja irradiancia. En la segunda etapa de esta investigación, el submodelo anterior se ha integrado en un modelo tecnoeconómico 3D basado en sistemas de información geográfica (GIS) capaz de evaluar el PVSC económico para una muestra de edificios residenciales. Además, el modelo incorpora modelos de sombras y estimaciones de demanda eléctrica horaria para evaluar una muestra de edificios residenciales. Una base de datos de simulación, derivada de los resultados anteriores, ha permitido el desarrollo de una metodología para entrenar un modelo basado en regresión y con ello estimar la producción y el periodo de retorno económico (PB) a escala de edificio con una precisión asumible para fines de planificación energética. Como último paso, se mejoró el submodelo de demanda empleando datos reales agregados de series temporales para múltiples patrones de consumo y proporcionando estimaciones realistas para otras tipologías de edificios. Además de las restricciones espaciales, el modelo optimiza el tamaño de las instalaciones según su demanda y limitaciones económicas, maximizando la relación entre autosuficiencia (SS) y el PB. Además, la metodología basada en regresión se ha ampliado para estimar, además del retorno de la inversión, múltiples indicadores clave de desempeño (KPIs) como la tasa interna de retorno (IRR), la tasa de autoconsumo (SC) y SS. A través de una adecuada identificación de predictores y una metodología de entrenamiento y validación, estas correlaciones permitieron estimaciones de rendimiento con una desviación aceptable respecto al modelo físico. La disponibilidad de datos relacionados con la construcción está aumentando progresivamente en la mayoría de los países, lo que permite una amplia aplicación y generalización de las metodologías propuestas y reduce el costo de simulación de estos estudios para cubrir áreas urbanas más extensas. Como aplicación de las metodologías anteriores, se analizaron los resultados del potencial económico fotovoltaico del parque inmobiliario completo de un municipio mediterráneo bajo diferentes escenarios económicos y de demanda a escala de edificio y municipal. Para el escenario que cumple con la regulación actual en España, la SS municipal oscila entre el 22%-43% para los escenarios más optimista y pesimista, respectivamente. El dimensionamiento óptimo de las instalaciones según las curvas de carga en la modalidad de Net Billing (NB) es crucial para obtener resultados económicos competitivos. En consecuencia, la generación fotovoltaica anual representó el 68% del consumo eléctrico total anual.[CA] El sector de l'edificació representa el 20% i el 40% de l'energia primària mundial, contribuint al 30% de les emissions de CO2, un desafiament amplificat pel creixement de la població. No obstant això, el creixent interés en les fonts d'energia renovables ja madures, com l'energia solar fotovoltaica (PV), ofereix oportunitats per a mitigar els anteriors impactes, així com potencials beneficis econòmics, ambientals i socials. El present treball investiga les possibilitats i limitacions en el desplegament massiu de sistemes PVSC en àrees urbanes des d'una perspectiva de planificació urbana, considerant les limitacions tècniques i econòmiques actuals. A aquest efecte, aquesta tesi empra estratègies basades en dades per a desenvolupar models físics i models àgils basats en regressions com a eines d'avaluació del potencial tècnic i econòmic dels sistemes PVSC en contextos urbans. En primer lloc, s'ha desenvolupat i validat un submodel empíric de producció fotovoltaica amb mesuraments climàtics i de producció recopilats d'una planta fotovoltaica de 50MW en funcionament. A més, s'han investigat diverses millores en el modelatge del performance ràtio (PR) en entorns de baixa irradiància. En la segona etapa d'aquesta investigació, el submodel anterior s'ha integrat en un model tecnoeconòmic 3D basat en sistemes d'informació geográfica (GIS) capaç d'avaluar el PVSC econòmic per a una mostra d'edificis residencials. A més, el model incorpora models d'ombres i estimacions de demanda elèctrica horària per a avaluar una mostra d'edificis residencials. Una base de dades de simulació, derivada dels resultats anteriors, ha permés el desenvolupament d'una metodologia per a entrenar un model basat en regressió i amb això estimar la producció i la període de retorn econòmic (PB) a escala d'edifici amb una precisió assumible per a fins de planificació energètica. Com a últim pas, es va millorar el submodel de demanda emprant dades reals agregats de sèries temporals per a múltiples patrons de consum i proporcionant estimacions realistes per a altres tipologies d'edificis. A més de les restriccions espacials, el model optimitza la grandària de les instal·lacions segons la seua demanda i limitacions econòmiques, maximitzant la relació entre la taxa d'autosuficiència (SS) i PB. A més, la metodologia basada en regressió s'ha ampliat per a estimar, a més del retorn de la inversió, múltiples indicadors clau d'acompliment (KPIs) com la taxa interna de retorn (IRR), la taxa d'autoconsum (SC) i la SS. A través d'una adequada identificació de predictors i una metodologia d'entrenament i validació, aquestes correlacions van permetre estimacions de rendiment amb una desviació acceptable respecte al model físic. La disponibilitat de dades relacionades amb la construcció està augmentant progressivament en la majoria dels països, la qual cosa permet una àmplia aplicació i generalització de les metodologies proposades i redueix el cost de simulació d'aquests estudis per a cobrir àrees urbanes més extenses. Com a aplicació de les metodologies anteriors, es van analitzar els resultats del potencial econòmic fotovoltaic del parc immobiliari complet d'un municipi mediterrani baix diferents escenaris econòmics i de demanda a escala d'edifici i municipal. Per a l'escenari que compleix amb la regulació actual a Espanya, la taxa d'autosuficiència municipal oscil·la entre el 22%-43% per als escenaris més optimista i pessimista, respectivament. El dimensionament òptim de les instal·lacions segons les corbes de càrrega en la modalitat de Net Billing (NB) és crucial per a obtindre resultats econòmics competitius. En conseqüència, la generació fotovoltaica anual va representar el 68% del consum elèctric total anual.[EN] The building sector in developed countries consumes 20% to 40% of global primary energy, contributing to 30% of the CO2 emissions, a challenge amplified by urban population growth. However, the rising interest in mature renewable energy sources, such as solar photovoltaic (PV), offers opportunities to mitigate these impacts and potential economic, environmental, and social benefits. The present research investigates the possibilities and constraints in the massive deployment of photovoltaic self-consumption (PVSC) systems in urban areas from an urban planning perspective, considering the current technical and economic limitations. To this end, this thesis employs data-driven strategies to develop both bottom-up physical and agile regression-based models as assessment tools for the technical and economic potential of PVSC systems in urban contexts. First, an empirical PV production submodel has been developed and validated with climate and production measurements collected from a 50MW utility-scale in operation. Additionally, several improvements in modeling the performance ratio (PR) in low-irradiance environments have been investigated. In the second stage of this research, the previous submodel has been integrated into a physical 3D GIS-based techno-economic model capable of assessing the economic PVSC for a sample of residential buildings. Additionally, the model incorporates shadow modeling and hourly electric demand estimations to assess sample residential buildings. A simulation database, derived from the previous results, has allowed the development of a methodology to train a regression-based model to estimate the production and the economic payback (PB) at a building scale with an assumable accuracy for energy planning purposes. As the last step, the demand submodel was improved by employing real aggregated time series data for multiple consumer patterns and providing realistic estimations for other building typologies. In addition to spatial restrictions, the model optimizes the sizing of the facilities according to their demand and economic constraints, maximizing the relationship between self-sufficiency (SS) and PB. Furthermore, the regression-based methodology has been extended to estimate, besides the payback, multiple key performance indicators such as internal rate of return (IRR), self-consumption rate (SC), and SS. Through an appropriate predictor identification and a training and validation methodology, these correlations allowed performance estimations with an acceptable deviation compared with the physical model. The availability of building-related data is progressively increasing in most countries, enabling widespread application and generalization of the proposed methodologies and reducing the simulation cost of these studies to cover larger urban areas. As an application of the previous methodologies, a complete-census economic PV potential results of a Mediterranean municipality's building stock was performed under different demand and economic scenarios at a building and municipality scale. For the scenario that meets the current regulation in Spain, the municipality SS ranged between 22%-43% for the most optimistic and pessimistic scenarios, respectively. The optimal sizing of the facilities according to the load curves in the Net Billing (NB) modality is crucial to obtaining competitive economic results. Consequently, the annual PV generation represented 68% of the annual total electricity consumption of the municipality for a net billing scenario, while a net metering scenario represented 103%. Owing to economies of scale and high demand intensity, a higher profitability was found in rooftops of apartment blocks and industrial buildings, which also achieve the highest savings in emissions.Fuster Palop, E. (2023). Modeling and Optimization of Photovoltaic Installations at Urban Scale [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202061Compendi

Case study of electric and DHW energy communities in a Mediterranean district

[EN] Energy communities can play a key role to move towxards a low-carbon and decentralized energy system with higher penetration of renewable energies, offering new opportunities for citizens to actively participate in the energy transition. However, the term energy community is practically exclusively addressed in literature as photovoltaic systems shared by several users to cover their electricity needs. The present work describes the georeferenced modelling and assessment of potential domestic hot water energy communities based on heat pumps and photovoltaic energy communities in 150 residential buildings in a representative Mediterranean city. The main objective is to widen the concept of energy communities and to quantify their potential. The aggregated economic and emission savings of domestic hot water in the district can reach up to 85% and 73% respectively for heat pumps, and 22% and 23% respectively with photovoltaic systems. The analysis shows that domestic hot water energy communities should be prioritized if the objective of the decision-maker is to reduce the CO2 emissions. However, photovoltaics energy communities reach higher economic savings. Combining the two energy communities could help reach the Fit for 55 package objectives for 2030, with emission savings up to 56%. The results show that 80% of emission savings can be achieved by acting only on 35% of the buildings.This work was supported by the Chair of Urban Energy Transition UPV Las Naves y Valencia Clima i Energia and Grupo ImpactE Planificacion Urbana.Masip, X.; Fuster-Palop, E.; Prades-Gil, C.; Viana-Fons, JD.; Payá-Herrero, J.; Navarro-Peris, E. (2023). Case study of electric and DHW energy communities in a Mediterranean district. Renewable and Sustainable Energy Reviews. 178:1-16. https://doi.org/10.1016/j.rser.2023.11323411617

Techno-Economic Potential of Urban Photovoltaics: Comparison of Net Billing and Net Metering in a Mediterranean Municipality

Solar photovoltaic self-consumption is an attractive approach to increase autarky and reduce emissions in the building sector. However, a successful deployment in urban rooftops requires both accurate and low-computational-cost methods to estimate the self-consumption potential and economic feasibility, which is especially scarce in the literature on net billing schemes. In the first part of this study, a bottom-up GIS-based techno-economic model has helped compare the self-consumption potential with net metering and net billing in a Mediterranean municipality of Spain, with 3734 buildings in total. The capacity was optimized according to load profiles obtained from aggregated real measurements. Multiple load profile scenarios were assessed, revealing that the potential self-sufficiency of the municipality ranges between 21.9% and 42.5%. In the second part of the study, simplified regression-based models were developed to estimate the self-sufficiency, self-consumption, economic payback and internal rate of return at a building scale, providing nRMSE values of 3.9%, 3.1%, 10.0% and 1.5%, respectively. One of the predictors with a high correlation in the regressions is a novel coefficient that measures the alignment between the load and the hours with higher irradiance. The developed correlations can be employed for any other economic or demand scenario

Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort

Objectives: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). Methods: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. Results: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. Conclusion: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective