Long Term Energy Transition Scenario Analysis for the City of Donostia

El artículo pertenece a Proceedings of the 5th Annual Sustainable Places International Conference, Middlesbrough, UK, 28–30 June 2017 (SP2017)The direction adopted for the energy transitions towards a low carbon future will have long lasting implications in other aspects beyond the Climate Change. However, cities are becoming increasingly complex and a detailed knowledge is required for a long-term energy planning, which is frequently not available in city decision making processes. This paper describes a multi-criteria ex-ante impact assessment methodology developed for the building sector energy planning, which combines energy modelling and life cycle analysis with the regional macroeconomic analysis through the supply chain evaluation. The methodology is applied to the city of Donostia, demonstrating the importance of simultaneously considering various potentially conflicting criteria for the prioritization of scenarios

Experiencia de implantación de una asignatura basada íntegramente en las metodologías activas: A.B.P. y A.C.

La comunicación presenta la experiencia en la implementación de una asignatura de grado mediante una docencia basada íntegramente en las metodologías activas de enseñanza-aprendizaje, concretamente en el Aprendizaje Basado en Problemas (A.B.P.) y en el Aprendizaje Cooperativo (A.C.). La experiencia se ha desarrollado dentro del programa ERAGIN de la UPV/EHU que pretende asesorar y profundizar en la utilización sistemática y coherente de metodologías activas, incorporando a la experiencia previa del docente nuevas estrategias y técnicas de enseñanza encaminadas hacia un aprendizaje más inductivo y más cercano a la resolución de situaciones profesionales reales de carácter abierto. Las metodologías activas conciben el aprendizaje como un proceso constructivo y no receptivo, en el que los estudiantes trabajan cooperativamente en equipos, discutiendo, argumentando y evaluando constantemente lo que aprenden. El punto de partida lo constituyen situaciones o problemas del mundo real o de la práctica profesional. Los miembros del grupo tendrán que repartirse las tareas para avanzar, asumiendo una responsabilidad con el trabajo eficiente del grupo así como con el desarrollo de su aprendizaje individual. La asignatura elegida ha sido Termodinámica, de 6 créditos ECTS, que se imparte de forma conjunta en los grados de Ingeniería Ambiental e Ingeniería en Organización Industrial, en el segundo cuatrimestre de 2º curso. Existen dos grupos, castellano y euskera, con 45 y 29 alumnos, respectivamente. La propuesta diseñada e implementada durante el curso 2013/14 supone el 100% de la asignatura y de su sistema de evaluación. Tomando como base un problema estructurante, dividido en varios subproblemas, se han diseñado una serie de actividades que completan la totalidad de las horas, tanto presenciales como no presenciales, de dedicación del estudiante. Los estudiantes, trabajando en pequeños equipos, identifican los conocimientos necesarios para abordar las tareas, buscan información para aprender lo necesario, aplicarlo, y llegar a la solución. Las exposiciones del docente en el aula prácticamente desaparecen y éste actúa como guía del proceso de autoaprendizaje de los grupos de estudiantes. La evaluación es formativa y continua, de forma que los estudiantes reciben una retroalimentación inmediata durante el proceso de aprendizaje, para valorar el progreso que están realizando en el desarrollo de las competencias y reorientar y adaptar la planificación docente a las necesidades que van surgiendo

Methodology to Determine Energy Efficiency Strategies in Buildings Sited in Tropical Climatic Zones; Case Study, Buildings of the Tertiary Sector in the Dominican Republic

The application of energy-efficiency strategies in buildings is a hot topic around the world; in some countries, there are regulations with more or less degree of compliance, but in most countries located in the tropical zone, there are no regulations, and it is not easy to transfer regulations of countries outside of tropical zone. For countries located in tropical zones, the implementation of strategies to reduce the heat flow from outside to inside buildings is a key point. As a case study, the Dominican Republic (DR) was chosen, and during 2020, an analysis focusing on buildings of the tertiary level was carried out with the goal of using scientific methodology focused on tropical climates that allows for a significant reduction in energy consumption by implementing Energy Efficiency Strategies (EESs) that are available, with minimal intrusion into the building and low cost. The study includes, as parts of the proposed methodology, the characterization of building parks, including the climatic zonification of the country, an in-depth study of the building typologies in DR, and a massive survey around the country about the technical characteristics of air conditioning units and their usage; the election and characterization of buildings, including simulation and validation throughout the monitoring of eight different buildings; ananalysis of the measures of energy efficiency and implementation in the models, including the election of a demonstrative building, the election of the most convenient EESs, modeling of EESs, implementing EESs in the building, monitoring, and validation; and ananalysis of the impact of the measures at the region or country level, throughout which important conclusions can be obtained in order to reduce energy consumption in the country. The results show that this methodology is a valid tool for countries situated in tropical areas in order to reduce the energy consumption associated with air conditioning units with low cost, availability, and no intrusive EESs

Development of a tool based on thermoeconomics for control and diagnosis building thermal facilities

[EN] This work develops a software to control and diagnose building thermal facilities based on thermoe-conomics. It is tested with the data obtained from three building blocks in the Basque Country (northern Spain) with the aim of detecting the potential energy saving points and mitigating environmental im-pacts. Some obstacles, solved, are related to the insufficient number of probes and the inherent errors of sensors. Besides, new methodologies for performing a thermoeconomic dynamic analysis are described. Apart from this, the inefficiencies of components are quantified, a dynamic cost calculation of all fiows is done and different operation modes are discussed. The outcomes of operation modes are discussed and their exergetic, economic and environmental average unit cost are calculated. In such way, the inter-vention of the control system is analysed and the operation modes with lower and higher fuel con-sumption are detected. The results show that domestic hot water (DHW) production has an average value of 13.72 c euro /kWh and heating of 12.92 c euro /kWh; in addition, boilers have 1,587 MWh of real losses. Besides, the operating modes dynamic analysis opens a new research line for thermoeconomics appli-cations. This information is a key fact for control optimization searching the high performance of buildings.The authors appreciate the financial support provided for this work by the Basque Government through the ERAIKAL 2019 project. The authors also acknowledge the support provided by the Laboratory for the Quality Control in Buildings of the Basque Government

Avoiding Thermal Issues During Fast Charging Starting with Proper Cell Selection Criteria

[EN] Proper cell selection is determinant to optimize systems and reduce risks for new and high demanding areas such as electromobility. Thermal performance must be an indispensable selection criterion to avoid thermal issues in these fields, so cells should be correctly characterised and modelled. In this paper, an improved cell selection methodology that focuses on the thermal performance criterion especially for fast charging applications is proposed. After a first selection, two cell candidates were characterised and their heat generation was modelled and compared. With the selected cell, heat generation rate was determined and a 3C fast charge was performed to evidence the predicted thermal performance. The improved methodology identified a cell with an advantageous entropic heat coefficient (EHC) for fast charging, decreasing the heat energy generation by 54% concerning the other candidate cell, which results in optimisation of the thermal management system (TMS). This emphasizes the importance of proper cell selection based on thorough thermal characterization.This paper was developed under the framework of the SELFIE project. This project has received funding from the European Union's Horizon 2020 research and innovation programunder Grant Agreement Nr. 824290 (https://eu-project-selfie.eu/)

Balance energético de turbinas de vapor húmedo en centrales termoeléctricas nucleares: aplicación a la central nuclear de Santa María de Garoña

En la presente comunicación se muestra la implementación de la metodología tradicional para la estimación del rendimiento y la potencia eléctrica generada por turbinas de vapor húmedo en centrales termoeléctricas nucleares en una instalación concreta: la Central Nuclear de Santa María de Garoña. Usando las variables instrumentadas del proceso durante diferentes pruebas de rendimiento, se simulan los valores de presiones, temperaturas, caudales másicos y potencias, de modo que los resultados puedan compararse con los medidos en cada caso. El objetivo final del trabajo es demostrar si la metodología tradicional es suficientemente precisa para la simulación de este tipo de centrales termoeléctricas, e identificar oportunidades de mejora del modelo que permitan minimizar las desviaciones entre los parámetros simulados y los valores realmente medidos

Simulation and Thermo-Energy Analysis of Building Types in the Dominican Republic to Evaluate and Introduce Energy Efficiency in the Envelope

The improvement of the energy performance in buildings is key for sustainable development, even more so in the case of the Dominican Republic (DR), which is committed to this goal but which has neither regulation nor specific social behavior in this field. The main goal of this work is double; on one hand it is aimed at providing useable information for those who have the responsibly of making regulation norms and on the other, it is desirable to give an essential, technically proven and handy tool to those involved in the construction sector in improving the envelopes of buildings and to introduce good practices into the management of the energy systems of buildings. A case study of eight administrative buildings located in different climatic zones of the DR was carried out. A simulation tool was used for the study, and one of the buildings was monitored to verify the simulation work. Those factors that affect the development of the buildings in relation to thermo-energy consumption have been detailed. The large-scale heat gains resulting from the common glazing used by the tertiary sector in the Dominican Republic (including office buildings, hospitals and shops among others) illustrate the need for economically viable solutions in this sector. As a conclusion, it has been proved that the incidental thermal load of buildings could be reduced by up to 40%, thus in turn reducing the costs associated with the electricity needed to maintain the users’ desired thermal comfort level, as their influence in this sector is significant

Flameless errekuntzak klima aldaketaren aurka

Gaur egun klima aldaketaren inguruan daukagun egoera hobetzeko, energia kontsumoa murriztu behar da eta teknologia eraginkorrak eta emisiorik gabekoak suspertu behar dira. Nahiz eta energia berriztagarrien alde apustu egin, gaur egungo datuen arabera, bai gaur egun zein etorkizunean erregai fosilen kontsumoa energia primarioa izango da. Egoera honen aurrean erregai fosiletan oinarritzen diren teknologiei buruz ikerkuntzak egitea beharrezkoa da, teknologia berderantz bideratzeko. Klima aldaketari aurre egiteko flameless errekuntza garatu da. Flameless errekuntza produktuen aerodinamikan oinarritzen da, eta horiek birzirkulatuz erreaktiboak diluitu egiten dira. Horri esker O2-aren kontzentrazioa murrizten da labeko gar tenperatura murriztuz. NOx gasen emisioak tenperaturarekin erlazionatuta daudenez, labe tenperatura murriztean, NOx emisioak murrizten dira. Gainera, produktuen birzirkulazioaren bitartez erreaktiboak aurreberotzen badira, energia eraginkortasuna hobetzen da. Teknologia berri horrek aplikazio zuzena izan dezake tenperatura altuko labe eta galdaretan; adibidez, potentzia termikoko instalazioetan, findegietan, industria kimikoan, zeramika, beira, zementu eta altzairu lantegietan, NOx emisioak eta energia kontsumoa murriztuz. Flameless teknologia hobeto ulertzeko helburuarekin ikertzaileak Fluido Dinamika Konputazionala (FDK)-ren bitartez esperimentuak eta simulazioak egiten ari dira. FDK programan dauden modeloekin ohiko errekuntzaren ezaugarriak zehaztasunez simula daitezke (bero transferentzia, jariakinen mekanika, erradiazio termikoa, erreakzio kimikoak eta turbulentzia-kimika interakzioa), baina ez flameless errekuntza, erreaktiboen diluzioa kontuan hartzen ez delako. Hori dela eta beste modelo berri batzuk garatu behar dira.; In order to improve nowadays climate change situation, energy consumption must be reduced and efficient and no-pollution technologies should be promoted. Although huge effort is made toward renewable energy technologies, according to nowadays data, today and in the near future fossil fuels consumption will be the primary source energy. Due to that, it is necessary to research in fossil fuel technologies in order to be more climate friendly.Flameless combustion was developed against climate change.Flameless combustion is based on the aerodynamic recirculation of flue gas, which diluted reactants.The dilution effect reduces O2 concentration and consequently furnace temperature is reduced. NOx emissions are directly related with furnace temperature, so that, once furnace temperature is reduced NOx emissions go down. Additionally, reactants can be preheated by recirculated product increasing energy efficiency. This new technology has a direct application in high temperature furnaces as well as in boilers; as example, thermal power plants, refineries, chemical industry, ceramic, glass, cement and steel factories, reducing NOx emissions and energy consumption. In order to understand better flameless combustion researches are working on experimental set-ups as well as on Computational Fluids Dynamics (CFD) modelling. The CFD’s models simulate accurately conventional combustions characteristics; heat transfer, fluids dynamics, thermal radiation, chemical reactions and turbulence-chemistry interaction, but not flameless combustion as reactant dilution is not considered. Consequently, new models must be developed for better simulation of flameless combustion

Assessing the thermal performance of a conventional architecture in a dry warm climate

In this article, we present the results of the evaluation of the thermal performance of a conventional home in a dry warm climate, a case study in Bucaramanga, Colombia. This simulation, evaluation, and analysis make it necessary since currently in the case study area there is no thermal assessment of the dwellings, which are old houses built with resistive and mechanical analyses, but without regard to thermal behavior or thermal housing comfort. This evaluation is done by means of software simulation. Thus, a valid simulation identifies the weather data present in a dry warm climate zone and determines the geographical location and behavior in the solar diagram. Likewise, the thermal characterization of the soil and the construction materials of support and envelopes of the architecture is performed, to establish its thermal transmittance, thermal resistance, and thermal capacity. As a result of the research, the thermal behavior of the house is presented by means of the calculations made that determine the thermal behavior of the envelopes, energy load balancing, and housing thermal comfort based on the ASHRAE 55 standard by Fanger's method. Consequently, with the above, the results of the simulation and a detailed analysis of the recorded data are presented in the document

Accounting for homeowners? decisions to insulate: A discrete choice model approach in Spain

This paper assesses Spanish households' willingness to thermally insulate their homes and the drivers that influence such a decision-making process. Stated preference data were collected through a discrete choice experiment (DCE). The final sample of 191 respondents and 1,145 observations was analysed by the use of a mixed logit model, weighing the factors that encourage homeowners to carry out facade energy renovations or not. The model enables the quantitative estimation of renovation adoption rates depending on the households' characteristics and public support instruments in place. The results show that homeowners are extremely interested in increasing the thermal insulation of their homes. The actual investment cost required in the existing building stock is lower than the obtained willingness-to-pay. Furthermore, it was found a relevant effect of a variety of household features on renovation choice (income, age, heating system, etc.), which should be contemplated in the energy efficiency policy design. Additionally, a case analysis is performed which comprises 3 household categories. The results reveal that the required subsidy level is different in each case, sometimes even unnecessary, although all of them lower than the grants set by existing aid programs. Thus, to reduce the free-riding effect, a closer perspective would enable targeted support mechanisms towards each household category. Moreover, the policy performance can be improved by combining subsidies with other measures such as low-interest loans or increased tax rebates, which could contribute to improving the cost effectiveness of the public expense associated with direct grants. Overall, an increased tax rebate is preferred to soft financing, although the influence of the latter increases in low-income households