Evaluation of the utilization of electric vehicles for building energy management in hotels

Governments are working in new policies to slow down total energy consumption and greenhouse gases (GHG) emissions, promoting the deployment of electric vehicles (EVs) in all countries. In order to facilitate this deployment and help to reduce the final costs of their batteries, additional utilization of EVs when those are parked has been proposed. EVs can be used to minimize the total electricity cost of buildings (named vehicle to building applications, V2B). In this paper an economic evaluation of EVs in the Building Energy Management System is shown. The optimal storage capacity and its equivalent number of EVs are determined. This value is then used for determining the optimal charging schedule to be applied to the batteries. From this schedule, the total expected profit is derived for the case of a real hotel in Spain.

Multiphase Current Controlled Buck Converter with energy recycling Output Impedance Correction Circuit (OICC)

This work is related to the output impedance improvement of a Multiphase Buck converter with Peak Current Mode Control (PCMC) by means of introducing an additional power path that virtually increases the output capacitance during transients. Various solutions that can be employed to improve the dynamic behavior of the converter system exist, but nearly all solutions are developed for a Single Phase Buck converter with Voltage Mode Control (VMC), while in the VRM applications, due to the high currents, the system is usually implemented as a Multiphase Buck Converter with Current Mode Control. The Output Impedance Correction Circuit (OICC) is used to inject or extract a current n-1 times larger than the output capacitor current, thus virtually increasing n times the value of the output capacitance during the transients. Furthermore, this work extends the OICC concept to a Multiphase Buck Converter system while comparing proposed solution with the system that has n times bigger output capacitor. In addition, the OICC is implemented as a Synchronous Buck Converter with PCMC, thus reducing its influence on the system efficiency

Experiences and methodology in a multidisciplinary energy and architecture competition: Solar Decathlon Europe 2012

Solar Decathlon Europe is an international competition among universities which promotes interdisciplinary learning in engineering and architecture. Students from different disciplines participate in teams guided by several professors during a 29 month preparation period plus five weeks of on-site contest. The educational project involves designing, building and testing a solar energy house connected to the electrical grid with the strategy of maximizing self-consumption, supported by bioclimatic technologies and maintaining a low environmental footprint. It culminates in a on-site contest in which teams must assembly the house themselves, test it with ordinary real life tasks and finally disassembly it. The event has also a divulgative aim, trying to make students and visitors get interested in discovering the problems presented by real engineering and architecture applications. In addition, SDE covers R&D aspects in different fields such as energy efficiency, solar energy and bioclimatic architecture. This article presents the methodology followed during the SDE 2012 edition, in which more than 850 students participated. The obtained results show that the educational competition was a success according to the technical and professional ambitions of the students, most of them considering that their knowledge had increased in areas related to technical and multidisciplinary aspects.

Electrical energy balance contest in Solar Decathlon Europe 2012

Solar Decathlon Europe (SDE) is an international multidisciplinary competition in which 20 universityteams build and operate energy-efficient solar-powered houses. The aim of SDE is not only scientificbut also educational and divulgative, making visitors to understand the problems presented by realengineering applications and architecture. From a research perspective, the energy data gathered dur-ing the competition constitutes a very promising information for the analysis and understanding of thephotovoltaic systems, grid structures, energy balances and energy efficiency of the set of houses. Thisarticle focuses on the electrical energy components of SDE competition, the energy performance of thehouses and the strategies and behaviors followed by the teams. The rules evaluate the houses? electricalenergy self-sufficiency by looking at the electricity autonomy in terms of aggregated electrical energybalance; the temporary generation-consumption profile pattern correlation; and the use of electricityper measurable area. Although the houses are evaluated under the same climatological and consump-tion conditions, production results are very different due to the specific engineering solutions (differentelectrical topologies, presence or absence of batteries, diverse photovoltaic module solutions, etc.)

M��quinas o atm��sferas: La est��tica de la energ��a en la arquitectura, 1750-2000 = From Machines to Atmospheres: The Aesthetics of Energy in Architecture, 1750-2000

La energ��a es ya un tema arquitect��nico, pero su incorporaci��n al proyecto ha sido hasta ahora fundamentalmente t��cnica, dando pie a una especie de funcionalismo ecol��gico cuyo destino es acaso repetir los errores de los viejos funcionalismos en su confianza de encontrar modos ���objetivos��� de transmutar la energ��a en forma construida, pero sin que en tal proceso parezca haber hueco para mediaciones de tipo est��tico. Sin embargo, son precisamente tales mediaciones las que necesitan analizarse para que la adopci��n de los temas energ��ticos resulte fruct��fera en la arquitectura, y asimismo para dar cuenta de otras perspectivas complementarias ���filos��ficas, cient��ficas, art��sticas��� que hoy forman el complejo campo sem��ntico de la energ��a. Partiendo de la fecha de 1750 ���que da comienzo simb��licamente al proceso de contaminaciones ���modernas��� entre la arquitectura y otras disciplinas���, esta tesis analiza los diferentes modos con los que proyectos y edificios han expresado literal y anal��gicamente ciertos temas o ideales energ��ticos, demostrando la existencia de una ���est��tica de la energ��a��� en la arquitectura y tambi��n de una tradici��n proyectual e intelectual sostenida en ella. Con este fin, se han seleccionados siete met��foras que vinculan tanto t��cnica como ideol��gicamente a la arquitectura con la energ��a: la met��fora de la m��quina, asociada al ideal de movimiento y la autorregulaci��n; las met��foras del arabesco, del cristal y del organismo, afines entre s�� en su modo de dar cuenta del principio de la morfog��nesis o energ��a creadora de la naturaleza; la met��fora de la actividad interna de los materiales; la met��fora del gradiente, que expresa la condici��n t��rmica y clim��tica de la arquitectura, y, finalmente, la de la atm��sfera que, recogiendo los sentidos anteriores, los actualiza en el contexto de la est��tica contempor��nea. La selecci��n de estas siete met��foras se ha llevado a cabo despu��s de un barrido exhaustivo de la bibliograf��a precedente, y ha estructurado un relato cuyo m��todo combina la perspectiva general ���que permite cartografiar las continuidades hist��ricas��� con la cercana ���que atiende a las problemas espec��ficos de cada tema o met��fora���, complement��ndolas con una aproximaci��n de sesgo iconogr��fico cuyo prop��sito es incidir en los v��nculos que se dan entre lo ideol��gico y lo morfol��gico. El an��lisis ha puesto de manifiesto c��mo detr��s de cada una de estas met��foras se oculta un principio ideol��gico com��n ���la justificaci��n de la arquitectura desde planteamientos externos procedentes de la ciencia, la filosof��a y el arte���, y c��mo en cada uno de los casos estudiados las asimilaciones m��s fruct��feras de la energ��a se han producido seg��n mecanismos de m��mesis anal��gica que inciden m��s en los procesos que en las formas que estos generan, y que en ��ltimo t��rmino son de ��ndole est��tica, lo cual constituye un indicio de los m��todos de la arquitectura por venir. ABSTRACT Although it is already an architectural theme, the matter of incorporating energy into projects has up to now been mainly technical, giving rise to a kind of ecological functionalism which may be bound to old funcionalist mistakes in hopes of finding ���objective��� ways of transmuting energy into built forms without aesthetic considerations. However, it is precisely such considerations that need to be analyzed if the adoption of energy issues in architecture is to bear fruit and also to account for other complementary perspectives ��� philosophical, scientific, artistic ��� which today form the complex fabric of the energy semantic field. Beginning in 1750 ��� symbolic start of ���modern��� contaminations between architecture and other disciplines ���, this thesis analyzes the different ways in which projects and buildings have literally and analogically expressed certain subjects or ideals on energy, and demonstrates the existence of an ���aesthetics of energy��� in architecture, as well as of an intellectual and design tradition based on such aesthetics. For this purpose, seven metaphors are selected to link energy to architecture both technically and ideologically: the machine���s metaphor, associated with the ideal of mouvement and self-regulation; the arabesque, glass and the organism���s metaphors, which account for the morphogenesis principle, i.e. creative energy of nature; the metaphor linked to matter and the ideal of internal activity; the gradient���s metaphor, which expressed the thermal and climatic condition of architecture, and, finally, that of the atmosphere which, collecting the above meanings, updates them in the context of contemporary aesthetics. The selection of these seven metaphors was carried out after a thorough scan of the preceding literature, and has structured a reasoning that combines the overview method ��� which accounts for historical continuities ��� with the nearby one ��� which meets the specifics problems of each theme or metaphor ���, both supplemented with an iconographic bias, the purpose of which is to visually express the links existing between the ideological and the morphological. So presented, the analysis shows how, behind each of these metaphors, lies a common ideological principle ��� the justification of architecture from scientific, philosophical and artistic ���external��� angles ���, and how in each of the studied cases the most successful assimilation of energy were those produced by aesthetic mechanisms of analogical mimesis not focused in forms but in processes that generate them: an indication of the methods of architecture to come.

Experimental analysis of energy savings and hygrothermal conditions improvement by means of air curtaines in stores with intensive pedestrian traffic

Current worldwide building legislation requirements aim to the design and construction of technical services that reduce energy consumption and improve indoor hygrothermal conditions. The retail sector in Spain, with a lot of outdated technical systems, demands energy conservation measures in order to reduce the increasingly electrical consumption for cooling. Climatic separation with modern air curtains and advanced hygrothermal control systems enables energy savings and can keep suitable indoor air temperature and humidity of stores with intense pedestrian traffic, especially when located in hot humid climates. As stated in the article, the energy savings in commercial buildings with these systems exceeds 30%

Integral energy performance characterization of semi-transparent photovoltaic elements for building integration under real operation conditions

In this paper, a methodology for the integral energy performance characterization (thermal, daylighting and electrical behavior) of semi-transparent photovoltaic modules (STPV) under real operation conditions is presented. An outdoor testing facility to analyze simultaneously thermal, luminous and electrical performance of the devices has been designed, constructed and validated. The system, composed of three independent measurement subsystems, has been operated in Madrid with four prototypes of a-Si STPV modules, each one corresponding to a specific degree of transparency. The extensive experimental campaign, continued for a whole year rotating the modules under test, has validated the reliability of the testing facility under varying environmental conditions. The thermal analyses show that both the solar protection and insulating properties of the laminated prototypes are lower than those achieved by a reference glazing whose characteristics are in accordance with the Spanish Technical Building Code. Daylighting analysis shows that STPV elements have an important lighting energy saving potential that could be exploited through their integration with strategies focused to reduce illuminance values in sunny conditions. Finally, the electrical tests show that the degree of transparency is not the most determining factor that affects the conversion efficiency.

Determination of the influence of specific building regulations in smart buildings

The automation of domestic services began to be implemented in buildings since the late nineteenth century, and today we are used to terms like ���intelligent buildings���, ���digital home��� or ���domotic buildings���. These concepts tell us about constructions which integrate new technologies in order to improve comfort, optimize energy consumption or enhance the security of users. In conjunction, building regulations have been updated to suit the needs of society and to regulate these new facilities in such structures. However, we are not always sure about how far, from the quantitative or qualitative point of view, legislation should regulate certain aspects of the building activity. Consequently, content analysis is adopted in this research to determine the influence of building regulations in the implementation of new technologies in the construction process. This study includes the analysis of different European regulations, the collection and documentation of such guidelines that have been established and a study of the impact that all of these have had in the way we start thinking an architectural project. The achievements of the research could be explained in terms of the regulatory requirements that must be taken into account in order to achieve a successful implementation of a home automation system, and the key finding has been the confirmation of how the design of smart buildings may be promoted through specific regulatory requirements while other factors, such as the global economic situation, do not seem to affect directly the rate of penetration of home automation in construction.

Reflectance properties analysis of mineral based mortars for renders: research of their energy performance

Passive performance of buildings is nowadays one of the key points, not only for reducing energy consumption of buildings, but also for decreasing ���fuel poverty���. Among the constructive systems in buildings, fa��ades are the ones having higher influence on thermal performance in urban spaces. Lime renders are specialized systems which can improve not only the durability of the support but also the thermal properties. According to previous researches, a modification of their radiative properties can reduce thermal fluxes between 24% and 89%. In this paper, the influences of the aggregate content in lime pastes, as well as the nature of the aggregates, colour and roughness, on the visible near and medium infrared reflectance are analyzed. Ten types of aerial lime mortars were prepared and two methods of reflectance determination were performed. Finally, the effect of the resulted reflectance on the constructive systems of fa��ades was analyzed using pseudotime-dependent software, for which an annulation of the thermal fluxes or significant reduction of them can be observed, when modifying the aggregate nature.

ICT Road map for supporting energy systems in smart cities

This paper introduces a road map for ICTs (Information and communication technologies) supporting planning, operation and management of energy systems in smart cities. The road map summarises different elements that form energy systems in cities and proposes research and technical development (RTD) and innovation activities for the development and innovation of ICTs for holistic design, planning and operation of energy systems. In addition, synergies with other ICT systems for smart cities are considered. There are four main target groups for the road map: 1) citizen; 2) building sector; 3) energy sector; and 4) municipality level. As an example for enabling active participation of citizens, the road map proposes how ICT can enable citizens? involvement among others into building design. The building sector roadmap proposes how ICTs can support the planning of buildings and renovations in the future, as well as how to manage building energy systems. The energy sector road map focuses on city?s energy systems and their planning and management, including e.g. demand side management, management of different district level energy systems, energy performance validation and management, energy data models, and smarter use of open energy data. Moreover, the municipality level road map proposes among others ICTs for better integration of city systems and city planning enabling maximised energy efficiency. In addition, one road map section suggests development needs related to open energy data, including among others the use of energy data and the development and harmonisation of energy data models. The road map has been assembled in the READY4SmartCities project (funded by EU 7th Framework Programme), which focuses on the energy system at the city level, consisting of centralised energy systems and connections to the national level energy grids, as well as interconnections to the neighbourhood and building level energy systems.

Integral energy behaviour of photovoltaic semi-transparent glazing elements for building integration

La hip��tesis general que esta tesis quiere demostrar es que la integraci��n arquitect��nica de sistemas fotovoltaicos semitransparentes (STPV) puede contribuir a mejorar la eficiencia energ��tica de los edificios. Por lo tanto, la investigaci��n se centra en el desarrollo de una metodolog��a capaz de cuantificar la reducci��n de la demanda energ��tica del edificio proporcionada por estas novedosas soluciones constructivas. Al mismo tiempo, los par��metros de dise��o de las soluciones STPV se han analizado para establecer cuales presentan el mayor impacto sobre el balance energ��tico global del edificio y por lo tanto tienen que ser cuidadosamente definidos a la hora de optimizar el comportamiento energ��tico del mismo. A la luz de estos objetivos, la metodolog��a de estudio se ha centrado en tres puntos principales: ��� Caracterizar el comportamiento energ��tico global de sistemas STPV en condiciones de operaci��n realistas, similares a las que se dar��an en un sistema real; ��� Caracterizar el comportamiento energ��tico global de sistemas STPV en condiciones controladas, con el objetivo de estudiar la variaci��n del comportamiento del los elementos en funci��n de par��metro de dise��o y operaci��n; ��� Evaluar el potencial de ahorro energ��tico global de los sistemas STPV en comparaci��n con soluciones acristaladas convencionales al variar de las condiciones de contorno constituidas por los par��metros de dise��o (como el grado de transparencia), las caracter��sticas arquitect��nicas (como el ratio entre superficie acristalada y superficie opaca en la fachada del edificio) y las condiciones clim��ticas (cubriendo en particular la climatolog��a europea). En s��ntesis, este trabajo intenta contribuir a comprender la interacci��n que existe entre los sistemas STPV y el edificio, proporcionando tanto a los fabricantes de los componentes como a los profesionales de la construcci��n informaci��n valiosa sobre el potencial de ahorro energ��tico asociado a estos nuevos sistemas constructivos. Asimismo el estudio define los par��metros de dise��o adecuados para lograr soluciones eficientes tanto en proyectos nuevos como de rehabilitaci��n. ABSTRACT The general hypothesis this work seeks to demonstrate is that the architectural integration of Semi-Transparent Photovoltaic (STPV) systems can contribute to improving the energy efficiency of buildings. Accordingly, the research has focused on developing a methodology able to quantify the building energy demand reduction provided by these novel constructive solutions. At the same time, the design parameters of the STPV solution have been analysed to establish which of them have the greatest impact on the global energy balance of the building, and therefore which have to be carefully defined in order to optimize the building operation. In the light of these goals, the study methodology has focused on three main points: ��� To characterise the global energy behaviour of STPV systems in realistic operating conditions, similar to those in which a real system will operate; ��� To characterise the global energy behaviour of STPV systems in controlled conditions in order to study how the performance varies depending on the design and operating parameters; ��� To assess the global energy saving potential of STPV systems in comparison with conventional glazing solutions by varying the boundary conditions, including design parameters (such as the degree of transparency), architectural characteristics (such as the Window to Wall Ratio) and climatic conditions (covering the European climatic conditions). In summary, this work has sought to contribute to the understanding of the interaction between STPV systems and the building, providing both components manufacturers and construction technicians, valuable information on the energy savings potential of these new construction systems and defining the appropriate design parameters to achieve efficient solutions in both new and retrofitting projects.

Guidelines for Linked Data generation and publication: an example in building energy consumption

Linked Data is the key paradigm of the Semantic Web, a new generation of the World Wide Web that promises to bring meaning (semantics) to data. A large number of both public and private organizations have published their data following the Linked Data principles, or have done so with data from other organizations. To this extent, since the generation and publication of Linked Data are intensive engineering processes that require high attention in order to achieve high quality, and since experience has shown that existing general guidelines are not always sufficient to be applied to every domain, this paper presents a set of guidelines for generating and publishing Linked Data in the context of energy consumption in buildings (one aspect of Building Information Models). These guidelines offer a comprehensive description of the tasks to perform, including a list of steps, tools that help in achieving the task, various alternatives for performing the task, and best practices and recommendations. Furthermore, this paper presents a complete example on the generation and publication of Linked Data about energy consumption in buildings, following the presented guidelines, in which the energy consumption data of council sites (e.g., buildings and lights) belonging to the Leeds City Council jurisdiction have been generated and published as Linked Data.

Urban wind energy: empirical optimization of high-rise building roof shape for the wind energy exploitation

El programa Europeo HORIZON2020 en Futuras Ciudades Inteligentes establece como objetivo que el 20% de la energ��a el��ctrica sea generada a partir de fuentes renovables. Este objetivo implica la necesidad de potenciar la generaci��n de energ��a e��lica en todos los ��mbitos. La energ��a e��lica reduce dr��sticamente las emisiones de gases de efecto invernadero y evita los riesgos geo-pol��ticos asociados al suministro e infraestructuras energ��ticas, as�� como la dependencia energ��tica de otras regiones. Adem��s, la generaci��n de energ��a distribuida (generaci��n en el punto de consumo) presenta significativas ventajas en t��rminos de elevada eficiencia energ��tica y estimulaci��n de la econom��a. El sector de la edificaci��n representa el 40% del consumo energ��tico total de la Uni��n Europea. La reducci��n del consumo energ��tico en este ��rea es, por tanto, una prioridad de acuerdo con los objetivos "20-20-20" en eficiencia energ��tica. La Directiva 2010/31/EU del Parlamento Europeo y del Consejo de 19 de mayo de 2010 sobre el comportamiento energ��tico de edificaciones contempla la instalaci��n de sistemas de suministro energ��tico a partir de fuentes renovables en las edificaciones de nuevo dise��o. Actualmente existe una escasez de conocimiento cient��fico y tecnol��gico acerca de la geometr��a ��ptima de las edificaciones para la explotaci��n de la energ��a e��lica en entornos urbanos. El campo tecnol��gico de estudio de la presente Tesis Doctoral es la generaci��n de energ��a e��lica en entornos urbanos. Espec��ficamente, la optimization de la geometr��a de las cubiertas de edificaciones desde el punto de vista de la explotaci��n del recurso energ��tico e��lico. Debido a que el flujo del viento alrededor de las edificaciones es exhaustivamente investigado en esta Tesis empleando herramientas de simulaci��n num��rica, la mec��nica de fluidos computacional (CFD en ingl��s) y la aerodin��mica de edificaciones son los campos cient��ficos de estudio. El objetivo central de esta Tesis Doctoral es obtener una geometr��a de altas prestaciones (u ��ptima) para la explotaci��n de la energ��a e��lica en cubiertas de edificaciones de gran altura. Este objetivo es alcanzado mediante un an��lisis exhaustivo de la influencia de la forma de la cubierta del edificio en el flujo del viento desde el punto de vista de la explotaci��n energ��tica del recurso e��lico empleando herramientas de simulaci��n num��rica (CFD). Adicionalmente, la geometr��a de la edificaci��n convencional (edificio prism��tico) es estudiada, y el posicionamiento adecuado para los diferentes tipos de aerogeneradores es propuesto. La compatibilidad entre el aprovechamiento de las energ��as solar fotovoltaica y e��lica tambi��n es analizado en este tipo de edificaciones. La investigaci��n prosigue con la optimizaci��n de la geometr��a de la cubierta. La metodolog��a con la que se obtiene la geometr��a ��ptima consta de las siguientes etapas: - Verificaci��n de los resultados de las geometr��as previamente estudiadas en la literatura. Las geometr��as b��sicas que se someten a examen son: cubierta plana, a dos aguas, inclinada, abovedada y esf��rica. - An��lisis de la influencia de la forma de las aristas de la cubierta sobre el flujo del viento. Esta tarea se lleva a cabo mediante la comparaci��n de los resultados obtenidos para la arista convencional (esquina sencilla) con un parapeto, un voladizo y una esquina curva. - An��lisis del acoplamiento entre la cubierta y los cerramientos verticales (paredes) mediante la comparaci��n entre diferentes variaciones de una cubierta esf��rica en una edificaci��n de gran altura: cubierta esf��rica estudiada en la literatura, cubierta esf��rica integrada geom��tricamente con las paredes (planta cuadrada en el suelo) y una cubierta esf��rica acoplada a una pared cilindrica. El comportamiento del flujo sobre la cubierta es estudiado tambi��n considerando la posibilidad de la variaci��n en la direcci��n del viento incidente. - An��lisis del efecto de las proporciones geom��tricas del edificio sobre el flujo en la cubierta. - An��lisis del efecto de la presencia de edificaciones circundantes sobre el flujo del viento en la cubierta del edificio objetivo. Las contribuciones de la presente Tesis Doctoral pueden resumirse en: - Se demuestra que los modelos de turbulencia RANS obtienen mejores resultados para la simulaci��n del viento alrededor de edificaciones empleando los coeficientes propuestos por Crespo y los propuestos por Bechmann y S��rensen que empleando los coeficientes est��ndar. - Se demuestra que la estimaci��n de la energ��a cin��tica turbulenta del flujo empleando modelos de turbulencia RANS puede ser validada manteniendo el enfoque en la cubierta de la edificaci��n. - Se presenta una nueva modificaci��n del modelo de turbulencia Durbin k ��� e que reproduce mejor la distancia de recirculaci��n del flujo de acuerdo con los resultados experimentales. - Se demuestra una relaci��n lineal entre la distancia de recirculaci��n en una cubierta plana y el factor constante involucrado en el c��lculo de la escala de tiempo de la velocidad turbulenta. Este resultado puede ser empleado por la comunidad cient��fica para la mejora del modelado de la turbulencia en diversas herramientas computacionales (OpenFOAM, Fluent, CFX, etc.). - La compatibilidad entre las energ��as solar fotovoltaica y e��lica en cubiertas de edificaciones es analizada. Se demuestra que la presencia de los m��dulos solares provoca un descenso en la intensidad de turbulencia. - Se demuestran conflictos en el cambio de escala entre simulaciones de edificaciones a escala real y simulaciones de modelos a escala reducida (t��nel de viento). Se demuestra que para respetar las limitaciones de similitud (n��mero de Reynolds) son necesarias mediciones en edificaciones a escala real o experimentos en t��neles de viento empleando agua como fluido, especialmente cuando se trata con geometr��as complejas, como es el caso de los m��dulos solares. - Se determina el posicionamiento m��s adecuado para los diferentes tipos de aerogeneradores tomando en consideraci��n la velocidad e intensidad de turbulencia del flujo. El posicionamiento de aerogeneradores es investigado en las geometr��as de cubierta m��s habituales (plana, a dos aguas, inclinada, abovedada y esf��rica). - Las formas de aristas m��s habituales (esquina, parapeto, voladizo y curva) son analizadas, as�� como su efecto sobre el flujo del viento en la cubierta de un edificio de gran altura desde el punto de vista del aprovechamiento e��lico. - Se propone una geometr��a ��ptima (o de altas prestaciones) para el aprovechamiento de la energ��a e��lica urbana. Esta optimizaci��n incluye: verificaci��n de las geometr��as estudiadas en el estado del arte, an��lisis de la influencia de las aristas de la cubierta en el flujo del viento, estudio del acoplamiento entre la cubierta y las paredes, an��lisis de sensibilidad del grosor de la cubierta, exploraci��n de la influencia de las proporciones geom��tricas de la cubierta y el edificio, e investigaci��n del efecto de las edificaciones circundantes (considerando diferentes alturas de los alrededores) sobre el flujo del viento en la cubierta del edificio objetivo. Las investigaciones comprenden el an��lisis de la velocidad, la energ��a cin��tica turbulenta y la intensidad de turbulencia en todos los casos. ABSTRACT The HORIZON2020 European program in Future Smart Cities aims to have 20% of electricity produced by renewable sources. This goal implies the necessity to enhance the wind energy generation, both with large and small wind turbines. Wind energy drastically reduces carbon emissions and avoids geo-political risks associated with supply and infrastructure constraints, as well as energy dependence from other regions. Additionally, distributed energy generation (generation at the consumption site) offers significant benefits in terms of high energy efficiency and stimulation of the economy. The buildings sector represents 40% of the European Union total energy consumption. Reducing energy consumption in this area is therefore a priority under the "20-20-20" objectives on energy efficiency. The Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings aims to consider the installation of renewable energy supply systems in new designed buildings. Nowadays, there is a lack of knowledge about the optimum building shape for urban wind energy exploitation. The technological field of study of the present Thesis is the wind energy generation in urban environments. Specifically, the improvement of the building-roof shape with a focus on the wind energy resource exploitation. Since the wind flow around buildings is exhaustively investigated in this Thesis using numerical simulation tools, both computational fluid dynamics (CFD) and building aerodynamics are the scientific fields of study. The main objective of this Thesis is to obtain an improved (or optimum) shape of a high-rise building for the wind energy exploitation on the roof. To achieve this objective, an analysis of the influence of the building shape on the behaviour of the wind flow on the roof from the point of view of the wind energy exploitation is carried out using numerical simulation tools (CFD). Additionally, the conventional building shape (prismatic) is analysed, and the adequate positions for different kinds of wind turbines are proposed. The compatibility of both photovoltaic-solar and wind energies is also analysed for this kind of buildings. The investigation continues with the buildingroof optimization. The methodology for obtaining the optimum high-rise building roof shape involves the following stages: - Verification of the results of previous building-roof shapes studied in the literature. The basic shapes that are compared are: flat, pitched, shed, vaulted and spheric. - Analysis of the influence of the roof-edge shape on the wind flow. This task is carried out by comparing the results obtained for the conventional edge shape (simple corner) with a railing, a cantilever and a curved edge. - Analysis of the roof-wall coupling by testing different variations of a spherical roof on a high-rise building: spherical roof studied in the litera ture, spherical roof geometrically integrated with the walls (squared-plant) and spherical roof with a cylindrical wall. The flow behaviour on the roof according to the variation of the incident wind direction is commented. - Analysis of the effect of the building aspect ratio on the flow. - Analysis of the surrounding buildings effect on the wind flow on the target building roof. The contributions of the present Thesis can be summarized as follows: - It is demonstrated that RANS turbulence models obtain better results for the wind flow around buildings using the coefficients proposed by Crespo and those proposed by Bechmann and S0rensen than by using the standard ones. - It is demonstrated that RANS turbulence models can be validated for turbulent kinetic energy focusing on building roofs. - A new modification of the Durbin k ��� e turbulence model is proposed in order to obtain a better agreement of the recirculation distance between CFD simulations and experimental results. - A linear relationship between the recirculation distance on a flat roof and the constant factor involved in the calculation of the turbulence velocity time scale is demonstrated. This discovery can be used by the research community in order to improve the turbulence modeling in different solvers (OpenFOAM, Fluent, CFX, etc.). - The compatibility of both photovoltaic-solar and wind energies on building roofs is demonstrated. A decrease of turbulence intensity due to the presence of the solar panels is demonstrated. - Scaling issues are demonstrated between full-scale buildings and windtunnel reduced-scale models. The necessity of respecting the similitude constraints is demonstrated. Either full-scale measurements or wind-tunnel experiments using water as a medium are needed in order to accurately reproduce the wind flow around buildings, specially when dealing with complex shapes (as solar panels, etc.). - The most adequate position (most adequate roof region) for the different kinds of wind turbines is highlighted attending to both velocity and turbulence intensity. The wind turbine positioning was investigated for the most habitual kind of building-roof shapes (flat, pitched, shed, vaulted and spherical). - The most habitual roof-edge shapes (simple edge, railing, cantilever and curved) were investigated, and their effect on the wind flow on a highrise building roof were analysed from the point of view of the wind energy exploitation. - An optimum building-roof shape is proposed for the urban wind energy exploitation. Such optimization includes: state-of-the-art roof shapes test, analysis of the influence of the roof-edge shape on the wind flow, study of the roof-wall coupling, sensitivity analysis of the roof width, exploration of the aspect ratio of the building-roof shape and investigation of the effect of the neighbouring buildings (considering different surrounding heights) on the wind now on the target building roof. The investigations comprise analysis of velocity, turbulent kinetic energy and turbulence intensity for all the cases.

Experimental study of the thermal-energy performance of an insulated vegetal facade under summer conditions in a continental mediterranean climate

The use of vegetal systems in facades affects the reduction of the buildings' energy demand, the attenuation of the urban heat island (UHI) and the filtration of pollutants present in the air. Even so, up to now the knowledge about the effect of this type of systems on the thermal performance of insulated facades is limited. This article presents the results of an experimental study carried out in a vegetal facade located in a continental Mediterranean climate zone. The objective is to study the effect of a vegetal finishing, formed by plants and substrate, on the thermal-energy performance of an insulated facade under summer conditions. To this effect, the thermal data obtained from two full-scale experimental mock-ups of the same dimensions and composition of the enclosure and only different in the south facade's enclosure where one incorporates a vegetation layer are compared and analysed. The results show that, in spite of the high thermal resistance of the enclosure, the effect of the vegetation is very positive, particularly in the warmer hours of the day. Therefore, vegetal facades can be used as a passive cooling strategy, reducing the consumption of energy for refrigeration and improving the comfort conditions of the users. (C) 2014 Elsevier Ltd. All rights reserved.

Adapting micro-economy of energy corporations to macroeconomy policies aiming at a sustainable economy

Esta Tesis surgi�� ante la intensidad y verosimilitud de varias se��ales o ���warnings��� asociadas a pol��ticas dirigidas a reducir el peso del petr��leo en el sector energ��tico, tanto por razones econ��micas, como geopol��ticas, como ambientales. Como tal Tesis se consolid�� al ir incorporando elementos novedosos pero esenciales en el mundo petrol��fero, particularmente las ���tecnolog��as habilitantes���, tanto de incidencia directa, como el ���fracking��� como indirecta, del cual es un gran ejemplo el Veh��culo El��ctrico (puro). La Tesis se defini�� y estructur�� para elaborar una serie de indagaciones y disquisiciones, que comportaran un conjunto de conclusiones que fueran ��tiles para las corporaciones energ��ticas. Tambi��n para la comprensi��n de la propia evoluci��n del sector y de sus prestaciones t��cnicas y econ��micas, de cara a dar el servicio que los usuarios finales piden. Dentro de las tareas anal��ticas y reflexivas de la Tesis, se acu��aron ciertos t��rminos conceptuales para explicar m��s certeramente la realidad del sector, y tal es el caso del ���Investment burden���, que pondera la inversi��n espec��fica (���/W) requerida por una instalaci��n, con la duraci��n del per��odo de construcci��n y los riesgos tanto tangibles como regulatorios. Junto a ello la Tesis propone una herramienta de estudio y prognosis, denominada ���Market integrated energy efficiency���, especialmente aplicable a dicotom��as. Tal es el caso del coche t��rmico, versus coche el��ctrico. El objetivo es optimizar una determinada actividad energ��tica, o la productividad total del sector. Esta Tesis propone varias innovaciones, que se pueden agrupar en dos niveles: el primero dentro del campo de la Energ��a, y el segundo dentro del campo de las corporaciones, y de manera especial de las corporaciones del sector hidrocarburos. A nivel corporativo, la adaptaci��n a la nueva realidad ser�� funci��n directa de la capacidad de cada corporaci��n para desarrollar y/o comprar las tecnolog��as que permitan mantener o aumentar cuota de mercado. Las conclusiones de la Tesis apuntan a tres opciones principalmente para un replanteamiento corporativo: - Diversificaci��n energ��tica - Desplazamiento geogr��fico - Benefici��ndose de posibles nuevos nichos tecnol��gicos, como son: ��� En upstream: Recuperaci��n estimulada de petr��leo mediante uso de energ��as renovables ��� En downstream: Aditivos orientados a reducir emisiones ��� En gesti��n del cambio: Almacenamiento energ��tico con fines operativos Algunas pol��ticas energ��ticas siguen la tendencia de crecimiento cero de algunos pa��ses de la OCDE. No obstante, la realidad mundial es muy diferente a la de esos pa��ses. Por ejemplo, seg��n diversas estimaciones (basadas en bancos de datos solventes, referenciados en la Tesis) el n��mero de veh��culos aumentar�� desde aproximadamente mil millones en la actualidad hasta el doble en 2035; mientras que la producci��n de petr��leo s��lo aumentar�� de 95 a 145 millones de barriles al d��a. Un aumento del 50% frente a un aumento del 100%. Esto generar�� un curioso desajuste, que se empezar�� a sentir en unos pocos a��os. Las empresas y corporaciones del sector hidrocarburos pueden perder el monopolio que atesoran actualmente en el sector transporte frente a todas las dem��s fuentes energ��ticas. Esa p��rdida puede quedar compensada por una mejor gesti��n de todas sus capacidades y una participaci��n m��s integrada en el mundo de la energ��a, buscando sinergias donde hasta ahora no hab��a sino distanciamiento. Los productos petrol��feros pueden alimentar cualquier tipo de maquina t��rmica, como las turbinas Brayton, o alimentar reformadores para la producci��n masiva de H2 para su posterior uso en pilas combustible. El almacenamiento de productos derivados del petr��leo no es ning��n reto ni plantea problema alguno; y sin embargo este almacenamiento es la llave para resolver muchos problemas. Es posible que el comercio de petr��leo se haga menos vol��til debido a los efectos asociados al almacenamiento; pero lo que es seguro es que la eficiencia energ��tica de los usos de ese petr��leo ser�� m��s elevada. La Tesis part��a de ciertas amenazas sobre el futuro del petr��leo, pero tras el an��lisis realizado se puede vislumbrar un futuro prometedor en la fusi��n de pol��ticas medioambientales coercitivas y las nuevas tecnolog��as emergentes del actual portafolio de oportunidades t��cnicas. ABSTRACT This Thesis rises from the force and the credibility of a number of warning signs linked to policies aimed at reducing the role of petroleum in the energy industry due to economical, geopolitical and environmental drives. As such Thesis, it grew up based on aggregating new but essentials elements into the petroleum sector. This is the case of ���enabling technologies��� that have a direct impact on the petroleum industry (such as fracking), or an indirect but deep impact (such as the full electrical vehicle). The Thesis was defined and structured in such a way that could convey useful conclusions for energy corporations through a series of inquiries and treatises. In addition to this, the Thesis also aims at understating la evolution of the energy industry and its capabilities both technical and economical, towards delivering the services required by end users. Within the analytical task performed in the Thesis, new terms were coined. They depict concepts that aid at explaining the facts of the energy industry. This is the case for ���Investment burden���, it weights the specific capital investment (���/W) required to build a facility with the time that takes to build it, as well as other tangible risks as those posed by regulation. In addition to this, the Thesis puts forward an application designed for reviewing and predicting: the so called ���Market integrated energy efficiency���, especially well-suited for dichotomies, very appealing for the case of the thermal car versus the electric car. The aim is to optimize energy related activity; or even the overall productivity of the system. The innovations proposed in this Thesis can be classified in two tiers. Tier one, within the energy sector; and tier two, related to Energy Corporation in general, but with oil and gas corporations at heart. From a corporate level, the adaptation to new energy era will be linked with the corporation capability to develop or acquire those technologies that will yield to retaining or enhancing market share. The Thesis highlights three options for corporate evolution: - diversification within Energy - geographic displacement - profiting new technologies relevant to important niches of work for the future, as: o Upstream: enhanced oil recovery using renewable energy sources (for upstream companies in the petroleum business) o Downstream: additives for reducing combustion emissions o Management of Change: operational energy storage Some energy policies tend to follow the zero-growth of some OECD countries, but the real thing could be very different. For instance, and according to estimates the number of vehicles in use will grow from 1 billion to more than double this figure 2035; but oil production will only grow from 95 million barrel/day to 145 (a 50% rise of versus an intensification of over a 100%). Hydrocarbon Corporation can lose the monopoly they currently hold over the supply of energy to transportation. This lose can be mitigated through an enhanced used of their capabilities and a higher degree of integration in the world of energy, exploring for synergies in those places were gaps were present. Petroleum products can be used to feed any type of thermal machine, as Brayton turbines, or steam reformers to produce H2 to be exploited in fuel cells. Storing petroleum products does not present any problem, but very many problems can be solved with them. Petroleum trading will likely be less volatile because of the smoothing effects of distributed storage, and indeed the efficiency in petroleum consumption will be much higher. The Thesis kicked off with a menace on the future of petroleum. However, at the end of the analysis, a bright future can be foreseen in the merging between highly demanding environmental policies and the relevant technologies of the currently emerging technical portfolio.