Thesis (M. Sc.)--University of Hong Kong, 1993.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2008. / Includes bibliographical references (leaves 121-130). Also available online.

Thesis (M.S.)--Mississippi State University. Department of Mechanical Engineering. / Title from title screen. Includes bibliographical references.

Στην παρούσα εργασία αναπτύχθηκε ένα θεωρητικό πλαίσιο, το οποίο αναλύει την ενεργειακή αποτελεσματικότητα, τους προσδιοριστικούς παράγοντες που ευθύνονται για το ενεργειακό παράδοξο και επικεντρώνεται ιδιαίτερα στον ρόλο της αβεβαιότητας και των προσδοκιών στην πραγματοποίηση επενδύσεων εξοικονόμησης ενέργειας. Επιπλέον αναπτύχθηκε ένα εμπειρικό μοντέλο που εκτιμήθηκε με τη μέθοδο OLS και το υπόδειγμα Tobit για να προσδιοριστούν οι παράγοντες που επιδρούν στις επενδύσεις εξοικονόμησης ενέργειας. Σα εμπειρικά αποτελέσματα αναδεικνύουν ότι οι επενδύσεις σε ΣΕΕ, στην περίπτωση της Ελληνικής Βιομηχανίας είναι στενά συνδεδεμένες με τον κλάδο που δραστηριοποιείται η επιχείρηση. Ο κλάδος δραστηριοποίησης επιδρά και στην επενδυτική συμπεριφορά της επιχείρησης καθορίζοντας τη στάση που κα ακολουθήσει. Ένα άλλο συμπέρασμα είναι ότι η ύπαρξη εναλλακτικού επενδυτικού σχεδίου είναι σημαντικό εμπόδιο στις επενδύσεις εξοικονόμησης ενέργειας. Από την άλλη πλευρά, η θετική στάση της επιχείρησης απέναντι στην σπουδαιότητα των επενδύσεων εξοικονόμησης ενέργειας επιδρά θετικά στην πραγματοποίηση τους. Ομοίως στην περίπτωση των ελληνικών βιομηχανιών, οι μεγάλες επιχειρήσεις και οι επιχειρήσεις που έχουν μεγάλο χρόνο ζωής προωθούν τις επενδύσεις εξοικονόμησης ενέργειας. Τέλος η αβεβαιότητα και οι προσδοκίες είναι κρίσιμοι παράγοντες για την απόφαση των επιχειρήσεων να επενδύσουν σε τεχνολογίες εξοικονόμησης ενέργειας. Για την εγχώρια βιομηχανία η προσδοκία για αύξηση του εργασιακού κόστους είναι αποτρεπτικός παράγοντας για τις επενδύσεις εξοικονόμησης ενέργειας, ενώ η αβεβαιότητα για τις επιπτώσεις στο περιβάλλον αποδεικνύεται ισχυρό κίνητρο για την πραγματοποίησή τους. / Uncertainty and expectations in energy conservation investments.

Esta dissertação propõe um modelo de caracterização de recursos energéticos do lado da demanda que pretende abranger todos os tipos de ações e medidas referentes ao gerenciamento da demanda e à conservação energética, avaliando-as de forma holística, dentro de quatro dimensões: técnico-econômica, ambiental, social e política. Os recursos considerados na composição do modelo são submetidos às fases de Inventário de Recursos Energéticos do Lado da Demanda, Caracterização das Dimensões e Atributos de Avaliação de Recursos, Formulação dos Potenciais Energéticos e Aplicação do Modelo em Caso Piloto. O Inventário de Recursos Energéticos do Lado da Demanda pretende levantar, descrever e segmentar todas as alternativas energéticas de GLD e setores de consumo energético. A Caracterização da Avaliação de Recursos delimita as esferas de análise de recursos e a caracterização de seus atributos quanto a custos e benefícios provenientes de seu emprego. A Formulação dos Potenciais Energéticos define seu cálculo a partir de sua amplitude e restrições gerais de aplicação. O modelo é aplicado em um estudo piloto, na Região Administrativa de Araçatuba, por meio de um exercício de formulação do PIR, considerando a utilização de ferramentas de Avaliação dos Custos Completos, Cálculo de Potenciais Energéticos e Elaboração de Cenários de Projeção do Consumo Energético para um horizonte de tempo determinado. / This work presents a model for the characterization and assessment of demand side energy resources, which intends to comprehend every kind of action or measure related to demand side management and energy conservation, evaluated thouroughly into four dimensions: technical-economical, environmental, social and political. The resources included in the composition of the model are subjected to the stages of Inventary of Demand Side Resources, Characterization of Dimensions and Attributes of the Resources Assessment, Formulation of Energy Potentials and Model Application on a Real Case Study. The Inventary of Demand Side Resources intends to enlist, describe and segment all demand side management energy alternatives and their application in different economy sectors. The Characterization of the Resources Assessment defines the spheres of the assessment of resources and the characterization of its attributes as for costs and benefits resulting from their utilization. The Formulation of Energy Potentials defines their accounting based on their range and general application restrictions. The Model is applied in a case study, in the Administrative Region of Araçatuba, through an exercise of IRP formulation, regarding the utilization of Full Cost Accounting, Energy Potentials Accounting and Scenarios of Energy Consumption for a determined horizon.

Esse trabalho busca trazer uma contribuição efetiva e prática ao pensamento sustentável: \"Pense globalmente, aja localmente\", através da proposição de uma metodologia de avaliação assentada em uma visão integrada dos recursos naturais. Neste sentido, a necessidade de considerar a preservação dos recursos naturais, a redução da emissão de gases de efeito estufa, a conservação e a eficiência energética, se impõe como tema que deve ser abordado nos mais variados setores da economia, envolvendo desde uma visão global da matriz de consumo dos bens do planeta até uma abordagem microlocal, como, por exemplo, em empreendimentos relacionados aos setores residencial (residências, condomínios, prédios, áreas urbanas, etc.) e comercial (hotéis, shoppings, hospitais, restaurantes, etc.). A metodologia apresentada permite a análise da utilização dos recursos de forma racional, privilegiando, além da conservação e do uso eficiente, as sinergias nas suas utilizações. Assim, depois de levantadas as necessidades a serem atendidas em um empreendimento residencial ou comercial, bem como os recursos naturais disponíveis, será possível estabelecer, dentro das possibilidades factíveis, a combinação de recursos que represente o melhor aproveitamento na sua utilização como um todo, privilegiando de forma integrada a sustentabilidade. Para exemplificá-la e, simultaneamente, validá-la, a metodologia foi aplicada em um estudo de caso prático de uma residência. Assim, seguindo os passos metodológicos, inicialmente analisou-se a residência através de um balanço do fluxo de energia e matéria a partir das entradas de recursos naturais (energia, água, e outros recursos) e saídas (lixo, materiais e água com resíduos) que ocorrem nos processos e serviços da residência responsáveis pelo atendimento das necessidades humanas e do conforto, tais como: alimentação, higiene, iluminação, transporte, conforto térmico, lavagem de roupa, lazer e cultura, entre outros. Esta análise auxilia na identificação de perdas, desperdícios e possibilidades de transformações, permitindo, através da inclusão de tecnologias mais adequadas ambientalmente e do uso racional dos recursos, maior eficiência e conservação ao empreendimento. / This study aims to contribute effectively and practically to sustainable thinking: \"Think globally, act locally\", through the proposal of a methodology of evaluation established on an integrated vision of natural resources. Thus, the need to consider the preservation of natural resources, the reduction of gas emission which contributes to greenhouse effect, energy conservation and efficiency, stands as a subject that must be discussed in all economic sectors, involving a global view of the planet\'s natural resources to the microlocal approach, such as in residential sector entrepreneurship (houses, condominiums, buildings, urban areas, etc.) and commercial sectors (hotels, malls, hospitals, restaurants, etc.). The presented methodology allows the analysis of a rational way of utilization of resources, which enables conservation and efficient use, and the synergies of their utilizations. Thus, after identifying the needs to be met in a residential or commercial entrepreneurship, as well as the available natural resources, it will be possible to establish, within the feasibilities, a combination of resources which represents the best utilization as a whole, favoring sustainability in an integrated way. As an example, and also to validate it, the methodology was applied in a practical case study of a house. Thus, following the methodological steps, at first a house was analyzed through a balance of energy and materials based on natural resources inflow (energy, water, and others) and outflow (garbage and residual water or materials) which occurs in the household processes and services that attend to the human needs and comfort, such as: food, hygiene, lighting, laundry, cleaning, transportation, temperature control, leisure and culture, among others. This analysis helps to identify natural resources wastage and possibilities of changes, which warrant to the entrepreneurship a better efficiency and conservation, through the inclusion of technologies which are more suitable to the environment, and through a rational utilization of natural resources.

Made available in DSpace on 2014-10-09T12:43:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:03Z (GMT). No. of bitstreams: 1 06179.pdf: 13115772 bytes, checksum: 834101d8b8c603aa60f77d9ec56dea40 (MD5) / Tese (Doutoramento) / IPEN/T / Universidade Estadual de Campinas - UNICAMP

abstract: Phase Change Material (PCM) plays an important role as a thermal energy storage device by utilizing its high storage density and latent heat property. One of the potential applications for PCM is in buildings by incorporating them in the envelope for energy conservation. During the summer season, the benefits are a decrease in overall energy consumption by the air conditioning unit and a time shift in peak load during the day. Experimental work was carried out by Arizona Public Service (APS) in collaboration with Phase Change Energy Solutions (PCES) Inc. with a new class of organic-based PCM. This "BioPCM" has non-flammable properties and can be safely used in buildings. The experimental setup showed maximum energy savings of about 30%, a maximum peak load shift of ~ 60 min, and maximum cost savings of about 30%. Simulation was performed to validate the experimental results. EnergyPlus was chosen as it has the capability to simulate phase change material in the building envelope. The building material properties were chosen from the ASHRAE Handbook - Fundamentals and the HVAC system used was a window-mounted heat pump. The weather file used in the simulation was customized for the year 2008 from the National Renewable Energy Laboratory (NREL) website. All EnergyPlus inputs were ensured to match closely with the experimental parameters. The simulation results yielded comparable trends with the experimental energy consumption values, however time shifts were not observed. Several other parametric studies like varying PCM thermal conductivity, temperature range, location, insulation R-value and combination of different PCMs were analyzed and results are presented. It was found that a PCM with a melting point from 23 to 27 °C led to maximum energy savings and greater peak load time shift duration, and is more suitable than other PCM temperature ranges for light weight building construction in Phoenix. / Dissertation/Thesis / M.S. Mechanical Engineering 2010

With the astronomical increase in cellular traffic, there is need to cut down on the power consumption so as to reduce CO2 emissions and in the process lowering network operational expenditure (OPEX). In this thesis, one method that can be used to lower a Base Station energy consumption is proposed. Traditional cellular networks are designed to offer maximum coverage and connectivity for peak traffic. This is not energy efficient since a lot of energy will go to waste during the time cellular traffic is very low. The scheme that was developed, identifies Base Stations that have very low traffic loads and User Equipment that can all be transferred to neighbouring Base Stations and put the Base Stations to sleep for as long as necessary to save energy and to maintain Quality of Services (QoS) at an acceptable level. The Next Generation Networks (specifically 5G) will be heterogeneous networks as heterogeneous are a promising solution in increasing network performance especially in providing indoor and cell-edges coverage. The solution that was developed in this thesis was specifically designed to work with heterogeneous networks and its performance was also tested on heterogeneous networks. OMNeT++ V4.6 together with INET 2.3.0 and SimuLTE 9.1 were used for the validation of the proposed scheme. After extensive simulations were carried out, it was concluded that some Base Stations in a cellular network, can be put to sleep during the time that cellular traffic is low without compromising the Quality of Service. End-to-end delay, sum throughputs, queue length and Channel Quality Indicator were some of the performance metrics that were used to check whether the developed scheme did not reduce the QoS of a network. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)

Current regulatory and other policy trends in housing refurbishment relating to low-carbon performance standards tend to involve complex technologies and systems as well as innovative solutions to achieve 80% emissions reduction in line with the UK national target for 2050. Indicators of domestic energy performance tend to assume ideal performance of materials, complex systems and services, and that they are installed to high standards and under specific conditions, as well as rational occupant behaviour and interactions. Previous studies exploring the influence of socio-technical factors on the UK's domestic energy use highlight that one of the main reasons for under-performance of individual projects is the lack of understanding of how people interact with domestic technology. Considering this, and given that there is still little evidence on deep refurbishments that implement low-carbon 'whole house' approaches in the UK, this research explored occupants' interaction with heating and ventilation measures as these were designed, installed and operated. The main concern was to identify the type of interactions that occur between occupants (social housing tenants) and building systems (mainly low-carbon heating and ventilation systems), and how that influences actual energy use. Using a sample of 26 social housing properties involved in the Retrofit for the Future competition in the UK, the study employed an socio-technical mixed methods approach, in which qualitative and quantitative empirical data were explored together, cross-checking occupants' 'doings' and 'sayings'. A combination of theories was used to analyse the complex interrelated factors involved in users' interaction with building systems. The analysis identifies key factors that affect significantly occupants' everyday practices and their interactions with the new measures: thermal comfort and pastexperiences with measures and controls; knowledge and skills (of both occupants and those involved in the project); design of the technical interventions (systems/measures) and quality of their installation. The findings from this research showed that active measures (such as intelligent and conventional heating controls, MVHR boosters, etc.) fostered direct interaction with active users when there were no design or installation faults. On the contrary, low-carbon measures that are designed and installed to be passive (such as MVHR systems operation) tend, in practice, to involve indirect interactions with active users. The research findings provide an insight into the 'in-use' factors, demonstrating to policy makers and implementers of mass refurbishment programmes the need for a framework where critical combinations of different measures and design solutions are targeted on specific house types, locations and households, in order to achieve maximum savings. Higher standards in installation of the new measures and improved quality control are also found to be a key part of refurbishment policies.