Дисертації з теми "Green Energy Storage"
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Gebresilassie, Yosef. "Sizing and modeling a microgrid containing renewable energy production, energy storage, electrical vehicles and other green technologies." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289328.
Повний текст джерелаEtt mikronät som innehåller olika förnyelsebara energikällor behöver designas optimalt för kunna ha en både ekonomisk och teknisk genomförbar investering. I detta projekt studerades ett mikronät för en bostadsförening i Hudiksvall. Syftet med detta projekt var att studera hur elbilar kommer att kunna försörja nätet vid olika tillgänglighetstider hos bilarna. Utöver det syftade det här projektet också på att uppskatta den optimala effekten på solceller och solfångare för bostadsföreningen samt möjligheterna för energilagring för att utöka konsumtionen av närproducerad el och värme. En simulering i MATLAB/SIMULINK utfördes för att studera elbilarnas roll i att försörja mikronätet. För att få en bild av den optimala effekten på solcellerna utfördes en livscykelkostandsanalys. Den optimala effekten för solfångarna har beräknats genom f -chart metoden. Resultaten från denna studie visar att högre batterikapacitet på elbilar kommer att krävas när elbilarna är kopplade till mikronätet för längre perioder. Detta beror på den höga effektproduktionen från solcellerna samt den begränsade nivån för laddning/urladdning av elbilarnas batteri. Livcykelkostnadsanalysen gav ett lägre nuvärde samt längre återbetalningsperioder då en högre kapacitet på solcellerna installerades. Känslighetsanalysen som utfördes visar att nuvärdet av investeringen är mest känslig för investeringskostnaden. Med f -chart metoden kunde slutsatser gällande optimal solfångare och termisk energilagring dras.
Ezeigwe, Ejikeme Raphael. "Green synthesis of graphene-metal oxides composites as a promising electrode for energy storage." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52517/.
Повний текст джерелаYu, Candice Yau May. "Modeling the heating of the Green Energy Lab in Shanghai by the geothermal heat pump combined with the solar thermal energy and ground energy storage." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19280.
Повний текст джерелаKailas, Aravind. "Toward perpetual wireless networks: opportunistic large arrays with transmission thresholds and energy harvesting." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34720.
Повний текст джерелаGazey, Ross Neville. "Sizing hybrid green hydrogen energy generation and storage systems (HGHES) to enable an increase in renewable penetration for stabilising the grid." Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/947.
Повний текст джерелаLakshminarayanan, Srivathsan. "Nature Inspired Grey Wolf Optimizer Algorithm for Minimizing Operating Cost in Green Smart Home." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1438102173.
Повний текст джерелаEisenhart, Andrew. "Quantum Simulations of Specific Ion Effects in Organic Solvents." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1626356392775228.
Повний текст джерелаLewis, Courtney-Elyce. "Carbon-integrated vanadium oxide hydrate as a high-performance cathode material for zinc-ion batteries." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/230254/1/Courtney-Elyce_Lewis_Thesis.pdf.
Повний текст джерелаTizaoui, Abdelkhalek. "Etude théorique, numérique et expérimentale de l'échange de chaleur entre un fluide et le sol par un échangeur bitubulaire vertical." Valenciennes, 1989. https://ged.uphf.fr/nuxeo/site/esupversions/4e75693b-4fbb-4e3f-9f3d-b412562fb545.
Повний текст джерелаSilva, Newton Rocha da. "TI verde – o armazenamento de dados e a eficiência energética no data center de um banco brasileiro." Universidade Nove de Julho, 2015. https://bibliotecatede.uninove.br/handle/tede/1155.
Повний текст джерелаMade available in DSpace on 2015-07-27T16:22:43Z (GMT). No. of bitstreams: 1 Newton Rocha da Silva.pdf: 1739667 bytes, checksum: 9f957689d728b32603a096b0af84765b (MD5) Previous issue date: 2015-03-04
The Green IT focuses on the study and design practice, manufacturing, use and disposal of computers, servers, and associated subsystems, efficiently and effectively, with less impact to the environment. It´s major goal is to improve performance computing and reduce energy consumption and carbon footprint. Thus, the green information technology is the practice of environmentally sustainable computing and aims to minimize the negative impact of IT operations to the environment. On the other hand, the exponential growth of digital data is a reality for most companies, making them increasingly dependent on IT to provide sufficient and real-time information to support the business. This growth trend causes changes in the infrastructure of data centers giving focus on the capacity of the facilities issues due to energy, space and cooling for IT activities demands. In this scenario, this research aims to analyze whether the main data storage solutions such as consolidation, virtualization, deduplication and compression, together with the solid state technologies SSD or Flash Systems are able to contribute to an efficient use of energy in the main data center organization. The theme was treated using qualitative and exploratory research method, based on the case study, empirical and documentary research such as technique to data collect, and interviews with IT key suppliers solutions. The case study occurred in the main Data Center of a large Brazilian bank. As a result, we found that energy efficiency is sensitized by technological solutions presented. Environmental concern was evident and showed a shared way between partners and organization studied. The maintaining of PUE - Power Usage Effectiveness, as energy efficiency metric, at a level of excellence reflects the combined implementation of solutions, technologies and best practices. We conclude that, in addition to reducing the consumption of energy, solutions and data storage technologies promote efficiency improvements in the Data Center, enabling more power density for the new equipment installation. Therefore, facing the digital data demand growth is crucial that the choice of solutions, technologies and strategies must be appropriate not only by the criticality of information, but by the efficient use of resources, contributing to a better understanding of IT importance and its consequences for the environment.
A TI Verde concentra-se em estudo e prática de projeto, fabricação, utilização e descarte de computadores, servidores e subsistemas associados, de forma eficiente e eficaz, com o mínimo ou nenhum impacto ao meio ambiente. Seu objetivo é melhorar o desempenho da computação e reduzir o consumo de energia e a pegada de carbono. Nesse sentido, a tecnologia da informação verde é a prática da computação ambientalmente sustentável e tem como objetivo minimizar o impacto negativo das operações de TI no meio ambiente. Por outro lado, o crescimento exponencial de dados digitais é uma realidade para a maioria das empresas, tornando-as cada vez mais dependentes da TI para disponibilizar informações em tempo real e suficiente para dar suporte aos negócios. Essa tendência de crescimento provoca mudanças na infraestrutura dos Data Centers dando foco na questão da capacidade das instalações devido à demanda de energia, espaço e refrigeração para as atividades de TI. Nesse cenário, esta pesquisa objetiva analisar se as principais soluções de armazenamento de dados, como a consolidação, a virtualização, a deduplicação e a compactação, somadas às tecnologias de discos de estado sólido do tipo SSD ou Flash são capazes de colaborar para um uso eficiente de energia elétrica no principal Data Center da organização. A metodologia de pesquisa foi qualitativa, de caráter exploratório, fundamentada em estudo de caso, levantamento de dados baseado na técnica de pesquisa bibliográfica e documental, além de entrevista com os principais fornecedores de soluções de TI. O estudo de caso foi o Data Center de um grande banco brasileiro. Como resultado, foi possível verificar que a eficiência energética é sensibilizada pelas soluções tecnológicas apresentadas. A preocupação ambiental ficou evidenciada e mostrou um caminho compartilhado entre parceiros e organização estudada. A manutenção do PUE - Power Usage Effectiveness (eficiência de uso de energia) como métrica de eficiência energética mantida em um nível de excelência é reflexo da implementação combinada de soluções, tecnologias e melhores práticas. Conclui-se que, além de reduzir o consumo de energia elétrica, as soluções e tecnologias de armazenamento de dados favorecem melhorias de eficiência no Data Center, viabilizando mais densidade de potência para a instalação de novos equipamentos. Portanto, diante do crescimento da demanda de dados digitais é crucial que a escolha das soluções, tecnologias e estratégias sejam adequadas, não só pela criticidade da informação, mas pela eficiência no uso dos recursos, contribuindo para um entendimento mais evidente sobre a importância da TI e suas consequências para o meio ambiente.
Polato, Ivanilton. "Energy savings and performance improvements with SSDs in the Hadoop Distributed File System." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/45/45134/tde-31102016-155908/.
Повний текст джерелаAo longo da última década, questões energéticas atraíram forte atenção da sociedade, chegando às infraestruturas de TI para processamento de dados. Agora, essas infraestruturas devem se ajustar a essa responsabilidade, adequando plataformas existentes para alcançar desempenho aceitável enquanto promovem a redução no consumo de energia. Considerado um padrão para o processamento de Big Data, o Apache Hadoop tem evoluído significativamente ao longo dos últimos anos, com mais de 60 versões lançadas. Implementando o paradigma de programação MapReduce juntamente com o HDFS, seu sistema de arquivos distribuídos, o Hadoop tornou-se um middleware tolerante a falhas e confiável para a computação paralela e distribuída para grandes conjuntos de dados. No entanto, o Hadoop pode perder desempenho com determinadas cargas de trabalho, resultando em elevado consumo de energia. Cada vez mais, usuários exigem que a sustentabilidade e o consumo de energia controlado sejam parte intrínseca de soluções de computação de alto desempenho. Nesta tese, apresentamos o HDFSH, um sistema de armazenamento híbrido para o HDFS, que usa uma combinação de discos rígidos e discos de estado sólido para alcançar maior desempenho, promovendo economia de energia em aplicações usando Hadoop. O HDFSH traz ao middleware o melhor dos HDs (custo acessível por GB e grande capacidade de armazenamento) e SSDs (alto desempenho e baixo consumo de energia) de forma configurável, usando zonas de armazenamento dedicadas para cada dispositivo de armazenamento. Implementamos nosso mecanismo como uma política de alocação de blocos para o HDFS e o avaliamos em seis versões recentes do Hadoop com diferentes arquiteturas de software. Os resultados indicam que nossa abordagem aumenta o desempenho geral das aplicações, enquanto diminui o consumo de energia na maioria das configurações híbridas avaliadas. Os resultados também mostram que, em muitos casos, armazenar apenas uma parte dos dados em SSDs resulta em economia significativa de energia e aumento na velocidade de execução
Haddad, Maroua. "Sizing and management of hybrid renewable energy system for data center supply." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCD036.
Повний текст джерелаInformation and communication technologies haverecently become a major sector in energy consumption,particularly with the advent of large platforms on the Internet. These platforms use data centers, which concentrate a very large number of machines processing information and providing services, causing a high energy consumption. The use of renewable energy sources (RES)on-site is then a promising way to reduce their ecological impact. However, some renewable energies such as solar and wind energy are intermittent and uncertain,being related to weather conditions. Since a data center must maintain a certain quality of service, using these sources effectively requires the usage of storage devices.This thesis explores an efficient sizing and management methods for a hybrid renewable energy infrastructure composed of wind turbines, photovoltaic panels, batteries and a hydrogen system..A first contribution addresses the problem of sizing the electrical plateform in order to meet the data center demand. A sizing tool is proposed, taking several metrics into account and providing three different system configurations as solutions. The user therefore chooses an appropriate configuration, according to his global economic plan of his H2 ecosystem. A second contribution studies the problem of energy management using amixed integer linear programming approach. An optimal management tool is therefore provided to find various source schedules according to different user’s objectives.The obtained solutions are discussed with several metrics considering different time horizon in order to find the beststorage management to meet the data center requests.Finally, a third contribution aims to forecast the weather data to obtain a preciser sizing of the sources using SARIMA model in order to reduce forecasts errors
Andreasson, Tobias, and Emelia Lindh. "Förnybar energi på Svalbard." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-36878.
Повний текст джерелаMonfors, Lisa, and Corinne Morell. "Byggnadsutformning för ett framtida varmare klimat : Klimatscenariers påverkan på energianvändning och termisk komfort i ett flerbostadshus och alternativa byggnadsutformningar för att förbättra resultatet." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-79953.
Повний текст джерелаWhen buildings are designed climate files from 1981 to 2010 are used to construct the building and its energy system. This leads to building being designed to a climate that has been and not to a future warmer climate that will come. SMHI has developed different climate scenarios for the future that describe different paths the climate can take depending on continued emissions of greenhouse gas. This climate scenarios are called RCP (Representative Concentration Pathways) In this study two of the climate scenarios, RCP4,5 and RCP8,5 are used. The number in the name stands for the radiation forcing that is expected in the year 2100. In RCP4,5 the mean average air temperature will increase with 3 °C until year 2100 compared to the reference period 1961-1990. In the same time period RCP8,5 will increase with 5 °C. An apartment building certified according to Miljöbyggnad 2.2 level silver placed in Vallentuna, Stockholms län is used as a reference building. The building is simulated through the simulation software program IDA ICE where it´s exposed to RCP4,5 and RCP8,5. The results demonstrate that the reference building would not meet Miljöbyggnad 2.2 requirement in the indicator about thermal comfort during summer. The operative temperature in the building is too high unless comfort cooling is used. The design of the building changes to see what factors can improve the results regarding the thermal comfort. The results demonstrate that thermal conductivity and solar shading has the greatest impact on thermal comfort. In this study several combinations of different building designs were made. Only the combination of a concrete frame with windows with low g-value met the requirement of Miljöbyggnad 2.2 regarding the thermal comfort during summer without using comfort cooling in RCP4,5 and RCP8,5. The combination had the lowest energy demand in RCP8,5 of all the combinations tested in the study. A combination of cross laminated wood frame with low U-value, windows with low g-value and comfort cooling had the lowest energy demand in the original climate file and RCP4,5 despite the use of comfort cooling. The questing about which building construction is the best from a sustainable perspective is difficult to answer. To answer that question the building´s total climate footprint in both production and use must be calculated. Regardless of the choice of building construction it is important to have in mind when designing a building that comfort cooling and solar shading should be easily applied when a warmer climate will prevail.
Ku, Kuo-Shun, and 古國順. "Green Energy Storage and Management for a Small System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/g4vut7.
Повний текст джерела國立虎尾科技大學
電機工程研究所在職專班
99
This thesis presents an energy storage and management study for low power green energy system. It consists of a voltage protection unit, a self-charge unit, an over charge/discharge protection of battery, a protection mechanism for LED driver, and a system for estimation of battery energy storage. Depending on the proposed system, the unstable/used lead-acid battery can be reused and its lifetime can be extended. Because the battery has different capacities and limited voltage margin, the capacity can be amended by setting parameters. In addition, using green energy technology for the low power system and the used devices on saving energy, the environmental education can be realized in the life. The complicated circuit design and cost problems can be improved. In this thesis, a microcontroller is employed to manage the low power green energy system. We will use the microcontroller 89S52 and other simple devices to manage green energy storage and output. Therefore, we can realize a green energy system for the electrical network of the house and make green energy popularization. The designs can be implemented by use of the used devices and lead-acid battery. Experiment results show that the proposed design approach is valid for saving energy. Keywords : green energy, lead-acid battery, used device, solar energy, 89S52, energy storage management.
Yeh, Chih-Tsen, and 葉致岑. "The Study of Vanadium Redox Battery Combine Green Energy Storage Systems." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/54540371519166714082.
Повний текст джерела健行科技大學
電機工程系碩士班
104
This paper is about Vanadium Redox Battery Combine Green Energy Storage Systems Use green energy power with digital signal processor (TMS320F28335) as the generation system in order to protect environment, also use simulate software (PSIM) to construct a model for boosting the converter and the full-bridge inverter, and discuss each correlative value and works. The generation system by 1.2kW proton exchange membrane fuel cell and 220W solor cell .The first set of power system solar cell 220W / DC 38 V to the buck converter 13V to charge for vanadium redox flow battery energy storage, and battery storage of electricity generated by the boost converter (Converter VRB) to DC 200V, and then by the full-bridge inverter converted to AC 110V for the load, while the second group sucked 1.2kW / DC38V fuel cell boost converter (converter FC) to DC 200V, and then by the full-bridge inverter output AC 110V for the load.
Shen, You-Sheng, and 沈佑陞. "Design and Implementation of Novel DC/DC Converters for Green-Energy and Energy-Storage Systems." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/a29x4e.
Повний текст джерела國立高雄第一科技大學
工學院工程科技博士班
106
The objective of this dissertation is to propose four kinds of high-efficiency DC/DC power converters for green-energy and energy-storage systems are proposed. In addition, a novel maximum power point tracking (MPPT) for PV panel is also presented. The design core of the four proposed converters is how to reduce component count and simplify converter configuration so as to improve conversion efficiency and accomplish easy control. In this dissertation, a simplest analog circuit is first discussed, which fulfills MPPT based on double-linear approximation (DLA) criterion. With the analog circuit, the maximum power point (MPP) of a PV panel can be determined quickly and accurately without complicated calculations even under varying atmospheric conditions. After the exploring of the DLA criterion, four novel converters, which are dual-input PV-wind converter (DIPWC), high-step-up DC/DC converter (HSUDC), isolated bidirectional DC/DC converter (IBDC) and bidirectional DC/DC converter (BDC), are presented. The DIPWC is capable of dealing with photovoltaic and wind-turbine energies simultaneously, while the HSUDC is for the achievement of high voltage ratio with interleaved operation for PV panel. The IBDC is a DC/DC converter having the features of high voltage-conversion ratio and bidirectional energy control, which is suitable for energy storage system. At last, the BDC is discussed. Even though this converter is also a kind of bidirectional DC/DC converter, it can perform soft-switching feature at all power switches. All the proposed converters and the DLA method are simulated and then tested by hardware. Simulations and practical measurements have validated the four converters and the DLA criterion. Keywords : MPPT, high voltage ratio, interleaved operation, bidirectional DC/DC converter, soft-switching feature.
Langels, Hanna, and Oskar Syrjä. "Hydrogen Production and Storage Optimization based on Technical and Financial Conditions : A study of hydrogen strategies focusing on demand and integration of wind power." Thesis, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-435176.
Повний текст джерелаLin, Chieh-Hung, and 林杰宏. "The Analysis of Taiwanese Intelligent Green Building Policies and the Big-Data of Convenience Store Energy Consumption Characteristics." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7bx962.
Повний текст джерела國立臺灣科技大學
材料科學與工程系
107
In 2010, Taiwan launched a plan called “the Four Emerging Intellectual Industries, which covers intelligent green buildings. The aim of promoting intelligent green buildings is to stimulate the architecture technology industry. This has been combined with information and communication technology and the concept of green buildings to provide a safe and healthy living environment while reducing carbon emissions and saving energy. This study investigated intelligent green building policies and their promotion in Taiwan using cases from 1988 to 2014. Key success factors were derived from analyzing and summarizing intelligent green building experiences in Taiwan. This was done through secondary data analyses by: 1) establishing clear norms and standards for intelligent green building design and improvement; 2) carrying out policies in the public sector in order to provide field trials and safeguarded market opportunities for industries; 3) implementing rating-based assessments in order to raise the quality of design; 4) introducing mandatory or incentive policies that depend on local specialties and conditions; 5) respectively planning incentives for relevant interested parties in the industrial chain; 6) linking the Smart Green Building policy chain to industrial development to drive the development of the overall construction industry; and 7) strengthening marketing efforts and proactively promoting policies. In order to promote Taiwan's Intelligent Green Building Policy, this study engaged scientific quantitative analysis, provided follow-up decision-making for the evaluation process of the construction industry promotion policy, and used Fuzzy Hierarchical Analysis (FHA) and the Fuzzy Transformation Matrix (FTM) as tools to extract the experts’ collective intelligence upon in-depth interviews. The experts collectively assessed the contribution weights of various policy tools that are used to achieve the Intelligent Green Building policy objectives. The green building label, intelligent building label, and green building material label during the years from 1999 to 2015 were assessed. The findings on the implementation of the labeling policy measures, the integrated analysis of the results of the evaluation for the growth and decline of the applications, the spontaneous participation of people, and the change of the evaluation grading were as follows: 1) FHA and FTM could be used to extract the collective expert opinions and establish a policy evaluation method with a reference value; 2) additional bulk incentives for private buildings, mandatory control for public buildings, and mandatory incorporation of green public purchasing into green building materials are the most effective policy measures in Taiwan; and 3) the implementation of control measures during the design and planning stage for new buildings is superior to the use of control measures during the operation and management stage. This study was aimed at the promotion of green convenience stores, and used Big Data mining, machine learning analysis, and traditional statistical methods to explore the energy consumption characteristics and feasible energy-saving measures of Taiwan's convenience stores. A total of 1,052 surveys were conducted by the TABC (Taiwan Architecture and Building Center) team in 2014 using the open source software (OSS) WEKA and Minitab 18 as tools. This study was focused on obtaining information and comprehensively exploring the convenience stores’ energy performance information, including: 1) the building space environment and geographical condition-related factors; 2) the influence of business type; 3) the influence of business equipment; 4) the influence of local climatic conditions; and 5) the influence of the socio-economic conditions of consumers in service areas. According to the validation results, the quality of analysis could be upgraded and the convenience stores could be provided with specific and feasible energy saving and carbon reduction improvement proposals. The outcome of this study could provide convenience stores with the following directions: 1) convenience stores could receive accurate predictions of energy consumption performance to optimize the architectural space, business equipment, and operations management mode; 2) design planners could obtain the optimum design and cost/performance ratio by determining the thresholds of various key factors; and 3) decision support could be provided for government energy and environment departments to create energy saving and carbon emission reduction policies for the convenience store industry. In the analysis results, through the analysis of the data attributes, the key factors affecting the energy consumption of the convenience stores and their intensity ranking were discovered. Regression analysis and classification techniques were used to establish a numerical prediction model of energy consumption. Cluster analysis was applied to compare the differences between different clusters of data. The correlation between factors affecting the energy consumption characteristics of the convenience stores was judged, and the energy consumption obtained through the above analysis was obtained. The statistical analysis method used a multiple regression model to establish a prediction model for the convenience stores’ energy consumption and discuss the contribution of various influencing factors through the correlation coefficient analysis of each influencing variable. The results could provide the following benefits: 1) owners could be provided with an accurate prediction of energy consumption performance that could help them optimize the construction space, business equipment, and operation management methods; 2) design planners could obtain the best design for the investment/price ratio based on threshold value planning and the forecasting of various key factors in the model; and 3) decision support could be provided for government energy and environment departments for the establishment of energy conservation and carbon reduction policies as well as to estimate and set up energy consumption standards for the convenience store industry.
Almasri, Abdullah Mahmoud. "Google Play apps ERM: (energy rating model) multi-criteria evaluation model to generate tentative energy ratings for Google Play store apps." Doctoral thesis, 2021. http://hdl.handle.net/10284/9671.
Повний текст джерелаUm problema comum entre utilizadores de smartphones Android tem sido a necessidade de economizar a energia das baterias, de modo a evitar a utilização de recursos de recarga. O aumento significativo no uso de smartphones tem sido acompanhado por um aumento, também significativo, na necessidade de mais energia. Esta relação operacional entre tecnologia moderna e energia gera aplicações muito exigentes no seu consumo de energia e, portanto, perfis de utilizadores que requerem níveis de energia crescentes. Com muitos das aplicações que se enquadram numa mesma categoria da loja de aplicações (Google Store), essas aplicações geralmente também partilham funcionalidades semelhantes. Como os criadores destas aplicações seguem abordagens diferentes de diversas escolas de design e desenvolvimento, cada aplicação possui as suas próprias caraterísticas de consumo de energia. Como as aplicações partilham recursos semelhantes, um utilizador final com acesso limitado a recursos de recarga prefere uma aplicação que consome menos energia do que uma aplicação mais exigente em termos de consumo energético, ainda que seja popular. No entanto, as lojas de aplicações não fornecem uma indicação sobre o comportamento energético das aplicações oferecidas, o que faz com que os utilizadores escolham aleatoriamente as suas aplicações sem entenderem o correspondente comportamento de consumo de energia. Adicionalmente, no que diz respeito à questão de investigação, a solução de uma aplicação de economia de energia consume muita eletricidade, o que a torna limitada; estudos anteriores indicam claramente que há muita perda de bateria devido a vários fatores, não constituindo solução para muitos utilizadores e para os fabricantes de smartphones. A principal contribuição de nossa pesquisa é projetar uma ferramenta que possa atuar como um fator de suporte à decisão eficaz para que os utilizadores finais tenham uma indicação inicial do comportamento de consumo de energia de uma aplicação, antes de a instalar. A ideia central da filosofia proposta é a de atuar "antes da instalação", evitando assim a situação em se instala uma aplicação para perceber à posteriori o seu impacto no consumo energético e depois ter que o monitorizar e otimizar (talvez ainda recorrendo a uma aplicação de monitorização do consumo da bateria, o que agrava ainda mais o consumo energético). Assim, como o processamento requer energia, é nossa prioridade evitar o consumo de alguma energia para conservar uma quantidade maior de energia. Portanto, é proposta uma estratégia preventiva que não requer processamento em nenhuma camada do smartphone. Para resolver este problema, é proposto um modelo de avaliação por classificação baseado em níveis e identificado por estrelas (SREM). Esta abordagem gera uma etiqueta de classificação energética provisória para cada aplicação. Para isso, o SREM adapta as atuais ferramentas de refatoração com reconhecimento de energia para demonstrar o nível de consumo de energia de uma aplicação, apresentando o resultado num esquema de classificação por estrelas semelhante ao dos rótulos ecológicos usados em eletrodomésticos. O SREM também se propõe influenciar quem desenvolve e produz as aplicações, a criarem diferentes versões destas, com diferentes perfis de consumo energético, de modo a atender às necessidades de diferentes categorias de utilizadores e assim classificar as suas próprias aplicações. Para avaliar a eficiência do modelo como um complemento às aplicações da loja Google Play, que atuam como uma rotulagem para orientação dos utilizadores finais. A investigação também analisa a literatura existente relevante, especificamente a que abrange as várias técnicas e ferramentas de economia de energia, propostas para smartphones Android. Uma análise secundária foi ainda realizada, focando nos trabalhos de pesquisa que avaliam a perceção dos utilizadores em relação à energia do dispositivo, a partir da bateria. Em complemento, a pesquisa destaca um problema de que as notificações sobre a economia de energia mostradas na tela parecem explorar muita bateria. Este estudo permitiu refletir sobre as formas que podem auxiliar os utilizadores a economizar a bateria do telefone sem usar energia da mesma bateria e, mesmo assim, o poderem fazer de maneira eficiente. A pesquisa oferece uma visão global das alternativas que podem ser usadas para conservar com mais eficiência a energia do smartphone, propondo um modelo que envolve os utilizadores finais no processo.
Un problème fréquent rencontré par les utilisateurs de smartphones Android a été, tout en l’étant toujours, d’économiser leur batterie et d’éviter la nécessité d’utiliser des ressources de recharge. La croissance considérable de l’utilisation des smartphones s’accompagne clairement d’une augmentation des besoins en énergie. Cette relation préopérationnelle entre la technologie moderne et l’énergie génère des applications gourmandes en énergie, et donc des utilisateurs finaux qui le sont tout autant. De nombreuses applications relevant de la même catégorie dans une boutique partagent généralement des fonctionnalités similaires. Étant donné que les développeurs adoptent différentes approches de conception et de développement, chaque application a ses propres caractéristiques de consommation d’énergie. Comme les applications partagent des fonctionnalités similaires, un utilisateur final disposant d’un accès limité aux ressources de recharge préférerait une application écoénergétique plutôt qu’une autre gourmande en énergie. Cependant, les boutiques d’applications ne donnent aucune indication sur le comportement énergétique des applications qu’elles proposent, ce qui incite les utilisateurs à choisir des applications au hasard sans comprendre leurs caractéristiques en ce domaine. En outre, en ce qui concerne les questions de recherche sur le fait que les applications d’économie d’énergie consomment beaucoup d’électricité, des études antérieures indiquent clairement que la décharge d’une batterie est due à plusieurs facteurs. Ce problème est devenu une préoccupation majeure pour les utilisateurs et les fabricants de smartphones. La principale contribution de notre étude est de concevoir un outil qui peut agir comme un facteur d’aide efficace à la décision pour que les utilisateurs finaux aient une indication initiale du comportement de consommation d’énergie d’une application avant de l’installer. L’idée de base de la philosophie « avant l’installation » est simplifiée par le concept contradictoire d’installer l’application pour ensuite la contrôler et l’optimiser. Puisque les opérations de traitement exigent de l’énergie, éviter la consommation d’une partie d’entre elles pour l’économiser devrait être notre priorité. Nous proposons donc une stratégie préventive qui ne nécessite aucun traitement sur une couche quelconque du smartphone. Pour résoudre ce problème, nous proposons un modèle d’évaluation au moyen d’étoiles (star-rating evaluation model ou SREM), une approche qui génère une note énergétique indicative pour chaque application. À cette fin, le SREM adapte les outils actuels de refactoring sensibles à l’énergie pour démontrer le niveau de consommation d’énergie d’une application et la présente dans un schéma de classement par étoiles similaire aux labels écologiques utilisés sur les appareils électroménagers. Le SREM incitera également les développeurs et les fournisseurs d’applications à mettre au point plusieurs versions avides d’énergie d’une même application afin de répondre aux besoins des différentes catégories d’utilisateurs et d’évaluer leurs propres applications. Nous avons proposé d’ajouter le SREM au Google Play Store afin de générer le label d’efficacité énergétique pour chaque application. Celui-ci servira de guide à la fois pour les utilisateurs finaux et les développeurs sans exécuter de processus sur le smartphone des utilisateurs finaux. Notre recherche passe également en revue la littérature existante pertinente, en particulier celle qui couvre divers outils et techniques d’économie d’énergie proposés par divers auteurs pour les smartphones Android. Une analyse secondaire a été effectuée en évaluant les documents de recherche et les enquêtes antérieurs qui ont été réalisés pour évaluer la perception des utilisateurs concernant l’alimentation téléphonique depuis leur batterie. En outre, l’étude met en évidence un problème selon lequel les notifications concernant les économies d’énergie affichées à l’écran semblent elles-mêmes soumettre les batteries à une forte utilisation. Par conséquent, cette étude a été entreprise pour refléter les façons qui pourraient aider les utilisateurs à économiser efficacement la batterie de leur téléphone sans pour autant la décharger. L’étude offre un bon aperçu des nouvelles façons d’économiser plus efficacement l’énergie des smartphones, en proposant un cadre qui implique les utilisateurs finaux dans le processus.