Dissertations / Theses on the topic 'Green Energy Storage'

Optimal design of a microgrid containing renewable energy sources in a residential sector is important to have a technical and economical feasible investment. In this project a microgrid (MG) for a house cooperative in Hudiksvall, Sweden has been studied. The aim of this study is to estimate how the electric vehicles (EVs) will aid the MG assuming different availabilities. Furthermore, this study aims to investigate optimal sizes of photovoltaic (PV) power and solar collectors for the households as well as possible energy storage capacity to increase the self-consumption. To study the role of the EVs in aiding the MG a simulation was carried in MATLAB/SIMULINK. To estimate the optimal sizes of the PV cells a life cycle cost assessment (LCCA) was carried out. The optimal output from the SC was estimated by using the f -chart method. The results from this study points out that a higher EV capacity will be required when the EVs are available for longer hours of the day, which is mainly due to the large share of PV power produced and the limited range of charging/discharging capacity of the EV battery. The LCCA shows that a high PV capacity will lead to a low net present value and a longer payback period. The sensitivity analysis which was carried out indicates that the PV system investment is mostly sensitive to the investment cost. The f -chart method gives the recommended values for SC output and an estimation of the thermal energy storage capacity.
Ett 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.

The key motivation of this study is to investigate the potential of graphene/metal oxides nanocomposites as electrodes for electrochemical capacitor applications. It is envisioned that the positive synergistic effect between graphene and metal oxides (where novel graphene material acts as a highly conductive platform for ease of ion transfer kinetics and metal oxide acts as spacers to avoid the restacking of graphene sheets to make available more active surface areas) results in excellent electrode material for high performance electrochemical capacitor. In this thesis, a series of hybrid composites comprising of graphene and low cost transition metal oxides were synthesised and characterised for their potential as electrode for electrochemical capacitor applications. In order to achieve this, the graphene used in the preparation of the hybrid composites was successfully synthesised from highly pyrolytic graphene in a proper ratio of ethanol and water before the integration of the metal oxides via a solvothermal route. A parametric study was carried out in a step by step approach to validate the success of the composite synthesis before the electrochemical stage. X-ray Diffraction, Field emission and Transmission scanning electron microscopy, energy-dispersive X-ray and Raman spectroscopy, cyclic voltammetry and galvanostatic charge/discharge tests were used to verify the integrity of the as-produced graphene/metal oxide composites and their applicability to electrochemical capacitors. Upon the completion of the experimental work, the electrochemical tests demonstrated that the introduction of graphene to the metal oxide improved the electrochemical performance in-terms of capacitance, energy density, power density, equivalent series resistance and cycling stability. The results also indicated that the ratio of graphene to metal-oxide plays a significant role in the electrochemical performance of the composite. In comparison with the different graphene/Zinc oxide (ZnO) nanocomposites studied, the electrode material with a weight ratio of 1:8 (graphene: ZnO) displayed a specific capacitance of 236 F/g at a scan rate of 10 mV/s with energy and power densities of 11.80 Wh/kg and 42.48 kW/kg respectively. The specific capacitance of the graphene-Manganese oxide (MnO2) composite electrode material with a weight ratio of 1:16 (graphene: MnO2) demonstrated the best performance of 380 F/g at a scan rate of 5 mV/s among the four ratios studied. The G1Co4 composite electrode with a weight ratio of 1:8 (graphene: Co3O4) demonstrated a superior specific capacitance of 384 F/g at a current density of 0.3 A/g coupled with retention of 80% of its capacitance after 1000 cycles among the graphene-cobalt composites. The Graphene-Nickel cobaltite composite electrode with weight ratio of 1:8 (graphene: NiCo2O4) labelled G-8NC2 displayed a superior specific capacitance (698 F/g at a current density of 0.5 A/g) and good cycling stability (74% capacity retention after 5000 cycles at current density of 1 A/g). The 1:8 ratio exhibited well attached Nickel molybdate nanorods on the surface and edges of the graphene sheets with the highest specific capacitance of 670 F/g at 0.3 A/g, as compared to other tested composites. The significance of these findings details a synthesis route that provides an effective, simple and practical method of preparing graphene-metal oxide composite materials for electrochemical capacitor applications.

This work involves the study of heating systems that combine solar collectors, geothermal heat pumps and thermal energy storage in the ground. Solar collectors can reduce the electricity use in these systems by reducing the operation time of the geothermal heat pump and by increasing the ground source temperature. These systems can be designed in many ways, consequently the complexity is high. The purpose of this study has been to develop simulation models to study the behavior of these systems, with emphasis on the thermal energy storage in the ground. A simulation tool with several models has been developed in the simulation software TRNSYS based on the proposed heating system at the GEL under the metrological conditions of Shanghai. The program was used for an intensive simulation study, in which the interaction with the borehole heat exchanger, the geothermal heat pump, the evacuated tube collector and the load requirements could be analyzed. A base case was developed to make it possible to vary and compare the design parameters of interest, such as the ground storage volume, the flow rate of the solar collector and the solar collector area. The base case was based on the design parameters of the GEL. The GEL was used as reference building and was simulated in TRNBuild with the thermal characteristics of the building material. From the simulations the heating demand of the building could be obtained and the building model could later on be used as a heat load for the other simulation models. The results showed that the there were heating demand from November to March. The four operation modes of the proposed heating system at the GEL were presented. All of the operation modes were simulated in TRNSYS. The four operation modes were solar thermal ground storage, solar direct heating, direct heat exchange with the ground storage and geothermal heat pump. The operation modes worked in two different seasons, storage season and heating season. The ground storage mode was studied thoroughly by varying the parameters of interest. To test the significance of the borehole configuration, the storage volume was kept constant and the number of boreholes and the borehole spacing were varied. It was found that a compact pattern with a high number of boreholes and small borehole spacing is favorable for borehole thermal energy storages. The performance of a ground storage is directly linked to the storage size. The solar collector efficiency is highly dependent on the return temperature of the storage. It was decided to continue to work with a compact pattern of the storage, rather than the base case of the GEL. This is because this kind of storage showed the most promising storage efficiency and also reached a high ground temperature during storage season.Simulations of the heating modes showed that the solar direct heating mode, the direct heat exchange with ground storage mode and the geothermal heat pump mode can each cover 37%, 25% and 38% of the heating demand respectively. For the simulations of the geothermal heat pump it was shown that the borehole depth is a very important factor for the system performance. Too short borehole depth will cause unstable and too low temperatures at the inlet of the evaporator. To compare the electricity use of a geothermal heat pump system with and without solar collectors there were also performed simulations for a traditional geothermal heat pump system. Results showed that 26.1% of the electricity consumption could be saved. The savings was mostly due to the reduced operation time of the heat pump, since other heating modes could be used. The studies showed that due to the complexity of such systems it is very important to perform simulations to optimize the performance. There are many factors that play an important role since there are so many components involved. The simulations showed that sizing of the system is critical for the system performance.

Solving the key issue of sustainability of battery-powered sensors continues to attract significant research attention. The prevailing theme of this research is to address this concern using energy-efficient protocols based on a form of simple cooperative transmission (CT) called the opportunistic large arrays (OLAs), and intelligent exploitation of energy harvesting and hybrid energy storage systems (HESSs). The two key contributions of this research, namely, OLA with transmission threshold (OLA-T) and alternating OLA-T (A-OLA-T), offer an signal-to-noise ratio (SNR) advantage (i.e., benefits of diversity and array (power) gains) in a multi-path fading environment, thereby reducing transmit powers or extending range. Because these protocols do not address nodes individually, the network overhead remains constant for high density networks or nodes with mobility. During broadcasting across energy-constrained networks, while OLA-T saves energy by limiting node participation within a single broadcast, A-OLA-T optimizes over multiple broadcasts and drains the the nodes in an equitable fashion. Another important contribution of this research is the design and analysis of a novel routing metric called communications using HESS (CHESS), which extends the rechargeable battery (RB)-life by relaying exclusively with supercapacitor (SC) energy, and is asymptotically optimal with respect to the number of nodes in the network.

A problem that has become apparently growing in the deployment of renewable energy systems is the power grids inability to accept the forecasted growth in renewable energy generation integration. To support forecasted growth in renewable generation integration, it is now recognised that Energy Storage Technologies (EST) must be utilised. Recent advances in Hydrogen Energy Storage Technologies (HEST) have unlocked their potential for use with constrained renewable generation. HEST combines Hydrogen production, storage and end use technologies with renewable generation in either a directly connected configuration, or indirectly via existing power networks. A levelised cost (LC) model has been developed within this thesis to identify the financial competitiveness of the different HEST application scenarios when used with grid constrained renewable energy. Five HEST scenarios have been investigated to demonstrate the most financially competitive configuration and the benefit that the by-product oxygen from renewable electrolysis can have on financial competitiveness. Furthermore, to address the lack in commercial software tools available to size an energy system incorporating HEST with limited data, a deterministic modelling approach has been developed to enable the initial automatic sizing of a hybrid renewable hydrogen energy system (HRHES) for a specified consumer demand. Within this approach, a worst-case scenario from the financial competitiveness analysis has been used to demonstrate that initial sizing of a HRHES can be achieved with only two input data, namely – the available renewable resource and the load profile. The effect of the electrolyser thermal transients at start-up on the overall quantity of hydrogen produced (and accordingly the energy stored), when operated in conjunction with an intermittent renewable generation source, has also been modelled. Finally, a mass-transfer simulation model has been developed to investigate the suitability of constrained renewable generation in creating hydrogen for a hydrogen refuelling station.

This thesis investigates the viability of a new vanadium oxide cathode material to improve the performance of zinc ion battery technologies. Such systems promote the development of eco-friendly, renewable energy storage, and green portable devices. The focus material was thoroughly tested and characterised to gain a deeper understanding of the internal reaction and mechanisms of the battery cells, providing valuable insights relevant to the wider energy storage research community.

La thèse est consacrée à l’étude de l’échange de chaleur entre un fluide et un milieu solide tel que le sol par l’intermédiaire d’un échangeur bitubulaire vertical. Un modèle mathématique du comportement du système a été élaboré. Pour résoudre l’ensemble des équations, un algorithme de calcul numérique, basé sur l’utilisation des fonctions de Green afin de réduire le problème tridimensionnel à un problème bidimensionnel, a été mis au point. L’application du théorème de Duhamel a permis d’introduire la notion de réponse caractéristique de ce type d’échangeur. En vue de valider le modèle mathématique et numérique, une expérience a été réalisée en laboratoire. Les résultats des tests effectués avec des conditions aux limites différentes confirment avec une très bonne approximation les résultats théoriques. Ce modèle peut être alors utilisé comme un outil intéressant pour concevoir des échangeurs à puits multiples efficaces contribuant ainsi à l’élaboration de chaînes énergétiques rentables.

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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.

Energy issues gathered strong attention over the past decade, reaching IT data processing infrastructures. Now, they need to cope with such responsibility, adjusting existing platforms to reach acceptable performance while promoting energy consumption reduction. As the de facto platform for Big Data, Apache Hadoop has evolved significantly over the last years, with more than 60 releases bringing new features. By implementing the MapReduce programming paradigm and leveraging HDFS, its distributed file system, Hadoop has become a reliable and fault tolerant middleware for parallel and distributed computing over large datasets. Nevertheless, Hadoop may struggle under certain workloads, resulting in poor performance and high energy consumption. Users increasingly demand that high performance computing solutions address sustainability and limit energy consumption. In this thesis, we introduce HDFSH, a hybrid storage mechanism for HDFS, which uses a combination of Hard Disks and Solid-State Disks to achieve higher performance while saving power in Hadoop computations. HDFSH brings, to the middleware, the best from HDs (affordable cost per GB and high storage capacity) and SSDs (high throughput and low energy consumption) in a configurable fashion, using dedicated storage zones for each storage device type. We implemented our mechanism as a block placement policy for HDFS, and assessed it over six recent releases of Hadoop with different architectural properties. Results indicate that our approach increases overall job performance while decreasing the energy consumption under most hybrid configurations evaluated. Our results also showed that, in many cases, storing only part of the data in SSDs results in significant energy savings and execution speedups
Ao 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

Le secteur du numérique est récemment devenu un secteur majeur de la consommation d’électricité dans le monde, notamment avec l’avènement des data centers qui concentrent un très grand nombre de machines traitant des informations et fournissant des services. L’utilisation de sources d’énergie renouvelables sur site est un moyen prometteur de réduire l’impact écologique des data centers. Cependant, certaines énergies renouvelables comme les énergies solaire et éolienne sont intermittentes, étant liées aux conditions météorologiques. Étant donné qu’un centre de données doit maintenir une certaine qualité de service, l’utilisation efficace de ces sources nécessite l’utilisation de stockages. Cette thèse explore à la fois une méthode dimensionnement et une méthode de gestion optimale d’une infrastructure hybride d’énergie renouvelable, composée de panneaux photovoltaïques, d’éoliennes, de batteries et de système de stockage hydrogène.Une première contribution aborde le problème du dimensionnement de cette infrastructure électrique afin de répondre à la demande du data center. Un outil de dimensionnement est proposé, prenant en compte plusieurs métriques et fournissant trois configurations différentes. L’utilisateur choisit donc la configuration approprié, en fonction de son plan économique global de son écosystème H2. Une deuxième contribution étudie le problème de la gestion de l’énergie par programmation linéaire en nombres entiers. Un outil de gestion optimal est fourni pour trouver différents engagements optimaux des sources en fonction des objectifs de l’utilisateur. Les solutions obtenues sont ensuite discutées avec plusieurs métriques et avec différents horizons temporelles afin de trouver la meilleure solution pour répondre à la demande du data center. Enfin, une troisième contribution vise à prévoir évolution temporelle de l’ensoleillement et de la vitesse du vent à gros grain pour obtenir un dimensionnement plus précis à l’aide du modèle SARIMA
Information 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

This degree thesis investigates the possibilities of producing food inside a container at Svalbard, using renewable energy and energy storage. The idea was to be able to place the container at remote places without the need of being connected to the grid. We chose Svalbard, where it is cold and the sun is shining 24 hours a day at summertime. In the winter the opposite occurs and the sun is absent from the sky. The work is divided into theoretical studies and results based on different calculations. Such as economical evaluations (LCOE), and simulations using the computer programs Matlab and PVsyst. We have investigated if solar power and wind power is suitable as energy sources. Options for storage were batteries, grid and hydrogen storage. Different cases with Photovoltaics- and wind power plants, with batteries or grid, were compared against each other. It is not possible to use the grid as storage. This resulted in different sizing of our cases, with no excess energy production. The result showed that a 5 kWp photvoltaic plant with dual axis tracking system, was the most profitable. The Pay off would be 14 years and the total profit 63 453 SEK. If it will become possible in the future to use the grid at Svalbard as storage, it will open up opportunites for bigger systems. This will lead to higher profit than with smaller ones. Our results show that it is now most profitable with solar power.

När byggnader projekteras används klimatfiler från 1981-2010 för att dimensionera konstruktionen och energisystemet. Detta leder till att byggnader dimensioneras för ett klimat som varit och inte ett framtida klimat. SMHI har tagit fram olika klimatscenarier för framtiden som beskriver möjliga utvecklingar klimatet kan ta beroende på fortsatt utsläpp av växthusgaser. Dessa scenarier kallas för RCP (Representative Concentration Pathways). I denna studie används två olika klimatscenarier, RCP4,5 och RCP8,5. Siffran i namnet står för den strålningsdriving som förväntas uppnås år 2100. I RCP4,5 kommer medelårstemperaturen öka med 3 °C fram till år 2100 jämfört med referensperioden 1961-1990.  För samma tidsperiod sker en ökning på 5 °C enligt RCP8,5.  Ett flerbostadshus certifierad enligt Miljöbyggnad 2.2 nivå silver placerat i Vallentuna i Stockholms län används i denna studie som referensbyggnad. Byggnaden simuleras i programmet IDA ICE där den utsätts för RCP4,5 och RCP8,5. Resultatet visar att byggnaden inte skulle klara av kraven för Miljöbyggnad 2.2 gällande termiskt klimat sommar i något av de två klimatscenarierna. De operativa temperaturerna blir för höga i byggnaden utan att tillsätta komfortkyla.  Byggnaden ändras för att se vilka faktorer som kan förbättra resultatet gällande det termiska klimatet. Resultatet visar att värmelagringsförmåga hos byggmaterial och solavskärmning har störst påverkan på det termiska klimatet.  I studien gjordes flertal olika kombinationer av byggnadsutformningar. Enbart kombinationen av en tung stomme av betong tillsammans med fönster med lägre g-värde klarar kraven för Miljöbyggnad 2.2 i RCP4,5 och RCP8,5 utan komfortkyla. Kombinationen får lägst energianvändning i RCP8,5 av de olika kombinationerna som testats i studien.  En kombination av tung stomme av KL-trä med lågt U-värde, fönster med lägre g-värde och komfortkyla får lägst energianvändning i grundklimatet och RCP4,5 av de olika kombinationerna som testats i studien trots användningen av komfortkyla.  Frågan om vilket alternativ som är bäst ur ett hållbarhetsperspektiv är svårt att svara på. Det finns många aspekter som behöver tas i hänsyn till som byggnadens totala klimatavtryck både i tillverkning och användning. Oavsett val av konstruktion är det viktigt att projektera för att komfortkyla och solavskärmning skall kunna appliceras när ett varmare klimat råder.
When 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.

碩士
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.

碩士
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.

博士
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.

There has recently been an increased interest in hydrogen, both as a solution for seasonal energy storage but also for implementations in various industries and as fuel for vehicles. The transition to a society less dependent on fossil fuels highlights the need for new solutions where hydrogen is predicted to play a key role. This project aims to investigate technical and economic outcomes of different strategies for production and storage of hydrogen based on hydrogen demand and source of electricity. This is done by simulating the operation of different systems over a year, mapping the storage level, the source of electricity, and calculating the levelized cost of hydrogen (LCOH). The study examines two main cases. The first case is a system integrated with offshore wind power for production of hydrogen to fuel the operations in the industrial port Gävle Hamn. The second case examines a system for independent refueling stations where two locations with different electricity prices and traffic flows are analyzed. Factors such as demand, electricity prices, and component costs are investigated through simulating cases as well as a sensitivity analysis. Future potential sources of income are also analyzed and discussed. The results show that using an alkaline electrolyzer (AEL) achieves the lowest LCOH while PEM electrolyzer is more flexible in its operation which enables the system to utilize more electricity from the offshore wind power. When the cost of wind electricity exceeds the average electricity price on the grid, a higher share of wind electricity relative to electricity from the grid being utilized in the production results in a higher LCOH. The optimal design of the storage depends on the demand, where using vessels above ground is the most beneficial option for smaller systems and larger systems benefit financially from using a lined rock cavern (LRC). Hence, the optimal design of a system depends on the demand, electricity source, and ultimately on the purpose of the system. The results show great potential for future implementation of hydrogen systems integrated with wind power. Considering the increased share of wind electricity in the energy system and the expected growth of the hydrogen market, these are results worth acknowledging in future projects.

博士
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.

A common issue that is shared among Android smartphones users was and still related to saving their batteries power and to avoid the need of using any recharging resources. The tremendous increase in smartphone usage is clearly accompanied by an increase in the need for more energy. This preoperational relationship between modern technology and energy generates energy-greedy apps, and therefore power-hungry end users. With many apps falling under the same category in an app store, these apps usually share similar functionality. Because developers follow different design and development schools, each app has its own energy-consumption habits. Since apps share similar features, an end-user with limited access to recharging resources would prefer an energy-friendly app rather than a popular energy-greedy app. However, app stores give no indication about the energy behaviour of the apps they offer, which causes users to randomly choose apps without understanding their energy-consumption behaviour. Furthermore, with regard to the research questions about the fact that power saving application consumes a lot of electricity, past studies clearly indicate that there is a lot of battery depletion due to several factors. This problem has become a major concern for smartphone users and manufacturers. The main contribution of our research is to design a tool that can act as an effective decision support factor for end users to have an initial indication of the energy-consumption behaviour of an application before installing it. The core idea of the “before-installation” philosophy is simplified by the contradicting concept of installing the app and then having it monitored and optimized. Since processing requires power, avoiding the consumption of some power in order to conserve a larger amount of power should be our priority. So instead, we propose a preventive strategy that requires no processing on any layer of the smartphone. To address this issue, we propose a star-rating evaluation model (SREM), an approach that generates a tentative energy rating label for each app. To that end, SREM adapts current energy-aware refactoring tools to demonstrate the level of energy consumption of an app and presents it in a star-rating schema similar to the Ecolabels used on electrical home appliances. The SREM will also inspire developers and app providers to come up with multiple energy-greedy versions of the same app in order to suit the needs of different categories of users and rate their own apps. We proposed adding SREM to Google Play store in order to generate the energy-efficiency label for each app which will act as a guide for both end users and developers without running any processes on the end-users smartphone. Our research also reviews relevant existing literature specifically those covering various energy-saving techniques and tools proposed by various authors for Android smartphones. A secondary analysis has been done by evaluating the past research papers and surveys that has been done to assess the perception of the users regarding the phone power from their battery. In addition, the research highlights an issue that the notifications regarding the power saving shown on the screen seems to exploit a lot of battery. Therefore, this study has been done to reflect the ways that could help the users to save the phone battery without using any power from the same battery in an efficient manner. The research offers an insight into new ways that could be used to more effectively conserve smartphone energy, proposing a framework that involves end users on the process.
Um 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.