Dissertations / Theses on the topic 'Energy efficiency'
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Mandryka, V. "Energy efficiency in energy consumption systems." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40670.
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There has been used four times more energy in the world compared to 1950 year. The main share falls primarily on households and the growing industry. The economic downturn in Ukraine and the countries of former USSR does not influence the consumption of energy – it remains high.
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Skogfeldt, Alexander. "Energy efficiency measures and energy pricing : The effect of different price schemes on energy efficiency measures." Thesis, Uppsala universitet, Matematiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325895.
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This project investigates the relationship between energy efficiency measures in the Swedish building stock and different price schemes based on energy prices. Data from different categories was gathered and used in a regression model. They were based on what type of pricing and fees that are behind the energy prices for electricity and district heating. These predictors were used to get an equation of the temperature corrected energy use which can be linked to how much energy efficiency measures have been implemented over the investigated time period. The result for the main equation, that includes all the studied building types, indicated that it is possible to predict energy efficiency measures with different price schemes,and therefore it is possible to increase the rate at which measures are implemented. It showed that there is a negative relationship between energy consumption and theprice of energy from district heating. If the price of district heating increases the temperature corrected energy use decreases. The other relationships between predictors and the dependent variable were positive. It also described the geographical location as a statistically significant variable, regarding all climate zones in Sweden.
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Beita-Kiser, Gabriel. "Energy Efficient Homes in Tucson: How to Make Cost-Effective Energy Efficiency Retrofits." The University of Arizona, 2015. http://hdl.handle.net/10150/552896.
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Max, Talbak. "Efficient Households : Energy efficiency in small apartments in Stockholm." Thesis, KTH, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175161.
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The energy consumption of the first world has reached unexpected heights, and is increasing every day. Because of this, energy efficiency has become a hot subject, both on a small and large scale. Every individual has a possibility to improve their energy efficiency and energy use alike by substantial amounts, and should act on this for the sake of the environment. The report begins with a study of different regulations and standards regarding energy efficiency. After this, a literature study is conducted regarding the latest available technology in all areas of home appliances. Finally, a field study is conducted on an apartment in Stockholm to find out how much energy that actually can be saved, and what the economic results are from this. The result shows that in general, it isn’t economically viable to upgrade to the latest energy efficient technology within home appliances, but that one has to consider the environmental gains as incitement for action. Approximately 10% of the total annual energy consumption could be saved by changing all machinery and functions in the house, except the heating, ventilation and air conditioning part.Västvärldens energianvändning har nått oanade höjder, och ökar varje dag. Därför har energieffektivitet blivit ett hett ämne, både på liten och stor skala. Varje enskild individ har möjlighet att förbättra sin energieffektivitet och därmed sin energianvändning med märkbara skillnader, och bör agera därefter för miljöns skull. Rapporten börjar med en studie av olika regleringar och bestämmelser om energieffektivitet. Efter det kommer en litteraturstudie om vilken teknik som finns tillgänglig inom alla delar av hemmets energianvändning. Slutligen utförs en fältstudie på en lägenhet i Stockholm för att avgöra hur mycket energi som kan sparas, och vilka ekonomiska följder detta har. Resultatet visar att det i allmänhet inte är ekonomiskt hållbart att byta till den senaste energieffektiva tekniken inom hemmets apparater, utan att man får avse de miljömässiga vinsterna som incitament för dessa uppgraderingar. Ungefär 10% av den totala årliga energianvändningen kunde sparas genom att åtgärda alla apparater och funktioner i huset, utan avseende på uppvärmning och isolering.
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Jasonarson, Ivar Kristinn. "Digitalization for Energy Efficiency in Energy Intensive Industries." Thesis, KTH, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276987.
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A fourth industrial revolution (Industry 4.0) is on the horizon. It is enabled by advancements in information and communication technologies (i.e. digitalization) and concepts such as the Internet of Things and cyber-physical systems. Industry 4.0 is expected to have great impact on the manufacturing and process industries, changing how products are developed, produced and sold. However, Industry 4.0 is a novel concept and its impacts are still uncertain. An increasingly strict climate and energy agenda in Sweden is putting pressure on the industrial sector and it is, therefore, important that the sector exploits the full potential Industry 4.0 can provide for increased sustainability. This thesis examines the status of digitalization in the Swedish energy intensive industries (i.e. pulp and paper, steel, and chemical industries) and how it could impact energy efficiency in the sector. Qualitative research methods were used to carry out the study. A literature review and in-depth interviews with employees within the industries were conducted. The results show that, while digitalization is considered important for the future competitiveness of the Swedish energy intensive industries, the digital maturity of the sector is not considered high. Digital technologies can increase energy efficiency in a number of different ways (e.g. through better optimization tools, increased availability of processes and more efficient maintenance management). However, there is not a clear link between digital strategies and energy efficiency measures in the energy intensive industries in Sweden. Moreover, energy efficiency is not considered the main driver for implementing digital technologies, it is rather considered a positive side effect. To accelerate the implementation of digital technologies it is important to support further research in this area and encourage a closer cooperation between stakeholders as well as mitigating challenges such as uncertainty regarding return on investment and issues related to data security and ownership.Industrin är på väg in i en fjärde industriell revolution (Industri 4.0). Revolutionen möjliggörs av framsteg inom informations- och kommunikationsteknologier (digitalisering) och koncept som internet av saker och cyberfysiska system. Industri 4.0 förväntas ha en stor påverkan på tillverknings- och processindustrin, vilket kommer att förändra hur produkter utvecklas, produceras och säljs. Industri 4.0 är dock ett nytt koncept och dess effekter är fortfarande osäkra. I samband med att en allt strängare klimat- och energiagenda i Sverige sätter press på industrisektorn, är det viktigt att sektorn utnyttjar den fulla potentialen som Industri 4.0 kan bidrag med för en ökad hållbarhet. Det här examensarbetet analyserar det nuvarande läget för digitalisering inom de svenska energiintensiva industrierna (dvs. massa och pappers-, stål- och kemisk industrin) och hur det kan påverka energieffektiviteten i sektorn. Studien genomfördes med hjälp av kvalitativa forksningsmetoder. En litteraturstudie och fördjupade intervjuer med anställda inom branscherna genomfördes. Resultaten visar att trots att digitalisering anses vara viktig för de svenska energiintensiva industriernas framtida konkurrenskraft, anses sektorns digitala mognad inte vara hög. Digital teknik kan öka energieffektiviteten på ett antal olika sätt (t.ex. genom bättre optimeringsverktyg, ökad tillgänglighet av processer och effektivare underhållshantering). Det finns dock ingen tydlig koppling mellan digitala strategier och energieffektivitetsåtgärder i de energiintensiva industrierna i Sverige. Dessutom anses energieffektivitet inte vara den främsta drivkraften för att implementera digitala teknologier, utan anses snarare vara en positiv bieffekt. För att påskynda implementeringen av digital teknik är det viktigt att fortsätta stötta forskningen inom området och uppmuntra till ett närmare samarbete mellan olika aktörer samt bemöta utmaningar som osäkerheten kring framtida avkastningar på investeringar och frågor relaterade till datasäkerhet och ägande.
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Gibbs, Vance Scott. "State building energy efficiency determination using energy audits." Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2009m/gibbs.pdf.
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He, Ya. "Energy efficiency and financing mechanisms : the case of energy efficient lighting retrofit in hotels." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648468.
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Örn, Tomas. "Energy efficiency in heritage buildings : Conservation approaches and their impact on energy efficiency measures." Licentiate thesis, Luleå tekniska universitet, Arkitektur och vatten, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68405.
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The impeding climate change challenge urges for a reduction of energy use in the built environment. Buildings account for nearly 40% of the total energy use and about 35% of the greenhouse gas emissions in Europe. EU member states are required to improve the energy efficiency of the existing building stock, for example by sharpening building regulations and developing enforcement schemes. Since energy efficiency retrofits can affect irreplaceable values in heritage buildings, heritage buildings are often excluded from mandatory demands aiming at reducing the energy use in buildings. However, saving energy have gradually become embraced by the conservation community and heritage buildings with are seen as part of the solution. This licentiate thesis discusses the methods to identify heritage significance in a building and how the underlying theory determines different scenarios in a energy retrofitting process. The choice of conservation theory and conservation approach will affect the success the energy retrofitting process and determine how much the energy use that can be reduced. This thesis therefore suggests a framework to understand the different interpretation of the impacts that one could exert either by having an Objectivistic or Relative conservation value approach.. Based on this framework, a decision-support tool is developed to further detail the impacts of such approaches for different energy measures. Other results show that a majority of reviewed research publications focused on the operational energy in a building and only a few were concerned with energy use over the entire life- cycle of a building. These analyses are used to evaluate where most energy savings can be made, and often pinpoint weak spots in the building’s envelope or technical system. If it was mentioned at all, the influence of cultural and historical factors on energy efficiency measures as applied to heritage buildings tended to be assessed only briefly. Indeed, the majority does not describe conservation principles or even mention the methodology used – if any – for assessing or defining heritage values. Instead, researchers often show an explicit (sometimes an implicit) understanding of conservation as essentially something that is not destructive of original construction material and hence the authenticity of a building. This licentiate thesis is a compilation thesis, consisting of one separate sub-study, one literature review and an extended cover essay. The study is oriented towards a Swedish and European context, especially when it comes to climate conditions and discussions on building regulations and the theory and practice of architectural conservation. It addresses the growing research field of energy efficiency in heritage buildings and the thesis aims to contribute to an increased understanding on how the process of assessment and evaluation of heritage significance in buildings affects the making of heritage buildings more energy efficient. The main research question is: How do different approaches for assessing and evaluating heritage significance in buildings affect possible technical energy saving measures in heritage buildings?Klimatförändringarna driver utvecklingen mot att energianvändningen i den byggda miljön behöver minska. Byggnader står för nästan 40% av den totala energianvändningen och cirka 35% av utsläppen av växthusgaser i Europa. EUs medlemsländer är bundna att förbättra energieffektiviteten hos befintliga byggnader, till exempel genom att skärpa byggreglerna och utveckla handlingsplaner. Eftersom energieffektiviseringar kan påverka värden i kulturhurhistoriska byggnader, är dessa ofta undantagna från krav som syftar till att minska energianvändningen i byggnader. Energibesparing och resurshushållning har gradvis blivit omfamnad av kulturmiljösektorn och kulturhistoriska byggnader betraktas allt mer som en del av lösningen på klimatförändringarna. I licentiatavhandlingen diskuteras metoderna för att identifiera kulturhistoriska värden i en byggnad och hur den underliggande teorin påverkar olika scenarier i en energieffektiviseringprocess. Valet av bevarandeteori och bevarandestrategi påverkar framgångsfaktorn i energieffektivseringen och hur mycket energianvändningen i en kulturhistorisk byggnad kan minskas. I denna avhandling föreslås därför ett teoretiskt ramverk för att förstå effekterna av de olika kulturhistoriska bedömningar som kan göras, antingen genom att använda ett objektivistiskt eller en relativ syn på hur en en byggnads kulturhistoriska värden skapas och bäst bevaras. Utifrån detta teoretiska ramverk har ett stöd för beslutsfattande utvecklats för att ytterligare beskriva effekterna av de olika bevarandestrategiernas påverkan på implementeringen av olika energieffektiviserande åtgärder. Andra resultat visar att en majoritet av de granskade forskningspublikationerna fokuserade på den operativa energin i en byggnad och bara ett fåtal gällde energianvändning under hela livscykeln i en byggnad. Dessa analyser används för att utvärdera var de flesta energibesparingar kan göras och ofta identifiera svaga punkter i byggnadens klimatskal eller tekniska system. Om det nämndes alls tenderade inflytandet av kulturella och historiska faktorer på energieffektivitetsåtgärder som tillämpas på arvsbyggnader endast att bedömas kortfattat. Faktum är att majoriteten av de genomgångna publikationerna inte beskriver bevarandeprinciper och inte nämner den metod som används för att bedöma eller definiera kulturhistoriska värden. Istället används ofta en explicit (ibland en implicit) förståelse för bevarande som i huvudsak något som inte förstör ursprungligt material och därmed autenticitet i en byggnad. Denna licentiatavhandling består av en separat undersökning, en litteraturöversikt och en utökad kappa. Studien är inriktad på ett svenskt och europeiskt sammanhang, särskilt när det gäller klimatförhållanden och diskussioner om byggregler och teori och praktik för kulturhistoriskt bevarande av byggnader. Den är en del av det växande forskningsområdet energieffektivisering i kulturhistoriska byggnader och avhandlingen syftar till att bidra till en ökad förståelse för hur utvärderingen av kulturhistoriska värden i byggnader påverkar arbetet med att göra dem mer energieffektiva. Huvudforskningsfrågan är: Hur påverkar olika metoder för bedömning och utvärdering av kulturhistoriska värden energibesparande åtgärder i kulturhistoriska byggnader?
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Jung, Eun-Sun. "Energy efficiency in wireless networks." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2718.
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Energy is a critical resource in the design of wireless networks since wireless devices are
usually powered by batteries. Battery capacity is finite and the progress of battery technology
is very slow, with capacity expected to make little improvement in the near future.
Under these conditions, many techniques for conserving power have been proposed to increase
battery life.
In this dissertation we consider two approaches to conserving the energy consumed
by a wireless network interface. One technique is to use power saving mode, which allows
a node to power off its wireless network interface (or enter a doze state) to reduce energy
consumption. The other is to use a technique that suitably varies transmission power to
reduce energy consumption. These two techniques are closely related to theMAC (Medium
Access Control) layer.
With respect to power saving mode, we study IEEE 802.11 PSM (Power Saving Mechanism)
and propose a scheme that improves its energy efficiency. We also investigate the
interaction between power saving mode and TCP (Transport Control Protocol). As a second
approach to conserving energy, we investigate a simple power control protocol, called
BASIC, which uses the maximum transmission power for RTS-CTS and the minimum
necessary power for DATA-ACK. We identify the deficiency of BASIC, which increases
collisions and degrades network throughput, and propose a power control protocol that addresses
these problems and achieves energy savings. Since energy conservation is not an issue limited to one layer of the protocol stack, we study a cross layer design that combines
power control at the MAC layer and power aware routing at the network layer. One poweraware
routing metric is minimizing the aggregate transmission power on a path from source
to destination. This metric has been used along with BASIC-like power control under the
assumption that it can save energy, which we show to be false. Also, we show that the
power aware routing metric leads to a lower throughput. We show that using the shortest
number of hops in conjunction with BASIC-like power control conserves more energy than
power aware routing with BASIC-like power control.
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Frimodig, Love. "Energy efficiency in rotating equipment." Thesis, KTH, Marina system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101905.
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This paper reports the findings of the first stage of a study on how the efficiency of a centrifugal pump depends on the eccentricity of the impeller (rotor). The geometry of the pump is based on the ERCOFTAC centrifugal pump that has been used to validate computational fluid dynamics software with laboratory measurements. The pump is modelled using the CFD-code Comsol multi physics (tm) in order to get the pressure and velocity field. From the pressure and velocity field the efficiency and output power for the pump is calculated. The energy efficiency of the same pump with different static eccentricities is then compared, showing the effect of eccentricity To validate the CFD-model the velocity and pressure field for the pump is compared to results from another simulation of the same pump and an experiment. The comparison shows that the results are comparable and shows good agreement with experimental data. It is showed that the energy losses of the pump increase with increased static eccentricity of the impeller. The losses at 10% eccentricity are about 0.5% of the produced energy. The main contribution to the losses is the introduced asymmetry, eccentricity, of the pump, which causes an unsteady flow and also increases the total unbalance force on the rotor. It is further noted that rotor-stator interactions of the impeller and the stator blades have small influence on the energy losses. It is concluded that rotordynamic design can improve the energy efficiency of the process that the rotating equipment is involved in. Further research is suggested on whirling eccentric motion, experimental verification and more detailed simulation models.
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Reams, Charles. "Modelling energy efficiency for computation." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/244102.
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In the last decade, efficient use of energy has become a topic of global significance, touching almost every area of modern life, including computing. From mobile to desktop to server, energy efficiency concerns are now ubiquitous. However, approaches to the energy problem are often piecemeal and focus on only one area for improvement. I argue that the strands of the energy problem are inextricably entangled and cannot be solved in isolation. I offer a high-level view of the problem and, building from it, explore a selection of subproblems within the field. I approach these with various levels of formality, and demonstrate techniques to make improvements on all levels.
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Cullen, Jonathan M. "Engineering fundamentals of energy efficiency." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/225127.
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Using energy more efficiently is essential if carbon emissions are to be reduced. According to the International Energy Agency (IEA), energy efficiency improvements represent the largest and least costly savings in carbon emissions, even when compared with renewables, nuclear power and carbon capture and storage. Yet, how should future priorities be directed? Should efforts be focused on light bulbs or diesel engines, insulating houses or improving coal-fired power stations? Previous attempts to assess energy efficiency options provide a useful snapshot for directing short-term responses, but are limited to only known technologies developed under current economic conditions. Tomorrow's economic drivers are not easy to forecast, and new technical solutions often present in a disruptive manner. Fortunately, the theoretical and practical efficiency limits do not vary with time, allowingthe uncertainty of economic forecasts to be avoided and the potential of yet to be discovered efficient designs to be captured. This research aims to provide a rational basis for assessing all future developments in energy efficiency. The global fow of energy through technical devices is traced from fuels to final services, and presented as an energy map to convey visually the scale of energy use. An important distinction is made between conversion devices, which upgrade energy into more useable forms, and passive systems, from which energy is lost as low temperature heat, in exchange for final services. Theoretical efficiency limits are calculated for conversion devices using exergy analysis, and show a 89% potential reduction in energy use. Efforts should befocused on improving the efficiency of, in relative order: biomass burners, refrigeration systems, gas burners and petrol engines. For passive systems, practical utilisation limits are calculated based on engineering models, and demonstrate energy savings of 73% are achievable. Significant gains are found in technical solutions that increase the thermal insulation of building fabrics and reduce the mass of vehicles. The result of this work is a consistent basis for comparing efficiency options, that can enable future technical research and energy policy tobe directed towards the actions that will make the most difference.
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Xiao, Naiyuan. "Energy-efficiency building envelope technologies." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17697.
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In recent years, the excessive emission of greenhouse gas CO2, it causing globalwarming, already poses a serious threat to human survival. The problem catches theattention all over the world, and promoting the development of building energyefficiency. In order to the sustainable development of human beings, in 1992 theUnited Nations framework convention on climate change (UFCCC) organizationpublished the Kyoto protocol. In the Kyoto protocol, the European countriescommitted that during 2008 and 2012 they would reduce the amount of greenhouseemissions to 8% compare to 1990.[2] Building envelope technologies can helphouseholder reduce the energy consumption use in the building. Building envelopetechnologies used in the project Brogåden – Alingsås which save the energyconsumption from 204 kWh/ m2a to 95 kWh/ m2a in Sweden. While the cost just838SEK/m² or 8% of the total building costs. In China the envelope technologies usedin the project student apartment in Shandong building university save the energyconsumption about 72% compare with the old student apartments.
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Dandridge, Cyane Bemiss. "Energy efficiency in office technology." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12261.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1994.Includes bibliographical references (leaves 204-210).
This thesis, directed toward a wide variety of persons interested in energy efficiency issues with office technology, explores several issues relating to reducing energy use and improving energy efficiency of office equipment. Chapter 2 compares policies and programs in several European countries and the United States that could enhance the energy efficiency of office technology. Different programs are examined, including federal government programs where in some cases target values for power usage of office equipment have already been set. Large customer procurement programs, industry involvement, with emphasis on voluntary labeling programs, and research projects are also examined. Procedures that provide energy consumption measurements of various types of equipment are important for providing information to emerging procurement programs. Two sets of proposed test procedures for testing energy consumption of copiers, fax machines and printers are examined and compared. In Chapter 3, comparisons are made of the electrical power and energy used by computers, displays, copiers, printers and facsimile machines, both while operating and while idle. Technology options for reduced energy and power consumption and improved energy efficiency are examined. As the capability of office equipment has increased, there has been a trend toward increased electrical power requirements and energy consumption while equipment is in active operation. Computer power continues to grow rapidly. These factors will combine to exert an upward pressure for electrical power. However, some emerging technologies are lessening or in some cases reversing this trend, with little or no penalty in performance or production. The overall balance between increased service and efficiency is uncertain. Chapter 3 also examines the embodied energy of paper and office equipment. I compare it to the total energy required to produce a printed page of information, or required over the lifetime of the machine. Many difficulties were encountered in collecting and comparing data on power requirements of various machines. Procedures for testing the energy usage of office equipment are needed to make valid comparisons between machines. This thesis describes in Chapter 4, modifications to the procedure issued by the American Society for Testing and Materials (ASTM) to test energy consumption in copiers, to account for energy saver modes and double-sided copying. It also presents new procedures submitted to the ASTM committee for printers and fax machines. A fourth procedure is also presented here, one to test the energy consumption of personal computers. Typically, office equipment is not in use for much of the time it is turned on. Use of power management in office equipment can considerably decrease overall energy consumption. While energy saver modes are more prevalent in copiers, those printers that have incorporated this feature achieve more dramatic power reductions. Fax machines do not seem to utilize this technology at all, even though many have high power consumption when they are idle. How energy saving modes effect the overall energy consumption of machines is largely determined by operating profiles of the machines. The effect of operating profiles on energy usage with imaging equipment has not yet been examined. Methods of determining operating profiles of office equipment are presented in Chapter 5. A comparison is made between the energy use predicted by the ASTM procedures, energy use predicted by the ASTM procedures and actual operating profiles, and the actual energy usage of several copiers and printers. For copiers, the ASTM rated energy use per page was from 10-161 % different from the actual measured energy use per page. The use of the ASTM method with the measured operating profiles of the machine gave a 7-22% difference in energy use per page. For printers, the rated values using the ASTM method gave 61-317 % difference from the actual measured energy use per page, while using actual usage profiles with the ASTM method gave 0-6% difference. This thesis provides information on a variety of subject in the area of energy use and energy efficiency in office technology. The results provide information for emerging programs and provide a strong basis for a variety of further research.
by Cyane Bemiss Dandridge.
M.S.
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Dias, Luís Filipe. "High-efficiency electromagnetic energy-harvesting." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10180.
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Mestrado em Engenharia Eléctrónica e TelecomunicaçõesNuma época em que os avanços tecnológicos se concretizam a um ritmo frenético, verifica-se uma desproporcional evolução das capacidades das baterias, essencialmente nos equipamentos móveis de uso comum. Por outro lado aumentam os dispositivos cuja localização remota torna a manutenção de baterias algo expensiosa e por vezes insustentável, tais como as Wireless Sensor Networks (WSN) O intuito deste trabalho prende-se não só com o aumento da eficiência de sistemas de recolha de energia de radiação electromagnética da banda dos 100MHz, como também com a introdução de novos métodos úteis à a sua análise. Paralelamente é ainda proposto um sistema de iluminação alimentado por circuitos de rectificação com um enfoque mais específico e menos relacionado com as suas eficiências. Ao nível dos melhores resultados obtidos para os circuitos de alta eficiência, estes foram alcançados por um circuito rectificador série simples, com valores de eficiência experimental de _ 45% para uma potência de entrada de 5dBm, gerando uma tensão de saída de _ 1:6V . Relativamente aos circuitos desenvolvidos para o sistema de iluminação foi possível, através de um multiplicador de tensão, gerar tensões DC ligeiramente acima de 8V para uma potência de entrada de 10dBm, desta forma conseguindo alimentar uma célula de três LEDs de baixo consumo. Os resultados obtidos destinam-se não apenas a apresentar conclusões inovadoras, mas também a fornecer ferramentas adequadas a posteriores desenvolvimentos de sistemas similares, servindo desta forma como um contributo de utilidade para a comunidade científica.
At a time when technological advances happen every day, a disproportional evolution of batteries capabilities has been verified, specially for mobile devices. On the other hand the number of devices whose remote location makes battery maintenance very expensive, Wireless Sensor Networks (WSN), is increasing. The objective of this work is not only to increase the eficiency of energy harvesting systems on the frequency of 100MHz, as it is introducing new methods for it's analysis. At the same time a no-cost illumination system, fed with more specific rectification systems, with less consideration for the eficiency is proposed here. As of the best results obtained for the high eficiency circuits, these were achieved for a simple series rectifier, with eficiencies around 45% for an input power of 5dBm, thus generating output voltages of _ 1:6V . The circuits developed for the lighting system, consisting in voltage multipliers, generated output voltage values around 8V for Pin = 10dBm, that is, enough to power up a low consuming 3 Light-Emitting Diode (LED)s cell. These obtained results are destined not only to present innovative conclusions, but also to provide adequate tools for subsequent developments of similar circuits, thus serving as a contribute for the scientific community.
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Welniak, Sarah Elizabeth. "Energy efficiency in historic structures." Connect to this title online, 2009. http://etd.lib.clemson.edu/documents/1249066131/.
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MUTTILLO, MIRCO. "Energy efficiency of photovoltaic panel." Doctoral thesis, Università degli Studi dell'Aquila, 2020. http://hdl.handle.net/11697/147991.
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The need to increase the share of electricity produced from renewable resources has pushed the installation of photovoltaic systems. Solar sources in recent years have experienced strong growth both in terms of investments and installations. In fact, in 2018, solar energy had a global generation capacity of 43% compared to all other power generation technologies. In the coming years, the use of solar energy will grow rapidly, especially for use in different applications. Therefore, studying the behavior of photovoltaic panels and having a model that accurately describes their behavior is essential for the design of the system. Furthermore, increasing the efficiency of the panel in anomalous conditions such as defects, breaks or partial shading is essential. As described, the doctoral thesis is focused on increasing the efficiency of the panels, on the modeling of photovoltaic panels and on the preliminary study of the causes of loss of efficiency and power produced by finding solutions through monitoring systems and applications for reconfigurable panels. After the introduction of the photovoltaic panels, the thesis is followed by a chapter dedicated to mathematical modeling using an equivalent electric model of a photovoltaic panel. This chapter allows to describe the behavior of a photovoltaic panel under normal operating conditions and variable environmental conditions. From a preliminary review of the methods in the literature for the estimations of the parameters, a new method for the extraction of the parameters is proposed. This method starts from the data provided by the manufacturer in the datasheet of the panel and estimates the five parameters. These parameters are needed to model a panel with a single diode equivalent circuit. The proposed method was compared with some works in the literature and the error concerning the data provided by the manufacturer was evaluated A chapter follows on the modeling and simulation of photovoltaic panels through the PSpice environment. In the literature, there are various more or less complex PV Spice models. Some Spice models do not take into account irradiation and temperature variation significant for the design of electronic circuits to be connected to the photovoltaic panels. This proposed model can simulate a photovoltaic panel with temperature and solar radiation variation. With the proposed Spice model as a block is possible to simulate photovoltaic plants both at low power and high power and force partial shading conditions to understand their behavior. After the description of models for photovoltaic panels, the study on possible anomalies present in photovoltaic systems due to defects on the panels or breakages was presented. Thanks to the combination of thermography and electrical measurements for the reconstruction of the IV characteristic of the individual panels, it was possible to understand the various anomalies. Indeed, it is possible to estimate thresholds that will serve to understand if a panel is still good or a replacement is necessary. For this reason, the comparison between thermography and electrical measurements and simulations is provided. Furthermore, this study has allowed us to understand and calculate the annual efficiency loss of the panels and the percentage of voltage variation concerning the temperature not supplied by the manufacturer. The next chapter describes the study and design of an electronic system for monitoring photovoltaic panels connected to a plant. The monitoring of the single panels allows the recognition of possible anomalies and to identify the panel that is the cause. Usually, monitoring is done at the inverter or string level, which however does not allow the faulty panel to be identified in the event of anomalies. The proposed parameter extraction methods and Spice model were used for the design of the monitoring board. Finally, the last activity developed concerns the increase in power lost during partial shading.
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Alam, Ahmad Mahbubul. "Energy efficiency-spectral efficiency tradeoff in interference-limited wireless networks." Thesis, Rennes, INSA, 2017. http://www.theses.fr/2017ISAR0028/document.
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L'une des stratégies utilisée pour augmenter l'efficacité spectrale (ES) des réseaux cellulaires est de réutiliser la bande de fréquences sur des zones relativement petites. Le problème majeur dans ce cas est un plus grand niveau d'interférence, diminuant l'efficacité énergétique (EE). En plus d'une plus grande largeur de bande, la densification des réseaux (cellules de petite taille ou multi-utilisateur à entrées multiples et sortie unique, MU-EMSO), peut augmenter l'efficacité spectrale par unité de surface (ESuS). La consommation totale d'énergie des réseaux sans fil augmente en raison de la grande quantité de puissance de circuit consommée par les structures de réseau denses, réduisant l'EE. Dans cette thèse, la région EE-SE est caractérisé dans un réseau cellulaire hexagonal en considérant plusieurs facteurs de réutilisation de fréquences (FRF), ainsi que l'effet de masquage. La région EE-ESuS est étudiée avec des processus de Poisson ponctuels (PPP) pour modéliser un réseau MU-EMSO avec un précodeur à rapport signal sur fuite plus bruit (RSFB). Différentes densités de station de base (SB) et nombre d'antennes aux SB avec une consommation d'énergie statique sont considérées.Nous caractérisons d'abord la région EE-SE dans le réseau cellulaire hexagonal pour différentes FRF, avec et sans masquage. Avec le masquage en plus de la perte de propagation, la mesure de coupure ε-EE-ES est proposée pour évaluer les performances. Les courbes EE-ES présentent une grande partie linéaire, due à la consommation de puissance statique, suivie d'une forte diminution de l'EE, puisque le réseau est homogène et limité par les interférences. Les résultats montrent qu'un FRF de 1 pour les régions proches de la SB et des FRF plus élevés dans la région plus proche du bord de la cellule améliorent le point optimal du EE-ES. De plus, un meilleur compromis EE-ES peut être obtenu avec une valeur plus élevée de coupure. En outre, un FRF de 1 est le meilleur choix pour une valeur élevée de coupure en raison d'une réduction du rapport signal sur interférence plus bruit (RSIB).Les précodeurs sont utilisés en liaison descendante des réseaux cellulaires MU-EMSO à accès multiple par division spatiale (AMDS) pour améliorer le RSIB. La géométrie stochastique a été utilisée intensivement pour analyser de tels systèmes complexes. Nous obtenons une expression analytique de l'ESuS en régime asymptotique, c.-à-d. nombre d'antennes et d'utilisateurs infinis, en utilisant des résultats de matrices aléatoires et de géométrie stochastique. Les SBs et les utilisateurs sont modélisés par deux PPP indépendants et le précodage RSFB est utilisé. L'EE est dérivée d'un modèle de consommation de puissance linéaire. Les simulations de Monte Carlo montrent que les expressions analytiques sont précises même pour un nombre faible d'antennes et d'utilisateurs. De plus, les courbes d'EE-ESuS ont une grande partie linéaire avant une forte décroissante de l'EE, comme pour les réseaux hexagonaux. Les résultats montrent également que le précodeur RSFB offre de meilleurs performances que le précodeur forçage à zéro (FZ), qui est typiquement utilisé dans la literature. Les résultats numériques pour le précodeur RSFB montrent que déployer plus de SBs ou d'antennes aux BSs augmente l'ESuS, mais que le gain dépend du rapport des densités SB-utilisateurs et du nombre d'antennes lorsque la densité de l'utilisateur est fixe. L'EE augmente seulement lorsque l'augmentation de l'ESuS est plus importante que l'augmentation de la consommation d'énergie par unité de surface. D'autre part, lorsque la densité d'utilisateur augmente, l'ESuS dans la région limitée par les interférences peut être améliorée en déployant davantage de SB sans sacrifier l'EE et le débit ergodique des utilisateursOne of the used strategies to increase the spectral efficiency (SE) of cellular network is to reuse the frequency bandwidth over relatively small areas. The major issue in this case is higher interference, decreasing the energy efficiency (EE). In addition to the higher bandwidth, densification of the networks (e.g. small cells or multi-user multiple input single output, MU-MISO) potentially increases the area spectral efficiency (ASE). The total energy consumption of the wireless networks increases due to the large amount of circuit power consumed by the dense network structures, leading to the decrease of EE. In this thesis, the EE-SE achievable region is characterized in a hexagonal cellular network considering several frequency reuse factors (FRF), as well as shadowing. The EE-ASE region is also studied using Poisson point processes (PPP) to model the MU-MISO network with signal-to-leakage-and-noise ratio (SLNR) precoder. Different base station (BS) densities and different number of BS antennas with static power consumption are considered.The EE-SE region in a hexagonal cellular network for different FRF, both with and without shadowing is first characterized. When shadowing is considered in addition to the path loss, the ε-SE-EE tradeoff is proposed as an outage measure for performance evaluation. The EE-SE curves have a large linear part, due to the static power consumption, followed by a sharp decreasing EE, since the network is homogeneous and interference-limited. The results show that FRF of 1 for regions close to BS and higher FRF for regions closer to the cell edge improve the EE-SE optimal point. Moreover, better EE-SE tradeoff can be achieved with higher outage values. Besides, FRF of 1 is the best choice for very high outage value due to the significant signal-to-interference-plus-noise ratio (SINR) decrease.In downlink, precoders are used in space division multiple access (SDMA) MU-MISO cellular networks to improve the SINR. Stochastic geometry has been intensively used to analyse such a complex system. A closed-form expression for ASE in asymptotic regime, i.e. number of antennas and number of users grow to infinity, has been derived using random matrix theory and stochastic geometry. BSs and users are modeled by two independent PPP and SLNR precoder is used at BS. EE is then derived from a linear power consumption model. Monte Carlo simulations show that the analytical expressions are tight even for moderate number of antennas and users. Moreover, the EE-ASE curves have a large linear part before a sharply decreasing EE, as observed for hexagonal network. The results also show that SLNR outperforms the zero-foring (ZF) precoder, which is typically used in literature. Numerical results for SLNR show that deploying more BS or a large number of BS antennas increase ASE, but the gain depends on the BS-user density ratio and on the number of antennas when user density is fixed. EE increases only when the increase in ASE dominates the increase of the power consumption per unit area. On the other hand, when the user density increases, ASE in interference-limited region can be improved by deploying more BS without sacrificing EE and the ergodic rate of the users
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Kifleyesus, Biniam Okbaendrias. "Eneregy Management In Industries : Analysis of Energy Saving potential by Steam conedensate recovery." Thesis, Högskolan i Gävle, Energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-25090.
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When speaking about energy it means speaking about life, activity, economy, growth and environmental issues. The issue of energy has been the main article all over the world in recent years, this is due to the importance of energy to life and its impact on the environment. For example, Paris climate change meeting in 2015 is one of the recent global meeting which directly related to the energy use by nations. The meeting was mainly focused up on the restriction of greenhouse gas emission which implies that industries should think about other alternative energy resources rather than fossil fuel for positive impact on climatic change. This is one of the cases that led industries into greater competition in the global market. Industries must consider energy alternatives which is safe for the environment and by using such energy a competitive product with better quality and quantity should be produced. This challenge has motivated industries to look and study the energy that they are using currently. Studies and researches show that one of the main and most abundant energy resources that most of these industries can get is by improving the energy efficiency or managing the energy that they currently use. The main aim of this thesis is to provide Arizona chemical plant (Kraton) at Sandarne on the potential energy saving by managing their energy use. The first wisdom in energy utilization is managing and using the energy they possess efficiently. In Arizona plant at Sandarne, the product named “Pitch” (a natural viscoelastic polymer or rosin) is a fuel used as the primary energy supply for the production of steam by boilers. The steam may be utilized well but the energy in the condensate (after steam loses its latent heat) is not addressed well enough. Hence this paper has studied on how significant is the energy lost by the steam condensate is and how its recovery can be used to save energy and cost. The plant produces about an average of 11.42 ton of steam each hour in a year. This steam can be returned or fully recovered (100%) as condensate from the law of conservation of mass since only energy is lost from the steam. But the plant returns a maximum of about 3ton of condensate each hour. This amount is relatively low compared to the amount of condensate recovery possibility. Recovery possibility of condensate return showed that the plant at Sandarne can return at least 8.5 ton of condensate each hour. In comparison with the current return estimated 5.5 ton of condensate is being lost simply as waste each hour leading to about 400 SEK minimum cost loss. The calculation of cost is in minimum because the charge from water supply and condensate effluent disposal charge are not considered. In this paper only recovery from the easily recoverable steam condensate is being considered (25% of the system) which resulted in payback time of the proposed investment 1.88 years without considering the above explained charges. It is much motivating study considering the generalized approach and over simplified method. If a deeper investigation is made on the potential, it can be clearly shown that how significant the potential is in securing and sustaining energy and environmental issues. Ensuring the security and sustainability of energy which addresses the environmental issue precisely will help the plant to stay on the race of global market competition. Keywords: Energy efficiency, Boiler efficiency, Energy management, Condensate recovery,
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Dassonville, Ines. "Energy Efficiency of a French university." Thesis, KTH, Energiteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102705.
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COFELY-GDF SUEZ, a global energy services company, has signed an Energy Performance Contracting(EPC) agreement with the University Versailles Saint Quentin En Yvelines for a period of 25 years. The master thesis aims to identify all the different solutions to improve energy efficiency in the buildings and thus, achieve the objectives of the EPC: How reduce the energy consumption of the different buildings,which includes 19,000 students, by 33% for gas, by 11% for electricity and by 19% for water consumption. Another important aspect of the thesis is to manage and control CO2 emissions. The scope of the master thesis is thus to find some solutions well suited to decrease energy consumption in an university and to develop accurately one of these solutions: heat pumps. An extensive study of the different energy saving measures has been performed, based on visits onsite,feasibility studies conducting, and meetings with the university’s administration as well as geographic dataanalysis. In addition, a thorough analysis of one of these saving energy saving measures has been conducted: the installation of air source heat pumps. The effect of these air source heat pumps on energy consumption and carbon dioxide emissions has been studied. Moreover, a metering plan for energy and fluids is essential for following up the energy consumption and thus estimate the energy saving agreed bythe Energy Performance Contracting. Many obstacles have been encountered in energy efficiency of building systems and energy conservation.The technical and economical aspects must be taken into account when reducing gas, electricity and water consumption. Consequently, the energy saving strategies and measures described in the thesis have been implemented before, and therefore, are of a practical nature. The French Environmental Round Table defines the key points of government policy on ecological and sustainable development issues. At the end of it, improvement of building’s energy and environmental performance seems to be the best and preferred solution to answer this pressing situation, managed by the economic actors. Consequently, in order to face climate change, COFELY has to adapt to the new regulations and to tackle the different issues.
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Isukapatla, Kiran Kishore, and Chaitanya Sindhu Sontyana. "Energy Efficiency vs Quality of Experience." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2917.
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Over the years, there has been an exponential increase in the capabilities of networks, evolving from wired networks to wireless, and finally moving towards 4G networks. This evolution has brought forth many ways in which a user can access any service, particularly accessing the Internet. From emailing and social networking to file transferring, users are on a constant venture to exploit the advantages as much as possible. Predictions show that the demand will only increase with increasing number of mobile devices and subscribers. It becomes clearer that there will be rapid growth in the demand for more energy-efficient mobile devices. However, due to relatively slow increase in the battery technologies, the mobile users' expectations were not being met. This thesis highlights few interesting points on the energy consumptions by the most common Internet browsing tasks. It then presents the measurements of energy consumption on using various network connection technologies namely Ethernet, Wi-Fi and 3G to access the Internet. The obtained data from the experiments were then analyzed to arrive at an idea on the difference in energy consumptions across various browsing tasks and access technologies. Later, it involves a survey through which critical observations with respect to power efficiency and QoE are collected. The study concludes with a picture that would help users have an insight on the technologies that they may wish to choose to connect to the Internet. It helps manufacturers understand and consider the affect of an interface on the power consumption. It also helps researchers bring better solutions of designing the network interfaces. The aim would be to reduce the energy consumption by the product components rather than struggling to design powerful batteries to meet the increasing power demands from the network components. A wise choice of networking technologies is or what is may be required to gain better energy efficiency.
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Karlsson, Joakim. "Windows : Optical Performance and Energy Efficiency." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5147-0/.
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Prasad, Pratap Simha. "Energy efficiency in wireless sensor networks." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/PRASAD_PRATAP_30.pdf.
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Milbrandt, Robert Marcel. "Simulating energy efficiency in laboratory buildings." [Ames, Iowa : Iowa State University], 2008.
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Galimova, Veronica, and Diane Pétilon. "Building Efficiency Improvementand Renewable Energy IntegrationProject." Thesis, KTH, Uthålliga byggnadssystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127711.
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Akbari, Amir. "Energy efficiency contours for wireless networks." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548345.
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Vincent, Benjamin Thomas. "Neural energy efficiency in sensory systems." Thesis, University of Sussex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402672.
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In many biological systems, evolution has found solutions that balance function and structure with metabolic expense. This certainly seems to be the case in the energetically expensive locomotor system, and so maybe similar efficiency optimisations exist in the central nervous system which is also energy expensive. This notion is tested against three sensory coding systems which have been well characterised, these are monochromatic and chromatic sensitive neurons in the early visual system and sound sensitive neurons of the auditory system. Simple linear models are constructed to make predictions of the optimal receptive fields that balance information coding with energy efficiency. More specifically, synaptic energy efficiency is examined and is found to predict many aspects of luminance and spatiochromatic as well as auditory coding. This approach is extended from the neural level to the higher-level domain of statistical inference where organisms build models of their environment. Balancing predictive power with explanatory simplicity results in superior descriptions of the world
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Jeter, Teresa M. "A model residential energy efficiency program." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941726.
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The opportunity for reducing energy expenditures in homes has never been greater nor has the need been more pressing. Based on the current analysis of weatherization programs, millions of houses do not receive energy efficiency measures and houses that are being weatherized are not receiving the kinds of measures that generate the greatest energy savings. Many of these problems are attributed to program policies, regulations and funding limitations. Given these critical issues. The creative project is a model residential energy efficiency program. Its purpose is to serve as a guide for planning, designing, developing and implementing the kinds of residential energy efficiency programs that will maximize services and benefits. More specifically, the model will assist in the design and implementation of programs that are effective, efficient and can deliver the “right” energy measures to “any” house that needs them. A community in a small Midwestern city was selected to help demonstrate the various components of the model program.Department of Urban Planning
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Griffiths, A. J. "Energy efficiency of the foundry industry." Thesis, Cardiff University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372339.
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Pochaiya, Charernkiat. "Energy efficiency in cellular wireless networks." Thesis, University of Reading, 2018. http://centaur.reading.ac.uk/80733/.
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Energy efficiency of Long Term Evolution (LTE) cellular communication networks has become a major concern for network operators, not only to reduce the operational costs, but also to reduce their environmental effects. Within LTE cellular networks, base stations are responsible for most of the energy consumption, consuming 70-95% or more of the network power depending on the network topology, configuration, radio technology and data rates that are used. Power control is an important function in cellular wireless networks and refers to setting the output power levels of transmitters, termed eNodeB in the downlink and user equipment (UEs) in the uplink. LTE utilizes two different mechanisms for uplink power control: Open Loop Power Control (OLPC) and Closed Loop Power Control (CLPC). Uplink OLPC is performed by the UE following eNodeB configuration and can compensate for long term channel variation such as path loss and shadowing. The uplink CLPC mechanism attempts to improve power control performance by compensating fast channel variations due to multipath fading. In CLPC the eNodeB sends Transmit Power Control (TPC) commands to the UE to adjust the UE's transmit power. This thesis focuses on an Open Loop Power Control (OLPC) scheme for LTE uplink by using the Okumura-Hata propagation path loss model to set the User Equipment (UE) uplink transmit power control parameters in order to reduce the UE energy consumption. In general, the UE requires more power to connect to distant base stations than closer base stations and therefore this thesis analyses the required power levels using the Okumura-Hata propagation path loss model. Estimation of path loss is very important in initial deployment of wireless network and cell planning. This thesis analyses the Okumura-Hata propagation path loss in different receiver antenna heights (h_bs), different path loss compensation factor (α) and different eNodeB sensitivity (P_o) in urban, suburban and rural environments. The results from this analysis can be used to optimally set the UE transmit power, but also to create improved relay sections in a hybrid link in order to achieve optimum data rate transfer while maximizing battery lifetime of the UE. This work is one further step toward 'green' cellular networks.
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Nitu, Vlad-Tiberiu. "Improving energy efficiency of virtualized datacenters." Phd thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/23799/1/NITU_Vlad%20Tiberiu.pdf.
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Nowadays, many organizations choose to increasingly implement the cloud computing approach. More specifically, as customers, these organizations are outsourcing the management of their physical infrastructure to data centers (or cloud computing platforms). Energy consumption is a primary concern for datacenter (DC) management. Its cost represents about 80% of the total cost of ownership and it is estimated that in 2020, the US DCs alone will spend about $13 billion on energy bills. Generally, the datacenter servers are manufactured in such a way that they achieve high energy efficiency at high utilizations. Thereby for a low cost per computation all datacenter servers should push the utilization as high as possible. In order to fight the historically low utilization, cloud computing adopted server virtualization. The latter allows a physical server to execute multiple virtual servers (called virtual machines) in an isolated way. With virtualization, the cloud provider can pack (consolidate) the entire set of virtual machines (VMs) on a small set of physical servers and thereby, reduce the number of active servers. Even so, the datacenter servers rarely reach utilizations higher than 50% which means that they operate with sets of longterm unused resources (called 'holes'). My first contribution is a cloud management system that dynamically splits/fusions VMs such that they can better fill the holes. This solution is effective only for elastic applications, i.e. applications that can be executed and reconfigured over an arbitrary number of VMs. However the datacenter resource fragmentation stems from a more fundamental problem. Over time, cloud applications demand more and more memory but the physical servers provide more an more CPU. In nowadays datacenters, the two resources are strongly coupled since they are bounded to a physical sever. My second contribution is a practical way to decouple the CPU-memory tuple that can simply be applied to a commodity server. Thereby, the two resources can vary independently, depending on their demand. My third and my forth contribution show a practical system which exploit the second contribution. The underutilization observed on physical servers is also true for virtual machines. It has been shown that VMs consume only a small fraction of the allocated resources because the cloud customers are not able to correctly estimate the resource amount necessary for their applications. My third contribution is a system that estimates the memory consumption (i.e. the working set size) of a VM, with low overhead and high accuracy. Thereby, we can now consolidate the VMs based on their working set size (not the booked memory). However, the drawback of this approach is the risk of memory starvation. If one or multiple VMs have an sharp increase in memory demand, the physical server may run out of memory. This event is undesirable because the cloud platform is unable to provide the client with the booked memory. My fourth contribution is a system that allows a VM to use remote memory provided by a different rack server. Thereby, in the case of a peak memory demand, my system allows the VM to allocate memory on a remote physical server.
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Forssell, Henrik. "Energy Efficiency of Heterogeneous LTE Networks." Thesis, KTH, Kommunikationsteori, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169910.
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Awareness of climate change and our environment is affecting the field of mobile communications. The challenge of reducing the carbon footprint and operating expenditures, while the demand for coverage and capacity is growing exponen-tially, is driving the trend of studying energy efficiency of mobile networks. Providing services in a resource efficient way have benefits both for the operator and the environment, which is why requirements on energy performance will be a part of the specifications of future 5G networks. In long term evolution (LTE) networks, indoor small cells are deployed inlarge volume to improve performance in areas with poor macro coverage or high traffic demand. This type of network topology, that consists of several types of access nodes, is called a heterogeneous network (HetNet). In this master thesis we study the energy efficiency of various HetNet deployments in a dense urban environment. The small cells deployments investigated are pico base stations and micro distributed antenna systems. Dense and sparse deployment strategies with varying transmit powers are compared. Furthermore, we investigate the potential for energy savings by setting the small cells into a low power sleep state under certain conditions. Both short sleep periods between transmissions, called discontineous transmission (DTX), and longer sleep cycles during periods of low activity is investigated.This thesis was carried out as a project at Ericsson Systems & Technology in Kista, Stockholm 2015. To be able to evaluate the energy consumption at network level, realistic models for the power consumption of various base station types had to be implemented into a static radio network simulator. Results show good performance of the considered HetNets but at a cost ofhigher power consumption than a macro only network. For example, a pico HetNet with twice the macro capacity consume 75% more energy over one day. However, results show that with DTX and sleep modes enabled, the daily energy consumption of the same HetNets is only 30% higher than the macro only network. Therefore, the main conclusion is that energy saving techniques will be of great importance for improving capacity without increasing network energyconsumption.Medvetenhet om klimatförändringar i vår miljö påverkar även utvecklingen avmobila kommunikationssystem. Att minska utsläppen av CO2 från kommu-nikationsindustrin samt minska operatörernas kostnader samtidigt som kravenpå nätverkens kapacitet och täckning ökar är en utmaning. Denna utmaningdriver en ny trend att studera energi-effektivitet i mobila nätverk. Att levereratjänster på ett resurs-effektivt sätt är likväl lönsamt för operatörerna som förvår miljö. Detta är en anledning till att tydliga krav på nätverkens energiför-brukning nyligen har lagts till på listan över krav på framtida 5G nätverk. Bas-stationer med låg uteffekt, så kallade “small cells", är vanligt förekommande idagens Long Term Evolution (LTE) nätverk. De placeras ut i områden medantingen dålig täckning eller höga krav på data trafik. Sådana nätverk, sombestår av flera typer av access-noder, kallas för heterogena nätverk. I dettaprojekt studeras energi-effektiviteten av heterogena LTE nätverk i tätbebyggdstadsmiljö. Access-noderna som studeras är så kallade Pico-noder samt olika“distributed-antenna -system". Flera olika nätverks-topplogier undersöks samthur förändringar i access-nodernas ut-effekt påverkar energi-effektiviteten. Vi-dare studeras möjligheterna att spara energi genom att under vissa förutsät-tningar köra bas-stationer i ett läge av låg effektförbrukning. Dessa perioder kanvariera i storleksordningen av en mikrosekund varvid det kallas “discontineoustransmission", ända upp till flera timmar. De olika metoderna utvärderas medhjälp av ett statiskt simulerings-program för LTE nätverk. För att utvärderaenergiförbrukning har realistiska modeller för bas-stationernas effektförbrukningimplementerats i simulerings-programmet.
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Giraldo, Juan Sebastian Piedrahita. "Adaptable VLIW microprocessor for energy efficiency." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/147966.
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O consumo de energia tem sido uma variável cada vez mais importante nos projetos de implementação de microprocessadores nas últimas décadas. A arquitetura VLIW é um exemplo representativo desta tendência, devido ao seu design simples e desempenho competitivo, resultado da exploração do paralelismo entre instruções (ILP) em tempo de compilação. Neste trabalho, é realizada uma análise da economia de energia obtida através da adaptação da microarquitetura dos processadores VLIW de acordo com as diferentes fases dos programas executados. Primeiramente, o potencial de otimização é abordado, através da execução de um grupo de benchmarks no processador configurável ρ-vex, e estudando o impacto da largura do processador (i.e.: número de issues) na performance, consumo de energia, e área. A partir desta informação, um experimento levando em conta o caso ótimo (usando um oráculo) foi realizado com o objetivo de variar dinamicamente a largura do processador de acordo com a fase do programa, considerando duas granularidades diferentes. A economia de energia usando este tipo de adaptação pode ser de até 81,5% comparado com uma versão estática do mesmo processador executando o grupo de benchmarks MiBench. Com base nestes resultados, duas técnicas de power gating nas unidades funcionais são propostas. A primeira é baseada em lógica adicional, inserida no processador, para controlar os circuitos de power gating associados com cada unidade funcional. Mostra-se que estas unidades podem ser desabilitadas em até 63% do tempo de execução para os multiplicadores e 30% para as ALUs, com um custo em performance de 13%, em média. A segunda técnica proposta propõe uma técnica para ser usada em conjunto com o compilador para aplicar power gating nas unidades funcionais, assim como nos blocos do banco de registradores. Esta operação é realizada inserindo instruções específicas em tempo de compilação, tendo em conta a análise das probabilidades de instruções de saltos e informação dos blocos básicos, obtidos através de instrumentação de código. Utilizando este tipo de estratégia, é possível economizar até 20% em energia com perda marginal de desempenho.The development of energy efficient hardware has been a trend in microprocessor design for the last two decades. VLIW processors are a representative example, since they have a simpler design and competitive performance, due to their static ILP exploitation. In this work, we study the energy savings that could be obtained by adapting such microarchitecture according to the current program phase. First we analyze the potential of optimization, by executing a set of benchmarks on the ρ-vex configurable softcore VLIW processor, and by modifying the number of issues. With this data in hand, we develop an oracle experiment to dynamically vary the issue width of the processor according to the phase behavior, considering two different phase granularities. The potential energy savings using this policy could be as high as 81.5% when compared with the static version, executing the MiBench set. Taking into account this information, two techniques for power gating the functional units are proposed. The first approach is based on additional hardware logic to control the power gating circuitry of each Functional Unit. Our results show that these units can be put to sleep on average 63% of the execution cycles for the multipliers and 30% for the ALUs, at a performance loss of 13%. The second approach handles intelligent use of the compiler for power gating the Functional Units as well as blocks of the Register File. We do so by inserting customized instructions at compile time, based on the analysis that involves probabilities of conditional branches and basic block information obtained via dynamic profiling. By using this technique, it is possible to save up of 20% in the total energy consumption with marginal losses in performance.
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Пімоненко, Тетяна Володимирівна, Татьяна Владимировна Пимоненко, Tetiana Volodymyrivna Pimonenko, Сергій Вячеславович Лєонов, Сергей Вячеславович Леонов, Serhii Viacheslavovych Lieonov, and Y. Shaforost. "Energy efficiency gap on national economy." Thesis, Economic Laboratory for Transition Research, 2020. https://essuir.sumdu.edu.ua/handle/123456789/81065.
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The unsynchronized of the country's environmental, energy and economic policies raises the dilemma of the priority of a fundamentally new trajectory of the country's development and the achievement of the Sustainable Development Goals in the field of energy efficiency and energy saving. At the same time, reinforcing of environmental conflicts, increasing tendency of energy consumption and greenhouse gas emissions requires a primary focus on the formation of effective mechanisms for solving and energy problems and providing energy security. In this direction, the formation of a fundamentally new model of stakeholder interaction in providing the country's energy security by minimizing the existing energy efficiency gaps (mismatch between optimal and actual energy efficiency levels in the absence of opportunistic behaviour of stakeholders), modelling explicit and making energy-efficient decisions; constructive modelling of causal socio-ecological economic interdependencies in energy-efficient decision-making in the state-business-society chain. In this case, it is necessary to develop the economicmathematical model for checking the causal links between stakeholders in energy efficiency decisions, which will describe and formalize the patterns of complementary effects and risks of energy efficiency decisions to achieve a balance between optimal and current levels of energy efficiency. The authors proposed to develop the optimal and time-balanced road map of sustainable energy development of Ukraine, which will contain guidelines and criteria for decision-making by stakeholders to minimize energy efficiency gaps which will contribute to the country's energy breakthrough in the context of global development trends.
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Demianchuk, O., and A. Chaikivska. "Energy efficiency and the economic crisis." Thesis, SumyState University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45288.
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At this stage of the Ukrainian economy development the problem of energy shortages has escalated, as a result of resources of energy-intensive production, inefficient use of fuel and energy resources (FER), reducing own sources and increasing prices for imported ones. Economic growth in Ukraine depend on the amount of own available resources, potential of energy efficiency and energy intensity of leading industries.
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Gay, Alanis Leon F. "Measuring Energy Efficiency of Water Utilities." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/34231.
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Water infrastructure systems worldwide use large amounts of energy to operate. Energy efficiency efforts are relevant because even relatively small gains in efficiency have the potential to bring significant benefits to these utilities in terms of financial savings and enhanced sustainability and resiliency. In order to achieve higher efficiency levels, energy usage must be measured and controlled.
A common tool used to measure energy efficiency in water utilities and perform comparisons between utilities is metric benchmarking. Energy benchmarking scores are intended to measure how efficient water systems are among their peers, in a simple and accurate fashion. Although many different benchmarking methods are currently used, we chose to use the segregated benchmarking scores proposed by Carlson on his research report from 2007 (Carlson, 2007).
The research objective is to improve these production energy use and treatment energy use benchmarking scores by analyzing the systemâ s particular characteristics that might skew the results, such as topology, water loss and raw water quality. We propose that benchmarking metrics should be always used within a particular context for each specific utility being analyzed. A complementary score (Thermodynamic Score) was developed to provide context on how energy efficient is the utility not only compared with other utilities, but also compared with the potential maximum efficiency the utility can reach itself.
We analyzed eight utilities from Virginia to obtain production and treatment energy use benchmarking scores and also thermodynamic scores using the minimum required energy approach. Benchmarking scores were skewed in 50% of the studied utilities. This means that benchmarking scores should never be used as a black box. The thermodynamic score proved to be useful for measurement of energy efficiency of a water utility on its production phase. In addition, some utilities can detect significant financial saving opportunities using the minimum required energy analysis for production operations.Master of Science
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Fawkes, Howard. "Energy efficiency in South African industry." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/5544.
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Rault, Tifenn. "Energy-efficiency in wireless sensor networks." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2228/document.
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Dans cette thèse, nous avons proposé des solutions originales et performantes pour l’économie d’énergie dans les réseaux de capteurs sans fil (RCSF). Ces contributions s'organisent autour de deux grands axes : les réseaux de capteurs génériques et les réseaux de capteurs sans fil dédiés aux applications santé. Dans un premier temps, nous avons réalisé un état-de-l’art des mécanismes d'économie d’énergie pour les RCSF. Nous avons ensuite proposé deux solutions originales : la première optimise le déplacement d’une station de base, ainsi que la façon dont les données sont stockées dans les capteurs et routées vers le puit mobile ; la seconde optimise le déploiement de chargeurs mobiles, qui une fois dans le réseau permettent de satisfaire la demande en énergie des nœuds via la transmission d’énergie sans fil sur plusieurs sauts. Dans un second temps, nous nous sommes intéressés plus particulièrement aux applications des RCSF pour la supervision de patients à distance. Nous avons introduit une nouvelle classification des techniques économes en énergie adaptées à la spécificité de ces applications santé. Nous avons ensuite proposé une nouvelle architecture pour la supervision de patient à distance à l’aide de capteurs sans fil qui permet de prolonger la durée de vie des capteurs et de la station de base. Cette solution prend en compte l’environnement du patient et l’hétérogénéité des appareils. Nos résultats montrent que la durée de vie des réseaux de capteurs sans fil peut être étendue en utilisant les différentes stratégies proposées. L’efficacité de ces approches a été confirmée à l’aide de nombreuses expérimentations numériques et simulationsIn this thesis, we propose new strategies for energy conservation in wireless sensor networks, so that the operational time of these networks can be extended. The work can be divided into two main focus area, namely general wireless sensor networks, and healthcareoriented wearable sensor networks. In the first part of this thesis we provide a comprehensive survey of the existing energy-efficient mechanisms. Then, we propose two new solutions: the first one optimizes the displacement of a mobile base station as well as buffer usage and data routing at sensor nodes; the second one optimizes the deployment of wireless chargers in the network to satisfy the energy demand of the sensors. The second part of this thesis is dedicated to healthcare application where wearable sensors are used to remotely supervise a patient. We begin with a state-of-the-art of the energy-efficient techniques existing in the literature. We then introduce a new energy-efficient architecture that allows to optimize the lifetime of both the sensor and the base station. This is a context-aware solution that takes into consideration heterogeneous devices. Our results show that the lifetime of the sensor networks can be extended using the proposed strategies. All the results obtained are supported by numerical experiments and extensive simulations
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Osman, Niemah Izzeldin. "Energy efficiency in content delivery networks." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/7866/.
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The increasing popularity of bandwidth-intensive video Internet services has positioned Content Distribution Networks (CDNs) in the limelight as the emerging provider platforms for video delivery. The goal of CDNs is to maximise the availability of content in the network while maintaining the quality of experience expected by users. This is a challenging task due to the scattered nature of video content sources and destinations. Furthermore, the high energy consumption associated with content distribution calls for developing energy-efficient solutions able to cater for the future Internet. This thesis addresses the problem of content placement and update while considering energy consumption in CDNs. First, this work contributed a new energy-efficient caching scheme that stores the most popular content at the edge of the core network and optimises the size of cached content to minimise energy usage. It takes into account the trend of daily traffic and recommends putting inactive segments of caches in sleep-mode during off-peak hours. Our results showed that power minimisation is achieved by deploying switch-off capable caches, and the trend of active cache segments over the time of day follows the trend of traffic. Second, the study explores different content popularity distributions and determines their influence on power consumption. The distribution of content popularity dictates the resultant cache hit ratio achieved by storing a certain number of videos. Therefore, it directly influences the power consumption of the cache. The evaluation results indicated that under video services where the popularity of content is very diverse, the optimum solution is to store the few most popular videos in caches. In contrast, when video popularities are similar, the most power efficient scheme is either to cache the whole library or to avoid caching completely depending on the size of the video library. Third, this thesis contributed an evaluation of the power consumption of the network under real world TV data and considering standard and high definition TV programmes. We proposed a cache replacement algorithm based on the predictable nature of TV viewings. The time-driven proactive cache replacement algorithm replaces cache contents several times a day to minimise power consumption. The algorithm achieves major power savings on top of the power reductions introduced by caching. CDNs are expected to continue to be the backbone for Internet video applications. This work has shown that storing the right amount of popular videos in core caches reduces from 42% to 72% of network power consumption considering a range of content popularity distributions. Maintaining up-to-date cache contents reduces up to 48% and 86% of power consumption considering fixed and sleep-mode capable caches, respectively. Reducing the energy consumption of CDNs provides a valuable contribution for future green video delivery.
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Satheeskumar, Varma Vineeth. "Energy efficiency optimization in wireless networks." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112123/document.
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Le principal objectif de la thèse était d'établir un cadre d’étude des communications efficace énergétiquement en définissant et en justifiant de nouvelles mesures d'efficacité énergétique pour divers systèmes sans fils. En général, le rendement énergétique est défini comme le rapport entre le débit total et la puissance totale consommée par l'émetteur. Cette définition implique que, lorsqu’une re-transmission est autorisée (dans le cas d'une erreur sur les paquets), la maximisation de l'efficacité énergétique peut conduire directement à minimiser l'énergie dépensée lors de la transmission d'une unité d'information. Ce travail développe un cadre pour l'efficacité énergétique pour les cas généraux de contrôle de puissance dans la couche physique avec MIMO et inter-couche avec une arrivée de paquets sporadique. Des algorithmes centralisés et décentralisés pour atteindre un point de fonctionnement économe en énergie pour les systèmes à l'étude ont été proposés. Les résultats mettent en évidence le compromis entre la consommation d'énergie et les taux de date en ce qui concerne l'efficacité énergétique des réseaux sans fil. Le principal objectif de la thèse était d'établir un cadre d’étude des communications efficace énergétiquement en définissant et en justifiant de nouvelles mesures d'efficacité énergétique pour divers systèmes sans filThe main objective of the thesis was to establish a framework for energy-efficient communication by defining and justifying novel energy-efficiency metrics for various wireless systems and settings. In general, the energy-efficiency is defined as the ratio of the total data rate to the total power consumed at the transmitter. This definition implies that, when re-transmission is allowed (in the case of outage), maximizing energy-efficiency can directly lead to minimizing the energy spent in transmitting a unit of information. This work develops a framework for energy-efficiency for the general cases of power control in the physical layer with MIMO and cross-layer with a sporadic packet arrival. Both centralized and decentralized algorithms for achieving an energy-efficient working point for the systems under consideration were proposed. The results highlight the trade-off between power consumption and date rates in energy efficient wireless networks
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BURLON, FABIO. "Energy Efficiency Improvement in Professional Ovens." Doctoral thesis, Università degli Studi di Trieste, 2018. http://hdl.handle.net/11368/2920073.
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Tackling the climate change by reducing energy consumption is among the biggest,
most urgent challenges society is facing and requires a continuous efficiency improvement of thermal systems.With the aim of reducing energy consumption and improving energy efficiency of
professional appliances, this thesis is the results of the investment Electrolux Professional
Spa has made. The industrial research started with an analysis of the state of
the art of the energy standards applied to a professional oven. It continues, identifying
a new methodology for the energy efficiency evaluation of a combined oven structured
on the experimental analysis of the balance of fluxes in coming and out coming
from the oven in different cooking modalities. The new developed methodology is
based on the first principle of thermodynamics and it helped in the identification
and application of a series of technical options for improving the energy efficiency of
an oven. From the analysis is emerged that the thermal insulation and the washing
system were among the main potential energy savings improvements in the overall
efficiency. Based
on the constitutive energy conservation equations of a professional oven, a dynamic
model has been developed. It was build up in order to get a general understanding
of the best possible configurations and combinations of insulation materials for the
cavity walls. The code was developed in Matlab© and it was validated by comparison
with a set of experimental data obtained with a current production model. After the model development, the washing plant of a professional appliance was optimized
in terms of energy efficiency, water consumption, detergent and rinsing agent
consumption. During the experimental test on a prototype of the washing circuit,
a possible cavitation problem has appeared. Generally, in the hydraulic circuit
of a professional appliances, in particular in a oven, the working fluid is a solution of
water and detergent at 70 °C. The actual trend in this kind of professional appliances
is to reduce both energy consumption and time needed for cleaning process: this involves
short washing cycles conducted at low temperatures with a solution of water
and highly concentrated chemistry. High concentrated chemistry could impact on
the working conditions of the pump and on cavitation. The wide range of variables
affecting cavitation has led to the development of a laboratory rig for testing different
sizes of centrifugal pumps with aqueous solutions representative of those used in the
warewashing sector.
This test rig permits measuring pump performances at various operating conditions,
in order to obtain its characteristic curves, and also forcing cavitation to
measure its Net Positive Suction Head required (NPSHr) at different flow rates.
The pump test rig allows also testing various configurations of the pump at different
cavitation conditions, obtained by changing not only the suction pressure and
temperature of the fluid but also its properties, adding detergents and additives.
Cavitation inception can be detected measuring both the corresponding prevalence decrease and the change of vibration and noise level. A representative chemical
component present in detergents (Polyox WSR 301) has been selected and tested at
different concentrations in the rheometer in order to identify the concentration values
at which the solution switch from the diluted to the concentrated regime. It has been
also measured the influence of the chemical components on the pump characteristic
curves and the vibration level. The results are quite impressive, because with the
increasing of the concentration there is a decreasing of the pump vibrations and also
the characteristic curves at certain conditions are improved. In literature there are
no studies analyzing the impact of detergent components on pump vibration induced
by cavitation.
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AHMAD, ARSALAN. "Energy Efficiency in Optical Network Planning." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2532689.
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Telecommunications operators are continuously exploring new lternatives to up-grade their networks in order to handle the ever increasing Internet traffic demand. However, increase in bandwidth have been accompanied with the increase in power consumption which is an important subject to be addressed. For the said purpose my research is focused on developing methods of bringing energy efficiency in the core telecommunications networks. The target of this thesis is the improvement of the energy efficiency in wired telecommunication networks. Indeed, several research studies have underlined that the already huge energy consumption is destined to increase in the next years since the traffic in telecommunication networks will continue to grow constantly due to the
increasing popularity of new bandwidth-consuming applications, and the increase of population using them. This situation thus urges to find strategies that can mitigate the demand of energy in the networks. The main contributions concern the definition of algorithms and strategies that incorporate and exploit the knowledge of the network topology, the carried traffic and the power behavior of network devices to achieve energy efficiency in the network. In particular, during the three years, research work targeting the energy efficient designing of conventional fixed grid (Wavelength Division Multiplexing) WDM networks and Orthogonal Frequency Division Multiplexing (OFDM) based elastic
optical networks is being carried out. The problem is tackled using Mixed Integer Linear Programming (MILP), greedy heuristics and sophisticated meta-heuristics. Results show that an appropriate design can increase energy efficiency in fixed-grid WDM and flexible-grid elastic optical networks. The problem of power-efficient design of IP-over-WDM networks is investigated through explicitly targeting the minimization of power consumption. Results, obtained over an extensive set of scenarios and networks, indicate that both the MILP and heuristics provide solutions for power-efficient networks. Moreover, it was observed that most of the power in an IP-over-WDM network is consumed by routers and line cards, even when high power consumption of OLAs and WDM terminals is
assumed. The other topic covered during my research activity is the investigation of energy-efficient design of flexible-grid networks. The activity was mainly focused on the design of the logical layer, which is usually disregarded when dealing with flexible-grid networks. More precisely, the impact of introducing an energy-aware electronic traffic grooming in flexible-grid network design is evaluated. Two greedy heuristics for the network design are proposed, one exploiting traffic grooming, and their energy efficiency is compared. In summary, this thesis makes important contributions to the networking research community providing new methods and approaches for the definition of energy efficient networking techniques.
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Kidd, Matthew Donald. "Bicycle chain efficiency." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/1245.
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Logan, Joel Clifton. "Energy efficiency enhancements to a low energy high performance building." [Ames, Iowa : Iowa State University], 2008.
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Faki, Hisham. "Energy policy, energy efficiency and the UK electricity supply industry." Thesis, Aberystwyth University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315868.
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Nehler, Therese. "The Non-Energy Benefits of Industrial Energy Efficiency : Investments and Measures." Licentiate thesis, Linköpings universitet, Energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131831.
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Improved industrial energy efficiency is viewed as an important means in the reduction of CO2 emissions and climate change mitigation. Various energy efficiency measures for improving energy efficiency exists, but even evaluated as cost-effective, there seems to be a difference between the energy efficiency measures that theoretically could be undertaken and which measures that actually are realised. On the other hand, industrial energy efficiency measures might yield extra effects, denoted as non-energy benefits, beyond the actual energy savings or energy cost savings. Based on interviews and a questionnaire, results showed that the Swedish industrial firms studied had observed various non-energy benefits. However, few of the non-energy benefits observed were translated into monetary values and included in investment calculations. Results indicated that this non-inclusion could be explained by lack on information on how to measure and monetise the benefits, but even if not translated into monetary values, some of the non-energy benefits were sometimes used qualitatively in investment decisions. The utilisation of the benefits seemed to depend on the type and the level of quantifiability among the perceived benefits. This thesis has also explored energy efficiency measures and non-energy benefits for a specific industrial energy-using process – compressed air. A literature review on energy efficiency in relation to compressed air systems revealed a large variation in which measures that could be undertaken to improve energy efficiency. However, few publications applied a comprehensive perspective including the entire compressed air system. Few non-energy benefits of specific energy efficiency measures for compressed air systems were identified, but the study provided insights into how non-energy benefits should be studied. This thesis suggests that energy efficiency and non-energy benefits in compressed air systems should be studied on specific measure level to enable the observation of their effects. However, the studies also addressed the importance of having a systems perspective; the whole system should be regarded to understand the effects of energy efficiency measures and related non-energy benefits.
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Amendolara, Maria Grazia. "Energy efficiency retrofit. A comparative analysis of different strategies to optimise the energy efficiency of a building." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The building sector is one of the key consumers of energy in Europe; consequently, European Union has enacted several directives dealing, directly and indirectly, with energy efficiency in building aiming to reduce the buildings energy use. Hence, retrofitting of the current built environment offers significant opportunities to decrease energy consumption and greenhouse gas emissions.
Aim of this paper is to investigate the potential of energy-efficient retrofitting strategies of existing buildings. The approach is structured according to three main phases: (a) the building performance assessment at the state-of-art; (b) the analysis of results to identify the possible retrofitting strategies; (c) the investigation of potential energy saving measures.
The case study is an accommodation of the University of Milan, located in a residential area of Milan (Northern Italian city). The building behaviour is analysed to detect the most dispersant structures and the plants systems with the lowest efficiency. Afterwards, several simulations are implemented on Edilcima ® to estimate in which extent different typologies of retrofitting contribute to the whole energy performance. The global performance index in reference to non-renewable sources, i.e. the total energy consumed by the air-conditioned zones per square meter of surface every year, is used as indicator to compare the outcomes.
The results show that, with reference to the existing conditions of the case study, by coupling the insulation of the most dispersing surfaces, the replacement of less efficient plants and the installation of a rooftop photovoltaic system, it is possible to decrease the whole primary energy consumption approximately by 30.52%.
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Bhattacharjee, Suchismita. "Analytical Framework to Study Energy Efficiency Policy Portfolios across Countries/States." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/28386.
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Energy conservation and implementation of effective energy efficiency policies have become imperative to curbing the escalating consumption of energy. The imbalance in the supply and demand of a country's energy has increased the importance of implementing energy efficiency policies. Proper replication of strategic energy efficiency policies that are known to be successful in one country, along with development of new approaches, can be helpful in developing the energy policy portfolio of another country. Some OECD (Organization of Economic Cooperation and Development) countries like Denmark, Finland, France, Germany, Italy, the United Kingdom and the United States have benefited from their energy policies during the most recent energy crisis. The motivation of this research is to provide a tool for developing countries, which are still in the stage of formulating their energy efficiency policies, to compare energy efficiency policy portfolios across countries. These countries can improve their energy efficiency policy portfolios based on lessons learned from the developed countries.
The research develops a framework to compare energy efficiency policy portfolios across countries / states. Although this framework can be adopted for any type of energy policy, targeting any sector with few modifications, the current focus is on policies that target the residential building sector to reduce energy consumption. The research begins with identification of the functional domains that influence human behavior–people, economy, environment and technology–followed by identification of the factors affecting household energy consumption. It uses the four functional domains as the evaluation framework's four axes. The various factors affecting household energy consumption are positioned in the framework based on association with the functional domains. The energy efficiency policies implemented in a country are positioned in the same framework based on the pattern of diffusion of each type of policy. In addition, a prototype method is developed to identify the factors targeted by each energy efficiency policy implemented in a country. This evaluation method allows for a uniform assessment process of how energy efficiency policies target specific socio-economic factors that are known to affect energy consumption. The proposed framework will facilitate the work of policy makers and other decision makers with a powerful tool for evaluating and comparing their individual policies, or their complete portfolio of energy efficiency policies, to those from other states or countries, and to benefit from the lessons learned.Ph. D.
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Sandberg, Maria. "Efficient treatment of forest industrial wastewaters : Energy efficiency and resilience during disturbances." Doctoral thesis, Karlstads universitet, Fakulteten för teknik- och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13031.
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This work concerns the efficient treatment of wastewaters from pulp and paper mills by means of aerobic biological processes. For treatment processes there are many aspects of efficiency and the present study investigates both energy efficiency and purification efficiency during disturbances. Special focus is put on wood extractives, such as resin acids and fatty acids, since they can cause negative effects in fish and other organisms in the receiving waters. They can furthermore be toxic to microorganisms in a biological treatment plant. They also affect oxygen transfer, which is important for energy efficient aeration of aerobic biological treatment processes. This thesis includes five papers/studies and presents a strategy for efficient treatment of forest industrial wastewaters. The results should help creating resilient wastewater treatment strategies with efficient use of energy. One new strategy proposed here includes separation of extractives before the wastewater is treated biologically, and the use of the extra amount of sludge as an energy source, shifting the energy balance from negative to positive.
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Wilhelmsson, Jessica, and Signe Åkerblom. "Improving energy performance within the framework of the Energy Efficiency Directive." Thesis, KTH, Industriell ekonomi och organisation (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168738.
Full textAbstract:
Det är nödvändigt för stora företag att förstå och kunna anpassa sig till den industriella omvandling mot ett ökat fokus på energieffektivitet som sker idag. Energieffektiviseringsdirektivet som Europeiska Unionen har utfärdat har ökat fokus på att arbeta med energieffektivitet i stora företag. Vidare har den svenska regeringen infört lagen om energikartläggning i stora företag som är baserad på Energieffektiviseringsdirektivet. Dessa lagstadgade krav uppmuntrar företag att utveckla ett ledningssystem som ställer krav på genomförande av energikartläggningar samt föreslå kostnadseffektiva åtgärder. Energieffektivitet är redan en riktigdel i många företags miljöarbete dock krävs ett mer Utvecklat och systematiskt arbetssätt än det många företag redan har för att uppnå kraven i Energieffektiviseringsdirektivet och den svenska lagen. Företaget som har undersökts i denna studie är ett världsledande teknikföretag med mer än 9000 anställda i Sverige. För närvarande har de energi som en signifikant aspekt i sitt miljöarbete i enlighet med den internationella standarden för miljöledningssystem ISO14001dag utvecklar de även sitt energiarbete genom att utföra energikartläggningar för att uppfylla den nya lagstiftningen. Detta ger en mer detaljerad insikt över energianvändningen och möjliga förbättringar som kan göras, men för att säkerställa ständiga förbättringar över en längre tidsperiod krävs ytterligare åtgärder. I den här studien har det undersökts vilka åtgärder som ett stort företag måste införa för att öka energiprestandan och följa lagstiftningen. Genom en litteraturstudie som fokuserade på ledningssystem i kombination med intervjuer på det undersöka företaget, en kompletterande studie av två företag som omfattas av direktivet samt tre expertintervjuer identifierades fem nyckelfaktorer. Dessa faktorer är högsta ledningens engagemang, medvetenhet, mål, mätningar och utvärdering. En modell för att strukturera faktorerna utvecklades sedan. Vidare presenterades konkreta förslag på hur dessa faktorer ska implementeras. Genom att öka fokus på dessa nyckelfaktorer och implementera föreslagna åtgärder kommer företag öka sin energiprestanda och medvetenhet i organisationen om hur olika handlingar påverkar företagets energiprestanda.It is necessary for large companies to understand and be able to adapt to the industrial Transformation towards an increasing focus on energy efficiency, which takes place today. The Energy Efficiency Directive (EED)issued by the European Union has enlarged the focus on working with energy efficiency within large companies. Further, the Swedish government has introduced the law about energy auditing in large companies, which is based on the EED. These regulations encourage companies to develop a management system that includes requirements on conducting energy audits and propose cost Deffective measures. Energy efficiency is already an important aspect within many companies environmental work, however a more developed and systematic approach to energy efficiency than most companies already have is needed in order to fulfill the legal requirements. The Company investigated in this study is one the worlds leading technology companies with more than 9000 employees in Sweden. Currently, they have energy as a significant aspect in their environmental work according to the international management system standard ISO 14001. Today they are also developing their energy work by conducting energy audits in order to comply with the new legislation. This gives a mor detailed view of the energy use and potential improvements that can be done, but in order to ensure continual improvements over a long period of time further measures are needed. Within this study it was investigated what measures a large company needs to implement in order to increase their energy performance and comply with the legislation. By a literature review focusing on management systems as well as interviews within the Company, a complementary study with two companies covered by the EED and three expert interviews, five key factors were identified. These factors are, top management commitment, awareness, goals, measurements and evaluation. A model was then developed aligning these factors. Further, concrete proposals for action to manage these factors were presented. By!increasing focus on these key factors and implement proposed measures companies will increase their energy performance and also make the organization aware of how actions affect a company’s energy performance