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Dissertations / Theses on the topic 'Energy efficient technology'
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Flynn, David Walter. "Energy-efficient SOC design technology and methodology." Thesis, Loughborough University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479318.
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Proser, Noah. "Energy Storage: Technology for a More Efficient Grid." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cmc_theses/264.
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Energy storage technologies have the potential to revolutionize the electric grid by allowing for the integration of renewable generation while increasing the utilization and efficiency of current grid assets. These technologies include pumped hydroelectric storage, compressed air energy storage (CAES), flywheels, batteries, thermal energy storage (TES), super capacitors, and superconducting magnetic energy storage (SMES). While energy storage has been implemented in some areas, its benefits are greatly undervalued by current regulatory frameworks leading to suboptimal outcomes for grid operators, utilities, and ratepayers. Large-scale adoption of storage technologies will require regulatory frameworks that recognize the benefits of grid-scale storage across generation, and transmission and distribution. This thesis discusses the need for storage, currently available and developing storage technologies, and the present regulatory environment.
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Biswas, Avishek Ph D. Massachusetts Institute of Technology. "Energy-efficient SRAM design in 28nm FDSOI Technology." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91095.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.<br>48<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 75-81).<br>As CMOS scaling continues to sub-32nm regime, the effects of device variations become more prominent. This is very critical in SRAMs, which use very small transistor dimensions to achieve high memory density. The conventional 6T SRAM bit-cell, which provides the smallest cell-area, fails to operate at lower supply voltages (Vdd). This is due to the significant degradation of functional margins as the supply voltage is scaled down. However, Vdd scaling is crucial in reducing the energy consumption of SRAMs, which is a significant portion of the overall energy consumption in modern micro-processors. Energy savings in SRAM is particularly important for batteryoperated applications, which run from a very constrained power-budget. This thesis focuses on energy-efficient 6T SRAM design in a 28nm FDSOI technology. Significant savings in energy/access of the SRAM is achieved using two techniques: Vdd scaling and data prediction. A 200mV improvement in the minimum SRAM operating voltage (Vdd,min) is achieved by using dynamic forward body-biasing (FBB) on the NMOS devices of the bit-cell. The overhead of dynamic FBB is reduced by implementing it row-wise. Layout modifications are proposed to share the body terminals (n-wells) horizontally, along a row. Further savings in energy/access is achieved by incoporating data-prediction in the 6T read path, which reduces bitline switching. The proposed techniques are implemented for a 128Kb 6T SRAM, designed in a 28nm FDSOI technology. This thesis also presents a reconfigurable fully-integrated switched-capacitor based step-up DC-DC converter, which can be used to generate the body-bias voltage for a SRAM. 3 reconfigurable conversion ratios of 5/2, 2/1 and 3/2 are implemented in the converter. It provides a wide range of output voltage, 1.2V-2.4V, from a fixed input of 1V. The converter achieves a peak efficiency of 88%, using only on-chip MOS and MOM capacitors, for a high density implementation.<br>by Avishek Biswas.<br>S.M.
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Olgun, Ugur. "Efficient Microwave Energy Harvesting Technology and its Applications." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1348776239.
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Simmons, Brian Spencer. "Lowest cost building technology selection for energy efficient design." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45941.
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The thesis project explores the use of an optimization methodology for selecting the lowest monetary cost combinations of technologies to meet a set operational energy efficiency targets for buildings. The optimization approach, which is operated on a normative energy model, is compared with existing prescriptive methodologies for selecting technology combinations and a metric is developed for ranking their effectiveness; the E/C Ratio. The energy savings/ cost ratio is also the objective function that the optimization algorithm is set to maximize. The optimization routine is coded in to a custom MATLAB script and is used in two case studies to optimize a proto-typical Korean apartment and office building. The optimization methodology finds technology combinations that are much more cost effective than the prescriptive methodology at meeting an energy savings target and can generically be applied to other buildings given a palette of technology alternatives and the corresponding cost data.
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Campbell, Jonathan Thomas. "Energy-efficient bounded-diameter tree scatternets for bluetooth networks." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Spring2005/J%5FCampbell%5F050605.pdf.
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Ferreira, de paiva leite Thiago. "FD-SOI technology opportunities for more energy efficient asynchronous circuits." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT002/document.
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Afin de suivre le rythme effréné des évolutions des systèmes embarqués et des dispositifs portables, il s’avère aujourd’hui indispensable d’optimiser la gestion de l’énergie sans pour autant compromettre la performance et la robustesse des circuits. Dans ce contexte, cette thèse étudie de nouveaux dispositifs de gestion de l’énergie ainsi que leur mise en œuvre, en combinant deux approches: la logique asynchrone et les techniques de polarisation du substrat (Adaptive Body Biasing - ABB). Cette thèse comporte quatre contributions permettant la conception de circuits asynchrones énergétiquement plus efficaces. 1) Une unité arithmétique et logique (UAL) asynchrone quasi insensible aux délais (Quasi Delay Insensitive - QDI) a été conçue et utilisée pour mener une analyse comparative entre systèmes synchrones et asynchrones. Cette étude démontre notamment la meilleure efficacité énergétique et la plus grande robustesse des circuits asynchrones QDI, surtout lorsqu’ils fonctionnent à basse tension. 2) Une cellule standard a été spécialement développée pour mettre en œuvre nos schémas d’adaptation dynamique du substrat (ABB) qui ajustent la tension de seuil (Vth) des transistors. En outre, cette cellule s’est révélée très utile pour la détection de fautes transitoires causées par des radiations environnementales. Cette cellule est en outre un élément clé pour exploiter la polarisation du substrat, un des intérêts majeurs de la technologie FD-SOI, et d’améliorer la fiabilité du système. 3) Trois stratégies de polarisation de substrat ont été évaluées. Ces stratégies reposent sur la détection automatique de l’activité des circuits asynchrones QDI et de la polarisation de multiples domaines dans le substrat (Body Biasing Domains - BBD). De plus, une méthode pour analyser l’efficacité énergétique des stratégies de polarisation pour les circuits asynchrones QDI a également été proposée dans le cadre de cette thèse. 4) Enfin, un flot de conception de circuits numériques intégrés a été proposé et développé. Ce flot, basé sur des cellules standards, permet d’exploiter des stratégies de polarisation (ABB) avec plusieurs domaines (BBD) en utilisant la cellule standard spécialement développée. Un testchip a été conçu et fabriqué pour valider notre flot de conception et évaluer l’efficacité de la cellule proposée<br>Keeping the fast evolving pace of embedded systems of portable devices require ameliorations of power management techniques, without compromising the circuit performance and robustness. In this context, this thesis studies novel energy management schemes, and how to implement them, by using two main design approaches: asynchronous logic and adaptive body biasing (ABB) techniques. Four main contributions have been done, thus enabling the design of more energy efficient asynchronous circuits. 1) We contributed with the design of a Quasi-delay Insensitive (QDI) asynchronous ALU architecture, used in a comparative analysis of asynchronous versus synchronous systems. This first study has demonstrated the energy efficiency and robustness of QDI circuits, especially if operating at low power supply (Vdd ). 2) We proposed a new body built-in cell for implementing ABB schemes by tuning the circuit threshold voltage (Vth) on-the-fly; and detecting short-duration and long-duration transient faults (TF) caused by environmental radiation. The proposed cell is a key building block to fully benefit from body biasing features of the FD-SOI technology while enhancing system’s reliability. 3) We assessed three different ABB strategies - based on automatic activity detection and multiple body-biasing domains (BBDs) - for QDI asynchronous circuits. Furthermore, a methodology for analyzing energy efficiency of ABB strategies in QDI asynchronous circuits is also proposed in this work. 4) We developed a standard cell-based IC design flow to apply ABB strategies with multiple BBDs by using the proposed body built-in cells. A testchip has been designed and fabricated to validate the developed design flow and the efficacy of the body built-in cell
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Luco, Nicolas, and Keren Zhu. "Energy efficient cornering : Simulation and verification." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234837.
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The purpose of this master thesis is to study the energy efficiency of a vehicle when it is cornering. To achieve this, a Simulink model was built from a simple basic bicycle model and theoretically validated. This model was then analysed and successively improved by adding velocity and yaw moment control. A study of the vehicle model behaviour by changing parameters such as cornering stiffness and centre of gravity position was the nconducted. The traction force needed for a constant radius was calculated and methods such as torque vectoring have been tested using the model to obtain the lowest traction force. The model was compared with different vehicle types and further validated by comparing the simulation results with experimental data acquired from a field test. The rolling resistance and aerodynamic resistance were taken into account when the model was validated with the experimental data and the result suggest that by distributing the required traction force (using torque vectoring between inner and outer driven wheels) the energy efficiency could be improved by 10%. This report ends with recommendations for future work.
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Onwunta, Onwunta Emea Kalu. "Enhanced energy-efficient parallel pumping using variable speed drive (VSD) technology." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2198.
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Thesis (MTech(Electrical Engineering))--Cape Peninsula University of Technology, 2011.<br>Global economic meltdown appears to be a new phenomenon in this 21 st century because
worldwide poor financial situation seemed forgotten after the Great Depression of the 1930s.
However, energy crisis has been a common worldwide issue and challenge since the October
1973 war in the Middle East which triggered the first of two waves of energy-price increases
in the 1970s. That event catapulted the debate about energy and conservation, from its
obscure beginnings, in academic and policy circles to sudden public prominence. The recent
co-incidence of South Africa's energy crisis with the global financial crisis was a double
tragedy. The main reason for the 2007 to 2008 energy crisis in South Africa was the
imbalance between electricity supply and demand
Globally about 40% of industrial electricity is consumed by Electric Motor-Driven Systems
(EMDS) and South African estimates are around 60%. Pumping systems are crucial industrial
EMDS and their energy demand ranges from 25% to 50% of the energy usage in certain
industrial plant operations. In South Africa, an estimated 15% of generated electrical power is
consumed by pumping systems.
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Lagerhult, Christopher. "Smartphone CPU : An Energy efficient alternative to the GPU." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-397426.
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Linnaus, Betty May 1929. "Energy efficient window design and technology applicable for residences of the Southwest." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/278504.
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Windows are an essential design element of desert homes that provide a view, light, ventilation, egress and filter the environment. Windows may account for 10 to 25 percent undesirable heat loss or gain to interiors. All desert dwellers can save energy and money by becoming educated in basic principles of solar benefits and user management and control. People relocating from other climates often do not understand window design strategies that ameliorate the extreme desert climate. The design strategies and technology necessary for control is presented in this thesis. This thesis presents current window technology and proven interior and exterior window shading design strategies that save energy yet maintain a pleasant visual and physically healthy interior comfort. Architects, interior designers and residents of the southwest will find this information useful as a decision base for specification of energy efficient windows and design.
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Vangal, Sriram. "Performance and Energy Efficient Network-on-Chip Architectures." Doctoral thesis, Linköpings universitet, Institutionen för systemteknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11439.
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The scaling of MOS transistors into the nanometer regime opens the possibility for creating large Network-on-Chip (NoC) architectures containing hundreds of integrated processing elements with on-chip communication. NoC architectures, with structured on-chip networks are emerging as a scalable and modular solution to global communications within large systems-on-chip. NoCs mitigate the emerging wire-delay problem and addresses the need for substantial interconnect bandwidth by replacing today’s shared buses with packet-switched router networks. With on-chip communication consuming a significant portion of the chip power and area budgets, there is a compelling need for compact, low power routers. While applications dictate the choice of the compute core, the advent of multimedia applications, such as three-dimensional (3D) graphics and signal processing, places stronger demands for self-contained, low-latency floating-point processors with increased throughput. This work demonstrates that a computational fabric built using optimized building blocks can provide high levels of performance in an energy efficient manner. The thesis details an integrated 80- Tile NoC architecture implemented in a 65-nm process technology. The prototype is designed to deliver over 1.0TFLOPS of performance while dissipating less than 100W. This thesis first presents a six-port four-lane 57 GB/s non-blocking router core based on wormhole switching. The router features double-pumped crossbar channels and destinationaware channel drivers that dynamically configure based on the current packet destination. This enables 45% reduction in crossbar channel area, 23% overall router area, up to 3.8X reduction in peak channel power, and 7.2% improvement in average channel power. In a 150-nm sixmetal CMOS process, the 12.2 mm2 router contains 1.9-million transistors and operates at 1 GHz at 1.2 V supply. We next describe a new pipelined single-precision floating-point multiply accumulator core (FPMAC) featuring a single-cycle accumulation loop using base 32 and internal carry-save arithmetic, with delayed addition techniques. A combination of algorithmic, logic and circuit techniques enable multiply-accumulate operations at speeds exceeding 3GHz, with singlecycle throughput. This approach reduces the latency of dependent FPMAC instructions and enables a sustained multiply-add result (2FLOPS) every cycle. The optimizations allow removal of the costly normalization step from the critical accumulation loop and conditionally powered down using dynamic sleep transistors on long accumulate operations, saving active and leakage power. In a 90-nm seven-metal dual-VT CMOS process, the 2 mm2 custom design contains 230-K transistors. Silicon achieves 6.2-GFLOPS of performance while dissipating 1.2 W at 3.1 GHz, 1.3 V supply. We finally present the industry's first single-chip programmable teraFLOPS processor. The NoC architecture contains 80 tiles arranged as an 8×10 2D array of floating-point cores and packet-switched routers, both designed to operate at 4 GHz. Each tile has two pipelined singleprecision FPMAC units which feature a single-cycle accumulation loop for high throughput. The five-port router combines 100 GB/s of raw bandwidth with low fall-through latency under 1ns. The on-chip 2D mesh network provides a bisection bandwidth of 2 Tera-bits/s. The 15-FO4 design employs mesochronous clocking, fine-grained clock gating, dynamic sleep transistors, and body-bias techniques. In a 65-nm eight-metal CMOS process, the 275 mm2 custom design contains 100-M transistors. The fully functional first silicon achieves over 1.0TFLOPS of performance on a range of benchmarks while dissipating 97 W at 4.27 GHz and 1.07-V supply. It is clear that realization of successful NoC designs require well balanced decisions at all levels: architecture, logic, circuit and physical design. Our results demonstrate that the NoC architecture successfully delivers on its promise of greater integration, high performance, good scalability and high energy efficiency.
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Lövgren, Simon. "Simulating Energy-Efficient Hardware The Software Out-of-order Processor." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-332801.
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The modern trends for technology scaling are not extremely bright. The cost of transistors have leveled off recently, effectively halting the ability to put additional transistors on a chip for the same price. In addition, Dennard Scaling, what has allowed for switching additional transistors whilst scaling to smaller nodes isslowing significantly. This thesis, with focus on the hardware, proposes anenhanced stall-on-use in-order core hardware/software co-design which improves performance and energy efficiency by allowing out-of-program-order executionthrough allowing the hardware and software to communicate with one another --allowing the hardware to make dynamic decisions on how to direct execution flowto expose additional memory- and instruction level parallelism.The results are very promising where we see an increase in both performance (upto 3.7x speedup) and energy efficiency (up to 59% increase). While additional worki is needed to evaluate the extent of the benefits across a wide range of applications, SWOOP looks to be a good option for energy efficiency without compromisingperformance for memory-bound applications with MLP.
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Danestig, Maria. "Efficient heat supply and use from an energy-system and climate perspective." Doctoral thesis, Linköpings universitet, Energisystem, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17219.
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The aim of this thesis is to illustrate whether the heat demand in district heating systems can be seen as a resource that enables efficient energy utilization, how this can be achieved and to discuss consequences of this assumption. Based on the answers to posed research questions and on the studies included in this thesis, it is concluded that the hypothesis “A common system approach for energy supply and heat demand will show climate and economic efficient solutions” is true. In cold-climate countries, energy for heating of buildings is essential and heating options that interplay with the power system through electricity use or generation have potential for efficiency improvements. In Sweden, district heating is used extensively, especially in large buildings but to a growing extent also for small houses. Some industrial heat loads and absorption cooling can complement space heating demand so that the production resources may be more evenly utilised during the seasons of the year. Rising electricity prices in recent years cause problems for the extensive use of electric heating in Sweden and further switching to district heating should be a possible option. To be economically favourable, district-heating systems require a certain heat load density. New low-energy houses and energy-efficiency measures in existing buildings decrease the heat demand in buildings and, thus, in district heating systems. Optimisation models have been used in several studies of large, complex energy systems. Such models allow scenarios with changing policy instruments and changed consumer behaviour to be analysed. Energy efficiency measures as well as good conditions for efficient electricity generation, which can replace old, inefficient plants, are needed to reduce carbon dioxide emissions from the energy sector. Results when having a European energy perspective to studies of changes in Sweden differ from when having for example a Swedish energy system perspective The effects on global carbon dioxide emissions, when studying combined heat and power electricity generation in Sweden, are greater than it is on local emissions.<br>Eftersom höjda elpriser under senare år orsakar problem för den stora användningen av elvärme, kommer ytterligare konvertering till fjärrvärme att vara ett möjligt alternativ. För att vara ekonomiskt fördelaktigt kräver fjärrvärme en viss värmetäthet. Nya lågenergihus och energieffektiviseringsåtgärder i befintliga byggnader minskar värmebehovet i byggnaderna och då även i fjärrvärmesystemen.Syftet med denna avhandling är att visa om värmebehovet i fjärrvärmesystem kan betraktas som en resurs som möjliggör ett effektivt energiutnyttjande, hur detta i så fall kan uppnås och att diskutera följderna av att göra ett sådant antagande. Baserat på svaren på ställda forskningsfrågor och studier som genomförts har hypotesen som lyder; En gemensam systemsyn för både tillförsel och användning av energi för uppvärmningsändamål leder till ekonomiskt såväl som ur klimatsynpunkt effektiva lösningar, visat sig stämma. I länder med kallt klimat är energi för uppvärmning av byggnader viktigt och uppvärmningsalternativ som samverkar med elsystemet genom elanvändning eller elproduktion har potential för effektivitetsförbättringar. I Sverige är fjärrvärmeanvändningen utbredd, speciellt i större byggnader men användningen ökar också i småhus. Vissa industriella värmelaster och absorptionskyla kan fungera som komplement till andra värmebehov i fjärrvärmesystem så att produktionsresurser kan användas mer jämnt fördelat över året. Optimeringsmodeller har använts i flera studier för stora, komplexa energisystem. I dessa kan scenarier med olika styrmedel och förändrad energianvändning analyseras. Nya användningsområden för spillvärme, som att använda värme till absorptionskyla och att växla från olja och el till fjärrvärme i industriella processer kan också studeras. Energieffektiviseringsåtgärder såväl som bra förutsättningar för effektiv elproduktion, som kan ersätta gamla ineffektiva anläggningar behövs för att minska koldioxidutsläppen från energisektorn. Resultaten då ett europeiskt energisystemperspektiv använts, för att studera förändringar i Sverige, skiljer sig från när endast ett svenskt systemperspektiv använts. Påverkan på globala koldioxidutsläpp, då elproduktion från kraftvärme i Sverige studeras, är större än vad påverkan på lokala utsläpp är.
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Aquino, Eddie Villanueva. "PREDICTING BUILDING ENERGY PERFORMANCE: LEVERAGING BIM CONTENT FOR ENERGY EFFICIENT BUILDINGS." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1077.
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Reducing and managing the environmental impacts of building structures has become a priority of building stakeholders and within the architecture, engineering and construction (AEC) community; although, conflicting approaches and methods to combat the issues are present. For example, green building standards are widespread throughout the world; however each one has its own characteristics and consequently its own specific requirements. While all have proven to be effective rating systems and have similar requirements, the distinguishing characteristic that separates them is their treatment of performance and prescriptive metrics. The feature they all severely lack or currently limit is the inclusion of strict engineering evaluation through energy simulations; hence, the reason why they fail to offer procedural steps to meet performance metrics. How can design professionals design energy efficient buildings with such constraints? Fortunately, advances in technology have allowed design professionals access to content found in Building Information Modeling (BIM). However, extracting pertinent information for specific use in energy analysis is problematic because BIM software currently available is filled with interoperability issues when placed in external software for energy analysis and energy analysis software itself is created with many assumptions that affect the tabulated energy results.
This research investigates current building rating systems, determines how current professionals meet energy requirements, and prove that it is possible to create an add-on feature to Autodesk Revit that will allow design professionals to extract the needed information to meet energy goals with actual prescribed methods of mechanical systems selection and evaluation.
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Aslam, Ahmad Moeed. "Energy Efficient Analysis for WCDMA/ 3G Homogeneous and Heterogeneous Deployments in Indoor Environment." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-90809.
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In near future, the cellular traffic will increase rapidly with majority of the increase coming from Indoor traffic. To cope up with the ever increasing demand, more Base Stations are being deployed in limited areas, which can increase the capacity but will also be responsible for increased energy consumption. Since power is a valuable commodity today both economical and environmental wise, energy efficient deployment along with capacity improvement is crucial for both incumbent and new telecom operators. The objective of this Thesis is to evaluate Power consumption and Capacity for Indoor users, both in Homogeneous and Heterogeneous infra structure cases for the 3G WCDMA/UMTS technology. The comparison is done for Uniform and Non-Uniform Traffic Distributions. In homogeneous case, results indicate that there is a tradeoff between Area Power Consumption, APC and Area Spectral Efficiency, ASE. Large Macro Base Stations covering a limited Indoor Area use less APC but provides low ASE. Small Micro Base Stations which cover the same Indoor Area consumes little more APC then Macro BS but increases the ASE manifold. In Heterogeneous case results suggest that Heterogeneous Networks (HETNET) cases enhance the Area Throughput significantly with a small increase in Area Power Consumption. MACRO+10WLAN 1is the best HETNET case in both Uniform and Non-Uniform Traffic with up to 40% Energy savings and higher data/user compared to MACRO Only deployment. The traffic patterns, number of active users in a cell and Inter Site Distances between Base Stations strongly influence the energy saving and capacity enhancements.
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Sciullo, Luca. "Energy-efficient wireless sensor networks via scheduling algorithm and radio Wake-up technology." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14539/.
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One of the most important requirements for wireless sensor networks (WSNs) is the
energy efficiency, since sensors are usually fed by a battery that cannot be replaced
or recharged. Radio wake-up - the technology that lets a sensor completely turn
off and be reactivated by converting the electromagnetic field of radio waves into
energy - is now one of the most emergent strategies in the design of wireless sensor
networks. This work presents Scheduled on Demand Radio WakeUp (SORW), a
flexible scheduler designed for a wireless sensor network where duty cycling strategy
and radio wake-up technology are combined in order to optimize the network
lifetime. In particular, it tries to keep sensors sleeping as much as possible, still
guaranteeing a minimum number of detections per unit of time. Performances
of SORW are provided through the use of OMNet++ simulator and compared
to results obtained by other basic approaches. Results show that with SORW it
is possible to reach a theoretical lifetime of several years, compared to simpler
schedulers that only reach days of activity of the network.
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Chan, Wai Sang Samuel. "An energy efficient approach for radon management in a HVAC environment : executive summary." Thesis, University of Warwick, 2000. http://wrap.warwick.ac.uk/2705/.
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Radioactive radon gas, after being released from rocks, soils and building structures, can pose a significant health threat to the building occupants. This is of particular concern in tight HVAC (Heating, Ventilating and Air-Conditioning) serviced buildings where there is re-circulating air with limited fresh air intake. A thorough survey was initiated at the Hong Kong University of Science and Technology (HKUST) in 1996 and results indicate a radon average concentration of 107 Bq/m3, which is approximately 50% of the World Health Organisation's (WHO) recommended standard (200 Bq/m3). About 10% of the measurements were in excess of this WHO limit, while 46% of the samples also showed average peak radon concentrations (264 Bq/m3) in excess of this WHO limit. To overcome these elevated indoor radon concentrations, their characteristics at HKUST was studied. Radon level was found to increase linearly as a function of the length of the HVAC shut off period, and decrease exponentially upon system resumption. Radon level predictive models were developed after a series of room chamber experiments with modification factors defined to account for the indoor sinks in an effort to enhance the accuracy and applicability of the models. Following a campus-wide energy audit, two energy efficient radon management approaches were derived from the predictive models and were subsequently integrated into the existing HKUST operations. The first was defined as an Active Radon Control Approach (ARCA), where HVAC operation schedules were modified to yield an energy saving potential of around HK$2.7 Million a year. ARCA is optimised to reduce the radon dose to the HKUST occupants following the radiation protection principle of "As Low as Reasonably Achievable (ALARA)", and with considerations of economical and operational constraints. The other was a Passive Radon Control Approach (PRCA) using Polyurethane-based (P-u) paint to cover building material surfaces to reduce the radon emission.
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Sørnes, Kari. "Heating and Ventilation of Highly Energy Efficient Residential Buildings: Environmental Assessment of Technology Alternatives." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13635.
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The aim of this study was to determine the level of environmental impact and primary energy resulting from demands placed on residential ventilation and heating systems; a conventional residential house built to the 2007 Norwegian building code with a standard heating system was compared against three technology scenarios used in a passive house of the equivalent size. Both houses have wooden framework and cladding and are projected by the Norwegian building company Norbohus. An economical evaluation of the heating systems was also done. The alternative heating option for the conventional house, Stord TEK 07, was based on current Norwegian energy consumption patterns; a combination of electricity and firewood is used to meet heating demand. This heating mix was also modeled as an option for the heating requirements of the passive house, named Stord Passive S1. Additionally, a solar collector system (Stord Passive S2) and an air-to-water heat pump (Stord Passive S3) were modeled for the passive house. Finally, a balanced mechanical ventilation system was evaluated for both buildings. The life-cycle assessment method used was the ReCiPe method and the electricity used in the operation phase was based on the Nordic electricity mix.The results of this study indicate that Stord TEK 07 has the largest emission output in relation to output of CO2-eq, presented in the impact category “Climate change”. From a life-cycle perspective, the heating system requirements of a Stord TEK 07 house are 47.5 and 45 percent higher than the renewable energy solutions of passive house scenarios S2 and S3, respectively. Total life-cycle primary energy requirements in the Stord TEK 07 house were almost twice that of the renewable solutions in the passive house. Using the Norwegian standard heating system of Stord TEK 07 in a passive house as was done in Stord Passive S1, also results in a large improvement; output of CO2-eq and use of primary energy was reduced by 34-35 percent. Stord TEK 07 has also the highest emission output in most of the other impact categories and the largest present value costs, when building constructing costs are excluded. The heat pump solution, Stord Passive S3, has the lowest impact in most categories; however, the solar collector system Stord Passive S2, had lower output of CO2-eq. Stord Passive S2 has also lower present value costs then the air-water heat pump Stord Passive S3.A balanced ventilation system with 80 percent heat recovery was studied for both the houses. The benefit of heat recovery is recognizable in all the impact categories considered. The energy consumption and potential harmful emissions resulting from the electrical energy used by fans during the life cycle far exceed the environmental impacts that result from manufacture and transportation of the ventilation unit. The study revealed that the heat-recovery system must have efficiency greater than 15 percent to achieve reduction concerning output of CO2-eq and use of primary energy for Stord TEK 07; this requirement increases to 42 percent in houses built to the passive house standard house, Stord Passive.
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Saleh, Ahmed. "Enhancement of the IEEE 802.15.4 standard by energy efficient cluster scheduling." Thesis, University of Huddersfield, 2015. http://eprints.hud.ac.uk/id/eprint/28530/.
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The IEEE 802.15.4 network is gaining popularity due to its wide range of application in Industries and day to day life. Energy Conservation in IEEE 802.15.4 nodes is always a concern for the designers as the life time of a network depends mainly on minimizing the energy consumption in the nodes. In ZigBee cluster-tree network, the existing literature does not provide combined solution for co-channel interference and power efficient scheduling. In addition, the technique that prevents network collision has not been provided. Delay and reliability issues are not addressed in the QoS-aware routing. Congestion is one of the major challenges in IEEE 802.15.4 Network. This network also has issues in admitting real time flows. The aim of the present research is to overcome the issues mentioned above by designing Energy Efficient Cluster Scheduling and Interference Mitigation, QoS Aware Inter-Cluster Routing Protocol and Adaptive Data Rate Control for Clustered Architecture for IEEE 802.15.4 Networks. To overcome the issue of Energy efficiency and network collision energy efficient cluster scheduling and interference mitigation for IEEE 802.15.4 Network is proposed. It uses a time division cluster scheduling technique that offers energy efficiency in the cluster-tree network. In addition, an interference mitigation technique is demonstrated which detects and mitigates the channel interference based on packet-error detection and repeated channel-handoff command transmission. For the issues of delay and reliability in cluster network, QoS aware intercluster routing protocol for IEEE 802.15.4 Networks is proposed. It consists of some modules like reliability module, packet classifier, hello protocol module, routing service module. Using the Packet classifier, the packets are classified into the data and hello packets. The data packets are classified based on the priority. Neighbour table is constructed to maintain the information of neighbour nodes reliabilities by Hello protocol module. Moreover, routing table is built using the routing service module. The delay in the route is controlled by delay metrics, which is a sum of queuing delay and transmission delay. For the issues of congestion and admit real-time flows an Adaptive data rate control for clustered architecture in IEEE 802.15.4 Networks is proposed. A network device is designed to regulate its data rate adaptively using the feedback message i.e. Congestion Notification Field (CNF) in beacon frame received from the receiver side. The network device controls or changes its data rate based on CNF value. Along with this scalability is considered by modifying encoding parameters using Particle Swarm Optimization (PSO) to balance the target output rate for supporting high data rate. Simulation results show that the proposed techniques significantly reduce the energy consumption by 17% and the network collision, enhance the performance, mitigate the effect of congestion, and admit real-time flows.
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DiTomaso, Dominic F. "Improving Energy Efficiency of Network-on-Chips Using Emerging Wireless Technology and Router Optimizations." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1337627400.
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Vupparige, Vijaykumar Sanjana. "A Cost-Efficient Bluetooth Low Energy Based Indoor Positioning System for IoT Applications." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-162208.
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The indoor positioning system is a series of networking systems used to monitor/locate objects at indoor area as opposed that of GPS which does the same at outdoor. The increase in the popularity of the Internet of Things made the demand for Bluetooth Low Energy technology more and more essential due to their compatibility in the smartphones which makes it to access easier. The BLE’s reliable signal and accuracy in calculating the distance has a cutting edge on others in IPS. In this thesis, the Bluetooth Low Energy indoor positioning system was designed and implemented in the office area, and the positionofIoTdevicesweremonitored. OntheIoTdevices,thebeaconswereplaced. And thesebeaconswerecoveringtheofficearea. Thereceiver,smartphoneinourcase,recorded theReceivedSignalStrengthIndicationofthetransmittedsignalsfromthebeaconswithin the range of the signal and stored the collected data in a database. Two experiments have beenconducted. Oneisforbeaconsthatarestationaryandonethatismoving. Toevaluate these experiments, a few tests were performed to predict the position of beacons based on therecordedreceivedsignalstrength’s. Inthecaseofstationarybeacons, itoffersaccuracy range from 1 m to 5 m, and 3 m to 9.5 m in anticipating the position of each beacon in the case of moving beacon. This methodology was a mixture of fingerprinting and an algorithm of multilateration. Finally, the experiments show that the algorithm used provides the most accurate indoor position using BLE beacons that can be monitored through an Android-based application in real-time.
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Khan, Waqar. "Methodology for estimating thermal performance of buildings for better planning and energy efficient investments." Thesis, KTH, Hållbara byggnader, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284686.
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This master thesis aims to find a method to separate the household-electricity usage fromheating-electricity and to estimate the thermal performance of buildings using the datasetavailable. The dataset includes electricity consumption of buildings, number of occupants, typeof heating system, climate data (temperature, wind speed etc.) which would be used toestimate the thermal performance of the single-family dwellings. The data set comprises ofhourly data of total electric consumption for those buildings that do not have solar photovoltaicsystem. For households that do have solar PV systems, it is gross PV production, sold and boughtelectricity (hourly based).The challenge in this study was developing a dynamic data driven model that could be applied toa large building dataset. Each building is located in a different climate zone, have a different size,number of inhabitants, and a different type of heating system. The buildings were thus analyzedaccording to the climate zone they were located in. The model gets building id from the userand locates other buildings that are situated in the same climate zone. It then develops energysignature for all these buildings and disintegrates the total consumption into base load, spaceheating load and intermittent load.The model evaluated 162 buildings, out of which 100 buildings had error in the data (all of theenergy consumption values were 0). The 62 buildings left were analyzed, and some buildingsshowed good results whereas some showed strange and absurd results. Overall, the model findsgood results for 45% of the buildings (28 out of 62) whereas the rest of the buildings (34 out of62) show bad results due to error in data such as missing hourly electricity consumption values,cooling load and the behavior of the power meter.The overall heat loss coefficient of the building is found by using regression analysis on thepower signature curve. The slope of the regression line gives the overall heat loss coefficient ofthe building which is a representation of the sum of transmission and ventilation losses and is animportant energy performance characteristic of a building. By comparing the value of heat losscoefficient obtained from the model to the theoretical value of heat loss coefficient calculated,we can see that when data quality is good the model calculates a good estimate of the heat losscoefficient.The results show that the data analysis and machine learning techniques can provide valuableinsights for the building stock. The thermal performance can be evaluated by developing modelssuch as energy signature to estimate overall heat loss factor which has big importance for theenergy performance. These insights can help to understand how the energy efficiency can beimproved in buildings. The overall heat loss factor can be used to find the U-value of the buildingwhich is also an important indicator of the thermal performance of the building.
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Tervo, O. (Oskari). "Transceiver optimization for energy-efficient multiantenna cellular networks." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526219356.
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Abstract This thesis focuses on the timely problem of energy-efficient transmission for wireless multiantenna cellular systems. The emphasis is on transmit beamforming (BF) and active antenna set optimization to maximize the network-wide energy efficiency (EE) metric, i.e., the number of transmitted bits per energy unit. The fundamental novelty of EE optimization is that it incorporates the transceivers' processing power in addition to the actual transmit power in the BF design. The key features of the thesis are that it focuses on sophisticated power consumption models (PCMs), giving useful insights into the EE of current cellular systems in particular, and provides mathematical tools for EE optimization in future wireless networks generally. The BF problem is first studied in a multiuser multiple-input single-output system by using a PCM scaling with transmit power and the number of active radio frequency (RF) chains. To find the best performance, a globally optimal solution based on a branch-reduce-and-bound (BRB) method is proposed, and two efficient designs based on zero-forcing and successive convex approximation (SCA) are derived for practical applications. Next, joint BF and antenna selection (JBAS) is studied, which can switch off some RF chains for further EE improvements. An optimal BRB method and efficient SCA-based algorithms exploiting continuous relaxation (CR) or sparse BF are proposed to solve the resulting mixed-Boolean nonconvex problem (MBNP). In a multi-cell system, energy-efficient coordinated BF is explored under two optimization targets: 1) the network EE maximization and 2) the weighted sum EEmax (WsumEEmax). A more sophisticated PCM scaling also with the data rate and the associated computational complexity is assumed. The SCA-based methods are derived to solve these problems in a centralized manner, and distributed algorithms relying only on the local channel state information and limited backhaul signaling are then proposed. The WsumEEmax problem is solved using SCA combined with an alternating direction method of multipliers, and iterative closed-form algorithms having easily derivable computational complexity are developed to solve both problems. The work is subsequently extended to a multi-cell multigroup multicasting system, where user groups request multicasting data. For the MBNP, a modeling method to improve the performance of the SCA for solving the CR is proposed, aiming at encouraging the relaxed Boolean variables to converge at the binary values. A second approach based on sparse BF, which introduces no Boolean variables, is also derived. The methods are then modified to solve the EE and sum rate trade-off problem. Finally, the BF design with multiantenna receivers is considered, where the users can receive both unicasting and multicasting data simultaneously. The performances of the developed algorithms are assessed via thorough computer simulations. The results show that the proposed algorithms provide 30-300% EE improvements over various conventional methods in the BF optimization, and that JBAS techniques can offer further gains of more than 100%<br>Tiivistelmä Tämä väitöskirja keskittyy ajankohtaiseen energiatehokkaaseen lähetinsuunnitteluun langattomissa solukkoverkoissa, joissa suorituskykymittarina käytetään energiatehokkuuden (energy efficiency (EE)) maksimointia, eli kuinka monta bittiä pystytään lähettämään yhtä energiayksikköä kohti. Työn painopiste on lähettimien keilanmuodostuksen (beamforming (BF)) ja aktiivisten lähetinantennien optimoinnissa. EE-optimoinnin uutuusarvo on ottaa lähettimien prosessoinnin tehonkulutus huomioon keilanmuodostuksen suunnittelussa, varsinaisen lähetystehon lisäksi. Työ antaa hyvän käsityksen erityisesti tämänhetkisten solukkoverkkojen energiatehokkuudesta, ja luo työkaluja EE-optimointiin tulevaisuuden järjestelmissä. Ensin suunnitellaan keilanmuodostus yksisolumallissa, jossa tehonkulutus kasvaa lähetystehon ja aktiivisten radiotaajuusketjujen lukumäärän mukana. Ongelmaan johdetaan optimaalinen ratkaisu, ja kaksi käytännöllistä menetelmää perustuen nollaanpakotukseen tai peräkkäinen konveksi approksimaatio (successive convex approximation (SCA)) -ideaan. Seuraavaksi keskitytään keilanmuodostuksen ja antenninvalinnan yhteisoptimointiin (joint beamforming and antenna selection (JBAS)), jossa radiotaajuusketjuja voidaan sulkea EE:n parantamiseksi. Tähän ehdotetaan optimaalinen menetelmä ja kaksi käytännöllistä SCA-menetelmää perustuen binääristen ja jatkuvien muuttujien yhteisoptimointiongelman relaksaatioon, tai harvan vektorin optimointiin. Monisoluverkon EE-optimoinnissa käytetään yksityiskohtaisempaa tehonkulutusmallia, joka skaalautuu myös datanopeuden ja prosessoinnin monimutkaisuuden mukaan. Työssä käytetään kahta suorituskyvyn mittaria: 1) koko verkon energiatehokkuuden, ja 2) painotettujen energiatehokkuuksien summien maksimointia (weighted sum EEmax (WsumEEmax)). Ensin johdetaan keskitetyt ratkaisut SCA-ideaa käyttäen. Tämän jälkeen keskitytään hajautettuun optimointiin, joka pystytään toteuttamaan paikallisen kanavatiedon avulla, kun matalanopeuksinen skalaariarvojen jako on käytettävissä tukiasemien välillä. Ensin WsumEEmax-ongelma ratkaistaan yhdistämällä SCA ja kerrointen vaihtelevan suunnan menetelmä, ja lisäksi ehdotetaan iteratiivinen suljetun muodon ratkaisu molempiin ongelmiin, joka mahdollistaa tarkan laskennallisen monimutkaisuuden määrityksen. Lopussa työ laajennetaan monisoluverkkoon, jossa tukiasemat palvelevat käyttäjäryhmiä ryhmälähetyksenä. Keskittymällä JBAS-ongelmaan, ensin ehdotetaan lähestymistapa parantaa SCA-menetelmän suorituskykyä yhteisoptimointiongelman relaksaation ratkaisemisessa. Toinen yksinkertaisempi lähestymistapa perustuu harvan vektorin optimointiin, joka ei vaadi binäärisiä muuttujia. Lisäksi menetelmiä muunnellaan myös energiatehokkuuden ja summadatanopeuden kompromissin optimointiin. Lopussa työ ottaa huomioon vielä moniantennivastaanottimet, joka mahdollistaa sekä täsmälähetyksen että ryhmälähetyksen samanaikaisesti. Menetelmien suorituskykyä arvioidaan laajamittaisilla tietokonesimulaatioilla. Tulokset näyttävät väitöskirjan menetelmien lisäävän energiatehokkuutta 30-300% verrattuna lukuisiin perinteisiin menetelmiin BF-optimoinnissa, ja JBAS-menetelmät antavat vielä yli 100% lisää suorituskykyä
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Ono, Masahiro S. M. Massachusetts Institute of Technology. "Energy-efficient control of a smart grid with sustainable homes based on distributing risk." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70413.
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Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 135-145).<br>The goal of this thesis is to develop a distributed control system for a smart grid with sustainable homes. A central challenge is how to enhance energy efficiency in the presence of uncertainty. A major source of uncertainty in a smart grid is intermittent energy production by renewable energy sources. In the face of global climate change, it is crucial to reduce dependence on fossil fuels and shift to renewable energy sources, such as wind and solar. However, a large-scale introduction of wind and solar generation to an electrical grid poses a significant risk of blackouts since the energy supplied by the renewables is unpredictable and intermittent. The uncertain behavior of renewable energy sources increases the risk of blackouts. Therefore, an important challenge is to develop an intelligent control mechanism for the electrical grid that is both reliable and efficient. Uncertain weather conditions and human behavior pose challenges for a smart home. For example, autonomous room temperature control of a residential building may occasionally make the room environment uncomfortable for residents. Autonomous controllers must be able to take residents' preferences as an input, and to control the indoor environment in an energy-efficient manner while limiting the risk of failure to meet the residents' requirements in the presence of uncertainties. In order to overcome these challenges, we propose a distributed robust control method for a smart grid that includes smart homes as its building components. The proposed method consists of three algorithms: 1) market-based contingent energy dispatcher for an electrical grid, 2) a risk-sensitive plan executive for temperature control of a residential building, and 3) a chance-constrained model-predictive controller with a probabilistic guarantee of constraint satisfaction, which can control continuously operating systems such as an electrical grid and a building. We build the three algorithms upon the chance-constrained programming framework: minimization of a given cost function with chance constraints, which bound the probability of failure to satisfy given state constraints. Although these technologies provide promising capabilities, they cannot contribute to sustainability unless they are accepted by the society. In this thesis we specify policy challenges for a smart grid and a smart home, and discuss policy options that gives economical and regulatory incentives for the society to introduce these technologies on a large scale.<br>by Masahiro Ono.<br>S.M.in Technology and Policy
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Cheng, Chia-Chin. "Electricity demand-side management for an energy efficient future in China : technology options and policy priorities." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33679.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2005.<br>Includes bibliographical references (p. 278-289).<br>The main objective of this research is to identify robust technology and policy options which achieve substantial reductions in electricity demand in China's Shandong Province. This research utilizes a scenario-based approach to identify sensible and feasible energy efficiency and load reduction strategies. The research consists of technical analyses through the development of an hourly load simulation model to study the time and temperature sensitive impacts on electricity demand growth by different demand-side management (DSM) scenarios and a policy analysis to formulate policy priorities based on the socio-economic and environmental realities in China. This bottom-up comprehensive study helps inform decision-making given the technological, consumption and socio-economic conditions in large-scale electricity grid systems of Shandong and China, thus preferred DSM strategies are identified, and sensible policy recommendations are made with respect to Shandong province and China as a whole. This study developed a computer-based modeling tool for peak-load based electric demand analysis and long-term projections.<br>(cont.) The model simulates disaggregated hourly electric loads by end-user types with temperature-sensitive load simulation capability, which takes into account time use patterns, life-style and behavioral factors, distributed consumption behaviors of electricity users, appliances and equipment utilization patterns, environmental factors, and industrial structural and operational parameters. The simulation and scenario based research methodology provides a comparative basis, and dynamic insights to electricity demand in areas when limited generation and consumption information is available, which is especially appropriate for electricity sector studies in developing countries. The research showed that demand side management strategies could result in significant reduction in the peak loads as well as the total electricity consumption in Shandong.<br>(cont.) The results of the technical analysis concluded that (1) temperature sensitive load makes up the fastest growing demand within the entire consumption profile; (2) implementation of building energy efficiency strategies demonstrates the largest energy saving potential; (3) implementation of appliances standards, has limited effects on energy saving; (4) load management strategies to induce changes in consumption behaviors also shows great potential, however, they are difficult to estimate; and (5) urbanization policies also have a strong impact on electricity consumption. The recommended DSM policy priorities are based on the energy-saving potentials of the DSM strategies, which are listed in priority order: (1) improvement of building technology, (2) management of new installation first (3) management of temperature sensitive loads, (4) implementation of behavioral and load management strategies, (5) better management of urbanization policies (6) promotion of aggressive industrial motor substitution measures & industrial structural changes, and (6) improvement of appliance efficiency.<br>(cont.) This research also formulated integrated DSM policy recommendations to the Chinese government that are centered by the development of coordinated DSM policy framework, and that are based upon the current technological, managerial and institutional capacities of Chinese industry and governmental agencies. The details include moving away from the traditional utility centered IRP/DSM framework, developing a robust energy efficiency services industry, setting correct DSM priorities and implementing them, developing and upgrading the domestic energy efficiency product industry, and engaging end-user participation. The thesis recognized the barriers and difficulties in the policy implementation and stressed the importance of continuous adaptation and institutional learning in the implementation process.<br>by Chia-Chin Cheng.<br>Ph.D.
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Hill, Ryan. "Green ozone technology for water and wastewater treatment : an energy-efficient, cost effective and sustainable solution." Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680079.
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Antonopoulos, Chrissi Argyro. "Diffusion of Energy Efficient Technology in Commercial Buildings: An Analysis of the Commercial Building Partnerships Program." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1532.
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This study presents findings from survey and interview data investigating replication of green building measures by Commercial Building Partnership (CBP) partners that worked directly with the Pacific Northwest National Laboratory (PNNL). PNNL partnered directly with 12 organizations on new and retrofit construction projects, which represented approximately 28 percent of the entire U.S. Department of Energy (DOE) CBP program. Through a feedback survey mechanism, along with personal interviews, quantitative and qualitative data were gathered relating to replication efforts by each organization. These data were analyzed to provide insight into two primary research areas: 1) CBP partners' replication efforts of green building approaches used in the CBP project to the rest of the organization's building portfolio, and, 2) the market potential for technology diffusion into the total U.S. commercial building stock, as a direct result of the CBP program. The first area of this research focused specifically on replication efforts underway or planned by each CBP program participant. The second area of this research develops a diffusion of innovations model to analyze potential broad market impacts of the CBP program on the commercial building industry in the United States.
Findings from this study provided insight into motivations and objectives CBP partners had for program participation. Factors that impact replication include motivation, organizational structure and objectives firms have for implementation of energy efficient technologies. Comparing these factors between different CBP partners revealed patterns in motivation for constructing energy efficient buildings, along with better insight into market trends for green building practices. The optimized approach to the CBP program allows partners to develop green building parameters that fit the specific uses of their building, resulting in greater motivation for replication. In addition, the diffusion model developed for this analysis indicates that this method of market prediction may be used to adequately capture cumulative construction metrics for a whole-building analysis as opposed to individual energy efficiency measures used in green building.
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Hoigt, Julia. "Adoption and sustained use of energy efficient stoves in rural Uganda." Thesis, Uppsala universitet, Naturresurser och hållbar utveckling, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-380346.
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In 2011, Energy saving (mud) stoves were introduced in villages around the Kachung Forestplantation in rural Uganda as part of an effort to support local sustainable development. Initial fieldwork showedthat the stoves had not been adopted as much as the apparent benefits would suggest. This has been a commonissue with improved cooking stove projects around the world. In order to find out why the stoves are notadopted, 67 women in charge of the cooking were interviewed additionally participant observations of cooking,other daily work routines and building stoves conducted, as well as interviews with other relevant stakeholders.Results show that women struggle to find enough firewood and are bothered by the smoke produced whencooking, which makes them generally very interested in improved mud stoves. Indeed many women hadadopted a local version of the mud stove in order to ease the burden of firewood collection. The reason for notadopting a mud stove in general can be mainly attributed to work burden in constructing it. As for the moresophisticated energy saving mud stoves introduced, additional factors were that the implementation strategyshows weaknesses in how the knowledge on how to build the stove is supposed to spread. Further, the stoveintroduced is rather complex in the way it is supposed to be built, which makes it difficult to spread theknowledge of how to build it. The implementation strategy needs to be revised under consideration of the localcircumstances in order to achieve a higher adoption rate.
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Ankerfors, Mikael. "Microfibrillated cellulose : Energy-efficient preparation techniques and key properties." Licentiate thesis, KTH, Fiberteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102949.
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This work describes three alternative processes for producing microfibrillated cellulose (MFC) in which pulp fibres are first pre-treated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated with a combined enzymatic and mechanical pre-treatment. In the two other processes, cell wall delamination was facilitated by pre-treatments that introduced anionically charged groups into the fibre wall, by means of either a carboxymethylation reaction or irreversibly attaching carboxymethyl cellulose (CMC) onto the fibres. All three processes are industrially feasible and enable production with low energy consumption. Using these methods, MFC can be produced with an energy consumption of 500–2300 kWh/tonne, which corresponds to a 91–98% reduction in energy consumption from that presented in earlier studies. These materials have been characterized in various ways and it has been demonstrated that the produced MFCs are approximately 5–30 nm wide and up to several microns long.<br><p>QC 20120928</p>
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Shahzad, Khurram. "Energy Efficient Wireless Sensor Node Architecture for Data and Computation Intensive Applications." Doctoral thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-21956.
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Wireless Sensor Networks (WSNs), in addition to enabling monitoring solutions for numerous new applications areas, have gained huge popularity as a cost-effective, dynamically scalable, easy to deploy and maintainable alternatives to conventional infrastructure-based monitoring solutions. A WSN consists of spatially distributed autonomous wireless sensor nodes that measure desired physical phenomena and operate in a collaborative manner to relay the acquired information wirelessly to a central location. A wireless sensor node, integrating the required resources to enable infrastructure-less distributed monitoring, is constrained by its size, cost and energy. In order to address these constraints, a typical wireless sensor node is designed based on low-power and low-cost modules that in turn provide limited communication and processing performances. Data and computation intensive wireless monitoring applications, on the other hand, not only demand higher communication bandwidth and computational performance but also require practically feasible operational lifetimes so as to reduce the maintenance cost associated with the replacement of batteries. In relation to the communication and processing requirements of such applications and the constraints associated with a typical wireless sensor node, this thesis explores energy efficient wireless sensor node architecture that enables realization of data and computation intensive applications. Architectures enabling raw data transmission and in-sensor processing with various technological alternatives are explored. The potential architectural alternatives are evaluated both analytically and quantitatively with regards to different design parameters, in particular, the performance and the energy consumption. For quantitative evaluation purposes, the experiments are conducted on vibration and image-based industrial condition monitoring applications that are not only data and computation intensive but also are of practical importance. Regarding the choice of an appropriate wireless technology in an architecture enabling raw data transmission, standard based communication technologies including infrared, mobile broadband, WiMax, LAN, Bluetooth, and ZigBee are investigated. With regards to in-sensor processing, different architectures comprising of sequential processors and FPGAs are realized to evaluate different design parameters, especially the performance and energy efficiency. Afterwards, the architectures enabling raw data transmission only and those involving in-sensor processing are evaluated so as to find an energy efficient solution. The results of this investigation show that in-sensor processing architecture, comprising of an FPGA for computation purposes, is more energy efficient when compared with other alternatives in relation to the data and computation intensive applications. Based on the results obtained and the experiences learned in the architectural evaluation study, an FPGA-based high-performance wireless sensor platform, the SENTIOF, is designed and developed. In addition to performance, the SETNIOF is designed to enable dynamic optimization of energy consumption. This includes enabling integrated modules to be completely switched-off and providing a fast configuration support to the FPGA. In order to validate the results of the evaluation studies, and to assess the performance and energy consumption of real implementations, both the vibration and image-based industrial monitoring applications are realized using the SENTIOF. In terms of computational performance for both of these applications, the real-time processing goals are achieved. For example, in the case of vibration-based monitoring, real-time processing performance for tri-axes (horizontal, vertical and axial) vibration data are achieved for sampling rates of more than 100 kHz. With regards to energy consumption, based on the measured power consumption that also includes the power consumed during the FPGA’s configuration process, the operational lifetimes are estimated using a single cell battery (similar to an AA battery in terms of shape and size) with a typical capacity of 2600 mA. In the case of vibration-based condition monitoring, an operational lifetime of more than two years can be achieved for duty-cycle interval of 10 minutes or more. The achievable operational lifetime of image-based monitoring is more than 3 years for a duty-cycle interval of 5 minutes or more.
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Mohamed, Omar R. Ibrahim. "Study of energy efficient supercritical coal-fired power plant dynamic responses and control strategies." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3662/.
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The world is facing the challenge of global warming and environment protection. On the other hand, the demand of electricity is growing fast due to economic growth and increase in population. Since the growth in demand is also a heavy factor in energy equations, then the renewable energy alone is not able to generate enough electricity to fill the gap within a short time of period. Therefore, fossil fuel such as coal fired power plants cannot be ruled out immediately due to their generation capacity and flexibility in load following. However, any new coal fired stations should be cleaner compared with traditional power plants. Supercritical power plants are one of the most suitable choices for environmental enhancement and higher efficiency. However, there has been an issue of whether or not to adopt this technology in the UK because it is not clear whether the performance for SC plants can satisfy the British Gird Code requirement. This thesis reports a study of dynamic responses of SC power plants through mathematical modeling, and simulation for Gird Code compliance. It also presents a new control strategy based on an alternative configuration of generalized predictive control for power plant control.
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Khatib, Amer. "A Novel and an Efficient Design of an Inverted F-Antenna for Bluetooth Low Energy Communications." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-40523.
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Constantly, antenna plays an important role in expanding the wireless communication systems in different technology applications for example, but not limited to, IoT communications and automotive radar systems. On the other hand, the Bluetooth-Low-Energy (BLE) benefits different sorts of applications, as it offers (i) a very low power consumption, (ii) a very fast data transfer, (iii) and an inexpensive/efficient solution as well. This research is a part of AES-Nordic AB projects, which intends to improve the connection between remote vibration sensors and the measurement device. The vibration sensor sends the captured data to the receiver via a wired connection which, in turn, creates a lot of complications, in terms of access limitation and a connection loss vulnerability. The aim of this thesis is to remove these limitations and improve the overall performance using a wireless connection over BLE. This thesis project presents a novel and an efficient system that eliminates the wired-connections shortcomings by involving a new inverted F-antenna design which transfers data from remote sensors to the measurement device. The produced antenna needs to satisfy the following conditions: (i) resonant frequency of 2.44GHz, (ii) isotropic directivity, (iii) minimum coverage of 20-meters. The other goal of this thesis is to compare the presented antenna with commercially available solutions, such as helical and monopole antennas for the purpose of showing the efficiency of the presented solution. The produced antennas were tested in the anechoic chamber and the measurement results show that the designed inverted F-antenna has a comparatively better performance than its peers.
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Lewandowski, Samantha Whitney. "Consumer Engagement With Efficient And Renewable Energy Technology: Case Studies On Smart Meter Utilization And Support For A Community Anaerobic Biodigester System In Vermont." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/859.
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Residential electricity consumption in the United States has many adverse impacts, such as greenhouse gas emissions, dependence on fossil fuels, and costs. Efficient and renewable energy technologies have the potential to help mitigate some of these impacts, but appear to be under-utilized in the United States. One major barrier to expanding the deployment of these kinds of technologies and maximizing the benefits they can provide is a lack of consumer engagement. The overall purpose of this thesis is to better understand the extent to which efficient and renewable energy technologies are being engaged with and what factors may influence such engagement (or lack thereof) through case studies on smart meters and a community anaerobic digester system (CADS) in Vermont. In this thesis, engagement involves awareness, support, and utilization. Additionally, a subset of awareness (a precursor to awareness for many) was examined in each of these studies, which is interest in receiving additional information on the technology. While each case study focuses on different aspects of engagement that are unique to each smart meters and CADS, there is some overlap on the topics explored, especially when it comes to awareness of the technology, potential concerns about the technology, and interest in receiving additional information on it.
The focus of the first study is on how efficiently smart meters have been utilized by residential electricity customers in Vermont and what factors may influence this. This study was conducted via a statewide telephone survey in Vermont and involved a sample that was statistically representative of the state. These data were analyzed via quantitative analysis. The focus of the second study is on local support of a CADS in Vermont and what factors may influence this. This study was conducted via a mailout survey to houses located in or near the area where the community anaerobic digester was located, and the data were analyzed via quantitative and qualitative analysis.
In both studies, limitations to engagement with the technologies were found. In the smart meter study, less than 50% of the surveyed customers reported having a smart meter and, for those who did report having a smart meter, less than 20% of them thought that the smart meter had reduced their electricity use. In the CADS study, 52.1% of respondents reported being familiar with the CADS project, and 69.8% reported support for the project. However, other forms of support for the project, such as WTP for the Cow Power program or willingness to drop of food scraps to the CADS, were more limited. Additionally, a variety of demographic and other factors were found to have a statistically significant impact on or relationship to consumer engagement with these technologies. Overall, the results show that there is some engagement with these technologies, but more can be done to bolster engagement with them. One potential strategy to increase engagement with these technologies may be to tailor outreach according to factors that correspond to different levels of engagement. It is hoped that the results from these studies can be used to help improve consumer engagement with these and other efficient and renewable energy technologies, thus hopefully expanding their utilization and benefits they can provide in the process.
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Zayene, Mariem. "Cooperative data exchange for wireless networks : Delay-aware and energy-efficient approaches." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0033/document.
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Avec le nombre croissant d’appareils intelligents à faible puissance, au cours ces dernières années, la question de l’efficacité énergétique a joué un rôle de plus en plus indispensable dans la conception des systèmes de communication. Cette thèse vise à concevoir des schémas de transmission distribués à faible consommation d’énergie pour les réseaux sans fil, utilisant la théorie des jeux et le codage réseau instantanément décodable (IDNC), qui est une sous-classe prometteuse du codage réseau. En outre, nous étudions le modèle de l'échange coopératif de donnée (CDE) dans lequel tous les périphériques coopèrent en échangeant des paquets codés dans le réseau, jusqu’à ce qu’ils récupèrent tous l’ensemble des informations requises. En effet, la mise en œuvre du CDE basé sur l’IDNC soulève plusieurs défis intéressants, notamment la prolongation de la durée de vie du réseau et la réduction du nombre de transmissions afin de répondre aux besoins des applications temps réel. Par conséquent, contrairement à la plupart des travaux existants concernant l’IDNC, nous nous concentrons non seulement sur le délai, mais également sur l’énergie consommée. En premier lieu, nous étudions le problème de minimisation de l’énergie consommée et du délai au sein d’un petit réseau IDNC coopératif, entièrement connecté et à faible puissance. Nous modélisons le problème en utilisant la théorie des jeux coopératifs de formation de coalitions. Nous proposons un algorithme distribué (appelé “merge and split“) permettant aux nœuds sans fil de s’auto-organiser, de manière distribuée, en coalitions disjointes et indépendantes. L’algorithme proposé garantit une consommation d’énergie réduite et minimise le délai de complétion dans le réseau clustérisé résultant. Par ailleurs, nous ne considérons pas seulement l'énergie de transmission, mais aussi la consommation de l'énergie de calcul des nœuds. De plus, nous nous concentrons sur la question de la mobilité et nous analysons comment, à travers la solution proposée, les nœuds peuvent s’adapter à la topologie dynamique du réseau. Par la suite, nous étudions le même problème au sein d’un réseau large et partiellement connecté. En effet, nous examinons le modèle de CDE multi-sauts. Dans un tel modèle, nous considérons que les nœuds peuvent choisir la puissance d’émission et change ainsi de rayon de transmission et le nombre de voisin avec lesquels il peut entrer en coalition. Pour ce faire, nous modélisons le problème avec un jeu à deux étages; un jeu non-coopératif de contrôle de puissance et un jeu coopératif de formation de coalitions. La solution optimale du premier jeu permet aux joueurs de coopérer à travers des rayons de transmission limités en utilisant la théorie des jeux coopérative. En outre, nous proposons un algorithme distribué “merge and split“ afin de former des coalitions dans lesquelles les joueurs maximisent leurs utilités en termes de délai et de consommation d’énergie. La solution proposée permet la création d’une partition stable avec une interférence réduite et une complexité raisonnable. Nous démontrons que la coopération entre les nœuds au sein du réseau résultant, permet de réduire considérablement la consommation d’énergie par rapport au modèle coopératif optimal qui maintient le rayon de transmission maximal<br>With significantly growing number of smart low-power devices during recent years, the issue of energy efficiency has taken an increasingly essential role in the communication systems’ design. This thesis aims at designing distributed and energy efficient transmission schemes for wireless networks using game theory and instantly decodable network coding (IDNC) which is a promising network coding subclass. We study the cooperative data exchange (CDE) scenario in which all devices cooperate with each other by exchanging network coded packets until all of them receive all the required information. In fact, enabling the IDNC-based CDE setting brings several challenges such us how to extend the network lifetime and how to reduce the number of transmissions in order to satisfy urgent delay requirements. Therefore, unlike most of existing works concerning IDNC, we focus not only on the decoding delay, but also the consumed energy. First, we investigate the IDNC-based CDE problem within small fully connected networks across energy-constrained devices and model the problem using the cooperative game theory in partition form. We propose a distributed merge-and-split algorithm to allow the wireless nodes to self-organize into independent disjoint coalitions in a distributed manner. The proposed algorithm guarantees reduced energy consumption and minimizes the delay in the resulting clustered network structure. We do not only consider the transmission energy, but also the computational energy consumption. Furthermore, we focus on the mobility issue and we analyse how, in the proposed framework, nodes can adapt to the dynamic topology of the network. Thereafter, we study the IDNC-based CDE problem within large-scale partially connected networks. We considerate that each player uses no longer his maximum transmission power, rather, he controls his transmission range dynamically. In fact, we investigate multi-hop CDE using the IDNC at decentralized wireless nodes. In such model, we focus on how these wireless nodes can cooperate in limited transmission ranges without increasing the IDNC delay nor their energy consumption. For that purpose, we model the problem using a two-stage game theoretical framework. We first model the power control problem using non-cooperative game theory where users jointly choose their desired transmission power selfishly in order to reduce their energy consumption and their IDNC delay. The optimal solution of this game allows the players at the next stage to cooperate with each other through limited transmission ranges using cooperative game theory in partition form. Thereafter, a distributed multihop merge-and-split algorithm is defined to form coalitions where players maximize their utilities in terms of decoding delays and energy consumption. The solution of the proposed framework determines a stable feasible partition for the wireless nodes with reduced interference and reasonable complexity. We demonstrate that the co-operation between nodes in the multihop cooperative scheme achieves a significant minimization of the energy consumption with respect to the most stable cooperative scheme in maximum transmission range without hurting the IDNC delay
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Gustafsson, Marcus. "Energy Efficient Renovation Strategies for Swedish and Other European Residential and Office Buildings." Doctoral thesis, KTH, Strömnings- och klimatteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206186.
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The high energy use in the European building stock is attributable to the large share of old buildings with poor energy performance. Energy renovation of buildings is therefore vital in the work towards energy efficiency and reduced environmental impact in the EU. Yet, the strategies and energy system implications of this work have not been made clear, and the rate of building renovation is currently very low. The aim of this thesis is to investigate the economic and environmental aspects of energy renovation strategies, with two main objectives: Renovation of Swedish district heated multi-family houses, including life-cycle cost and environmental analysis and impact on the local energy system; Renovation of European residential and office buildings, including life-cycle cost and environmental analysis and influence of climatic conditions. Buildings typical for the respective regions and the period of construction 1945-1970 were simulated, in order to determine the feasibility and energy saving potential of energy renovation measures in European climates. A variety of systems for heating, cooling and ventilation were studied, as well as solar energy systems, with focus on heat pumps, district heating, low-temperature heating systems and air heat recovery. Compared to normal building renovation, energy renovation can often reduce the life-cycle costs and environmental impact. In renovation of typical European office buildings, as well as Southern European multi-family houses, more ambitious renovation levels can also be more profitable. Exhaust air heat pumps can be cost-effective complements in district heated multi-family houses, while ventilation with heat recovery is more expensive but also more likely to reduce the primary energy use. From a system perspective, simple exhaust ventilation can reduce the primary energy use in the district-heating plant as much as an exhaust air heat pump, due to the lower electricity use.<br>Byggnadssektorn står för omkring 40 % av den totala energianvändningen i EU. Den höga energianvändningen i Europeiska byggnader kan till stor del tillskrivas den stora andelen gamla byggnader med dålig energiprestanda. Energirenovering av byggnader, eller energieffektivisering genom renovering, kan därför anses utgöra en central del i arbetet mot EU:s klimat- och energimål för år 2030. Trots detta är det ännu inte helt klarlagt vilka strategier som ska tillämpas för att uppnå detta och hur det påverkar energisystemet, och i nuläget är renoveringstakten fortfarande väldigt låg. Målet med denna avhandling är att undersöka ekonomiska och miljömässiga aspekter av strategier för energirenovering, såväl byggnadsskalsåtgärder som aktiva system, för typiska bostads- och kontorsbyggnader i Sverige och i andra Europeiska regioner. Mer specifikt har arbetet följande två inriktningar: Renovering av svenska, fjärrvärmevärmda flerfamiljshus, inklusive livscykelkostnadsanalys och livscykelmiljöanalys samt påverkan på det lokala energisystemet; Renovering av Europeiska bostads- och kontorsbyggnader, inklusive livscykelkostnadsanalys och livscykelmiljöanalys samt påverkan av klimatförutsättningar. Byggnader typiska för respektive region och byggnadsperioden 1945-1970 modellerades och användes i simuleringar för att fastställa den övergripande möjligheten och energibesparingspotentialen för olika renoveringsåtgärder i Europeiska klimat. En rad system för värme, kyla och ventilation studeras, samt solenergisystem, med fokus på värmepumpar, fjärrvärme, lågtemperaturvärmesystem och värmeåtervinning ur frånluft. Jämfört med renovering av byggnader utan energieffektiviseringsåtgärder kan energirenovering i många fall minska såväl livscykelkostnaden som miljöpåverkan. Vid renovering av typiska Europeiska kontorsbyggnader lönar det sig mer att renovera ner till ett uppvärmningsbehov på 25 kWh/(m²∙år) än 45 kWh/(m²∙år), då den minskade kostnaden för köpt energi väger upp den ökade kostnaden för isolering. För flerfamiljshus i södra Europa kan mer ambitiösa mål gällande värmebehov också vara lönsamma, medan en mer måttlig nivå är lämplig för småhus. Solvärme- eller solelsystem kan användas för att minska byggnaders miljöpåverkan. Utan subventioner eller inmatningstariff för överskottsel kan det bli svårt att få lönsamhet i dessa system för kontorsbyggnader i Nord- och Centraleuropa samt för småhus. För flerfamiljshus kan solenergisystem dock sänka den totala livscykelkostnaden, såväl i södra som i norra Europa. Värmeåtervinning och lågtemperaturvärmesystem visade sig båda ha större inverkan i kallare klimat. Lågtemperaturvärmesystem förbättrar värmefaktorn för värmepumpar, i synnerhet när uppvärmningsbehovet är stort i förhållande till varmvattenbehovet. Vid renovering av byggnader med vattenburna radiatorer kan konvertering till tilluftsradiatorer sänka framledningstemperaturen i värmesystemet. I svenska flerfamiljshus kan frånluftsvärmepump vara ett kostnadseffektivt komplement till fjärrvärme, medan från- och tilluftsventilation med värmeåtervinning är dyrare men mer sannolikt att ge en minskad primärenergianvändning. I ett systemperspektiv kan frånluftsventilation utan värmeåtervinning minska primärenergianvändningen i fjärrvärmeverket lika mycket som en frånluftsvärmepump, tack vare den lägre elanvändningen.<br><p>QC 20170509</p><br>iNSPiRe
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Sutrisno, Harry. "Techno-Economic Study on The Alternative Power and Cooling Systems Design for Cost & Energy-Efficient Edge Cloud Data Center(s)." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302990.
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The 5G technology has enabled performance-sensitive applications with low latency and high bandwidth requirements, which has put more low latency requirements on computing services. To answer this need, a small-scale data center called edge cloud is predicted to grow fast in the future. Due to its nature of being close to the end-users, the growth of edge clouds in the populated area may cause a problem with the existing power system. Besides this power system challenge, the edge cloud also requires a higher resource cost than the hyper-scale data center because of the economies of scale. In this thesis, four viable alternative power and cooling technologies are introduced to address those challenges. These four technologies are solar PV, Vertical Axis Wind Turbine (VAWT), Rear Door Heat Exchanger (RDHx), and immersion cooling. Detailed data of edge cloud are required to understand the contribution of these four technologies. However, due to the infancy state of edge cloud, those data are unavailable, and assumptions regarding data are made. Besides that, a cost model for an edge cloud is also required to show how significant the contribution of those alternative technologies is if compared to the total cost of ownership. In this thesis, the cost model for the edge cloud is extended for the alternative power and cooling system scenarios. Along with the assumed data of an edge cloud, sensitivity analysis is performed to determine whether the alternative power and cooling technologies can bring down the cost of edge cloud resources or not. Through the cost modeling, it was found out that VAWT and immersion cooling is not feasible for the particular assumed data center. On the other hand, solar PV can save 4.55% of data center electricity consumption (equal to 0.21% reduction of the total expense when calculated using the current electricity price). Furthermore, RDHx performed better with 22.73% of data center electricity expenses (equivalent to 8.35% of saving from total cost when calculated using the current electricity price).<br>5G-tekniken har möjliggjort prestandakänsliga applikationer med låg latens och höga bandbreddskrav, vilket har ställt högre krav på låg latens för datatjänster. För att möta detta behov förutspås ett småskaligt datacenter - edge cloud – växa i framtiden. På grund av dess användarnära natur kan tillväxten av edge clouds i tätområden orsaka problem med det befintliga kraftsystemet. Förutom denna kraftsystemutmaning kräver edge cloud också en högre resurskostnad än storskaliga datacenter på grund av skalfördelarna. I denna avhandling introduceras fyra alternativa energi- och kyltekniker för att hantera dessa utmaningar. Dessa fyra tekniker är solpanel, vertikalaxel vindturbin (VAWT), bakdörrvärmeväxlare (RDHx), och nedsänkningskylning. Detaljerad information om edge cloud erfordras för att förstå bidraget från dessa fyra tekniker. På grund av edge clouds tidiga stadium är all nödvändig data dock inte tillgänglig, vaför antaganden om görs. Förutom det krävs också en kostnadsmodell för edge cloud för att visa hur betydande bidraget från den alternativa tekniken är om den jämförs med den totala ägandekostnaden. I denna avhandling utökas kostnadsmodellen för edge cloud för de alternativa energi- och kylsystemscenarierna. Med antagen data för ett edge cloud genomförs en känslighetsanalys för att avgöra om alternativa energi- och kyltekniker kan sänka kostnaden för edge cloud-resurser eller inte. Kostnadsmodelleringen visar att VAWT och nedsänkningskylning inte är möjlig för det specifika antagna datacentret. Å andra sidan kan solpanel spara 4,55% av datacentrets elförbrukning (motsvarande 0,21% minskning av den totala kostnaden när den beräknas med det aktuella elpriset). Dessutom presterade RDHx bättre med 22,73% av datacenters elutgifter (motsvarande 8,35% av besparingen från totalkostnaden när den beräknas med det aktuella elpriset).
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Hasselrot, Rasmus. "Investigation and evaluation of high-rise buildings in IDA ICE : A comparative study of energy efficient residential high-rise buildings in different climates." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-103874.
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This thesis is part of the major EU project EE-Highrise. The main objective of the EU project is to investigate high-rise buildings in different climates considering energy use, sustainability and cultural and economic differences in different countries. A demo high-rise building has been built in the capital of Slovenia. The purpose of this thesis was to build a model of the demo building in the simulation program IDA Indoor Climate and Environment. The model’s energy performance was then to be simulated in three different regions: Scandinavia, Central Europe and in the Mediterranean. Improvements to the climate shell and the ventilation system were to be examined and the results were then to be compared to European and Swedish Passive House certification schemes. A model was built in the simulation program IDA Indoor Climate and Environment according to the provided drawings of the demo building in Slovenia. Most of the building’s parameters were provided by the project group in Slovenia. When specific parameters were missing or difficult to motivate, standardized values were assumed. The model was modified into five cases: the base case, increased insulation of the external walls, improved glazing and frames for the windows, increased effective heat recovery efficiency and a combination of the energy saving measures. The model’s energy performance was then simulated at five different locations: Naples in Italy, Ljubljana in Slovenia, Malmo in southern Sweden, Karlstad in the middle of Sweden and Kiruna in the northern Sweden. When comparing the results to the requirements for the European Passive House certification, none of the investigated cases met the requirements due to a too large primary energy demand. However, if the requirement regarding the primary energy demand were to be disregarded, then the building in Slovenia would pass the requirements with an increased effective heat recovery efficiency for the ventilation system. Also the building in southern Sweden would pass the requirements with a combination of increased insulation for the external walls, improved windows and increased effective heat recovery efficiency. The Swedish Passive House certification would be fulfilled for the models in Malmo and Karlstad with an increased effective heat recovery efficiency, while the model in Kiruna did not pass the requirements. However, with a combination of the energy saving measures the model in Kiruna came very close to meeting the requirements. The conclusion was that an increased effective heat recovery efficiency had the largest impact on the building’s space heating demand and that improving the windows increased the cooling demand in Naples by a large amount.
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Sullivan, Joe. "How effective are UK policies at addressing factors affecting consumer decisions to carry out energy efficient renovation?" Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-66128.
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The UK’s housing stock is among the oldest and least efficient in Europe. 85% of the UK’s existing homes will still be standing and in use in 2050. Improving the energy efficiency of UK housing stock is an essential requirement in order for the UK to meet its 2008 Climate Change Act obligations. Energy efficiency in buildings is the focus of European (EU) policies with the intention of creating a low-carbon economy by 2020. Reducing energy consumption in existing buildings is essential to achieving this. Government policies are the primary mechanism for lowering energy consumption through changing consumer behaviour, promoting low carbon technology and energy efficient renovations of old building stock.The objective of this thesis is to investigate the effectiveness of UK policies at addressing factors affecting consumer decisions to carry out energy efficient renovations. This is with the intention of determining if UK policies are effectively contributing to the government’s long term climate change commitments.Using a theory developed by Parker (2000) as a conceptual framing of policy compliance, this study conducts interviews with consumers in order to analyse their awareness, understanding and perception of UK energy efficiency policies. Therefore, it can be determined how effective policies are at affecting consumer decisions to carry out energy efficient renovations.The thesis informs that consumers are motivated and willing to comply with policies but there are several key barriers preventing them from complying with these policies and therefore adopting energy efficient renovations. Policies are deemed to be somewhat ineffective at affecting consumer decisions to carry out energy efficient renovations.
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Salehi, Farshid. "The Study and Practical Application of Sustainable and Energy Efficient Design and Technology for HVAC and Centralised Solar Hot Water Systems in the Al Zeina Development, Abu Dhabi, United Arab Emirates." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14003.
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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.<br>Includes bibliographical references (leaves 204-210).<br>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.<br>by Cyane Bemiss Dandridge.<br>M.S.
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Robert, Andersson, and Rasmus Becke. "Assessment of energy renovation with new design solution of a single-familyhouse in southern Sweden." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105319.
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To reach the EU directives and Sweden ́s energy- and climate goals, there is a needto implement new innovative- and technical solutions in each sector. The Swedishgovernment predicts that the buildings sectors energy demand could be reduced byrenovating the existing building stock. The research examines the opportunities to implement indoor design solutionsassociated with an energy renovation measure of an existing single-family house inSweden. The research will cover a broader picture of the concept's feasibility-, addedvalues, and financial cost and benefits. This will be done within the requirements ofthe current building regulations on altering an existing building in Sweden 2021. The research outcome showed that implementing the design solution concept willconstitute a financial benefit on energy renovation measure ́s payback time. Theresult showed that one of the suggested design concepts with the energy renovationmeasures would have a payback time of 8.5 years. Besides, implementing the designsolution concept predicts several beneficial added values, e.g., environment, buildingdesign and society.
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Da, Silva Ralston A. "Green Computing – Power Efficient Management in Data Centers Using Resource Utilization as a Proxy for Power." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259760420.
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Strübing, Dietmar [Verfasser], Jörg E. [Akademischer Betreuer] Drewes, Jörg E. [Gutachter] Drewes, Largus T. [Gutachter] Angenent, and Lars D. M. [Gutachter] Ottosen. "H2/CO2 biomethanation in anaerobic thermophilic trickle bed reactors - Development of a flexible and efficient energy conversion technology / Dietmar Strübing ; Gutachter: Jörg E. Drewes, Largus T. Angenent, Lars D. M. Ottosen ; Betreuer: Jörg E. Drewes." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1212178165/34.
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Canal, Corretger Ramon. "Power- and Performance - Aware Architectures." Doctoral thesis, Universitat Politècnica de Catalunya, 2004. http://hdl.handle.net/10803/5984.
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The scaling of silicon technology has been ongoing for over forty years. We are on the way to commercializing devices having a minimum feature size of one-tenth of a micron. The push for miniaturization comes from the demand for higher functionality and higher performance at a lower cost. As a result, successively higher levels of integration have been driving up the power consumption of chips. Today, heat removal and power distribution are at the forefront of the problems faced by chip designers.<br/>In recent years portability has become important. Historically, portable applications were characterized by low throughput requirements such as for a wristwatch. This is no longer true.<br/>Among the new portable applications are hand-held multimedia terminals with video display and capture, audio reproduction and capture, voice recognition, and handwriting recognition capabilities. These capabilities call for a tremendous amount of computational capacity. This computational capacity has to be realized with very low power requirements in order for the battery to have a satisfactory life span. This thesis is an attempt to provide microarchitecture and compiler techniques for low-power chips with high-computational capacity.<br/>The first part of this work presents some schemes for reducing the complexity of the issue logic. The issue logic has become one of the main sources of energy consumption in recent years. The inherent associative look-up and the size of the structures (crucial for exploiting ILP), have led the issue logic to a significant energy budget. The techniques presented in this work eliminate or reduce the associative logic by determining producer-consumer relationships between the instructions or by scheduling the instructions according to the latency of the operations.<br/>An important effort has been deployed to reduce the energy requirements and the power dissipation through novel mechanisms based on value compression. As a result, the second part of this thesis introduces several ultra-low power and high-end processor designs. First, the design space for ultra-low power processors is explored. Several designs are developed (at the architectural level) from scratch that exploit value compression at all levels of the data-path. <br/>Second, value compression for high-performance processors is proposed and evaluated. At the end of this thesis, two compile-time techniques are presented that show how the compiler can help in reducing the energy consumption. By means of a static analysis of the program code or through profiling, the compiler is able to know the size of the operands involved in the computation. Through these analyses, the compiler is able to use narrower operations (i.e. a 64-bit addition can be converted to an 8-bit addition due to the information of the size of the operands).<br/>Overall, this thesis compromises the detailed study of one of the most power hungry units in a processor (the issue logic) and the use of value compression (through hardware and software) as a mean to reduce the energy consumption in all the stages of the pipeline.
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Haikola, Matilda, and Malin Söderberg. "Grid Tariff Design for Efficient Utilisation of the Distributor Grid : A qualitative study with actors on the Swedish electricity market." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279515.
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The Swedish electricity system is transitioning due to the establishment of climate policy goals and trends related to technology and demographics. The transition has resulted in an increased demand for electricity. The increased demand for electricity in combination with lack of forecasts, planning and coordination between actors in the electricity sector has led to the occurrence of grid congestion. Extending the network is time-consuming and requires substantial investments. Instead, an alternative is to utilise the available grid capacity more efficiently by implementing flexibility solutions. Flexibility can be achieved by implementing incentives such as grid tariffs. This solution has recently gained much attention in Sweden, but it is not apparent how grid tariffs should be designed. The purpose of this thesis is to investigate how distribution grid tariffs could be designed to incentivise different actors to contribute to flexibility in a way that results in an efficient use of the electrical grid. A qualitative study was performed, collecting empirical data through semistructured interviews with actors in the Swedish electricity market. The aim is that the results from this thesis will act as a basis for DSOs planning to design grid tariffs with the purpose to utilise the grid more efficiently. The findings present a ToU capacity charge with off-peak periods that are free of charge as the preferable main price signal in the tariff to achieve efficient utilisation of the grid. It is further argued that other structural elements can complement the ToU capacity charge. A small fixed charge could be added in order to contribute to the cost reflectiveness of the grid tariff. A small energy charge could be incorporated in order to provide consumer with incentives to be flexible below the current metered maximum power and strengthen the signal from the ToU capacity charge. A small energy charge can avert difficulties related to providing incentives below the current metered maximum, as it still can provide some incentives to be flexible, or strengthen the signal from the ToU capacity charge. Further, the energy charge can ensure sustainability if customers respond well to a ToU capacity charge and to compensate solar PV customers. Furthermore, recommendations to further enable the grid tariffs potential to provide price signals include shifting the focus of the revenue cap from CapEx to OpEx and exploring the hampering signals of the energy tax as well as contradicting price signals from the wholesale electricity price.<br>Det svenska elsystemet genomgår en förändring till följd av införandet av klimatmål och trender relaterade till teknik och demografi. Denna förändring har resulterat i ett ökat effektbehov. Ett ökat effektbehov i kombination med bristande prognostisering, planering och samordning mellan aktörer inom elsektorn har lett till uppkomsten av kapacitetsbrist. Att bygga ut elnätet är tar tid och kräver större investeringar. Ett alternativ är att istället utnyttja det befintliga elnätet mer effektivt genom att implementera flexibilitetslösningar. Flexibilitet kan uppnås genom att införa incitament i form av elnätstariffer. Denna lösning har nyligen fått mycket uppmärksamhet i Sverige, men det är inte klart inte hur dessa elnätstariffer ska utformas. Syftet med detta arbete är att undersöka hur distributionsnätets tariffer kan utformas för att stimulera olika aktörer att bidra med flexibilitet på ett sätt som resulterar i en effektiv användning av det befintliga elnätet. En kvalitativ studie genomfördes där empiriska data samlades in genom semistrukturerade intervjuer med aktörer på den svenska elmarknaden. Syftet är att resultaten från detta arbete ska fungera som ett underlag för nätägare som planerar att utforma elnätstariffer med syftet att utnyttja nätet mer effektivt. Resultaten visar att en ToU-effektavgift med gratis off-peak perioder bör vara den huvudsakliga prissignalen i en elnätstariff som ämnar att utnyttja det befintliga nätet mer effektivt. Det visar även att andra strukturella element kan komplettera ToU-effektavgiften. En mindre fast avgift kan adderas i syfte att göra elnätstariffen mer kostnadsriktig. En mindre energiavgift kan införas för att ge kunder incitament att vara flexibla även under den nuvarande uppmätta maximala effekten och stärka signalen från ToU-effektavgiften. Vidare kan energiavgiften säkerställa tillräckliga intäkter för nätägaren om kunderna svarar bra på en ToU-effektavgift och för att kompensera kunder med solceller. Ytterligare rekommendationer för att möjliggöra prissignaler genom elnätstariffer inkluderar att skifta fokus på intäktsramen från CapEx till OpEx och utforska de hämmande prissignalerna från energiskatten och de motstridiga prissignalerna från elhandelspriset.
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Svanbäck, Martina, and My Lindström. "Simulering och utvärdering av en klimatpositiv byggnads energisystem : Energibedömning och fördelar kring förnybara resurser i ETC Bygg AB:s nollenergibyggnader av flerbostadstyp." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55027.
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Purpose: The purpose with this project was to evaluate the environmental, social, and economic aspects regarding two climate positive buildings in Västerås municipality in Sweden. The company responsible for the buildings, ETC Bygg AB, has assigned this task tothe research group Future Energy Center (FEC) at Mälardalen University. Method: The buildings was simulated with the programs IDA ICE and PVGIS to obtain the overall energy consumption and building efficiency as well as the PV system potential. Regarding transportation, vehicle and driver statistics was studied and adapted to the case study to estimate the tenant’s climate impact. Results: The results showed that the electricity obtained from the PV system both covers the building’s, and tenant’s estimated yearly electricity consumption, but also with a surplus available for storage or selling. The simulatedresults were compared to several previous studies with similar outcome, but with slightly different results. The tenants need for climate friendly transportation resulted in a suggestion of an electric mobility station consisting of electric cars, mopeds, and bicycles to lower the tenants carbon mitigation, costs, and energy consumption. Conclusions: Conclusions from the study was that the buildings meet both the BBR, and the FEBY18 Gold requirements with their high energy efficiency, as well as that the solar power system most likely will produce enough energy to cover both building, and tenant power consumption. A conclusion can be made that the transition to electric transportation have a potential to save both a considerable amount of energy and money for the tenants, but also the possibility to lower their collective yearly carbon mitigation. Also, that the life in a climate positive building have mostly, if not only, positive impacts on its residents.
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Happel, Julius, René Schnetzler, and Markus Laufenberg. "Multistable valve technology with magnetic shape memory alloy as passive element activated by a bidirectional solenoid actuator." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71264.
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Magnetic Shape Memory (MSM) alloys show a superelastic behaviour with possible deformation rates up to 6% until 12% and a sufficient lifetime performance [1, 2]. In this paper, a passive application for a superelastic Ni-Mn-Ga-alloy is presented by using the MSM element as an accurately defined inner friction in a system of a multistable actuator, in particular a multistable proportional valve. The multistable valve is characterized by a currentless holding of the valve displacement in any position of the stroke. This circumstance makes the concept a very low energy consumption valve, compared to conventional proportional valves with solenoid actuators. The new aspect of a rigid connection of MSM Materials enables an absorption of tension as well as compressive forces. To realize an applicable controlling valve, a simple and effective controlling strategy has been implemented. Due to the stabilizing effect of the MSM element, an accurate controlling of the valve stroke and the usage for example as a pressure-, mass-flow or temperature-controlling valve was made possible. Furthermore, some potential applications in pneumatics as well as in hydraulics are presented.
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Chen, Chao, and Yogesh Vishwas Bhamare. "Life Cycle Cost Analysis and Optimization of Wastewater Pumping System." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255866.
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Different attempts have been made to facilitate successful operation of Wastewater Pumping (WWP) system. The WWP units which are already existed in different parts of the world have been studied to identify its success, failure and different parameters associated with its suboptimal performance. The performance of WWP depends on three parameters namely pump, hydraulics, control system and pump station. These parameters are interdependent and must be carefully matched to achieve efficient WWP system. Nowadays the scenario has changed where organizations has started looking increasingly at the total cost of ownership, another way of saying Life Cycle Cost Analysis (LCCA) and recognizing the need to get most out of their equipment purchase. The master thesis includes theory part which describes the different parameters associated with WWP unit especially focusing on Xylems WWP system. This thesis is an attempt to help companies to know how LCCA could be productive management tool in order to minimize maintenance cost and maximize energy efficiency The study reported in this thesis work has been conducted to shed light over the use of Life Cycle Cost Analysis in WWP system. The current study tries to suggest and assess an adopted approach to ensure successful and efficient operation of WWP system with lowering energy demand and decrease in maintenance cost. Initial cost, Maintenance cost and Energy costs are important issues in the operation of WWP system since they are responsible for total cost over time. Therefore, description of each cost, formulas necessary for LCC calculations, data and survey structure, material and energy flow has been described. This work also aims to provide an extensive literature review, different survey and data collection techniques, analysis of collected data, statistical modelling, customer interaction by questionnaires and an interview with experts were used. LCC calculations were used to support the design and selection of most cost-efficient WWP system. Therefore, the given thesis work is an attempt to achieve better functional performance, improve existing design principles associated with WWP System, contribution to asses economic viability, support decision making to enhance operational quality to achieve efficient and successful WWP system.
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Martin, Eric Russell 1971. "Understanding the diffusion of energy efficiency technology in residential buildings." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/41422.
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