Climate change is one of the global challenges of our time. The energy sector is at the focus of the European efforts to combat climate change as it accounts for 80% of the total greenhouse gas emissions in the European Union. Buildings, on the other hand, represent 40% of the energy use and 33% of the total greenhouse gas emissions in the European Union, giving the buildings sector also a key role in the European climate strategy. There are, at the same time, strong interdependencies between the energy and buildings sectors due to the high amount of energy used by buildings and their rising importance as active components in the future energy systems. These interdependencies do not only influence the investment decisions in the energy and buildings sectors, but also the effectiveness of the European climate strategy. Cooperation between the energy and buildings sectors can create beneficial outcomes for the both sectors as well as the environment. It may also encourage innovation, improve the energy performance of buildings, and help achieve a higher penetration of renewable energy into the energy system. This licentiate thesis investigates the relationship between the energy and buildings sector at the inter-company level. Presenting the data collected from interviews and a web survey answered by the energy and buildings sectors in Sweden, this thesis examines the level of cooperation between these two sectors, discusses trust issues between stakeholders, presents the factors that negatively impact cooperation, and provides recommendations for the minimisation of these factors. The findings presented in this thesis indicate an insufficient level of cooperation between the energy and buildings sectors in Sweden, to which the following factors have been identified to contribute in a negative a way: district heating monopolies; energy efficiency in buildings; building regulations; self-generation of electricity; and energy use patterns. The emphasis on self-interest by stakeholders within the both sectors appears to create trust issues between stakeholders. Accordingly, shifting the focus from self-gains to mutual gains is deemed necessary to improve the cooperation between the energy and buildings sectors. This, however requires significant changes in current practices and business models. It has been identified that the development of smart energy systems that allow a closer interaction between the energy and buildings sectors through flexible energy supply and use would minimise many of the factors that negatively impact cooperation. / Klimatförändringen är en av de stora globala utmaningar vi står inför. I Europa läggs idag stort fokus på energisektorn, som står för 80 procent av det totala utsläppen av växthusgaser. Byggnader representerar 40 procent av energianvändningen och 33 procent av växthusutsläppen, vilket också ger byggsektorn en nyckelroll i den europeiska klimatstrategin. Samtidigt finns det starka beroendeförhållanden mellan energi- och byggsektorn på grund av den höga energianvändningen i byggnader och deras ökade betydelse som en aktiv komponent i det framtida energisystemet. Dessa beroendeförhållanden påverkar inte bara investeringsbeslut i de båda sektorerna, utan även effektiviteten i den europeiska klimatstrategin. Samarbete mellan energi- och byggsektorn kan få positiva effekter för både dem själva såväl som för miljön. Samarbete mellan sektorerna kan även uppmuntra innovation, förbättra energieffektiviteten i byggnader och tillåta en högre användning av förnyelsebar energi i energisystemet.  Denna licentiatavhandling utforskar förhållandet mellan energi- och byggsektorn på företagsnivå genom att analysera data som samlats in med hjälp av intervjuer och en webbaserad enkät.  Intervjuer och enkäter har besvarades av både energi- och byggsektorerna i Sverige. Denna avhandling studerar nivån av samarbete mellan de två sektorerna, diskuterar problem gällande förtroende mellan intressenter, presenterar de identifierade faktorer som försvårar samarbete och ger rekommendationer för att minimera dessa. Resultatet visar på en otillräcklig nivå av samarbete mellan energi- och byggsektorerna i Sverige. De faktorer som försvårar samarbetet är följande: fjärrvärmemonopol; energieffektivitet i byggnader; byggregler, egenproduktion av el och användarmönster. Naturligt finns ett egenintresse hos olika intressenter inom de båda sektorerna, och detta tycks ha skapat ett förtroendeproblem mellan de olika sektorerna Att byta fokus från egen vinning till gemensamma mål bedöms vara nödvändigt för att öka samarbetet mellan energi- och byggsektorerna. Detta fodrar dock stora förändringar både i nuvarande verksamhet samt i affärsmodellerna. Det har påvisats att utvecklandet av smarta energisystem som tillåter en större interaktion mellan energi- och byggsektorerna genom flexibel energiförsörjning och användning skulle minimera många av de faktorer som inverkar negativt på samarbetet.

Magister Legum - LLM / The methods of energy use and production in South Africa are currently unsustainable, and have dire environmental and health impacts. This is largely due to fossil fuel based energy generation and use. Currently 89% of energy generated in South Africa is derived from fossil fuels including coal, oil and gas. This figure is likely to increase in the near future with the construction of new coal-fired electricity generation and coal/gas to liquid fuels stations. South Africa has an abundance of both non-renewable and renewable energy resources.Renewable energy technologies will be key in the battle to reduce carbon and greenhouse gas (GHG) emissions, as they do not produce the large amounts of carbon and GHG emissions that conventional fossil-fuel based methods do. Renewable energy, as the name indicates, can be considered an infinite reserve. Most renewable energy is generated from solar power it can be relied upon as long as the sun keeps shining. Energy efficiency as well as improvements in technologies relating to energy generation can play a significant role in reducing carbon and GHG emissions. For example, the 'Basa njengo Magogo' method used to ignite coal in coal-fired power stations makes use of a 'top-down ignition process' which reduces smoke emissions by 80-90 percent, heats up quicker and uses less coal than the conventional method. The barriers to the implementation of sustainable and renewable energy measures are: the relatively cheap cost of coal based energy, due to the abundance of the resource in South Africa, as well as the uncoordinated nature of legislation dealing with energy, and the implementation of sustainable energy practices. However the means and resources do exist for South Africa to reduce its carbon and GHG emissions and reliance on carbon based energy. Therefore this paper will examine the legislative and international obligations government has to sustainable and renewable energy and what policies have been developed to give effect to these obligations. Section 24 of the Constitution explicitly recognises the obligation to promote justifiable 'economic and social development', which is essential to the well-being of human beings. Development both social and economic require energy, however South Africa's energy is derived mainly from fossil fuels, which when used have a significant detrimental effect on the environment.

This thesis discusses the implementation of EU Energy efficiency directive into national legislatures and the fulfilment of its goals. It expands on the past reports, correct for their mistakes and provide a new unique approach to track the current progress. The thesis analyzes all member states national action plans for energy efficiency (NAPEE) and compares them in between each other. The quality of NAPEEs is critically evaluated and described. In first section it explains and narrows the most crucial definitions. In second section it gives the basic summary of the regulation to interested readers. Followed by in depth analysis and evaluation of all EU member states national action plans for energy efficiency. The following chapter then deals with solely with Czech NAPEE. The last section provides the hard data and exclusively developed indices that tracks the progress toward EU 2020 goals.

In this paper, we propose an adaptive and multi-sector-based user clustering algorithm which increases energy efficiency in a cellular network. Adaptive sectoring with dynamically changing sector angles is illustrated with a number of randomly distributed mobile stations. Transmitted power is equally shared by sectors before adaptive user clustering. The sector angles vary from 30 to 360 degrees by merging neighboring sectors and a sector is switched off till the user density exceeds a threshold (Td). The Td value is computed from the total number of users that the cell can accommodate over the area of the cell. The sectors with less than Td density exhibits transmit power which approaches to zero or sleeping state and so that the cumulative power is saved. Simulation results show that an average of 45% to 50% energy can be saved in 10 iterations.

Spectral efficiency (SE), energy efficiency (EE), and transmission reliability are basic parameters to measure the performance of a cellular network. In this paper, spectral efficiency and energy efficiency tradeoff is considered keeping in mind the transmission reliability, where all the three are function of signal to noise ratio (SNR). SNR, in turn is a function of constellation size (or the number of bits per symbol) and data rate. Then, we propose a new power model which is as function of this SNR. Based on the power model, SE-EE trade-off function is evaluated taking transmission reliability in to consideration. Results confirmed that increasing constellation size results an increase in SNR and leads to a significant increase in energy efficiency without changing the transmit power. To demonstrate the validity of our analysis, channel gain and constellation size are varied keeping transmit power constant. The results also indicate that securing transmission reliability, the EE-SE trade-off is optimized by increasing the constellation size.

The point of departure for this thesis is how a traditional service sector shifts towards becoming more energy efficient and the processes that enable environmental action. Traditional services are generally considered to be poorly innovative and inclined towards routine activity; this leaves a gap in understanding how these adapt to the challenge of taking environmental action. The study argues that service firms adapt by deploying capabilities to multitask or to carry out innovative activity alongside routine activities related to service delivery. The research problem is addressed through three objectives: i) explicating how dynamic capabilities enable environmental action in traditional services with a focus on energy efficiency; ii) investigating the interface between the service firm and a type of intermediary, the knowledge intensive business service firm (KIBS), and how this acts as a locus for intermediation activity, or the exchange of knowledge about energy efficient technologies and measures; and iii) exploring how developments in the external context may influence the firm’s capabilities to adapt.The key contributions are two-fold. Firstly, the research links different combinations of capabilities with particular innovative behaviours in service firms; this underscores the presence of a differential multitasking potential across firms in the same sector. Secondly, it demonstrates a link between the service firm’s internal capabilities and the extent to which it mobilizes absorptive capacity to obtain knowledge about energy efficiency measures from its relation with KIBS.A qualitative study is designed with the hotel sector in Malta as the empirical setting. The fieldwork was undertaken through interviews with 26 hotel managers, 14 engineering consulting firms and 16 actors in the broader institutional environment. The data from the hotels were clustered to derive different adaptation modes characterized by particular capabilities and patterns of environmental action. Then, pairs of hotels and engineering consulting firms were identified in order to investigate the relational dynamics that may be influencing intermediation activity. The findings distinguish between hotels with a low multitasking potential that adopt a narrow range of energy efficient measures and those with a higher multitasking potential that modify activities and make deeper structural changes to shift towards improved energy efficiency. Accounting for the range of multitasking potential are different combinations of capabilities to sense signals in the external environment and interpret these in the firm and the capability for problem-solving for energy efficiency. The findings demonstrate a different pattern of KIBS use by hotels that is suggestive of a cluster differentiation. This is linked to different levels of absorptive capacity in hotels that determines whether intermediation activity and therefore the exchange of knowledge and learning about energy efficient measures is constrained or otherwise enhanced at the KIBS-client interface. The conclusion provides policy implications and areas for future research.

Modern data centers host hundreds of thousands of servers to achieve economies of scale. Such a huge number of servers create challenges for the data center network (DCN) to provide proportionally large bandwidth. In addition, the deployment of virtual machines (VMs) in data centers raises the requirements for efficient resource allocation and find-grained resource sharing. Further, the large number of servers and switches in the data center consume significant amounts of energy. Even though servers become more energy efficient with various energy saving techniques, DCN still accounts for 20% to 50% of the energy consumed by the entire data center. The objective of this dissertation is to enhance DCN performance as well as its energy efficiency by conducting optimizations on both host and network sides. First, as the DCN demands huge bisection bandwidth to interconnect all the servers, we propose a parallel packet switch (PPS) architecture that directly processes variable length packets without segmentation-and-reassembly (SAR). The proposed PPS achieves large bandwidth by combining switching capacities of multiple fabrics, and it further improves the switch throughput by avoiding padding bits in SAR. Second, since certain resource demands of the VM are bursty and demonstrate stochastic nature, to satisfy both deterministic and stochastic demands in VM placement, we propose the Max-Min Multidimensional Stochastic Bin Packing (M3SBP) algorithm. M3SBP calculates an equivalent deterministic value for the stochastic demands, and maximizes the minimum resource utilization ratio of each server. Third, to provide necessary traffic isolation for VMs that share the same physical network adapter, we propose the Flow-level Bandwidth Provisioning (FBP) algorithm. By reducing the flow scheduling problem to multiple stages of packet queuing problems, FBP guarantees the provisioned bandwidth and delay performance for each flow. Finally, while DCNs are typically provisioned with full bisection bandwidth, DCN traffic demonstrates fluctuating patterns, we propose a joint host-network optimization scheme to enhance the energy efficiency of DCNs during off-peak traffic hours. The proposed scheme utilizes a unified representation method that converts the VM placement problem to a routing problem and employs depth-first and best-fit search to find efficient paths for flows.

Orientador: Luiz Felipe Mendes de Moura / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-28T12:01:47Z (GMT). No. of bitstreams: 1 Nobrega_ClaudiaRosadoEspiritoSanto_M.pdf: 49731796 bytes, checksum: 231227e66649d1f3e29b15b3a64c3913 (MD5) Previous issue date: 2015 / Resumo: O presente trabalho refere-se a uma investigação experimental do comportamento de um sistema de refrigeração utilizando um compressor de rotação variável. Diante da necessidade do uso racional de energia elétrica, estudos entorno da eficiência energética são desenvolvidos como alternativas de redução do desperdiço em equipamentos, como desenvolvimento de dispositivos que necessite de menos consumo de energia sem comprometimento de sua eficiência, e possibilitando a acessibilidade destas alternativas para comunidade em geral. O uso do compressor de rotação variável tem sido estudado como alternativa de redução no consumo de energia por ser responsável por 80% do consumo total de energia consumida pelo sistema de refrigeração, que está cada vez mais presente nas indústrias e residências. Foi implementada uma bancada de teste composta por um subsistema de refrigeração por compressão a vapor e um subsistema secundário de resfriamento. Este estudo visa investigar experimentalmente a potência consumida, potência de compressão, coeficiente de performance (COP) e eficiência do sistema de refrigeração variando-se a carga térmica solicitada utilizando um compressor de rotação variável e o compressor em rotação fixa máxima fornecida pelo fabricante. Os resultados encontrados experimentalmente com a utilização do compressor em rotação variável apresentaram valores satisfatórios para os parâmetros avaliados e um melhor desempenho do sistema se comparado aos valores obtidos com o compressor em rotação fixa variando-se a carga térmica solicitada / Abstract: The present work relates to an experimental investigation of the behavior of a refrigeration system using a variable speed compressor. Faced with the need for rational use of energy, environment studies of energy efficiency are developed as wasting reduction alternatives in equipment such as developing devices that need less power consumption without compromising its efficiency and allowing the accessibility of these alternatives community. The use of variable speed compressor has been studied as alternative reduction in energy consumption to be responsible for 80 % of total energy consumption consumed by the cooling system, which is increasingly present in industry and households. A test bench comprising a subsystem vapor compression refrigeration and secondary cooling subsystem has been implemented. This study aims to experimentally investigate the consumed power, compression power, coefficient of performance (COP) and the refrigeration system efficiency by varying the thermal load applied using a variable speed compressor and the compressor at maximum fixed speed provided by the manufacturer. The results experimentally using the variable speed compressor showed satisfactory values for the parameters evaluated and improved system performance compared to the values obtained with fixed speed compressor in varying the required heat load / Mestrado / Termica e Fluidos / Mestra em Engenharia Mecânica

abstract: Due to extreme summer temperatures that regularly reach 122°F (50°C), cooling energy requirements have been responsible for 70% of peak demand and 45% of total electricity consumption in Kuwait. It is estimated that 50%-60% of electric power is consumed by the residential sector, mostly in detached villas. This study analyzes the potential impact of energy efficiency measures (EEM) and renewable energy (RE) measures on the electric energy requirements of an existing villa built in 2004. Using architectural plans, interview data, and the eQUEST building energy simulation tool, a building energy model (BEM) was developed for a villa calibrated with hourly energy use data for the year 2014. Although the modeled villa consumed less energy than an average Kuwaiti villa of the same size, 26% energy reductions were still possible under compliance with 2018 building codes. Compliance with 2010 and 2014 building codes, however, would have increased energy use by 19% and 3% respectively. Furthermore, survey data of 150 villas was used to generate statistics on rooftop solar area availability. Accordingly, it was found that 78% of the survey sample’s average total rooftop area was not suitable for rooftop solar systems due to shading and other obstacles. The integration of a solar canopy circumvents this issue and also functions as a shading device for outdoor activities and as a protective cover for AC units and water tanks. Combining the highest modeled EEMs and RE measures on the villa, the energy use intensity (EUI) would be reduced to 15 kWh/m2/year from a baseline value of 127 kWh/m2/year, close to net zero. Finally, it was determined that EEMs were able to reduce the entire demand profile whereas RE measures were most effective at reducing demand around mid-day hours. In future studies, more effort should be spent on collecting hourly data from multiple villas to assist in the development of a detailed hourly bottom-up residential energy modeling methodology. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2020

To broaden the application scenario and reduce energy consumption, we propose an energy-efficient fixed-gain (FG) amplify-and-forward (AF) relay assisted orthog- onal frequency-division multiplexing with index modulation (OFDM-IM) scheme in this thesis. The proposed system needs neither instantaneous channel state informa- tion (CSI) nor performing complicated processing at the relay node. It operates based on a new design of power allocation that minimizes the sum of transmit power at both source and relay node, given an outage probability constraint. Considering the actual situation and combining with the characteristics of normalization research, the pro- posed scheme can be discussed in two scenarios regarding to whether the subcarriers are interfered with by fading and noise independently. Based on the consistency of statistical CSI for each subcarrier, through a series of problem transformation and simplification, this thesis converts the original power allocation problem to a relaxed version and solve the relaxed problem using the convex optimization techniques. To reveal the computing efficiency of the proposed power allocation scheme, we analyze its computational complexity. Numerical simulations substantiate that the proposed optimization scheme has a neglectable loss compared with the brute force search, while the computational complexity could be considerably reduced. As for the sce- nario about the independence of statistical CSI for each subcarrier, an approach of artificial neural network (ANN) based on deep learning is incorporated into the sys- tem, enabling the proposed scheme to achieve a high accuracy comparing perfect optimization scheme. In the processing of power minimization, this study utilizes the adaptive moment estimation (Adam) method to implement back-propagation learn- ing and achieve the power allocation needed.