This project consists on the Energy audit carried out on a residential building in Skutskär, property of the company Älvkarlebyhus, which is placed in the Älvkarleby municipality, belonging to Uppsala County in Sweden. The aim of the Energy audit is to obtain how much Energy is used, when is it used and how is it used. As well as the costs of the Energy use. The aim of the Energy audit also consists in reduces the Energy use applying efficiency measures. The audit carried out consist on identifying the heat losses and heat gains of the building, thus establishing an Energy balance that will reflect the Energy state of the building and finally propose some efficiency measures that could be applied. With this purpose, a strong method was developed in order to obtain as accurate results as possible. This method studies separately each component of the balance in order to get a better approach. The idea when working and present the results is to manage all the information in an easy way and present it in an easily understandable way for everyone, thus was used a spreadsheet. The expected results have been achieved; the difference between the heat losses and gains is of 0 MWh, which represents the balance 0 and all the values obtained are according to the experience values, which achieve the expected results. The total heat gain of the balance accounts for 1575,23 MWh. It is compounded by the District heating consumption which accounts 742,22 MWh that represents the 47 % of the heat gain and by the free heating which accounts for 832,79 MWh that represents the 53 %. The free heating is compounded by solar radiation which accounts for 643,36 MWh representing 41 % and for Internal heating which accounts for 189,43 MWh that represents 12 %. The total heat loss of the balance accounts for 1575,23 MWh. It is compounded by transmission losses which accounts for 875,46 MWh that represents 56 %, mechanical ventilation which accounts for 369,89 MWh that represents the 23 %, natural ventilation which account for 182,88 MWh that represents 12 % and hot tap water which account for 147 and represents 9 %. The efficiency measures will improve the Energy use in the buildings; especially in the cases were the Energy usage is too high, as in the case of transmission losses. Thus, the efficiency measures will be proposed mainly to alleviate the high values but also to improve other inefficient uses of the Energy. There are some efficiency measures proposed for every component of the balance and there is also some recommendation for the company in order to implement the most attractive ones, taking into account its profitability. These measures are only proposed and not studied deeply because of the main limitation of this thesis. Therefore, it is recommended to continue the study in order to examine and analyse deeply each measure, according to the energetic survey already done.

This work is centered on low-frequency and high-frequency multiphysics problems of piezoelectric structures submerged in a quiescent fluid domain for the applications of vibration energy harvesting, biomimetic actuation, and contactless acoustic energy transfer. In the first part of this research, Macro-Fiber Composite (MFC)-based piezoelectric structures are employed for underwater mechanical base excitation and electrical biomimetic actuation in bending mode at low frequencies (the fundamental underwater bending resonance being in the infrasonic frequency range). The MFC technology (fiber-based piezoelectric composites with interdigitated electrodes) exploits the effective 33-mode of piezoelectricity, and strikes a balance between structural deformation and force levels for actuation to use in underwater locomotion, in addition to offering high power density for energy harvesting to enable battery-less aquatic sensors. Following in-air electroelastic composite model development, the fundamental research problem is to establish semi-analytical models that can predict the underwater dynamics of thin MFC cantilevers for different length-to-width aspect ratios. In-air analytical electroelastic dynamics of MFCs is therefore coupled with added mass and nonlinear hydrodynamic damping effects of fluid to describe the underwater electrohydroelastic dynamics in harvesting and actuation. To this end, passive plates of different aspect ratios are tested to extract and explore the repeatability of the inertia and drag coefficients in Morison’s equation. The focus is placed on the first two bending modes in this semi-empirical approach. In particular, electrode segmentation is studied for performance enhancement in the second bending mode. Additionally, nonlinear dependence of the output power density to aspect ratio is characterized theoretically and experimentally in the underwater base excitation problem. In the second part of this work, Ultrasonic Acoustic Energy Transfer via piezoelectric transduction is investigated theoretically and experimentally. Contactless energy transfer using acoustic excitation offers larger distances of power transmission as compared to well-studied inductive method. Various transmitter configurations (e.g. spherical, cylindrical, and focused) are explored for energy transfer to a piezoelectric receiver bar (operating in the longitudinal/thickness mode) that is shunted to a generalized resistive-reactive circuit. Fixed-free and free-free mechanical boundary conditions of the receiver are explored in detail. The resulting multiphysics analytical model framework is compared with finite-element simulations and experiments conducted in fluid (water and oil). Optimal piezoelectric receiver material and electrical loading conditions are sought for performance and bandwidth enhancement.

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<p> Environmental concerns are driving the automotive industry towards more sustainable and efficient forms of transportation such as electric vehicles. The electric drivetrains present in the various types of electric vehicles are much more efficient than traditional internal combustion engine drivetrains and produce fewer greenhouse gases. The most popular type of motor used in electric vehicle drivetrains is the permanent magnet synchronous motor. This can be attributed to its inherent high power density, large torque to weight ratio, and high reliability and efficiency. Advanced control techniques for permanent magnet synchronous motor drives must be developed in order to meet the high performance and efficiency demands of modern electric vehicles. Application of the nonlinear control method known as sliding mode control is the focus of this work. Both first order and higher order sliding mode methods are considered. These control methods provide robustness to modeling inaccuracies, internal parameter variations, and external disturbances. In addition to permanent magnet synchronous motors, the sliding mode control methods are also applied to the buck-boost type DC-DC converter. DC-DC converters have found extensive applications, ranging from consumer electronics to electric vehicles and smart grid synchronization. Computer simulation studies verify the efficacy of the proposed control techniques.</p>

Set in the context of the problems the UK has experienced in achieving effective economic policies, focusing primarily on the role of the civil service, the thesis examines the development and implementation of energy conservation policy, in the UK, from the mid-1970s until April 1992, concentrating mainly on the 1980s. Changes since April 1992 and the prospects for energy conservation in the remainder of the 1990s are considered briefly in the final chapter and conclusion. The thesis uses energy conservation as a case study to explore general theories of policy development and implementation. Comparisons are made with Japan and Denmark. In the case of Japan, the comparison is set in the context of Japanese economic success and the role of the Ministry of International Trade and Industry. In the case of Denmark, the context is the planning system and the role of local government. The thesis examines the relative importance of systems of administration and other factors including: prevailing ideological orthodoxies; the roles of policy communities and networks. The title - "Procedure over purpose" - reflects several themes within the thesis including: the differences between procedure and purpose governed states; the relevance of the 1980s and 1990s civil service reforms to procedure or purpose driven policy areas. A further important theme is efficiency, both in terms of the emphasis on efficiency in civil service reforms and because of a change of terminology from energy conservation to energy efficiency during the period under study. Conclusions are drawn on the extent to which development and implementation of energy conservation policy in the UK has been governed more by procedure than a sense of purpose; how far this differs from other countries (primarily Japan and Denmark); its effect on the UK's achievement of energy savings up to the late 1980s; and the implications for policy success or failure.

This thesis, based on a methodology borrowed from Science and Technologies Studies (STS), studies the implications of using energy modeling software for code compliance in the architectural design process. Specifically, the careful study of the development and use the of the software itself, including the assumptions and frameworks of its developers and users, is required to accurately examine the implications and practical effectiveness of using energy modeling to aid in reducing the environmental consequences of the built environment. I argue that the value in studying energy modeling software is not primarily to improve the scientific accuracy of the software. Rather, the value is to demonstrate how the assumptions used in the software’s calculation methodology can adversely influence the technological decisions made by building designers when using the software to demonstrate compliance with energy codes. To develop this hypothesis I have employed both historical and empirical methods. In my historical analysis, I find that the origins of modern building energy modeling software date back to the beginning of the air conditioning industry at the start of the 20th century. One consequence of this history is that assumptions built into the software measure the relative efficiency of building components under static and assumed average conditions, but not the dynamic rates of consumption caused by inhabitation. This, in-turn, prescribes the problem-at-hand of energy code compliance as primarily technical. However, as others have argued, dynamic social and circumstantial issues also influence energy consumption (Guy & Shove, 2000). Therefore as means to examine potential conflicts between the static and technical method of analysis employed by code compliance energy modeling software and the dynamic and circumstantial context in which buildings are designed, my empirical analysis is of a design process for a net-zero energy subdivision in Austin, Texas in which energy modeling was required and used extensively. The case study is designed to demonstrate how the problems-at-hand for each distinct group of stakeholders involved in the design process was varied and did not necessarily conform to the technical solution advocated by the energy modeling process. A primary conclusion of my analysis is that all mature technologies come to us with embedded assumptions that may subvert our intentions. A secondary conclusion is that the competing assumptions and problem definitions of building scientists and building designers tend to frustrate the goal of sustainable development. My hope in studying energy modeling, in relation to practice and code compliance, is to discover ways to better use the analytical power of energy modeling that is more directly responsive to the dynamic and contextual conditions of architectural production and real world resource consumption. / text

The building sector represents the largest energy consumer among the United States' end use sectors. As a result, the public and private sector will continue to place great emphasis on designing energy efficient buildings that minimize operating costs while maintaining a healthy environment for its occupants. Creating design-phase building energy models can facilitate the process of selecting life-cycle appropriate design strategies aimed at maximizing building energy efficiency. The primary objective of this research study is to gain greater insight into likely causes of variation between energy predictions derived from building energy models and building energy performance during post-occupancy. Identifying sources of error can be used to improve future modeling efforts that can potentially lead to greater accuracy and better decisions made during the building's design phase. My research approach is to develop a method for conducting retrospective analysis of building energy models in the areas that affect the building's predicted and actual energy consumption. This entails collecting pre-construction and post-occupancy related data from various entities that exhibit influence on the building's energy performance. The method is then applied to recently-constructed military dormitory buildings that utilized building energy modeling and now have actual, metered building energy consumption data. The study also examines how building occupancy impacts energy performance. The value of this work will provide additional insight to future building energy modeling efforts. / text

Communities across the United States have almost universal access to electricity services. However, there remains a large problem with fuel poverty, where households pay a significant and disproportionate amount of their gross income on energy bills. This is often a factor in those households’ continued poverty. Fuel poverty is especially prevalent in the unincorporated and often overlooked colonias communities in South Texas, near the border with Mexico, which are characterized by a high level of poverty, a large unbanked population that don’t have or are unapproved to have bank accounts, proportionally high energy costs, and substandard housing. There are government programs and charities that assist with bills, but the cycle of fuel poverty will continue without solutions that address the source of the disproportionately high bills: energy inefficiency. Public-private partnerships are needed to sustainably finance energy efficiency improvements and to break the cycle of poverty. One potential solution is the application of microfinance concepts geared solely at home efficiency improvements, where households can build credit while alleviating their home energy bill burden. / text

As the demand for safe and clean electricity increases, the New Zealand wind energy industry seems poised to expand. Many generating companies have projects in the planning stage and there are likely to be many more potential sites yet to be identified. Reliable wind climate predictions over a wide area and for different heights above grounds are often vital to determine the viability of wind farm projects. This study investigates the use of meteorological mesoscale models to determine the wind and energy resource, particularly in areas of complex terrain. Complex terrain environments are likely to be typical of where New Zealand wind energy developments will take place. Using the prognostic mesoscale meteorological model TAPM (The Air Pollution Model), regions of relatively high mean wind speed were identified for a number of regions, including Banks Peninsula and parts of Canterbury and Otago. The simulations were conducted for a one-year period (2001) and at different heights above ground level. Depending on the resolution of the model calculations, speed-up effects from the forcing of some topographic features were accounted for by this model. Where the modelling was considered reliable, hourly wind data were obtained from grid points within the inner grid and used as input data for the industry-standard wind energy assessment model WAsP (The Wind Atlas Analysis and Application Program). As WAsP is able to account for detailed topography and surface roughness features, wind and energy predictions at a specific site or over a wider area surrounding the site were made. Limitations of both models in complex terrain were identified. These limitations were due to a number of factors, including the grid spacing used for mesoscale model calculations, the complexity of the terrain, and difficulties in modelling some regional scale airflow regimes. Being aware of when and where model limitations are likely to occur is important in being able to overcome and account for them.

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