MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015 / Demand side management (DSM) initiatives have been introduced by Eskom to reduce the deficit between the electricity generation capacity and the electricity usage within the country. DSM projects enable Eskom to reduce electricity demand instead of increasing generation capacity. DSM projects are more economical and can be implemented much faster than constructing a new power station. One particular industry where DSM projects can be implemented is on mines. Mines consume about 14.5% of South Africa’s electricity. Producing compressed air, in particular, is one of the largest electricity users on mines. It consumes 17% of the electricity used on mines. The opportunity, therefore, arises to implement DSM projects on the compressed air system of mines. Not only do these projects reduce Eskom’s high electricity demand, but they also induce financial and energy savings for the mine itself. However, during the implementation of a compressed air energy savings project, various challenges arise. These include, among others, operational changes, control limitations, industrial actions and installation delays. All of these can lead to a project not being delivered on time, within budget or with quality results. The purpose of this study is to investigate and address various problems that occur during the implementation of such a compressed air energy savings project. The study shows that although these problems have an impact on the results achievable with the project, significant savings are still possible. Project savings are achieved by reducing the amount of compressed air that is supplied, thereby delivering sufficient compressed air while minimising the amount of compressed air being wasted. During this study, a gold mine’s compressed air network was optimised. The optimisation resulted in an evening peak-clip saving of 2.61 MW. This saving was achieved daily between 18:00 and 20:00 when Eskom’s electricity demand was at its highest. It is equivalent to an annual cost saving of R1.46 million based on Eskom’s 2014/2015 tariffs. When savings from all periods throughout the day are taken into account, the project will produce an annual cost saving of R1.91 million.

The objective of this thesis is to model and analyze the energy consumption in heterogeneous cellular systems and develop techniques to minimize it. First, the energy consumption is modeled and analyzed for multi-layered heterogeneous wireless systems. This work encompasses the characterization of all the energy consumed at the base stations. Then, a novel on-off and cell-association scheme is proposed to minimize the overall network energy consumption while satisfying the spatially- and temporally-varying traffic demands. Second, we exploit the use of multi-stream carrier aggregation not only to improve the energy efficiency, but also to balance it with the conflicting objective of capacity maximization. Third, we analyze the performance of discontinuous reception methods for energy savings within the user equipments. Then, for scenarios that support carrier aggregation, we develop a cross-carrier-aware technique that further enhances such savings with minimum impact on the packet delay. Fourth, the use of small cells as an energy-saving tool and its limitations are analyzed and modeled in OPNET, a high-fidelity simulation and development platform. To bypass such limitations, a novel small cell solution is proposed, modeled, and analyzed in OPNET and then compared against its existing alternative.

<p>The analyzed building in this project is located in Valbo, 9016 Stiftelsev 6. This house is a property of Gavlegårdarna, and it is being used as a house for disabled people. The building consists on five apartments, with one patient in each apartment. Some social workers help those patients in everything they need, making their living in the house as easy as possible.</p><p>The aim of this project is to find out the best option of reducing the energy consumption in this house. There are some alternatives to reduce the energy or the energy costs as; efficiency measures, load management and energy conversion.</p><p>This project is focused on the energy conversion for reducing the energy consumption. As it is the best option for obtaining a considerable reduction in the annual costs.</p><p>First of all the energy balance of the house is analyzed. By studying the energy balance it is possible to find out how the energy consumption of the house is divided. On one hand there is the heat supplied and on the other hand the heat losses.</p><p>As it was said before this project is focused in the reduction of the energy consumption by means of converting to another energy supplying method. Two alternatives have been studied: the installation of a heat pump and the connection to the district heating of Gävle.</p>

This study evaluated how well energy savings persisted over time in ten university buildings that had undergone retro-commissioning in 1996. The savings achieved immediately following retro-commissioning and in three subsequent years were documented in a previous study (Cho 2002). The current study expanded on this previous study by evaluating the performance of each building over nine additional years. Follow up retro-commissioning work performed in each building during that time was documented, as well as changes to the energy management control system. Savings were determined in accordance with the methodology outlined in the International Performance Measurement and Verification Protocol (IPMVP 2007), with ASHRAE Guideline 14 also serving as a reference. Total annualized savings for all buildings in 1997 (the year just after retro-commissioning) were 45(plus or minus 2)% for chilled water, 67(plus or minue 2)% for hot water, and 12% for electricity. Combining consumption from the most recent year for each building with valid energy consumption data showed a total savings of 39(plus or minus 1)% for chilled water, 64(plus or minus 2)% for heating water, and 22% for electricity. Uncertainty values were calculated in accordance with methodology in the IPMVP and ASHRAE Guideline 14, and were reported at the 90% confidence interval. The most recent year of data for most of the buildings was 2008-2009, although a few of the buildings did not have valid consumption data for that year. Follow up work performed in the buildings, lighting retrofits, and building metering changes beginning in 2005 were the major issues believed to have contributed to the high level of savings persistence in later years. When persistence trends were evaluated with adjustment for these factors, average savings for the buildings studied were found to degrade over time, and exponential models were developed to describe this degradation. The study concluded that on average energy savings after retro-commissioning will degrade over time in a way that can be modeled exponentially. It was also concluded that high levels of savings persistence can be achieved through performing retro-commissioning follow up, particularly when significant increases are observed in metered energy consumption data, but also at other times as retro-commissioning procedures and technology continually improve.

Simulation is one of the best Analytical tools for Building Research .Energy Efficient Buildings are of great concern which is gaining importance steeply in this energy scarcity’s world. Selected for the thesis work is a small Office building (Mariannelund), located in Jönköping. The building is single-storied with 26 rooms. The study motive involves Energy Survey and to provide, investigate Energy conservation measures. The Energy simulation software used is the IDA indoor climate and energy 3.0. (ICE).Data included was from the provided (Specifications) and with the review of architectural drawings. Energy saving measures was analyzed, documented with respect to their feasibility and practical operational strategies. Measures concerning the modifications in the building envelope; retrofit insulation, shading devices and other improvements leading to savings of energy have been tested and are supplemented with results. The Proposed Model which is with the combined Energy saving measures yields annual energy savings of about 70% and also working efficiency is increased by 37% compared to the existing building’s Baseline model.Considering the economic aspects together with the thermal response of employees the analyzed energy saving measures are highly recommended.

The analyzed building in this project is located in Valbo, 9016 Stiftelsev 6. This house is a property of Gavlegårdarna, and it is being used as a house for disabled people. The building consists on five apartments, with one patient in each apartment. Some social workers help those patients in everything they need, making their living in the house as easy as possible. The aim of this project is to find out the best option of reducing the energy consumption in this house. There are some alternatives to reduce the energy or the energy costs as; efficiency measures, load management and energy conversion. This project is focused on the energy conversion for reducing the energy consumption. As it is the best option for obtaining a considerable reduction in the annual costs. First of all the energy balance of the house is analyzed. By studying the energy balance it is possible to find out how the energy consumption of the house is divided. On one hand there is the heat supplied and on the other hand the heat losses. As it was said before this project is focused in the reduction of the energy consumption by means of converting to another energy supplying method. Two alternatives have been studied: the installation of a heat pump and the connection to the district heating of Gävle.

Energy security is probably one of the most challenging issues around the world. Therefore, the focus on methods of decreasing energy consumption and consequently its associated greenhouse gas (GHG) emissions is intensified by policy decision makers. Residential buildings are one of the potential sectors that can reduce its energy consumption in various ways, such as: improving thermal characteristics of the building, using more energy efficient appliances and using renewable energy resources. Among these methods, integration of solar technologies to buildings provides one of the substantial opportunities for reducing energy consumption and the associated GHG emissions in Canada’s residential sector. Therefore, this research work was conducted to assess the impact of solar technologies and solar technology integration strategies on the end-use energy consumption and the associated greenhouse gas (GHG) emissions in Canadian residential sector by using a new state-of-the-art end-use energy and GHG emissions model of the Canadian residential housing stock. The new Canadian residential end-use energy and emissions model that is used in this project incorporates a 17,000 house database developed using the latest data available from the Energuide for Houses database, Statistics Canada housing surveys, and other available housing databases, and utilizes an advanced building energy simulation program as its simulation engine. A new neural network methodology is incorporated into the model to estimate the socio-economic and demographic dependencies of the energy consumption of discretionary end-uses such as appliances, lighting and domestic hot water, while a new approach is used to incorporate occupancy, appliance, lighting and domestic hot water load profiles into the model. A new method is used to calculate the GHG emissions from electricity consumption used in the residential sector based on the actual electrical generation fuel mix and the marginal fuel used in each province as a function of time of the year. Each solar technology is added to the eligible houses to examine the interrelated effects of integrated solar technologies and practices on the housing stock. The objective is to conduct realistic assessments of the cost effectiveness, energy savings and GHG emission reduction benefits of integrated solar technologies for the entire Canadian housing stock (CHS) as well as for different regions, house type, and fuel types. The integrated solar technologies and practices that are assessed include passive solar with added thermal storage and motorized blinds, solar DHW system, and photovoltaic electricity and heat generation systems. This project provides a comprehensive techno-economic and emissions assessment of integrated solar technologies and practices, and will be useful for developing national and regional policies and strategies related with integrating solar energy into the residential sector.

This report looks at the modern cellular wireless network environment and the factors of energy consumption therein. The consumption of connectivity re- lated hardware is gradually becoming a larger part of the power consumption of virtually any mobile device. This report studies measurements of a mobile broadband module energy usage due to data transfer. It is found that switch- ing between technologies is still beneficial and savings are very feasible when using technologies with different traits if done correctly. Further the possibility of energy savings within a single high-bandwidth technology (3G) are assessed considering variations on response time and throughput. This is relevant as the need to handle highly dynamic loads becomes more and more important in the modern connectivity landscape. By gauging the savings available from schedul- ing link accesses and switching technology this is put in context by sampling a few common services namely Skype, Spotify and normal web browsing for their energy footprints. We will also look briefly at the background traffic generated by two common operating systems, Windows 7 and Ubuntu GNU/Linux.

As a result of the rising electrical energy costs in South Africa, a method was sought to reduce the overall electrical consumption of typical shaft systems. A typical shaft configuration was analysed and the primary energy consumers were identified. The ventilation fans for this system were found to consume a total of 15% of the total energy of the shaft system. It was calculated that more than 50% of this energy is consumed by the shaft itself, more specifically by the pressure losses that occur in the shaft as the ventilation air passes through it. It was recognised that there was therefore an opportunity to achieve an energy savings and therefore a costs savings in the total cost of operating a shaft system by reducing the overall resistance of the equipped downcast shaft. However, before any work could continue in this regard, the results noted above required validation. This was achieved though the comprehensive evaluation of the Impala #14 Shaft system. This system was tested and the pressure losses noted in the calculations were verified. In order to ensure that the theory being used was accurate, the next step was to evaluate a number of shafts both from a theoretical perspective by measuring the real shaft pressure losses against time. This was done and a total of five shafts were instrumented and the actual pressure losses over the shaft plotted against time. These shafts were then subjected to a theoretical evaluation using the theory as described by McPherson in 1987. Finally, in order to ensure a thorough understanding of the behaviour of the ventilation air in shaft systems, the systems were simulated using computational fluid dynamic (CFD) techniques. On the whole there was not a good correlation between the tests and either the theoretical calculations or the CFD simulations. This was attributed to the general imperfections in the shaft and the difficulty in obtaining exact values for the drag coefficients of the buntons. These differences highlight the difficulty in modeling the non-homogenous physical environment and providing a factor that can be used to ensure that the theoretical designs are aligned with the physical reality. This factor is approximately 30%. There were also significant discrepancies between the theoretical analysis and the CFD simulation during the initial comparisons. This discrepancy reduced as the complexity of the CFD models increased, until, when the complete shaft was modeled using the full buntons sets, the pipes and the flanges, the difference between the theoretical evaluation and the CFD simulation was small. The result demonstrates that the theory is insufficient and that the inter-related effect of the buntons and fittings has not been fully appreciated. The current theory however has been developed using drag coefficients and interference factors for the buntons sets which have been taken from measurements of similar configurations. This does account for the relative accuracy of the current theory in that there is little difference between the CFD result and that of the theory. However, as the shaft parameters are changed to reflect new layouts and scenarios, it is unlikely that theory will continue to prove accurate. The final phase of the work presented here was to evaluate the cost-effectiveness of using different bunton shapes and shaft configurations. It is shown that: <ul><li> The increase in the pressure losses and therefore the direct operating costs of the shaft can vary by as much as 80%, depending on the bunton configuration chosen.</li><li> The placement of the piping in the shaft can increase the pressure losses and therefore the direct operating costs of the shaft by as much as 12%, depending on the placement of the piping in the shaft; this effect includes the use of flanges. </li><li> The use of fairings on a large cage can reduce the resistance that the cage offers to the ventilation flow by as much as 30%. This, however, does not translate into a direct saving because as the cage moves through the shaft, the overall effect is transitory. </li> </ul> The savings discussed above can be significant when the items highlighted in this work are applied correctly. / Thesis (PhD(Eng))--University of Pretoria, 2012. / Mining Engineering / unrestricted

Legal instruments of energy efficiency Abstract and key words The diploma thesis deals with energy efficiency as a unique source of energy. The subject of this thesis is to specify key legal instruments of energy efficiency, i.e. conceptual, administrative and economical instruments. The diploma thesis is divided into five chapters. In the introductory chapter, being called Energy Policy, there is a brief outline of the background of energy politics on both the international and EU level, including environmental protection. This introductory chapter also ranks the Czech Republic among countries with high energy performance. Energy efficiency is the opportunity to lower its energy performance. The second chapter, Legal Instruments of Energy Efficiency, defines legal instruments of energy efficiency as a part of environmental protection. This chapter is a general one; the instruments are concretized in the following chapters. In addition, this chapter focuses on the principle of sustainable development, as well as issues related to human factor, climate conditions and rebound effect. The third chapter, called Conceptual Instruments, provides further information relating to conceptual strategies of energy efficiency. For the EU conceptions, key directives are mentioned to regulate energy efficiency, namely the...