Samhället idag är beroende av energi för att fungera och att eftersträva utveckling av förnybar energi bör ha högsta prioritet. År 2013 produceras 81,6% av världens totala energi av fossila bränslen. Bostads- och servicesektorn står idag för 38 % av Sveriges totala energianvändning. På grund av att bostäder och lokaler står för så stor del av energianvändningen är det väldigt viktigt att ha noggrann koll på energiprestandan av byggnader och lokaler samt vilka energieffektiviseringar som kan utföras. Sörbyskolan är belägen i södra delen av Gävle och fastigheten ägs och förvaltas av Gavlefastigheter. År 2015 planerar Gavlefastigheter en renovering av Sörbyskolan och vill ta fram energieffektiviseringsförslag. Skolan är uppdelad på sex byggnader som inkluderar en matsal, en gymnastiksal, en förskola och tre andra skolbyggnader. I denna rapport har förskolan med tillhörande passage undersökts. Förskolan och passagen är ett envåningshus med en area på 883 m2. Speciellt för passagen är att den är uppvärmd med direktverkande elenergi. Undersökningen har skett i simuleringsprogrammet IDA Indoor Climate and Energy. Boverket har satt upp riktlinjer och krav för hur mycket energi nybyggda lokaler och bostäder får använda beroende på vilken klimatzon byggnaden befinner sig i. Gävleborg befinner sig i klimatzon II och lokaler i denna klimatzon får max använda 100 kWh/m2, år. En basmodell av hur bygganden ser ut idag skapades för att identifiera vart de största energiförlusterna sker. Sedan jämfördes olika energieffektiviseringar med basmodellen för att se hur mycket energi som potentiellt skulle kunna sparas. Basmodellen skapades genom att få fram information om byggnaden och mata in i IDA ICE. Informationen skaffades bl.a. genom en fysisk undersökning, intervjuer, jämförelse med andra byggnader på Sörbyskolan m.m. Arbetet visar fördelningen av till- och bortförd energi i byggnaden och vilka energieffektiviseringsåtgärder som är mest lämpliga för att minska energianvändningen. Resultatet pekar på att byta till nya energieffektiva fönster ger den största energibesparingen och totalt sparas 19,8 kWh/m2,år. Om alla energieffektiviseringsåtgärder utförs ger det en energibesparing på 37,8 kWh/m2,år. Det har gjorts mycket antaganden och uppskattningar för att skapa basmodellen vilket gör att den skiljer sig en del ifrån verkligheten. För att få en mer korrekt modell skulle fler fysiska undersökningar och mätningar behöva utföras på byggnaden. / Today’s society is very dependent on energy to function and to pursue development of renewable energy should have the highest priority. In 2013 81.6 % of the total produced energy in the world came from fossil fuels. The residential and service sector stands for 38 % of Sweden’s total energy use. Due to that fact it’s very important to have careful track of the energy performance of buildings and premises and what energy efficiencies can be applied. The school is located in south of Gävle and the property is owned and managed by Gavlefastigheter. In 2015 Gavlefastigheter is planning a renovation of the school and wants to develop energy efficiency proposals. The school is divided into six buildings which includes a dining hall, a gymnasium, a preschool and three other school buildings. In this rapport the preschool with appurtenant passage have been examined. The preschool and the passage is a one story building with an area of 883 m2. Particularly for the passage is that it’s heated with direct electricity. The survey have been conducted in a simulation program called IDA Indoor Climate and Energy. Boverket has set up guidelines and requirements for how much energy the newly built premises and residences may use depending on which climate zone the building is located. Gävleborg is located in climate zone II and premises in this climate zone may use a maximum of 100 kWh/m2 per year. A base model of the buildings current state were created to identify where the biggest energy losses occur. Afterwards the different energy efficiency proposals were compared with the base model to see how much energy could be saved. The base model were created by collecting data to IDA ICE. The data was collected by a physical inspection, interviews, comparison with another building on the school of Sörby etc. This work shows the distribution of supplied and xx energy in the building and what energy efficiency action that is most suitable to reduce the energy use. The result points to switching to new energy efficient windows gives the biggest savings in energy and a total of 19.8 kWh/m2, year can be saved. If all proposals is performed that will give a total saving of 37.8 kWh/m2, year. There have been a lot of assumptions and estimates to create the base model which makes it somewhat different from reality. To get a more correct model more physical examinations and measurements would be needed.

This thesis describes an environment to evaluate and compare static schedulers for real pipelined streaming applications on massively parallel architectures, such as Intel Single chip Cloud Computer (SCC), Adapteva Epiphany, and Tilera TILE-Gx series. The framework allows performance comparison of schedulers in their execution time, or the energy usage of static schedules with energy models and measurements on real platform. This thesis focuses on the implementation of a framework evaluating the energy consumption of such streaming applications on the SCC. The framework can run streaming applications, built as task collections, with static schedules including dynamic frequency scaling. Streams are handled by the framework with FIFO buffers, connected between tasks. We evaluate the framework by considering a pipelined mergesort implementation with different static schedules. The runtime is compared with the runtime of a previously published task based optimized mergesort implementation. The results show how much overhead the framework adds on to the streaming application. As a demonstration of the energy measuring capabilities, we schedule and analyze a Fast Fourier Transform application, and discuss the results. Future work may include quantitative comparative studies of a range of different static schedulers. This has, to our knowledge, not been done previously.

Addressing building energy use is a pressing issue for building sector decisionmakers across Europe. In Sweden, some regions have adopted a target of reducingenergy use in buildings by 50% until 2050. However, building codes currently donot support as ambitious objectives as these, and novel approaches to addressingenergy use in buildings from a regional perspective are called for. The purpose ofthis licentiate thesis was to provide a deeper understanding of most relevant issueswith regard to energy use in buildings from a broad perspective and to suggestpathways towards reaching the long-term savings objective. Current trends inbuilding sector structure and energy use point to detached houses constructed before1981 playing a key role in the energy transition, especially in the rural areas ofSweden. In the Swedish county of Dalarna, which was used as a study area in thisthesis, these houses account for almost 70% of the residential heating demand.Building energy simulations of eight sample houses from county show that there isconsiderable techno-economic potential for energy savings in these houses, but notquite enough to reach the 50% savings objective. Two case studies from ruralSweden show that savings well beyond 50% are achievable, both when access tocapital and use of high technology are granted and when they are not. However, on abroader scale both direct and indirect rebound effects will have to be expected,which calls for more refined approaches to energy savings. Furthermore, researchhas shown that the techno-economic potential is in fact never realised, not even inthe most well-designed intervention programmes, due to the inherent complexity ofhuman behaviour with respect to energy use. This is not taken account of in neithercurrent nor previous Swedish energy use legislation. Therefore an approach thatconsiders the technical prerequisites, economic aspects and the perspective of themany home owners, based on Community-Based Social Marketing methodology, issuggested as a way forward towards reaching the energy savings target.

Large cooling systems consume up to 25% of the total electricity used on deep level mines. These systems are integrated with the water reticulation system to provide chilled service water and cool ventilation air. Improving the energy efficiency of these large cooling systems is an important electrical demand-side management initiative. However, it is critical that the service delivery and system performance be maintained so as to not adversely affect productivity. A novel demand-side management strategy, based on variable water flow, was developed to improve the energy efficiency of large cooling systems like those found on deep mines. The strategy focuses on matching the cooling system supply to the demand through the use of modern energy efficient equipment, such as variable speed drives. The strategy involves the modulation of evaporator, condenser, bulk air cooler and pre-cooling water according to partial load conditions. A unique central energy management system was developed to integrate the proposed strategies on large cooling systems. The system features a generic platform and hierarchical network architecture. Real-time energy management is achieved through monitoring, optimally controlling and reporting on the developed strategy. The system is robust and versatile and can be applied to various large cooling systems. The feasibility of the strategy and energy management system was first investigated through the use of an adapted and verified simulation model and a techno-economic analysis. The strategy was then implemented on four large mine cooling systems and its in situ performance was assessed as experimental validation. The results of the Kusasalethu surface cooling system are discussed in detail as a primary case study while the results of the Kopanang, South Deep South Shaft and South Deep Twin Shaft cooling systems are summarised as secondary case studies. The potential to extend the variable water flow strategy to other industrial cooling systems is assessed through an investigation on the cooling system of the Saldanha Steel plant. Results indicate that, over a period of three months, average electrical load savings of 606-2 609 kW (29.3-35.4%) are realised on the four systems with payback periods of 5-17 months. The average electrical load saving between the sites is 33.3% at an average payback period of 10 months. The service delivery and performance of the cooling system and its critical subsystems are not adversely affected. The potential to extend the method to other large cooling systems is also shown. The developed variable water flow strategy is shown to improve the energy efficiency of large cooling systems, making a valuable contribution towards a more sustainable future. This thesis is presented as a detailed discussion of the entire research process. The key results have also been summarised in a series of five research articles attached as independent annexures. Three articles have been published in international scientific journals, one has been presented at and published in the proceedings of an international conference and one is still under review. / Thesis (PhD (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013

The demand for electricity in South Africa has grown faster than the increase in generation capacity. However, it is expensive and time consuming to commission new power stations. Another approach is to reduce electricity demand through the implementation of energy efficiency projects. This alternative is usually less expensive. Compressed air on South African mines is a large electricity consumer with a reputation of wastage. This allows significant potential for electrical and financial savings. A typical mine compressed air system consists of multiple compressors at various locations, surface connection networks, underground distribution systems, thousands of users and leaks. The size, complexity and age of these systems provide a major challenge for electricity saving efforts. Simulating such an intricate system is difficult as it is nearly impossible to accurately gather all the required system parameters. Some initiatives focused on subsections of mine compressed air systems. This is not the best approach as changes to one subsection may adversely affect other systems. A new approach to simplify mine compressed air systems was developed to identify saving opportunities and to assess the true impact of saving efforts. This new approach enables easier system analysis than complex simulation models. Techniques to gather critical system information are also provided. A new implementation procedure was also developed to integrate different energy saving strategies for maximum savings. An electrical power saving of 109 MW was achieved through the implementation of the integrated approach on twenty-two mine compressed air systems. The savings is equivalent to a reduction of 0.96 TWh per annum that relates to a saving of 0.4% of South Africa’s total electricity consumption. Average compressor power consumption was reduced by 30%. The power consumption reduction relates to an estimated annual electricity cost saving of R315 million. A saving of 0.96 TWh per annum is equivalent to a carbon dioxide emission reduction of 0.98 million tonne. The implementation of the integrated approach could be applied to other industrial compressed air systems. A reduction in electricity consumption of 30% on all industrial compressed air systems has the potential to reduce global electricity demand by 267 TWh per annum. That is more than the total amount of electricity consumed in South Africa. / Thesis (PhD (Electrical Engineering))--North-West University, Potchefstroom Campus, 2013

Global climate change and the electricity supply constraints could possibly be one of the utmost strategic issues facing businesses and consumers of all sizes currently in South Africa. Energy Efficiency is the ability to produce the same output but with less energy. The implementation of Energy Efficiency strategies is pivotal in order to sustain the climatic conditions as well as mitigate the supply constraints the South African utility Eskom is experienced. The aim of this study was to reiterate the importance of energy efficiency strategies and to identify the barriers and challenges companies face towards implementing energy efficiency and energy management strategies. This dissertation identified incentives and rebate schemes available to promote energy efficiency strategies and discussed the policies and strategies the South African Government implemented towards realising the energy efficiency target of 12%.The literature review conclude with discussing best practices indentified by implementing corporate energy efficiency strategies. The level of preparedness and progress in implementing an energy management system and strategies between the different companies were assessed. The target population includes the high intensity user group (HIU), listed and SME companies in the different industry sectors in South Africa. The study concludes that there are still multiple challenges facing companies in implementing sustainable energy efficiency strategies. Although government and multiple stakeholders are initiating incentive and rebate models to promote the implementation of energy efficiency measures, industry still lacks the commitment to change their behaviour toward implementing energy management strategies. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.

Growing demand for electricity forces suppliers to expand their generation capacity. Financing these expansion programmes results in electricity cost increases above inflation rates. By reducing electricity consumption, additional supply capacity is created at lower costs than the building of conventional power stations. Therefore, there is strong justification to reduce electricity consumption on the supplier and consumer side. The mining and industrial sectors of South Africa consumed approximately 43% of the total electricity supplied by Eskom during 2012. Approximately 10% of this electricity was used to produce compressed air. By reducing the electricity consumption of compressed air systems, operating costs are reduced. In turn this reduces the strain on the South African electricity network. Previous energy saving projects on mine compressed air systems realised savings that were not always sustainable. Savings deteriorated due to, amongst others, rapid employee turnover, improper training, lack of maintenance and system changes. There is therefore a need to improve projects that have already been implemented on mine compressed air systems. The continuous improvement of equipment (such as improved control valves) and the availability of newer technologies can be used to improve existing energy saving strategies. This study provides a solution to reduce the electricity consumption and operating costs of a deep level mine compressed air system. This was achieved by modernising and improving an existing underground compressed air saving strategy. This improvement resulted in a power saving of 1.15 MW; a saving equivalent to an annual cost saving of R4.16 million. It was found that the improved underground compressed air DSM project realised significant additional electrical energy savings. This resulted in ample cost savings to justify the implementation of the project improvements. It is recommended that opportunities to improve existing electrical energy saving projects on surface compressed air systems are investigated. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Large cooling systems consume up to 25% of the total electricity used on deep level mines. These systems are integrated with the water reticulation system to provide chilled service water and cool ventilation air. Improving the energy efficiency of these large cooling systems is an important electrical demand-side management initiative. However, it is critical that the service delivery and system performance be maintained so as to not adversely affect productivity. A novel demand-side management strategy, based on variable water flow, was developed to improve the energy efficiency of large cooling systems like those found on deep mines. The strategy focuses on matching the cooling system supply to the demand through the use of modern energy efficient equipment, such as variable speed drives. The strategy involves the modulation of evaporator, condenser, bulk air cooler and pre-cooling water according to partial load conditions. A unique central energy management system was developed to integrate the proposed strategies on large cooling systems. The system features a generic platform and hierarchical network architecture. Real-time energy management is achieved through monitoring, optimally controlling and reporting on the developed strategy. The system is robust and versatile and can be applied to various large cooling systems. The feasibility of the strategy and energy management system was first investigated through the use of an adapted and verified simulation model and a techno-economic analysis. The strategy was then implemented on four large mine cooling systems and its in situ performance was assessed as experimental validation. The results of the Kusasalethu surface cooling system are discussed in detail as a primary case study while the results of the Kopanang, South Deep South Shaft and South Deep Twin Shaft cooling systems are summarised as secondary case studies. The potential to extend the variable water flow strategy to other industrial cooling systems is assessed through an investigation on the cooling system of the Saldanha Steel plant. Results indicate that, over a period of three months, average electrical load savings of 606-2 609 kW (29.3-35.4%) are realised on the four systems with payback periods of 5-17 months. The average electrical load saving between the sites is 33.3% at an average payback period of 10 months. The service delivery and performance of the cooling system and its critical subsystems are not adversely affected. The potential to extend the method to other large cooling systems is also shown. The developed variable water flow strategy is shown to improve the energy efficiency of large cooling systems, making a valuable contribution towards a more sustainable future. This thesis is presented as a detailed discussion of the entire research process. The key results have also been summarised in a series of five research articles attached as independent annexures. Three articles have been published in international scientific journals, one has been presented at and published in the proceedings of an international conference and one is still under review. / Thesis (PhD (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013

The demand for electricity in South Africa has grown faster than the increase in generation capacity. However, it is expensive and time consuming to commission new power stations. Another approach is to reduce electricity demand through the implementation of energy efficiency projects. This alternative is usually less expensive. Compressed air on South African mines is a large electricity consumer with a reputation of wastage. This allows significant potential for electrical and financial savings. A typical mine compressed air system consists of multiple compressors at various locations, surface connection networks, underground distribution systems, thousands of users and leaks. The size, complexity and age of these systems provide a major challenge for electricity saving efforts. Simulating such an intricate system is difficult as it is nearly impossible to accurately gather all the required system parameters. Some initiatives focused on subsections of mine compressed air systems. This is not the best approach as changes to one subsection may adversely affect other systems. A new approach to simplify mine compressed air systems was developed to identify saving opportunities and to assess the true impact of saving efforts. This new approach enables easier system analysis than complex simulation models. Techniques to gather critical system information are also provided. A new implementation procedure was also developed to integrate different energy saving strategies for maximum savings. An electrical power saving of 109 MW was achieved through the implementation of the integrated approach on twenty-two mine compressed air systems. The savings is equivalent to a reduction of 0.96 TWh per annum that relates to a saving of 0.4% of South Africa’s total electricity consumption. Average compressor power consumption was reduced by 30%. The power consumption reduction relates to an estimated annual electricity cost saving of R315 million. A saving of 0.96 TWh per annum is equivalent to a carbon dioxide emission reduction of 0.98 million tonne. The implementation of the integrated approach could be applied to other industrial compressed air systems. A reduction in electricity consumption of 30% on all industrial compressed air systems has the potential to reduce global electricity demand by 267 TWh per annum. That is more than the total amount of electricity consumed in South Africa. / Thesis (PhD (Electrical Engineering))--North-West University, Potchefstroom Campus, 2013

Global climate change and the electricity supply constraints could possibly be one of the utmost strategic issues facing businesses and consumers of all sizes currently in South Africa. Energy Efficiency is the ability to produce the same output but with less energy. The implementation of Energy Efficiency strategies is pivotal in order to sustain the climatic conditions as well as mitigate the supply constraints the South African utility Eskom is experienced. The aim of this study was to reiterate the importance of energy efficiency strategies and to identify the barriers and challenges companies face towards implementing energy efficiency and energy management strategies. This dissertation identified incentives and rebate schemes available to promote energy efficiency strategies and discussed the policies and strategies the South African Government implemented towards realising the energy efficiency target of 12%.The literature review conclude with discussing best practices indentified by implementing corporate energy efficiency strategies. The level of preparedness and progress in implementing an energy management system and strategies between the different companies were assessed. The target population includes the high intensity user group (HIU), listed and SME companies in the different industry sectors in South Africa. The study concludes that there are still multiple challenges facing companies in implementing sustainable energy efficiency strategies. Although government and multiple stakeholders are initiating incentive and rebate models to promote the implementation of energy efficiency measures, industry still lacks the commitment to change their behaviour toward implementing energy management strategies. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.