With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Energy consumption in the home depends on appliance ownership and use, space heating systems, control set-points and hot water use. It represents a significant proportion of national demand in the UK. The factors that drive the level of consumption are a complex and interrelated mix of the numbers of people in the home, the building and system characteristics as well as the preferences for the internal environment and service choices of occupants. Reducing the energy demand in the domestic sector is critical to achieving the national 2050 carbon targets, as upward of 60% reduction in demand is assumed by many energy system scenarios and technology pathways. The uptake of reduction measures has been demonstrated to be quite ad hoc and intervention studies have demonstrated considerable variation in the results. Additionally, a limitation of many studies is that they only consider one intervention, whereas a more holistic approach to the assessment of the potential of reduction measures in specific homes may yield a better understanding of the likely impact of measures on the whole house consumption and indeed would shed light on the appropriateness of the assumptions that underpin the decisions that need to be made regarding the future energy supply system and demand strategies. This work presents a systematic approach to modelling potential reductions for a set of seven family homes, feeding back this information to householders and then evaluating the likely reduction potential based on their responses. Carried out through a combination of monitoring and semi-structured interviews, the approach develops a methodology to model energy reduction in specific homes using monitoring data and steady-state heat balance principles to determine ventilation heat loss, improving the assumptions within the energy model regarding those variables affected by human behaviour. The findings suggest that the anticipated reductions in end use energy demand in the domestic sector are possible, but that there is no `one size fits all' solution. A combination of retrofitting and lifestyle change is needed in most homes and smart home technology may potentially be useful in assisting the home owner to achieve reductions where they are attempting to strike a balance between energy efficiency, service and comfort.

This research proposes the use of electric energy storage (EES) in conjunction with a power generation unit organic Rankine cycle system (PGU-ORC). The EES is used when available so that continuous operation of the PGU is not required. The potential of the PGU-ORC-EES system’s performance is evaluated in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE) from simulations of a restaurant building in twelve U.S. locations with different climate conditions. The performance of the proposed system is compared to a conventional system. Results indicate that the EES addition to the PGU-ORC system is beneficial for most locations. Ratios between electricity and fuel cost, CDE conversion factors, and PEC conversion factors are used to estimate potential performance benefits. The effect of the EES size and the capital cost available are also analyzed.

Government agencies have attempted to reduce energy consumption using executive orders, mandates, and agency policies. Despite these efforts, overall energy consumption of government facilities has not experienced significant energy reductions. Why haven't these efforts succeeded? The premise is that energy consumption decisions and their unintended outcomes contribute to this problem, and in this manuscript research focuses on cognitive bias, choice architecture, and decision making in relation to energy decisions answer this question. Potential impacts cognitive bias has on the decision maker is examined, and if it is possible to design better decision environments to account for cognitive bias and help decision makers maximize benefits (utility). This manuscript first examines the literature of cognitive bias, choice architecture, and government energy management, especially how these topics relate to meeting the country's energy goals. The next chapter examines cognitive bias that government facility managers encounter using qualitative analysis. In this study, the research indicates facility managers encounter loss aversion, risk aversion, choice overload, and the status quo bias during energy decisions. The last chapter examines applications of choice architecture, specifically attribute framing, to emphasize the utility maximizing choice of long term energy reductions over initial cost. This study found that decision makers did not see the utility of the energy efficient option without an intervention to draw their attention to the long term savings. Once the decision makers became aware of the potential savings, they chose the most efficient (and utility maximizing) option. / Master of Science / Government agencies have attempted to reduce energy consumption using executive orders, mandates, and agency policies. Despite these efforts, overall energy consumption of government facilities has not experienced significant energy reductions. Why haven’t these efforts succeeded? The premise is that energy consumption decisions made by facility managers, and their unintended outcomes, contribute to this underestimating of energy savings. This manuscript research focuses on how decisions can vastly effect energy efficiency, and how the structure of decisions can assist facility managers to make decisions which result in energy efficiency. This manuscript first examines the literature decision making in government energy management. The next chapter examines cognitive bias, which inhibits decisions that maximize benefits, that government facility managers encounter using interviews and survey results. In this study, the research indicates facility managers would rather avoid a loss of revenue than risk a potential gain in revenue, and are overwhelmed by the options of energy efficiency products and services available. The last chapter examines how to make the decisions easier for facility managers, by drawing attention to the benefits of long-term energy efficient products and services over initial (high) costs of products and services. This study found that decision makers did not see the benefit of the energy efficient products and services without an intervention to draw their attention to the long-term savings. Once the decision makers became aware of the potential savings, they chose the most efficient option.

The gold mining industry pollutes both water and air resources in numerous ways. Of these, air pollution from greenhouse gasses inducing climate change poses the highest threat to human existence, with water scarcity as a result of pollution presenting the third highest risk (Mathews, 2007; Akorede et al., 2012; Jones et al., 1988). Water pollution, indirect air pollution and direct air pollution should be mitigated for sustainable gold mining. Environmental impact reduction is achieved by the implementation of effective Environmental Management Systems (EMSs). These systems aim to achieve ISO 14001-compliance by setting targets and implementing a systematic approach to achieving these targets. However, ISO 14001-compliant systems do not ensure environmental impact reduction and give the mine no competitive edge (Hilson & Nayee, 2002). EMSs available are too generic for implementation on gold mines. Reporting on Key Performance Indicators (KPIs) on gold mines should also be improved as it is unclear exactly what values should be reported on. This is due to a general lack of an environmental reporting standard (Jones, 2010). Manpower and expertise to identify and implement projects is limited and the mines need assistance with the implementation of projects to effect resource pollution. Priority for the mines is an emphasis on production and safety rather than environmental impact reduction, so implementing projects to reduce pollution is often neglected. A novel sustainability framework is developed in this study. In this framework a database of electricity- and environmental impact reduction projects is created that can be implemented in the gold mining industry. Projects are automatically identified by monitoring key operational indicators. By involving a third party in the form of an Energy Services Company (ESCO), project funding for these sustainability projects can be attained. This novel approach to environmental impact reduction creates a situation where ESCOs implement these EMSs at a reduced cost to the mines. This reduces the cost of lowering the mine’s environmental impact, while aiding the ESCO in identifying sustainability projects. KPIs from various studies are consolidated to determine exactly what values should be reported on. These values are incorporated into a successful EMS. This allows the availability of all the necessary data for reporting to the Department of Energy (DoE) and the South African National Energy Development Institute (SANEDI) on electricity-savings. Projects are prioritised based on an integrated electricity- and environmental impact reduction payback approach. This approach allows funding options to be assessed for each project individually, based on both electricity- and environmental impact reduction advantages. This allowed the best funding option for each individual project to be determined. Automatic identification of these projects reduces the required manpower and resources to implement sustainability projects. Projects proposed by this study showed a combined energy efficiency reduction of 11.8 MW and achieved a load shift of 15.6 MW. In addition to electricity reduction, these projects also reduced the water usage by 1135 Ml per annum and the carbon dioxide equivalent production by 214 205 ton per annum. The proposed projects were effective at increasing the sustainability of gold mining. It also streamlined the implementation of these projects on gold mines. By applying this framework, sustainability improvements can now be achieved on gold mines worldwide. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

The gold mining industry pollutes both water and air resources in numerous ways. Of these, air pollution from greenhouse gasses inducing climate change poses the highest threat to human existence, with water scarcity as a result of pollution presenting the third highest risk (Mathews, 2007; Akorede et al., 2012; Jones et al., 1988). Water pollution, indirect air pollution and direct air pollution should be mitigated for sustainable gold mining. Environmental impact reduction is achieved by the implementation of effective Environmental Management Systems (EMSs). These systems aim to achieve ISO 14001-compliance by setting targets and implementing a systematic approach to achieving these targets. However, ISO 14001-compliant systems do not ensure environmental impact reduction and give the mine no competitive edge (Hilson & Nayee, 2002). EMSs available are too generic for implementation on gold mines. Reporting on Key Performance Indicators (KPIs) on gold mines should also be improved as it is unclear exactly what values should be reported on. This is due to a general lack of an environmental reporting standard (Jones, 2010). Manpower and expertise to identify and implement projects is limited and the mines need assistance with the implementation of projects to effect resource pollution. Priority for the mines is an emphasis on production and safety rather than environmental impact reduction, so implementing projects to reduce pollution is often neglected. A novel sustainability framework is developed in this study. In this framework a database of electricity- and environmental impact reduction projects is created that can be implemented in the gold mining industry. Projects are automatically identified by monitoring key operational indicators. By involving a third party in the form of an Energy Services Company (ESCO), project funding for these sustainability projects can be attained. This novel approach to environmental impact reduction creates a situation where ESCOs implement these EMSs at a reduced cost to the mines. This reduces the cost of lowering the mine’s environmental impact, while aiding the ESCO in identifying sustainability projects. KPIs from various studies are consolidated to determine exactly what values should be reported on. These values are incorporated into a successful EMS. This allows the availability of all the necessary data for reporting to the Department of Energy (DoE) and the South African National Energy Development Institute (SANEDI) on electricity-savings. Projects are prioritised based on an integrated electricity- and environmental impact reduction payback approach. This approach allows funding options to be assessed for each project individually, based on both electricity- and environmental impact reduction advantages. This allowed the best funding option for each individual project to be determined. Automatic identification of these projects reduces the required manpower and resources to implement sustainability projects. Projects proposed by this study showed a combined energy efficiency reduction of 11.8 MW and achieved a load shift of 15.6 MW. In addition to electricity reduction, these projects also reduced the water usage by 1135 Ml per annum and the carbon dioxide equivalent production by 214 205 ton per annum. The proposed projects were effective at increasing the sustainability of gold mining. It also streamlined the implementation of these projects on gold mines. By applying this framework, sustainability improvements can now be achieved on gold mines worldwide. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Commercial energy use in Arizona is different from the rest of the United States because of their high demand for air conditioning. Nearly half of the energy used in commercial buildings goes to heating, cooling, and ventilation. In an attempt to reduce overall every use in buildings, looking at these categories led to an examination of ventilation in buildings, which is the main cause for high heating and cooling costs. Ventilation of fresh air is required in order to provide a safe, healthy environment, with acceptable indoor air quality. Indoor air quality and pollution has continuously come to light as a major health concern for building occupants. Chemicals used in manufacturing allow consumers to buy and expose themselves to toxic substances such as volatile organic compounds on a daily basis. With minimal regulations on indoor air, it is important to find ways to better filter and clean it. The traditional solution is ventilation, but more fresh air ventilation means more heating and cooling. This paper explores the research that has been done on plants and phytoremediation and the applicability to indoor air quality. With the proof that certain combinations and amounts of plants can filter the air of volatile organic compounds, systems are explored for indoor air filtration instead of mechanical ventilation. This type of system can greatly reduce heating and cooling costs in buildings due to the reduction of outdoor air being brought in and requiring conditioning. A system of this type is a feasible solution to indoor air quality and can lead to a significant reduction in energy use. The proposed AIRMAPS is a system that in certain quantities can reduce the need for fresh air ventilation by 25%, which in turn has shown through the validation by eQUEST, that the energy used for heating, cooling, and ventilation fans can also be reduced by approximately the same amount. The plants used are spider plant, dumb cane, English ivy, and golden pothos. The average formaldehyde removal by each of these plants is a low approximation of 75% per cubic meter. This paper also considers the growing materials used for the plants; activated carbon, potting soil mix, and grow-stones, as well as their formaldehyde removal capabilities.

Current heterogeneous CPU-GPU architectures integrate general purpose CPUs and highly thread-level parallelized GPUs (Graphic Processing Units) in the same die. This dissertation focuses on improving the energy efficiency and performance for the heterogeneous CPU-GPU system. Leakage energy has become an increasingly large fraction of total energy consumption, making it important to reduce leakage energy for improving the overall energy efficiency. Cache occupies a large on-chip area, which are good targets for leakage energy reduction. For the CPU cache, we study how to reduce the cache leakage energy efficiently in a hybrid SPM (Scratch-Pad Memory) and cache architecture. For the GPU cache, the access pattern of GPU cache is different from the CPU, which usually has little locality and high miss rate. In addition, GPU can hide memory latency more effectively due to multi-threading. Because of the above reasons, we find it is possible to place the cache lines of the GPU data caches into the low power mode more aggressively than traditional leakage management for CPU caches, which can reduce more leakage energy without significant performance degradation. The contention in shared resources between CPU and GPU, such as the last level cache (LLC), interconnection network and DRAM, may degrade both CPU and GPU performance. We propose a simple yet effective method based on probability to control the LLC replacement policy for reducing the CPU’s inter-core conflict misses caused by GPU without significantly impacting GPU performance. In addition, we develop two strategies to combine the probability based method for the LLC and an existing technique called virtual channel partition (VCP) for the interconnection network to further improve the CPU performance. For a specific graph application of Breadth first search (BFS), which is a basis for graph search and a core building block for many higher-level graph analysis applications, it is a typical example of parallel computation that is inefficient on GPU architectures. In a graph, a small portion of nodes may have a large number of neighbors, which leads to irregular tasks on GPUs. These irregularities limit the parallelism of BFS executing on GPUs. Unlike the previous works focusing on fine-grained task management to address the irregularity, we propose Virtual-BFS (VBFS) to virtually change the graph itself. By adding virtual vertices, the high-degree nodes in the graph are divided into groups that have an equal number of neighbors, which increases the parallelism such that more GPU threads can work concurrently. This approach ensures correctness and can significantly improve both the performance and energy efficiency on GPUs.