Water utilities are facing pressure to continue to provide high-quality potable water in an increasingly energy constrained world; managing the ageing infrastructure that exists in many countries is a challenge in and of itself, but recently this has been coupled with political and public attention to the environmental impacts of the distribution system. Utility managers need to take a holistic approach to decision-making in order to determine all of the impacts of their plans. The intention of this thesis is to present a set of considerations for utility planners and managers to provide clarity to the trade-offs associated with any pipe replacement decision. This research has examined the energy relationships between operational energy reduction and the embodied energy tied to replacing deteriorated pipes in water distribution networks. These relationships were investigated through the development and application of a life-cycle energy analysis (LCEA) for three different pipe replacement schedules developed with the intent to reduce leakage in the system. The results showed that the embodied energy for pipe replacement is significant even when compared against the large amount of energy required to operate a large-scale water utility. The annual operational energy savings of between 8.9 and 9.6 million kWh achieved by 2070 through pipe replacement comes at a cost; 0.88-2.05 million kWh/mile for replacement with ductile iron pipes with diameters of 6” to 16” respectively. This imbalance resulted in a maximum energy payback period of 17.6 years for the most aggressive replacement plan in the first decade. Some of the assumptions that were used to complete the LCEA were investigated through a sensitivity analysis; specific factors that were numerically queried in this chapter include the break rate forecasting method, pumping efficiency, the leakage duration and the flow rate per leakage event. Accurate accounting of energy requirements for pipe replacement will become even more important as energy and financial constraints continue to increase for most water utilities, this thesis provides guidance on some of the complex relationships that need to be considered. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-08-21 16:51:18.963

This thesis reports on the research undertaken to minimise energy consumption within the production phase of a product lifecycle through modelling, monitoring and improved control of energy use within manufacturing facilities. The principle objective of this research is to develop a framework which integrates energy data at plant and process levels within a manufacturing system so as to establish how much energy is required to manufacture a unit product. The research contributions are divided into four major parts. The first reviews relevant literature in energy trends, related governmental policies, and energy tools and software. The second introduces an Embodied Product Energy framework which categorises energy consumption within a production facility into direct and indirect energy required to manufacture a product. The third describes the design and implementation of a simulation model based on this framework to support manufacturing and design decisions for improved energy efficiency through the use of what-if scenario planning. The final part outlines the utilisation of this energy simulation model to support a Design for Energy Minimisation methodology which incorporates energy considerations within the design process. The applicability of the research concepts have been demonstrated via two case studies. The detailed analysis of energy consumption from a product viewpoint provides greater insight into inefficiencies of processes and associated supporting activities, thereby highlighting opportunities for optimisation of energy consumption via operational or design improvements. Although the research domain for this thesis is limited to the production phase, the flexibility offered by the energy modelling framework and associated simulation tool allow for their employment other product lifecycle phases. In summary, the research has concluded that investment in green sources of power generation alone is insufficient to deal with the rapid rise in energy demand, and has highlighted the paramount importance of energy rationalisation and optimisation within the manufacturing industry.

Buildings are directly responsible for 40% of the final energy use in most developed economies and for much more if indirect requirements are considered. This results in huge impacts which affect the environmental balance of our planet.<p>However, most current building energy assessments focus solely on operational energy overlooking other energy uses such as embodied and transport energy. Embodied energy comprises the energy requirements for building materials production, construction and replacement. Transport energy represents the amount of energy required for the mobility of building users.<p>Decisions based on partial assessments might result in an increased energy demand during other life cycle stages or at different scales of the built environment. Recent studies have shown that embodied and transport energy demands often account for more than half of the total lifecycle energy demand of residential buildings. Current assessment tools and policies therefore overlook more than 50% of the life cycle energy use.<p>This thesis presents a comprehensive life cycle energy analysis framework for residential buildings. This framework takes into account energy requirements at the building scale, i.e. the embodied and operational energy demands, and at the city scale, i.e. the embodied energy of nearby infrastructures and the transport energy of its users. This framework is implemented through the development, verification and validation of an advanced software tool which allows the rapid analysis of the life cycle energy demand of residential buildings and districts. Two case studies, located in Brussels, Belgium and Melbourne, Australia, are used to investigate the potential of the developed framework.<p>Results show that each of the embodied, operational and transport energy requirements represent a significant share of the total energy requirements and associated greenhouse gas emissions of a residential building, over its useful life. The use of the developed tool will allow building designers, town planners and policy makers to reduce the energy demand and greenhouse gas emissions of residential buildings by selecting measures that result in overall savings. This will ultimately contribute to reducing the environmental impact of the built environment. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished