Composite materials are widely used in various sectors such as aerospace, automotive and wind energy. Global increase of demand, particularly for fibre reinforced plastic (FRP) composites, unavoidably lead to high volumes of manufacturing and end of life waste. Currently, the most common disposal route for composite waste is through landfill. However, current and impending legislations such as Directive on Landfill of Waste (1999/31/EC) and End of Life Vehicle (ELV) Directive (2000/53/EC), have limited the amount of composite waste permitted for landfilling. In addition, production of virgin composite materials requires higher energy input in comparison to other counterpart materials such as steel and aluminium. This calls for an urgent need for composite waste to be recycled and reused in close loop and cross sector applications. The composite materials have a heterogeneous nature. Thermoset matrixes, which are used in most high grade applications, have three dimensional cross-linked structures which make melting and remoulding impossible. Such complex nature requires appropriate composite recycling technologies, a number of which are currently under research and development. At this early stage it is important to select and develop sustainable solutions in terms of economic performance and reduced environmental impact. Unfortunately at present, there is limited high integrity environmental related data in literature to help assess the life cycle benefits of composite recycling. This information is vital in exploring environmental credentials of composite recycling processes, and to ensure resource efficient use of manufacturing and end of life composite waste. The work reported in this PhD thesis deals with the investigation of energy demand of composite recycling processes. Composite waste and demand in the UK market was captured through Sankey diagrams. The diagrams, combined with environmental footprints of virgin material and recycling processes, were used to identify resource benefits of composite recycling initiatives. Furthermore, environmental data for mechanical recycling of glass fibre composites was derived through new and novel bottom up process science inspired mathematical energy modelling approaches. It was found that the process specific energy demand is dependent on the processing rate. The effects of key process variables in mechanical recycling on process energy demand and recyclate quality were also investigated. This study highlights the importance of selecting the right conditions for running recycling processes and generating recyclate with a high market value. Potential of new recycling techniques, namely high voltage fragmentation, was also assessed. Performance of the method, which was originally developed for fracturing rocks, was compared to the mature mechanical recycling process. The final part of this study used a life cycle assessment method to evaluate end of life options for an automotive composite product with the highlights on positive environmental impacts of recycling scenarios. Collectively, the findings from this study have brought together considerations on environmental and maturity status of composite recycling processes, into a comprehensive and updated analysis. The vision is that the knowledge integration between environmental and performance aspects will promote the concept of sustainable use of composite materials and a circular economy. The new datasets developed will enable end of life options for composite waste to be evaluated in life cycle assessment. In the absence of such information, the life cycle impact of composite material use in products cannot be fully or correctly evaluated.

This study is concerned with the analysis of the long-run substitution pattern of primary energy sources for the Italian economy, over the period of 1960-1994. A neoclassical model, set in the cost function approach, has been used to retrieve the energy inputs derived demand functions, via Shephard's lemma, using a translog cost function specification. Four primary energy sources have been considered, namely, oil, electricity, natural gas and coal. Recent advances in time series econometric theory have provided tools devices for modelling long-run equilibrium relationships and their associated short-run dynamics jointly. The Engle and Granger (1987) and the Engle and Yoo (1989) cointegration approach has been utilised in this study to estimate the long-run share relationships, while the general to specific methodology has been followed to derive error correction formulations for the adjustment processes. Extensions to time-varying parameter cointegration, carried out in the framework of the structural time series approach, have also been considered. The applications of traditional and time-varying parameter cointegration to the Italian energy market are the main sources of originality of this work. The study is divided into three main parts. The first part introduces the economic and econometric frameworks employed in the analysis. The second part is concerned with the actual empirical analysis. This consists of data description, the structural time series approach and the application of traditional and time-varying parameter cointegration theory to estimate a derived factor demand model. Finally, the third part summarises and discusses the results of the analysis.

This study represents the first econometric study that has attempted to model energy demand exclusively for Jordan. In so doing, recent developments in time series econometrics modeling techniques are adopted to estimate total energy demand functions at the aggregate and sectoral levels together with demand functions for individual fuels for Jordan using a new data set covering the period (1968-2000). Different econometric approaches were employed to estimate the elasticities including OLS, Johansen's ML, DOLS and ARDL to enable a comparison of the statistical results and the estimated price, income, urbanization elasticities. The different econometric techniques therefore act as a check of the robustness of the results obtained. All estimates of the demand functions whether at the aggregate level or at the disaggregate levels are robust not only in terms of statistical competence but also in terms of economic intuition. At the aggregate level, the various econometric techniques yield almost identical elasticity estimates. The estimates indicate a long run elasticity of around unity with respect to per capita GDP, 0.35 with respect to per capita area constructed, -0.30 with respect to real energy prices, a coefficient around 0.1 for the dummy variable representing the level of conflict in the region and a coefficient around 0.7% p.a. for the time trend as a proxy to the Underlying Energy Demand Trend (UEDT). The income elasticity implies that economic growth is likely to be accompanied by proportional increases in energy consumption. The price elasticity suggests that taxes on their own are unlikely to achieve government goals for energy conservation or environmental improvement, although they may well be efficient for revenue raising. Furthermore, evaluating the impact of per capita area constructed on energy consumption levels helps provide guidance for the future need of power generation and refining capacities. The study present forecasts for aggregate energy, aggregate electricity and aggregate petroleum over the period 2001-2015 using 2000 forecasts from the Jordanian governments and international organizations for the exogenous variables. The forecasts are constructed using three different scenarios of the GDP and area constructed growth, with constant real energy price at the 2000 level and with real energy prices increasing by 2% annually. The low growth scenario assumes 4% annual growth of GDP and area constructed, the medium growth scenario assumes 6% for both annual growth of GDP and area constructed, and the high growth scenario assumes 8% annual growth of GDP and 6% annual growth of area constructed. With constant real energy price, the low growth scenario suggests that total energy demand will increase by an average annual growth rate of 3.9 % over the forecasted period. The medium growth scenario indicates that the total energy demand will increase by an average annual growth rate of 6.37 % over the forecasted period, implying that aggregate energy demand will double by the year 2012. The high growth scenario suggests that the total energy demand will increase by an average annual growth rate of 8.24 % over the forecast period and double by the year 2010.

This thesis analyzed Georgia's pre and post embargo consumption of gasoline and residential electricity from 1960 to 1982 to determine: 1) if the structure of gasoline demand was stable; 2) to investigate the arguments for conservation; and 3) to ascertain that the pricing mechanism is indeed able to adjust consumption to levels of supply. Elasticities were computed and they were used to address simple tax issues. The study was significant for several reasons: 1) it is the first ever known study of its kind done on Georgia; 2) Georgia has a ninety five percent dependence rate on other states and foreign countries (indirectly) for her supply of energy resources; 3) the impact of the oil embargo on consumption, prices and the economy at large is necessary both as a post moterm and for future policy decisions. The results overwhelmingly favored stability in the structure of these demands. As such, the restricted model was valid for any projections and conclusions. The short-term price and income elasticities for gasoline were .30 and .06 and the long-term coefficients were 1.5 and .20 respectively. For electricity, the short-term price and income elasticities were .22 and .37 and the long-term estimates were .81 and 1.33 respectively. The weather variables were very inelastic. All coefficients were significant by the usual criteria. With inelastic demands for these energy resources, taxation seemed a welcome proposition for controlling prices and consumption and for generating revenue. However, it is only to the extent that other monetary, fiscal and economic objectives of the government are not jeopardized. Thus, the arguments for conservation holds to a good degree. A hybrid of a comprehensive tax-pricing policy and conservation efforts is necessary for stability in the energy sector.

The domestic sector currently accounts for approximately a third of the UK s energy use and so energy demand reduction in the domestic sector is a key part of the UK s strategy for carbon reduction. However, energy demand reduction has typically been addressed from an engineering perspective, with little consideration of the requirements of users. This PhD submission aims to identify how qualitative information about users experiences, values and practices relating to UK domestic energy demand reduction can be collected and presented effectively to an engineering audience and incorporated into engineering-focused energy research. User centred design is presented as a viable approach to understanding the context of energy use in UK homes and specifying requirements of the householders; as a way of ensuring user needs are included in this socio-technical problem space. This requires presentation of information about human behaviour in a form that is timely and appropriate to the engineering audience, who take a positivist view, preferring facts and figures to descriptions and anecdotes. A collection of nine publications, mostly peer-reviewed journal papers, by the thesis author and her co-authors is presented. Publications spanning from 2006 to 2014 illustrate a range of approaches to providing user centred information, from literature review to complex householder studies, which can provide information to enhance the engineering data and so provide additional insight and understanding. The research findings within the individual papers add to the body of knowledge on domestic energy use. In addition, the research identifies a number of roles where user centred design contributes to understanding of home energy use. From providing background and raising awareness of the presence of users within a system, to contextual understanding and the specification of user requirements, through to more sophisticated user characterisation, it is argued that user centred design can offer a significant contribution to the field. Future application of user information into engineering models, together with large scale, longitudinal studies of home energy use are proposed, building on the contributions of this thesis.

This dissertation examines three facets of U.S. energy use and policy. First, I examine the Gulf Coast petroleum refining industry to determine the structure of the industry. Using the duality between cost-minimization and production functions, I estimate the demand for labor to determine the underlying production function. The results indicate that refineries have become more capital intensive due to the relative price increase of labor. The industry has consolidated in response to higher labor costs and costs of environmental compliance. Next, I examine oil production in the United States. An empirical model based on the theoretical framework of Pindyck is used to estimate production. This model differs from previous research by using state level data rather than national level data. The results indicate that the production elasticity with respect to reserves and the price elasticity of supply are both inelastic in the long run. The implication of these findings is that policies designed to increase domestic production through subsidies, tax breaks, or royalty reductions will likely provide little additional oil. We simulate production under three scenarios. In the most extreme scenario, prices double between 2005 and 2030 while reserves increase by 50%. Under this scenario, oil production in 2030 is approximately the same as the 2005 level. The third essay estimates demand for fossil fuels in the U.S. and uses these estimates to forecast CO2 emissions. The results indicate that there is almost no substitution from one fossil fuel to another and that all three fossil fuels are inelastic in the long run. Additionally, all three fuels respond differently to changes in GDP. The result of the differing elasticities with respect to GDP is that the energy mix has changed over time. The implication for forecasting CO2 emissions is that models that cannot distinguish changes in the energy mix are not effective in forecasting CO2 emissions.

The biogas plant Kungsängens gård, owned by Uppsala Vatten och Avfall AB, produces biogas and biomanure from organic household waste, food processing waste and slaughterhouse waste. In year 2012, 4.4 million Nm3 of biogas were produced from 25 200 tons of waste. Before digestion all substrate is sanitized by pasteurization at 70°C in order to kill pathogens. Another method, integrated thermophilic sanitation (ITS), is of interest in order to decrease the energy demand. The method implies that the substrate is sanitized during ten hours in the digestion chamber, where the temperature is 52°C. The purpose of this thesis was to compare pasteurization with integrated thermophilic sanitation from an energy point of view. The pasteurization´s impact on biogas production and energy yield was examined through experiments with two laboratory digesters, of which one was fed with pasteurized substrate and the other with non-pasteurized substrate. For the present pasteurization system, electricity and heat demand was surveyed. For the integrated thermophilic sanitation, a process design was developed and dimensioned and the electricity and heat demand was calculated. Thereafter, the energy yield and energy demand for the two sanitation systems were compared. The result showed that pasteurization had no effect on biogas production. The energy yield was on average 4.79 kWh/kg VS from non-pasteurized substrate and 4.74 kWh/kg VS from pasteurized substrate. There was no statistically significant difference between the reactors. The energy audit showed that pasteurization required 0.48 kWh/kg VS, which is 85 % of the total energy consumption at the facility. The digester warming demanded 0.077 kWh/kg VS for RK1 and 0.031 kWh/kg VS for RK2. The electricity consumption was 0.041 kWh/kg VS. The process of ITS was designed with a heat exchange from bio manure to substrate, followed by heating to 52°C by steam addition. The heat requirement was 0.24 kWh/kg VS and the electricity demand was 0.034 kWh/kg VS. The warming of the digesters was the same as in the present pasteurization system. The comparison between the existing pasteurization and the ITS showed that switching systems would save 0.243 kWh/kg VS or 46 % of the present energy consumption. This corresponds to annual savings of 1.22 GWh. A sensitivity analysis showed that the results were sensitive to assumptions regarding the heat exchanger in the case of ITS. 10 % energy losses resulted in smaller savings, 34 % or 0.91 GWh per year. There are increased risks of process disruptions if ITS is combined with an increased organic loading rate. 4.2 % reduction of the total biogas production erases the energy savings which means that it is important that process stability is ensured.

To achieve the aim of low carbon cities and zero energy districts, it is important to adapt the efficient technologies while maintaining the thermal comfort and sustainable environment. The new challenge in design and building new districts lies in a sustainable and smart way to minimize energy consumption and thus carbon emission. This challenge can be overcome by the use of early-stage energetic and environmental analysis of the planned districts, which can result in sustainable and efficient use of the resources. This thesis aims to assess the energy demand and the carbon emission for the proposed design of Jakobsgårdarna district in Borlänge, Sweden. The complete analysis of the neighbourhood is assessed through a tool - Urban Modeling Interface, a Rhinoceros-based plugin developed by the Sustainable Design Lab at Massachusetts Institute of Technology, USA. A base case scenario is evaluated for energetic performance, lighting, heating, cooling, hot water, daylight potential, walkability, and life cycle assessment. Then, a sensitivity analysis is addressed, in particular to evaluate the impact of daylight potential, archetypes, window to wall ratio, wall materials, future climate, and a possible lockdown, on energy consumption and carbon emission. In the base case, the analysis shows that preschool has the lowest specific energy consumption of 64.1 kWh/m2, while retail shops have the highest (92.2 kWh/m2) energy consumption. The simulated energy consumption of the offices and residential buildings is 72.1 kWh/m2, and 80.4 kWh/m2 respectively. The life cycle assessment reveals the advantage of the environment from building wooden houses instead of using concrete or masonry. The total embodied carbon for the whole district is 149.3 kgCO2/m2 divided as follow: 160.9 kgCO2/m2 for the school; 164.9 kgCO2/m2 for the offices, 159.6 kgCO2/m2 for the retail shops, 55.0 kgCO2/m2 for the wood residential buildings, 164.9 kgCO2/m2 for the masonry residential buildings. The sensitivity analysis explains exhaustively the influence, which has changes in the base case scenario. In particular, the future climate will decrease heating consumption due to the increase of the mean annual temperature and, on the other hand, increase cooling demand. While a possible lockdown to the district will rise consumption in residential buildings due to a higher use of equipment and lighting, but it will lower the energy use of offices and schools. The overall research results are expected to be useful to propose suggestions and recommendations for the next steps of design about Jakobsgårdarna district in Borlänge.

The residential sector was responsible for 25% of the Final Energy Demand (FED) in the European Union in 2015. Countries in Central and Eastern Europe such as the Czech Republic are particularly concerned with ensuring security of supply at the lowest possible cost in recent years. FED for space heating still corresponds to the largest fraction of the total FED in the residential sector in the Czech Republic. The vast majority of buildings constructed in 1990- 2000 do not comply with current standards for thermal protection and owners often rely on their own financial means when attempting to improve the overall Energy Performance (EP) of buildings. The goal(s) associated with renovation- or refurbishment measures must be defined to clarify the extent of work and consequently minimize investments. The aim of this thesis, a case study, was to use a whole building energy simulation program (IDA-ICE) to get insight into the potential of different retrofitting measures (represented by scenarios) to improve EP of a single-family summer house located in the South Bohemian Region of the Czech Republic. One of the simulated scenarios was the owner ́s suggestion to replace windows and entrance doors. The goal was to reduce FED for space heating to ≤50 kWh.m-2 floor area and year and by doing so attaining the status of a low-energy building. Simultaneously, reduced FED for space heating was supposed to be achieved without compromising air quality and should involve only the most efficient refurbishment measures to minimize the overall work. The scope was strictly limited to EP improving measures without consideration of mechanical ventilation or modification of the currently used space heating system. It was concluded that the owner's suggestion to merely replace windows and entrance doors would be an insufficient solution. SC-4 (i.e. the combined effect of windows and entrance doors replacement and the ground-floor insulation) and SC-5 (i.e. the combined effect of ground-floor insulation and the insulation of external walls and the roof) were deemed to represent the most optimal solutions from the simulated EP improving measures. The goal was achieved in both, i.e. 46.8 kWh.m-2 floor area and year in SC-4 and 44.3 kWh.m- 2 floor area and year in SC-5. Averages of zone air temperatures in selected zones were found to be more stable in SC-4, however, SC-5 performed better when comparing averages of CO2 concentration-values in selected zones on the first floor. Nevertheless, averages of relative humidity and CO2 concentration-values in all simulated scenarios were within the acceptable range of 35-60% and about 520 to 1000 ppm respectively (except for Bedroom 2 zone).

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