There is a growing need for geographic studies of energy to focus on consumption patterns rather than on energy production. Studies focused on production have tended to treat each energy source individually, yet technological developments are increasingly bringing energy sources into competition with one another. Excluding those energy demands which are specific to one energy source, markets for heat and power are supplied by a mixture of energy sources which are competing to retain or enlarge their respective shares of the market. A detailed energy consumption estimate for each of the four Western Provinces shows considerable variation of the energy mix in both space and time. Examination of the energy mix of each province in relation to the distribution of energy production and to hypothetical transport costs suggests that location is the primary factor in accounting for areal variations of the energy mix. Variation in time appears to be accounted for by changes in the location of markets arising from the construction of oil and gas pipelines from Alberta to the other provinces. Nevertheless, it is recognised that each provincial market exhibits several unique characteristics. The hypothesis posed in this study is that location is the primary factor determining the areal pattern of the energy mix, but that the mix is modified by inter-provincial differences of market structure, areal concentration of the Intra-provincial market, and historical legacies (i.e. inertia). These three factors, together with the location factor, are universal in that they apply to all provinces and all energy sources. This hypothesis provides a framework for an examination in turn of each major energy source, fuel wood, coal, petroleum, natural gas, and electricity. For each energy source the areal patterns and trends of provincial sales are sub-divided into two or three market sectors (domestic, industrial, and railway locomotive), and sales are related to the supply patterns of the energy source in particular, and also to the other three universal factors and factors specific to the energy source concerned. By proceeding from the more passive to the more active competing energy sources the competitive pattern is established and evaluation of the four universal factors can be made. The location of markets in relation to energy supplies is the primary factor accounting for variations in the energy mix at the inter-provincial level. The energy mix of the locomotive sector has an unique areal pattern, but this is the result of an energy supply pattern which differs from that of other market sectors. However, the energy mix at any point in time is modified by the legacy of previous consumption patterns because there is a delay before consumers change from one energy source to another. This historical legacy factor is the key modifier of the energy mix and was particularly prominent in the areal pattern of the I960 mix because large quantities of gas only became available outside Alberta after 1956. Nevertheless, the historical legacy factor is secondary to the location factor, because firstly competition of the energy sources is directed towards bringing the mix into equilibrium with the location factor, and secondly the delay in making gas available in all the major energy consuming centres outside Alberta is rooted in location. The distances from Alberta's gas fields to other provincial markets necessitated large throughput pipelines, and these pipelines could only be built when markets external to Western Canada were realised. Finally, this study suggests further research into the possibility of an energy region being nodal and research into the cartographic delimitation of the competitive frontiers of the various energy sources. / Arts, Faculty of / Geography, Department of / Graduate

As increasingly complex and capital-intensive energy supply and conversion systems are developed to exploit more dilute and inaccessible energy resources, larger quantities of indirect energy, embodied in the form of inputs of goods and services, are needed to build and operate such systems. Concern has arisen that market imperfections, including research and development subsidies and tax concessions to the energy industry, could result in an energy system being selected as financially viable, while requiring more energy in external inputs (i.e., non-feedstock energy) than it could produce. In response to these concerns, net energy analysis (NEA) has recently been developed as a technique which identifies and quantifies all energy inputs to energy supply and conversion systems, including the indirect energy embodied in goods and services. By providing this information, NEA may be used to establish whether a system is indeed a net yielder of energy, and to compare its overall efficiency of energy use to that of alternative systems. While NEA does not presently take into account the depletion of non-fossil stock energy resources, qualitative differences in energy forms, and intertemporal aspects of energy flows, there are various means of avoiding these problems or making partial allowances for them. Furthermore, although a number of boundary problems relating to NEA have been identified, most of them are also common to economic analysis. It has been stated that NEA should be judged according to the relative significance of indirect energy requirements since this is the only new component that the technique adds to the information base of the energy field. Studies to date have shown that the quantity of indirect energy requirements relative to feedstock flows is quite insignificant in many current energy supply and conversion systems. However, the relative importance of indirect energy requirements may increase considerably in the future, particularly as an increasing proportion of our energy is derived from renewable flows instead' of depletable feedstocks. A case study involving a net energy analysis of the Revel-stoke hydroelectric project was carried out to examine the applicability of this technique at a practical level and the results were compared with those of other net energy analyses. The project was calculated to pay back the quantity of energy invested in its capital facilities in less than 6 months, with a net energy return of more than 126 times the total amount of external energy put into the construction and operation of the project over its lifetime. Reliability of results could be most improved by a more up-to-date data base, and a further disaggregation of the commodity profile used as a basis for calculations. While net energy analysis has many potential applications, including the analysis of energy conservation measures to see if they achieve net energy savings, the technique has not been widely used in practice due to its relative immaturity and a general uncertainty as to its role in the overall decisionmaking process. Net energy analysis, in providing a quantitative description of the energy requirements of energy systems, is not intended to be used as an evaluative technique or to provide a single set of decision-making criteria. Instead, the energy-related impacts of a decision must be weighed ; against its environmental, socio-economic, and political impacts. Although such tradeoffs can be presented within the framework of benefit-costs analyses, no simple rules for the relative weighting given to net energy considerations can be formulated. Exercises of this nature are inherently value-based and should ultimately be made at the political rather than the bureaucratic level. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

Please read the abstract in the section 00front of this document / Dissertation (M Eng (Electrical Engineering))--University of Pretoria, 2007. / Electrical, Electronic and Computer Engineering / unrestricted

A Thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy in the School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, 2019 / Due to the energy- and carbon-intensive economic structure of South Africa (SA), the country has become one of the biggest contributors to greenhouse gas emissions, emitting more CO2 than any other African country. The ratio of greenhouse gas emissions compared to per capita economic benefit, the so called carbon intensity of the economy, is amongst the highest in the world. Carbon capture and storage (CCS) seems to be the most immediate form of action that can be implemented with the possibility of instantaneous reduction of CO2. The injection of CO2 into deep-unmineable coal seams, although not commercially viable for coal production, is a possible mitigation option under CCS for permanent underground storage of CO2. As a spin-off, useful coal-bed CH4, referred to as enhanced coal bed CH4 (ECBM), could be extracted from the coal seam following CO2 injection. In SA it has been estimated that approximately 1.2 Gt of CO2 could be stored in the coalfields. Although not currently the preferred option for geological storage, coalfields provide the largest onshore CO2 storage possibility. The current research project aimed to study the fundamental differences in CO2 adsorption in a variety of SA coal samples in order to access the CO2 sorption capacities and secondly to evaluate the potential CH4 characteristics of SA coals. The investigation aimed to identify the fundamental differences around the effects of increased pressure under simulated in-seam conditions including super-critical pressures up to ~90 bar for gaseous and supercritical CO2 injection. The effects on CO2 adsorption with regard to the difference in coal moisture contents, simulated in the range from ~0.5 – 4.4% and the influence of increased temperatures in the range of 35 to 55 ˚C were carried out on ten (10) SA coals taking into consideration differences in coal properties, samples with varying rank, ash and maceral compositions were sourced for this research. Then secondly, to evaluate the desorption potential of CH4 for seven (7) selected SA coals. A High Pressure Volumetric adsorption system (HPVAS) was successfully designed and constructed in order to conduct experimental tests to generate the adsorption isotherms for the various parameters tested. Results presented show comparable results with published literature in terms of the degree of variance in coal properties (with respect to rank, maceral and mineral content, ash contents and the effects of moisture, and temperature variance) and the uptake of CO2. Higher rank coals have a greater CO2 absorption propensity, whereas lower rank bituminous coals tend to exhibit lesser CO2 uptake, however, this is dependent on the coals’ petrographic composition. It was clear that samples in the range greater than a vitrinite reflectance of 0.7% (RoVmr) exhibited increased CO2 uptake due to larger macro, increasing meso porosity and micro-pore volumes. Findings related to coal properties; revealed that coals with a higher ash content exhibited a negating effect with regard to enhanced CO2 adsorption. On average, for a 1% increase in ash content in HRC and MRC coals, a decrease of CO2 adsorption capacity of 1.1 mmol/g and 0.018 mmol/g is observed respectively. While for maceral composition these findings suggest that a specific or ideal ratio between only the maceral components, in similar rank coals, is the controlling factor for best CO2 adsorption required. In terms of addressing the adsorption parameters, such as super-critical pressure, temperature and moisture variations inherent in natural coal seams, etc., it was determined that with increased pressure, more adsorption takes place for most coal types. A very positive correlation was found to exist between adsorption of CO2 and desorption of CH4, with increased pressure injections, ranging from sub-critical to super critical pressures, exhibiting increased sorption results, irrespective of coal moisture or temperature effects. From these findings for simulated conditions regarding the effects of coal seam moisture and temperature variations, it has been concluded that results displayed an obvious decrease in CO2 sorption ranging from sub-critical to supercritical pressures overall. The decrease in CO2 sorption was as much as 77% from dry (0%) to the maximum moisture simulated value of ~4.4%. Sorption decreased almost linearly for every 1% of coal moisture increase, until the maximum coal saturation was approached at around 4%. Sorption results relating to increased temperature also displayed an inverse relationship, and hence lower overall CO2 sorption capacities were calculated. The heats of adsorption for these coals were found to be between 21.9 and 39.9 kJ/mol confirming the nature of adsorption to be physical. Results confirm that the calculated heat of adsorption (KJ/mol) and the adsorption capacity (mmol/g) are positively correlative. For investigations pertaining to CH4 desorption for CH4 saturated simulated coals (CH4 added to and then removed from coal samples due to the unavailability of freshly cored coal samples), it was observed that CO2 uptake by pressurized injection for low - high pressures certainly enhances CH4 desorption rate. Results revealed that incremental CO2 injection pressures yielded higher CH4 desorption rates, for both the HRC and MRC coals. Generally there was an observed increase in the rate of CH4 desorbed for all coals tested at 55 oC as compared to 35 oC. This can as well be attributed to the fact that the increase in temperature causes the adsorbed CH4 molecules to vibrate more due to the increased kinetic energy of the molecules. This consequently leads to ease of desorption when CO2 is pumped under pressure into the coal structure, which clearly favours ECBM potentials. Some very good findings have been highlighted in the thesis from a SA coal perspective, and certainly serve as a very good starting point for further investigations pertaining to CO2, CH4, and coal interactions. However, from the vast literature already published globally, it can be seen that much more needs to be done in terms of addressing coal-CO2-CH4 research from a SA perspective, and indeed CCS in SA in general. It is apparent that the results and sum of the key findings presented in this thesis, are of importance for the selectivity and technical modelling for CO2 onshore coalbed storage and ECBM projects to be implemented in SA in the near future so as to meet the demands required to reduce CO2 emissions in SA as part of the global community. / PH2020

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 225-232). Also available via the World Wide Web.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2007. / Thesis Advisor(s): Daniel A. Nussbaum. "March 2007." Includes bibliographical references (p. 95-99). Also available in print.

The building sector is a major contributor to total energy consumption in most countries. Traditionally, researchers have focused on leveraging energy efficiency by improving building materials, in-house facilities and transmission equipment. More recently, however, there has been increased focus on research concerning demand-side energy consumption behavior. Current research suggests that energy efficient behavior of a building's occupants can be extensively enhanced through the sharing of energy consumption information among residents in a peer network. However, most of this research relies on experimental tests and does not theorize concepts related to peer network energy efficiency systematically. My dissertation addresses this research gap on two levels. First, I examined if and how the structure of peer networks can impact residents' conservation behaviors through network analysis by employing agent-based simulation techniques. Following confirmation of the impact that network structure has on user behavior, I created a layered network model to integrate information from various network layers and a block configuration model to reconstruct increasingly reliable random networks. In contrast to controlled energy efficiency experiments, real-world networks are large in size, heterogeneous in nature and regularly interact with other networks. By utilizing models developed in this dissertation, we are able to estimate the contribution of network structural coefficients to the energy consumption performance of peer networks. By comparing the layered network and block configuration model I developed with other conventional models, I prove the efficiency, accuracy and reliability of these improved models. These findings have implications for assessing network performance, creating accurate complex random networks for large-scale research, and developing strategies for network design to improve building energy efficiency. This research establishes a system to study residents' energy efficient behaviors from the perspective of peer networks and proposes some instructive models for further energy feedback system design.

This dissertation focuses on the economics of infrastructure development and public finance. The dissertation is composed of three papers: The first paper analyzes the optimal solutions for supplying electricity to national economies from both domestic as well as distant energy resources using transmission systems that can connect the huge renewable energy resources of Africa. The results point to options for achieving substantial increases in the sustainable energy supply and for improving access to energy across the continent. The second paper models a comparative local and national electricity distribution planning in Senegal by examining the trade-off between access and costs. The third paper uses exogenous variations in rainfall across municipalities in Mali to estimate the causal effect of household income shocks on municipal-level tax revenues. It also exploits a national tax collection incentive policy to measure the impacts of rainfall variation on intergovernmental transfers.

With extraordinary recent growth of the solar photovoltaic industry, it is paramount to address the biggest barrier to its high-penetration across global electrical grids: the inherent variability of the solar resource. This resource variability arises from largely unpredictable meteorological phenomena and from the predictable rotation of the earth around the sun and about its own axis. To achieve very high photovoltaic penetration, the imbalance between the variable supply of sunlight and demand must be alleviated. The research detailed herein consists of the development of a computational model which seeks to optimize the combination of 3 supply-side solutions to solar variability that minimizes the aggregate cost of electricity generated therefrom: Storage (where excess solar generation is stored when it exceeds demand for utilization when it does not meet demand), interconnection (where solar generation is spread across a large geographic area and electrically interconnected to smooth overall regional output) and smart curtailment (where solar capacity is oversized and excess generation is curtailed at key times to minimize the need for storage.) This model leverages a database created in the context of this doctoral work of satellite-derived photovoltaic output spanning 10 years at a daily interval for 64,000 unique geographic points across the globe. Underpinning the model's design and results, the database was used to further the understanding of solar resource variability at timescales greater than 1-day. It is shown that--as at shorter timescales--cloud/weather-induced solar variability decreases with geographic extent and that the geographic extent at which variability is mitigated increases with timescale and is modulated by the prevailing speed of clouds/weather systems. Unpredictable solar variability up to the timescale of 30 days is shown to be mitigated across a geographic extent of only 1500km if that geographic extent is oriented in a north/south bearing. Using technical and economic data reflecting today's real costs for solar generation technology, storage and electric transmission in combination with this model, we determined the minimum cost combination of these solutions to transform the variable output from solar plants into 3 distinct output profiles: A constant output equivalent to a baseload power plant, a well-defined seasonally-variable output with no weather-induced variability and a variable output but one that is 100% predictable on a multi-day ahead basis. In order to do this, over 14,000 model runs were performed by varying the desired output profile, the amount of energy curtailment, the penetration of solar energy and the geographic region across the continental United States. Despite the cost of supplementary electric transmission, geographic interconnection has the potential to reduce the levelized cost of electricity when meeting any of the studied output profiles by over 65% compared to when only storage is used. Energy curtailment, despite the cost of underutilizing solar energy capacity, has the potential to reduce the total cost of electricity when meeting any of the studied output profiles by over 75% compared to when only storage is used. The three variability mitigation strategies are thankfully not mutually exclusive. When combined at their ideal levels, each of the regions studied saw a reduction in cost of electricity of over 80% compared to when only energy storage is used to meet a specified output profile. When including current costs for solar generation, transmission and energy storage, an optimum configuration can conservatively provide guaranteed baseload power generation with solar across the entire continental United States (equivalent to a nuclear power plant with no down time) for less than $0.19 per kilowatt-hour. If solar is preferentially clustered in the southwest instead of evenly spread throughout the United States, and we adopt future expected costs for solar generation of $1 per watt, optimal model results show that meeting a 100% predictable output target with solar will cost no more than $0.08 per kilowatt-hour.

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: energy; security; 802.11 security protocols; wireless networks. Includes bibliographical references (p. 65-66).