This research examined what mix of building types result in the most efficient use of a technology known as Aquifer Thermal Energy Storage (ATES). Hourly energy simulation models for six different building archetypes were created based on representative building characteristic and energy use data from the Toronto area. A genetic algorithm optimization tool was then created to vary scheduling and production properties of the ATES system and the relative number of different building archetypes. The tool found that a cooling season from weeks 16‐42 maximized the useful energy output of the ATES and resulted in roughly 30% reduction in heating and cooling energy use and associated GHG emissions. It was also found that creating a mix consisting of a higher percentage of larger buildings than is currently found in most neighbourhoods could reduce energy usage by an additional 10%.

Rechargeable lithium sulfur (Li-S) batteries are potentially safe, environmentally friendly and economical alternative energy storage systems that can potentially be combined with renewable sources including wind solar and wave energy. Sulfur has a high theoretical specific capacity of ~1680 mAh/g, attainable through the reversible redox reaction denoted as S8+16Li ↔8Li¬2S, which yields an average cell voltage of ~2.2 V. However, two detrimental factors prevent the achievement of the full potential of the Li-S batteries. First, the poor electrical/ionic conductivity of elemental sulfur and Li2S severely hampers the utilization of active material. Second, dissolution of intermediate long-chain polysulfides (Li2Sn, 2<n<7) into the electrolyte and their shuttle between cathode and anode lead to fast capacity degradation and low Coulombic efficiency. As a result of this shuttle process, insoluble and insulating Li2S/Li2S2 precipitate on the surface of electrodes causing loss of active material and rendering the electrode surface electrochemically inactive. Extensive research efforts have been devoted to overcome the aforementioned problems, such as combination of sulfur with conductive polymers, and encapsulation or coating of elemental sulfur in different nanostructured carbonaceous materials. Noteworthy, sulfur-polyacrylonitrile (SPAN) composites, wherein sulfur is chemically bond to the polymer backbone and PAN acts as a conducting matrix, have shown some success in suppressing the shuttle effect. However, due to the limited electrical conductivity of polyacrylonitrile, the capacity retention and rate performance of the SPAN systems are still very modest, which shows only 67 % retention of the initial capacity after 50 cycles for the binary system. Recently, graphene has been intensively investigated for enhancing the rate and cycling performance of lithium sulfur batteries. Graphene, which has a two-dimensional, one-atom-thick nanosheet structure, offers extraordinary electronic, thermal and mechanical properties. Herein, a sulfur-polyacrylonitrile/reduced graphene oxide (SPAN/RGO) composite with unique electrochemical properties was prepared. PAN is deposited on the surface of RGO sheets followed by ball milling with sulfur and heat treatment. Infrared spectroscopy and microscopy studies indicate that the composite consists of RGO decorated with SPAN particles of 100 nm average size. The PAN/RGO composite shows good overall electrochemical performance when used in Li/S batteries. It exhibits ~85% retention of the initial reversible capacity of 1467 mAh/g over 100 cycles at a constant current rate of 0.1 C and retains 1100 mAh/g after 200 cycles. In addition, the composite displays excellent Coulombic efficiency and rate capability, delivering up to 828 mAh/g reversible capacity at 2 C. The improved performance stems from composition and structure of the composite, wherein RGO renders a robust electron transport framework and PAN acts as sulfur/polysulfide absorber.

Rechargeable lithium sulfur (Li-S) batteries are potentially safe, environmentally friendly and economical alternative energy storage systems that can potentially be combined with renewable sources including wind solar and wave energy. Sulfur has a high theoretical specific capacity of ~1680 mAh/g, attainable through the reversible redox reaction denoted as S8+16Li ↔8Li¬2S, which yields an average cell voltage of ~2.2 V. However, two detrimental factors prevent the achievement of the full potential of the Li-S batteries. First, the poor electrical/ionic conductivity of elemental sulfur and Li2S severely hampers the utilization of active material. Second, dissolution of intermediate long-chain polysulfides (Li2Sn, 2<n<7) into the electrolyte and their shuttle between cathode and anode lead to fast capacity degradation and low Coulombic efficiency. As a result of this shuttle process, insoluble and insulating Li2S/Li2S2 precipitate on the surface of electrodes causing loss of active material and rendering the electrode surface electrochemically inactive. Extensive research efforts have been devoted to overcome the aforementioned problems, such as combination of sulfur with conductive polymers, and encapsulation or coating of elemental sulfur in different nanostructured carbonaceous materials. Noteworthy, sulfur-polyacrylonitrile (SPAN) composites, wherein sulfur is chemically bond to the polymer backbone and PAN acts as a conducting matrix, have shown some success in suppressing the shuttle effect. However, due to the limited electrical conductivity of polyacrylonitrile, the capacity retention and rate performance of the SPAN systems are still very modest, which shows only 67 % retention of the initial capacity after 50 cycles for the binary system. Recently, graphene has been intensively investigated for enhancing the rate and cycling performance of lithium sulfur batteries. Graphene, which has a two-dimensional, one-atom-thick nanosheet structure, offers extraordinary electronic, thermal and mechanical properties. Herein, a sulfur-polyacrylonitrile/reduced graphene oxide (SPAN/RGO) composite with unique electrochemical properties was prepared. PAN is deposited on the surface of RGO sheets followed by ball milling with sulfur and heat treatment. Infrared spectroscopy and microscopy studies indicate that the composite consists of RGO decorated with SPAN particles of 100 nm average size. The PAN/RGO composite shows good overall electrochemical performance when used in Li/S batteries. It exhibits ~85% retention of the initial reversible capacity of 1467 mAh/g over 100 cycles at a constant current rate of 0.1 C and retains 1100 mAh/g after 200 cycles. In addition, the composite displays excellent Coulombic efficiency and rate capability, delivering up to 828 mAh/g reversible capacity at 2 C. The improved performance stems from composition and structure of the composite, wherein RGO renders a robust electron transport framework and PAN acts as sulfur/polysulfide absorber.

This research examined what mix of building types result in the most efficient use of a technology known as Aquifer Thermal Energy Storage (ATES). Hourly energy simulation models for six different building archetypes were created based on representative building characteristic and energy use data from the Toronto area. A genetic algorithm optimization tool was then created to vary scheduling and production properties of the ATES system and the relative number of different building archetypes. The tool found that a cooling season from weeks 16‐42 maximized the useful energy output of the ATES and resulted in roughly 30% reduction in heating and cooling energy use and associated GHG emissions. It was also found that creating a mix consisting of a higher percentage of larger buildings than is currently found in most neighbourhoods could reduce energy usage by an additional 10%.

On October 1st, 2013, a mandate was adopted by the California Public Utilities Commission (CPUC) requiring that 1.325 GW of energy storage capability be installed on the California electricity grid by 2024, through the actions of the state’s three investor-owned utilities. While this is a bold first step towards mandated energy storage in the United States, it may be only the beginning for an energy storage industry in this state. It has been well established that energy storage would prove to be a useful asset on the California electrical grid, but the development of storage capacity past the requirements of the mandate will depend upon whether storage can be made cost-effective. Much of the value that storage creates is a public good: many storage applications allow the grid to operate more efficiently as a whole, but not necessarily in a way that can be monetized by any particular party. As a public good, these systemic benefits of storage capacity will be supplied sub-optimally in the absence of government intervention. The energy storage industry will accordingly be one that is strongly affected by the tides of change in technology, regulation and economics in the California energy market. This report will focus primarily on the intersection of the second two of these factors, largely leaving the technological questions to more well-informed parties while seeking to establish what regulatory and economic considerations might be undertaken to ensure that the road to deployment of appropriate energy storage systems is made as clear as possible so that this technology can reach the socially efficient level on the California electricity grid. It is the aim of this report not to promote a specific technology or even an energy storage industry, but rather to shed some light on the effects that the development of such an industry could have on the California electricity market and the energy use paradigm that governs modern electricity grids worldwide. With the adoption of AB 2514, a grand experiment was set in motion that will benefit the entire world as California tests the uncharted technological, regulatory and economic territories of grid-scale energy storage capacity. It is a time of change in the electricity industry, and energy storage is a potentially transformative technology that could very well enable the shattering of an energy use paradigm that has held the world captive to fossil fuels for over a century.

Wind power installations are growing rapidly throughout the world due to environmental concerns associated with electric power generation from conventional generating units. Wind power is highly variable and its uncertainty creates considerable difficulties in system operation. Reliable operation of an electric power system with significant wind power requires quantifying the uncertainty associated with wind power and assessing the capacity value of wind power that will be available in the operating lead time. This thesis presents probabilistic techniques that utilize time series models and a conditional probability approach to quantify the uncertainty associated with wind power in a short future time, such as one or two hours. The presented models are applied to evaluate the risk of committing electric power from a wind farm to a power system. The impacts of initial wind conditions, rising and falling wind trends, and different operating lead times are also assessed using the developed methods. An appropriate model for day-ahead wind power commitment is also presented. Wind power commitment for the short future time is commonly made equal to, or a certain percentage, of the wind power available at the present time. The risk in meeting the commitment made in this way is different at various operating conditions, and unknown to the operator. A simplified risk based method has been developed in this thesis to assist the operator in making wind power commitments at a consistent level of risk that is acceptable to the system. This thesis presents a methodology to integrate the developed short-term wind models with the conventional power generation models to evaluate the overall operational reliability of a wind integrated power system. The area risk concept has been extended to incorporate wind power, evaluate the unit commitment risk and the well- being indices of a power system for a specified operating lead time. The method presented in this thesis will assist the operator to determine the generator units and the operating reserve required to integrate wind power and meet the forecast load for a short future time while maintaining an acceptable reliability criterion. System operators also face challenges in load dispatch while integrating wind power since it cannot be dispatched in a conventional sense, and is accepted as and when present in current operational practices. The thesis presents a method to evaluate the response risk and determine the unit schedule while satisfying a specified response risk criterion incorporating wind power. Energy storage is regarded as an effective resource for mitigating the uncertainty of wind power. New methods to incorporate energy storage with wind models, and with wind-integrated power system models to evaluate the wind power commitment risk and unit commitment risk are presented in this thesis. The developed methods and the research findings should prove useful in evaluating the operating risks to wind farm operators and system operators in wind integrated power systems.

This thesis describes the fabrication and modification of porous silicon and titania structures for the purposes of energy storage and conversion. The first chapter provides the reader with background information on porous silicon, batteries, and photocatalysis. The second chapter describes porous silicon fabrication methods and the equipment used in these studies. The third and fourth chapters are journal articles which describe the results of efforts to produce a porous silicon electrode for lithium ion batteries. The fifth chapter is a journal article detailing the fabrication of a thin, free-standing porous silicon film which can be activated for possible photovoltaic and microreactor applications. The last chapter describes the formation of novel silver/silver oxide seed structures for titania photocatalyst nanostructures to be prepared for deposition on a porous silicon support interface.

The heat flux demands for electronics cooling applications are quickly approaching the limits of conventional thermal management systems. To meet the demand of next generation electronics, a means for rejecting high heat fluxes at low temperatures in a compact system is an urgent need. To answer this challenge, in this work a gasketed chevron plate heat exchanger in conjunction with a slurry consisting of highly endothermic solid ammonium carbamate and a heat transfer fluid. A reduced-order 1-dimensional model was developed and used to solve the coupled equations for heat, mass, and momentum transfer. The feasibility of this chosen design for satisfying the heat rejection load of 2kW was also explored in this study. Also, a decomposition reaction using acetic acid and sodium bicarbonate was conducted in a plate heat exchanger (to simulate a configuration similar to the ammonium carbamate reactions). This enabled the experimental validation of the numerical predictions for the momentum transfer correlations used in this study (which in turn, are closely tied to both the heat transfer correlations and chemical kinetics models). These experiments also reveal important parameters of interest that are required for the reactor design. A numerical model was developed in this study and applied for estimating the reactor size required for achieving a power rating of 2 kW. It was found that this goal could be achieved with a plate heat exchanger weighing less than 70 kg (~100 lbs) and occupying a volume of 29 L (which is roughly the size of a typical desktop printer). Investigation of the hydrodynamic phenomena using flow visualization studies showed that the flow patterns were similar to those described in previous studies. This justified the adaptation of empirical correlations involving two-phase multipliers that were developed for air-water two-phase flows. High-speed video confirmed the absence of heterogeneous flow patterns and the prevalence of bubbly flow with bubble sizes typically less than 0.5 mm, which justifies the use of homogenous flow based correlations for vigorous gas-producing reactions inside a plate heat exchanger. Absolute pressure measurements - performed for experimental validation studies - indicate a significant rise in back pressure that are observed to be several times greater than the theoretically estimated values of frictional and gravitational pressure losses. The predictions from the numerical model were found to be consistent with the experimental measurements, with an average absolute error of ~26%

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 188-200.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Atchley, Anthony A. ; Hofler, Thomas J. "December 1990." Description based on title screen as viewed on March 31, 2010. DTIC Descriptor(s): Heat Transfer, Coupling (Interaction), Peak Values, Ratios, Temperature, Thermodynamics, Edges, Isolation, Sensitivity, Regions, Short Range (Time), Profiles, Plates, Internal, Acoustic Arrays, Pressure, Drives, Leading Edges, Mean, Amplitude, Sound Pressure, Stacking, Thermopiles. DTIC Identifier(s): Heat Pumps, Energy Conversion, Energy Storage, Heat Transfer, Thermoacoustic Couples, Theses Author(s) subject terms: Acoustics, Thermoacoustics, Thermoacoustic Heat Transport. Includes bibliographical references (p. 34). Also available in print.