Philosophiae Doctor - PhD / Today fossil fuels such as oil, coal and natural gas are providing for our ever growing energy needs. As the world’s fossil fuel reserves fast become depleted, it is vital that alternative and cleaner fuels are found. Renewable energy sources are the way of the future energy needs. A solution to the looming energy crisis can be found in the energy carrier hydrogen. Hydrogen can be produced by a number of production technologies. One hydrogen production method explored in this study is electrolysis of water.

State policy incentives for solar power have grown significantly in the past several years. This paper examines the effectiveness of policy incentives to increase residential solar PV capacity. County-level solar adoption data and controls for demographic characteristics, solar resources, and pro-environmental preferences are used to estimate a model of residential solar adoption. Empirical findings show that financial incentives, solar-specific mandates, and loan financing programs are important drivers of residential PV capacity growth. Incentives that reduce the up-front cost of adoption and that are subject to low uncertainty are found to have the largest impact. Results also point to a significant positive relationship between hybrid vehicle sales and residential PV capacity growth, indicating the importance of pro-environmental preference as a predictor of solar PV demand.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23294号 / エネ博第419号 / 新制||エネ||79(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 手塚 哲央, 教授 宇根﨑 博信, 准教授 MCLELLAN Benjamin / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Microgrid is an essential part of the nation’s smart grid deployment plan, recognized especially for improving efficiency, reliability, flexibility, and resiliency of the electricity system. Since microgrid consists of different distributed generation units, microgrid scheduling and real-time dispatch play a crucial role in maintaining economic, reliable, and resilient operation. The control and optimization performances of the existing online approaches degrade significantly in microgrid applications with missing forecast information, large state space, and multiple probabilistic events. This dissertation focuses on these challenges and proposes efficient online learning and optimization-based approaches. For addressing the missing forecast challenges on online microgrid operations, a new fitted rolling horizon control (fitted-RHC) approach is proposed in Chapter 2. The proposed fitted-RHC approach is designed with a regression algorithm that utilizes the empirical knowledge obtain from the day-ahead forecast to make microgrid real-time decisions whenever the intra-day forecast data is unavailable. Simulation results show that the proposed fitted-RHC approach can achieve the optimal policy for the deterministic case study and perform efficiently with the uncertain environment in the stochastic case study. / Includes bibliography. / Dissertation (PhD)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

This thesis discusses the coupling of a mechanical and electrical oscillator, an arrangement that is often encountered in mechatronics actuators and sensors. The dynamics of this coupled system is mathematically modeled and a low pass equivalent model is presented. Numerical simulations are then performed, for various input signals to characterize the nonlinear relationship between the electrical current and the displacement of the mass. Lastly a framework is proposed to estimate the mass position without the use of a position sensor, enabling the sensorless control of the coupled system and additionally providing the ability for the system to act as an actuator or a sensor. This is of value for health monitoring, diagnostics and prognostics, actuation and power transfer of a number of interconnected machines that have more than one electrical system, driving corresponding mechanical subsystems while being driven by the same voltage source and at the same time being spectrally separated and independent. / by Dimitrios Psarrou. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

This thesis analyzes the challenges associated with the countries in socioeconomic and political transition when on the path of integrating into the developed world unions or on the path of fulfilling projected renewable energy targets. As an example country, or as a study case here, The Republic of Serbia has been selected. The thesis addresses the question of how the Renewable Energy Market in Serbia is developing and how are the challenges being addressed. Thesis reveals that main obstacles come from the ownership of the energy and the power gird assets which are still entirely owned and controlled by the State. Due to this fact it is hard to introduce the planned renewable projects, mostly to be developed and owned by foreign entities, and at the same time to be forced to reduce domestic power production out of the thermal power plants. However, by being on the path to the EU, the renewable energy targets and the RES (Renewable Energy Sources) market have to be accomplished and the government has to show full legislative and policy support. It is also realized that there is a significant discrepancy between the "say and do" in the case of The Republic of Serbia, at least so far. The thesis highlights the important driving factors that, despite of the local resistance and sluggishness,...

Sustainable energy has taken center stage in materials research and global markets, which has encouraged an explosion in related materials development. Practical implementations of sustainable energy solutions rely upon high-performance and cost-effective materials for energy harvesting and storage. Organic electronics, a class of materials composed principally of carbon, are regarded as promising candidates in this respect. Carbon, when arranged with atomic precision and warped carefully into desirable conformations, can generate exceptionally inexpensive and high-performance materials. These materials can then be readily integrated into solar cells, capacitors, and transistors. This dissertation explores our progress in the field of high-performance organic electronics in the context of these practical devices, and aims to establish simple design principles for the future development of contorted organic electronics. Of principal importance to this thesis is the conclusion that localized molecular contortion seems to bestow unique and somewhat unexpected properties upon extended systems. Therefore, a key theme underlying our work herein is the idea that for specific applications, contorted or extended graphene nanoribbons can be shown to be superior to planar organics. This advantage has allowed us to report exceptionally high performance metrics in the fields of energy harvesting and storage. Chapter 1 comprises an overview of the entire body of work contained within this dissertation, in a highly condensed format. This includes in-depth specific background on the innovations of prior researchers who have enabled our present work. Chapter 2 details the elongation of the small graphene fragment perylene into long, electronically active, and ambient-stable nanoribbons. This chapter is assembled from three research manuscripts investigating the employment of these nanoribbons as electron transporting materials in photovoltaics and one set of preliminary results on their incorporation as potential surface arrays for chip technologies. Chapter 3 examines the expansion of our perylene-based nanoribbons into large single-molecule three-dimensional nanostructures up to 5 nm in wingspan. These structures, by consequence of their three-dimensional geometry and contorted nature, exhibit curious enhancements over their one-dimensional counterparts. Such enhancements, namely in photovoltaic efficiency and electron transport behavior, are investigated over the course of two research manuscripts. Chapter 4 explores the idea of organic energy storage through the lens of pseudocapacitance, and further expands the perylene toolbox by developing high-capacitance and highly stable polymer structures. These ideas ultimately culminate in the final subchapter, wherein our most recent work on contorted, semi-two-dimensional capacitive polymers is disclosed. The exceptionally strong and potentially economically viable results of our most recent energy storage architecture are enabled entirely by our understanding of molecular contortion. Namely, contortion’s unique ability to manifest long-range electronic conjugation concomitant with the prevention of aggregation, thus improving surface area for ion diffusion and bulk processability. In consideration of the impact these nanoscale ideas could have on the global scale, it is our belief that ideas concerning contortion within the context of organic electronics will continue to generate high-performance energy storing and harvesting materials. Our explorations towards such solutions have garnered substantial interest in the materials community thus far, and this dissertation seeks to add to that growing body of literature by inspiring numerous new twisted architectures.

One approach to enabling a larger penetration of renewable sources of energy is the implementation of hybrid power plants. This work presents a process to determine the preliminary optimal configuration of a concentrating solar power-coal hybrid power plant with low solar augmentation, and is demonstrated on a coal power plant in Castle Dale, UT. A representative model is developed and validated against published data for a coal power plant of a different configuration than Hunter Unit 3. The simplifications within the representative model include combining multiple feedwater heaters, combining turbines that operate across the same boundary states, and the mass-average calculation for extraction properties to the combined feedwater heaters. It is shown that the representative model can accurately and consistently simulate a coal power plant. Comparing net power generation and boiler heating estimates from the representative model to the benchmark power plant, the representative model is accurate to within +/- 1% the accepted value from the benchmark power plant. The methods for quantifying solar resource with data from the National Renewable Energy Laboratory are presented with the derivation of an algorithm to simulate a concentrating solar power field arrangement. The solar contribution to electrical power output is estimated using an exergy balance. A simplified financial model is also developed to estimate the solar marginal levelized cost of electricity and payback time using a cash-flow analysis. Estimates for solar resource, solar contribution, and financial performance are consistent with data published by the National Renewable Energy Laboratory or in archival literature. A multi-objective optimization routine is developed consisting of the representative model, the augmentation of solar energy into the solar integration model by means of feedwater heater bypass, solar contribution, levelized cost of electricity, and payback time. Because this study considered complete FWH bypass, higher solar augmentation (>3% of boiler heating) is required for a hybrid design to be considered feasible. However, for higher solar augmentation, the costs are also considerably higher and the financial benefit is insufficient to make any hybrid designs feasible unless a carbon tax is in place. A carbon tax will amplify the financial benefit of hybridization, so optimization results are provided assuming a carbon tax value equivalent to the value used in California's Emissions Trading System (16 USD sh.tn.^-1). The impact of a green energy premium price paid by consumers is also explored in the context of payback time. The resulting optimal design for the Hunter Unit 3 with a carbon tax and no premium is using parabolic trough collector technology at an augment fraction of k=9% to bypass feedwater heater 6. The resulting marginal solar levelized cost of electricity is 9.5 x 10^-4 USD kWh^-1 with an estimated payback time of 25.2 years. This process can be applied to any coal power plant for which operating data and meteorological data are available to evaluate preliminary hybridization feasibility.

Using biomass gasification to produce combustible gas is one of the promising sustainable energy optionsavailable for many countries. At present, a few small scale community based power generation systemsusing biomass gasifiers are in operation in Sri Lanka. However, due to the lack of proper knowledge, thesesystems are not being operated properly in full capacity. This stands as an obstacle for further expansionof the use of gasifier technology.The objective of this study was to identify the most influential parameters related to fuel wood gasificationwith a down draft gasifier in order to improve the gasification processes.A downdraft gasifier of 10kW electrical capacity was used to study the effect of equivalent ratio (Actual airfuel ratio to Stoicheometric air fuel ratio: ER) on the specific gas production, the heating value of gasproduced and the cold gas efficiency using three throat diameters (125mm, 150mm and 175mm). Six trialswere carried out for each throat diameter by varying the supply air flow to change the ER. The gassamples were tested for their compositions under steady state operating conditions. Using mass balancesfor C and N, the cold gas efficiencies, calorific values and the specific gas production rates weredetermined.The results showed that with all throat diameters the calorific value of gas reduced with the increase ofER. The cold gas efficiency reduced with ER in a similar trend for all three throat diameters. The specificgas production increased with ER under all throat diameters.Calorific value and specific gas production are changing inversely proportional manner. The ER to beoperated is depends on the type of application of the gas produced and engine characteristics. When alarge heat is required, low ER is to be used in which gas production is less. In the opposite way, when alarge amount of gas is needed, higher value of ER is recommended.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The recent climate change has forced people to live in extreme conditions, either excessive heat or cold, implying that they must adapt to survive in these situations. However, there are people who, because of their geographical condition and lack of resources, lack the means and tools to combat these climate changes. The context of this study is provided in a rural town located in the Arequipa region (Peru), whose inhabitants have to fight against frosts of up to −20 °C in an area without electricity. A viable solution to this problem is found through the design and implementation of a heating system using geothermal and photovoltaic energy, which are resources found in the area, according to a report of the Ministry of Energy and Mines. This study analyzes and researches the geographical and meteorological conditions of the region, for validating, through theory and simulations, whether the proposed system can supply the thermal energy required to maintain the indoor temperature at a minimum of 15 °C under extreme conditions. The system is designed after analyzing the best technological options and techniques currently available in the context studied for its ultimate financing and establishing guidelines and indicators for monitoring results.