The threat of climate change has led to many countries and regions adopting renewable targets. Scotland's is one of the most ambitious, with an aim to generate the equivalent to 100% of its electricity needs from renewable sources by 2020. Scotland has a very large renewable resource, primarily consisting of offshore and onshore wind, tidal stream, wave and hydro power; all of which are characterised by having variable output. Over a long period, such as a year, variability in renewable generation will average out and may meet or exceed total annual demand. This thesis investigates whether matching of demand and generation is possible within a timescale meaningful to electricity system users; that is whether renewable generation can meet electricity demand in any given hour. This was established by using historic data to create an hourly generation hindcast of Scotland's renewable generation over a 30 year climate “normal” period. These outputs are then compared to a hindcast of hourly demand based on observations over the most recent few years. The results demonstrated that it is possible for Scotland to rely entirely upon renewable generation to fulfil demand in any hour of the 30 year hindcast. However, it appears that the renewable capacity and storage currently built or within the Scottish planning system is only sufficient to match demand in 65% of the hours within the hindcast. The hindcast allows judgements to be made as to how 100% of demand could be met most effectively and provides the basis of a coherent planning strategy, with security of supply at its centre. Further wave and tidal stream capacity is shown to be of higher value than additional wind power but in the latter case, addressing the geographical diversity of wind power can enable maximise phasing between sites to increase the security of supply. Importantly this work provides a means of informing decision making about where best to develop wind, wave and tidal resources and what additional storage may be required in order to provide 100% security of supply. The results are also of particular importance to Scotland's renewable generation strategy in the case of assessing where new on- and off-shore wind farms should be developed, as wind is set to dominate Scotland's renewable portfolio for the foreseeable future.

The increasing demand for electricity, the rising price of energy from conventional sources and limited electricity supply are a global concern. The demand on electricity generation could be alleviated by diversifying the sources from which electricity is obtained to achieve the goals of long-term electricity supply. Diversification implies finding alternative sources of energy such as renewable energy for the production of electricity. The South African electricity system is under increased pressure to provide and maintain electricity supply to its users. Electricity production may be regarded as a key contributor to the social and economic development of South Africa. The challenges are so serious that it will gradually become increasingly difficult to extract sufficient resources to satisfy increasing electricity demand. Growth in the electricity and industrial sectors signifies profound changes in the entire energy industry. The South African power utility Eskom, supplies 94% of South Africa’s electricity but the risk of inadequate supply because of increasing electricity demand is mitigated through the employment of Independent Power Producers (IPPs) which supply to the grid. However, although a limited number of IPP entrepreneurs sell electricity to the Eskom grid, there is no enabling entrepreneurial environment in which they can thrive. There is no positive movement to inaugurate policies and processes. This has created an opportunity for Smart Grid access as a viable option to accommodate IPP entrepreneurs into the grid. Investing in renewable electricity sources may provide feasible alternatives for the electricity industry, it would alleviate pressure on current supply whilst creating an enabling entrepreneurial environment for IPP entrepreneurs and increase entrepreneurial activity. This study investigates a proposed model for an enabling entrepreneurial environment for IPPs in the RE sector that can be utilised to ensure increased entrepreneurial activity within the electricity industry. Establishing such an enabling environment would contribute positively to the alleviation of the electricity demand crisis, result in lower carbon emissions and create a sustainable, more diverse electricity generation mix. This proposed IPP industry model for an enabling entrepreneurial environment is presented to address the problems experienced at the different levels of the electricity industry. The model can be utilised to increase entrepreneurial activity while eradicating major electricity challenges at different levels in the South African electricity industry. The results indicate that that RE, in the form of solar and wind, has the potential to expand the South African electricity industry significantly. Therefore, in order to reform the South African electricity industry, stakeholders need to embrace entrepreneurship as IPP entrepreneurs. This can be done effectively by the incorporation of IPP entrepreneurs into the electricity network. However, an enabling entrepreneurial environment in which to operate must be ensured. In this study, five important variables support the establishment of an enabling entrepreneurial environment for IPP entrepreneurs. These have been identified as; Smart Grids, Entrepreneurship, Renewable electricity environment, SA policy and Stakeholder theory. An important contribution has been made towards Stakeholder Theory. This has proven to be instrumental within the RE sector of the electricity industry in South Africa, as the mentioned role players have a reciprocal role to play. Three surveys were conducted at three levels of the electricity industry, namely, at organisational, legislative and entrepreneurial levels and included Eskom Management, National Energy Regulator (NERSA) Management and Approved and Non-approved IPPs. Both qualitative and quantitative research methods were utilised in this research study. The results indicate that SA Policy is instrumental in assisting stakeholders to facilitate the IPP process and feed the power from RE generation into the network. Most respondents were positive about the role of Smart Grids in future electricity generation and their contribution towards creating an enabling entrepreneurial environment for IPP entrepreneurs. Respondents indicated that by policy decisions, greater emphasis can be placed on the results of climate change and environmental challenges. Emphasis on the incorporation of stakeholders proved imperative to this group (IPPs). The results indicated that stakeholder management is a key factor contributing to the establishment of an enabling entrepreneurial environment. The major contribution of this study is a proposed entrepreneurial model that can improve future sustainability of the electricity supply.

The study found that investing in solar water heater system (SWH) would be an economically, socially and environmentally viable option to implement within urban households; in which the hot water demand, volume of hot water consumption, water heating costs, and electricity tariffs are high. Investing in solar water heater technology should be the key focus of South African government; in order to enhance the wellbeing of the ordinary citizens. The study made use of the qualitative research approach to investigate solar water heater drivers and barriers; from the perspective of energy consumers. This will be achieved by focusing on the major drivers and barriers that consumers consider when making decisions on adoption of solar water heater system. It is believed that solar water heater drivers and barriers substantially influence the potential and urban development thereof. Solar heat is utilized in the residential sector for heating water for bathing, cleaning, washing and cooking food, but its availability is limited (Arora & Arora, 2013). Renewable energy has become a wild card internationally and regionally because of the technical, economic and environmental barriers affecting the disadvantaged individuals.

The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.

Given increasing problems in the availability, affordability and deliverability of commercial primary and secondary energy resources, coupled with growing macroeconomic uncertainties, the use of renewable, non-commercial energy resources has been actively promoted in rural areas of developing countries. This, in addition to the fact that conventional, 'state-of-the-art' energy facilities present technical problems, are inequitable and pose potential environmental hazards, has led to proposals for instituting alternative, intermediate or 'appropriate' technologies in rural settlements. This thesis identifies technical, economic, social, cultural and institutional barriers to the introduction of intermediate or 'appropriate' technologies in rural areas. The cases of solar and biogas technologies in Korea, Malaysia, Papua New Guinea the Philippines and Thailand are considered. Policy and planning process recommendations are made on the roles of government, voluntary aid-agencies and the rural user, to overcome the obstacles to implementing these technologies. These recommendations cover the micro (village) and macro (regional and national) levels over two time horizons, and stress the need for a comprehensive approach to discerning rural needs, followed by integrated technology diffusion through effective program and project implementation. In addition, this thesis identifies the need for a continuous collection of information on rural socio-economic conditions and potential for rural interfuel substitution and finally, recommends research into improving technical efficiencies of alternative energy technologies such as solar and biogas. Alternative or intermediate energy technologies such as solar and biogas can play an important role in augmenting rural energy supply. Unless steps are taken to remove the identified barriers to implementation in future technology diffusion efforts, this potential will not be realized. Policy and planning process recommendations made in this thesis present means through which these barriers could be removed. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

M.Phil. ( Energy Studies) / In contrast to conventional energy sources, the advantage of renewable energy lies in the fact that it is virtually inexhaustible and that its utilisation is accompanied by minima environmental pollution. I t is, furthermore, very appropriate especially seen in the light of the large Third World component of the South African energy economy. It therefore becomes necessary to evaluate the adequacy of Government strategy as far as the optimal development and utilisation of the renewable energy sources with the best potential in South Africa are concerned, against present and future needs for and the utilisation possibilities of these sources...

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.

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.

Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Law, 2016. / Africa is challenged by the lack of stable modern electricity which is essential for economic and social development. Many African communities, especially in rural and sub-urban areas, are not connected to the national grid and thus constrained from developing and their continued use of traditional sources of exhaustible energy cause environmental pollution. Distributed renewable energy technologies can help to address the problem of modern energy provision in many of Africa‘s communities. Finance plays a critical role in the development of renewable energy within countries. It bridges the gap in the development of renewable energy projects (REPs). Governments‘ efforts towards developing REPs for scaled-up renewable energy to impact the energy access challenge measurably have been inadequate. Thus, this dissertation focuses on increasing the financial contribution of the private sector in developing REPs, especially within rural communities. Models of financing REPs within selected African countries are analysed, with focus on financiers‘ perspectives and governments‘ ultimate goal in financing REP development. A key objective is to bridge the gap between private sector financiers and policymakers in government in this REP financing effort. The study uses the mixed methodology approach to develop a framework through which REP development is related to the perspectives of financiers and policymakers as to enable reliable and useful research findings. Broadly, the results show that while REP financiers are mainly focused on the profitability of their investments, policymakers are mainly focused on the prospects for sustainable economic development. This divergence presents a key obstacle to the development of renewable energy within African countries. Further, results show that traditional financing methods have been largely ineffective in promoting development of REPs in African countries, hence the need for innovative financing channels to increase REP development in Africa. Also, financiers of REPs in Africa consider renewable energy to be highly risky even when supported by government policies. The fledgling capital markets in many African countries need to be further developed to provide appropriate hedging mechanisms while financing small and medium scale REPs. This study also proposes financing models that amalgamate financiers into a small ―financing consortiums‖ using project finance to fund localised renewable energy service companies (ESCOs) with expertise in finance and REP development; kind of models that spread risk among a number of investors, thereby reducing the potential risks of investments while delivering on the objective of sustainable economic development.

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