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The hypothesis tested was that a site in Leflore County, Mississippi, located on the bluff above the Mississippi River flood plain (the Delta) would experience wind speeds adequate for power generation. Wind measurements were collected at a height of 55 m (above ground level) between October 2011 and October 2012. Winds at this height were predominately southeasterly with a mean wind speed less than 4 m/s. Winds did not accelerate above this bluff. Low surface friction of the Delta was not beneficial due to the predominant wind direction. To better understand Delta wind patterns, an S-mode varimax-rotated principal component analysis (RPCA) was performed on monthly 30 m North American Regional Reanalysis (NARR) wind data. Three areas for future wind resource assessment measurements were determined. Each pattern highlighted more energetic wind speeds areas, none of which included the measurement site. The RPCA method was successful in delineating homogeneous wind speed patterns.

Multimodular designs of electron donor-acceptor systems are the ultimate strategy in fabricating antenna-reaction center mimics for artificial photosynthetic applications. The studied photosystems clearly demonstrated efficient energy transfer from the antenna system to the primary electron donor, and charge stabilization of the radical ion pair achieved with the utilization of secondary electron donors that permits either electron migration or hole transfer. Moreover, the molecular arrangement of the photoactive components also influences the route of energy and electron transfer as observed from the aluminum(III) porphyrin-based photosystems. Furthermore, modulation of the photophysical and electronic properties of these photoactive units were illustrated from the thio-aryl substitution of subphthalocyanines yielding red-shifted Q bands of the said chromophore; hence, regulating the rate of charge separation and recombination in the subphthalocyanine-fullerene conjugates. These multicomponent photosystems has the potential to absorb the entire UV-visible-NIR spectrum of the light energy allowing maximum light-harvesting capability. Furthermore, it permits charge stabilization of the radical ion pair enabling the utilization of the transferred electron/s to be used by water oxidizing and proton reducing catalysts in full-scale artificial photosynthetic apparatuses.

Yes / The penetration of renewable energies in the energy market has increased significantly over the last two decades due to environmental concerns and clean energy requirements. The principal advantage of renewable energy resources (RESs) over non-RESs is that it has no direct carbonisation impact on the environment and that it has none of the global warming effects which are caused by carbon emissions. Furthermore, the liberalisation of the energy market has led to the realisation of the virtual power plant (VPP) concept. A VPP is a unified platform for distributed energy resources that integrates the capacities of various renewable energies together for the purpose of improving power generation and management as well as catering for the buying and selling of energy in wholesale energy markets. This review study presents a comprehensive review of existing approaches to planning, operation and scheduling of the VPP system. The methodologies that were adopted, their advantages and disadvantages are assessed in detail in order to benefit new entrants in the power system and provide them with comprehensive knowledge, techniques and understanding of the VPP concept.

The modern day expeditionary warfighter faces extraordinary challenges in the battle field and being a beast of burden should not be one of them. Currently the dismounted warfighter is impeded with carrying over 100lbs of tactical gear and supplies for multiday missions in remote territory. Expeditionary forces are also facing an energy and logistical crisis getting water, fuel, and batteries to the tip of the spear. Finding ways to enable self-sufficiency and reducing resupply tethers for small unit operations is a high priority for the armed forces. The Hybrid Electric Autonomous Tactical Support System directly and efficiently tackles both problems head on by synergizing efforts to lighten the load and self sustaining base power by combining the capabilities of the Ground Unmanned Support Surrogate (GUSS) and the Experimental Forward Operating Base projects. Hybridization of the drivetrain of the GUSS vehicle will provide the reliable power for onboard autonomous systems and also enable silent operation modes. The hybrid onboard generator can efficiently provide generous amounts of exportable DC and AC power on demand and is an ideally sized backup/primary power system for small unit bases and forward command posts. The vehicle's onboard energy storage and generator system can also be linked with renewable energy sources to demonstrate the tactical smart mini grid concept. This thesis develops the power requirements for an autonomous system, GUSS mission derived hybrid electric drivetrain specifications, and Marine Corps small echelon bases for the development of the multifunction Hybrid Electric Autonomous Tactical Support System. / Master of Science

At present, the world's transportation sector is being principally supplied by fossil fuels. However, energy consumption in this sector is drastically increasing and there are concerns with supply, cost, and environmental issues with the continuing use of fossil fuels. Utilizing non-petroleum ethanol in the transportation sector reduces the dependence on oil, and allows for cleaner burning of gasoline. Lignocellulose materials are structurally composed of five types of polymeric sugars, glucan, galactan, mannan, arabinan, and xylan. NREL has developed a quantitative saccharification (QS) method for determining carbohydrate composition. We proposed a new protocol based on the NREL 2006 Laboratory Analytical Procedure "Determination of Structural Carbohydrates and Lignin in Biomass" (Sluiter et al. 2006a) with a slight modification, in which xylose concentration was determined after the secondary hydrolysis by using 1% sulfuric acid rather than 4% sulfuric acid. We found that the current NREL protocol led to a statistically significant overestimation of acid-labile xylan content ranging from 4 to 8 percent. Lignocellulosic biomass is naturally recalcitrant to enzymatic hydrolysis, and must be pretreated before it can be effectively used for bioethanol production. One such pretreatment is a fractionation process that separates lignin and hemicellulose from the cellulose and converts crystalline cellulose microfibrils to amorphous cellulose. Here we evaluated the feasibility of lignocellulose fractionation applicable to the hurds of industrial hemp. Hurds are the remaining material of the stalk after all leaves, seeds, and fiber have been stripped from the plant. After optimizing acid concentration, reaction time and temperature, the pretreated cellulosic samples were hydrolyzed to more than 96% after 24 hours of hydrolysis (enzyme loading conditions of 15 FPU/g glucan Spezyme CP and 60 IU/g glucan Novozyme 188) at the optimal pretreatment condition (> 84% H₃PO₄, > 50 °C and > 1 hour). The overall glucose and xylose yields were 89% (94% pretreatment; 96% digestibility) and 61%, respectively. All data suggest the technical feasibility of building a biorefinery based on the hurds of industrial hemp as a feedstock and a new lignocellulose fractionation technology for producing cellulosic ethanol. The choice of feedstock and processing technology gives high sugar yields, low processing costs, low cost feedstock, and low capital investment. / Master of Science

The sustainability of the REIPPP programme was as yet unknown. Through this study control drivers critical for the sustainability of the REIPPP programme were identified and prioritised. As background sustainability was investigated on an international level and within the South African context. Control drivers are drivers that have a significant impact on the sustainability of the REIPPP programme and also have some level of controllability. These drivers were obtained and compiled based on appropriate literature. The Global Reporting Guideline (GRI) for sustainability was used as baseline for identifying control drivers. To further obtain and verify the relevant sustainability control drivers, input from the REIPPP programme’s key stakeholders were included in the research. The key stakeholders provided an impact and controllability rating via a questionnaire, which was used to prioritise the identified control drivers. Selected key stakeholder where requested to review control drivers that were identified and prioritised, providing the researcher a means of verifying the preliminary proposed control drivers. Obtaining a final list of prioritised control drivers critical for the sustainability of the REIPPP programme was achieved by integrating the drivers identified by the researcher, stakeholder selected alternative drivers and their self-suggested control drivers. The prioritised control drivers could be used to promote or control the sustainability of the REIPPP programme by addressing and/or supporting the control drivers having the most significant impact. The top 5 prioritised control drivers were selected to be used in an interview with high level key stakeholders. The interviewees provided their input on how these drivers could be supported or addressed to control or even promote the sustainability of the REIPPP programme. From the interview it was clear that the final list of prioritised control drivers was relevant and could influence the long-term sustainability of the REIPPP programme. Many insights were obtained which could provide significant role players, or even the South African Government, the guidance they need to take the REIPPP programme forward. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2015

The sustainability of the REIPPP programme was as yet unknown. Through this study control drivers critical for the sustainability of the REIPPP programme were identified and prioritised. As background sustainability was investigated on an international level and within the South African context. Control drivers are drivers that have a significant impact on the sustainability of the REIPPP programme and also have some level of controllability. These drivers were obtained and compiled based on appropriate literature. The Global Reporting Guideline (GRI) for sustainability was used as baseline for identifying control drivers. To further obtain and verify the relevant sustainability control drivers, input from the REIPPP programme’s key stakeholders were included in the research. The key stakeholders provided an impact and controllability rating via a questionnaire, which was used to prioritise the identified control drivers. Selected key stakeholder where requested to review control drivers that were identified and prioritised, providing the researcher a means of verifying the preliminary proposed control drivers. Obtaining a final list of prioritised control drivers critical for the sustainability of the REIPPP programme was achieved by integrating the drivers identified by the researcher, stakeholder selected alternative drivers and their self-suggested control drivers. The prioritised control drivers could be used to promote or control the sustainability of the REIPPP programme by addressing and/or supporting the control drivers having the most significant impact. The top 5 prioritised control drivers were selected to be used in an interview with high level key stakeholders. The interviewees provided their input on how these drivers could be supported or addressed to control or even promote the sustainability of the REIPPP programme. From the interview it was clear that the final list of prioritised control drivers was relevant and could influence the long-term sustainability of the REIPPP programme. Many insights were obtained which could provide significant role players, or even the South African Government, the guidance they need to take the REIPPP programme forward. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2015

Thesis (D. Tech. (Electrical Engineering)) -- Central University of Technology, Free State, 2014 / For a sustainable and clean electricity production in isolated rural areas, renewable energies appear to be the most suitable and usable supply options. Apart from all being renewable and sustainable, each of the renewable energy sources has its specific characteristics and advantages that make it well suited for specific applications and locations. Solar photovoltaic and wind turbines are well established and are currently the mostly used renewable energy sources for electricity generation in small-scale rural applications. However, for areas in which adequate water resources are available, micro-hydro is the best supply option compared to other renewable resources in terms of cost of energy produced. Apart from being capital-cost-intensive, the other main disadvantages of the renewable energy technologies are their resource-dependent output powers and their strong reliance on weather and climatic conditions. Therefore, they cannot continuously match the fluctuating load energy requirements each and every time. Standalone diesel generators, on the other hand, have low initial capital costs and can generate electricity on demand, but their operation and maintenance costs are very high, especially when they run at partial loads. In order for the renewable sources to respond reliably to the load energy requirements, they can be combined in a hybrid energy system with back-up diesel generator and energy storage systems. The most important feature of such a hybrid system is to generate energy at any time by optimally using all available energy sources. The fact that the renewable resources available at a given site are a function of the season of the year implies that the fraction of the energy provided to the load is not constant. This means that for hybrid systems comprising diesel generator, renewable sources and battery storage in their architecture, the renewable energy fraction and the energy storage capacity are projected to have a significant impact on the diesel generator fuel consumption, depending on the complex interaction between the daily variation of renewable resources and the non-linear load demand. V This was the context on which this research was based, aiming to develop a tool to minimize the daily operation costs of standalone hybrid systems. However, the complexity of this problem is of an extremely high mathematical degree due to the non-linearity of the load demand as well as the non-linearity of the renewable resources profiles. Unlike the algorithms already developed, the objective was to develop a tool that could minimize the diesel generator control variables while maximizing the hydro, wind, solar and battery control variables resulting in saving fuel and operation costs. An innovative and powerful optimization model was then developed capable of efficiently dealing with these types of problems. The hybrid system optimal operation control model has been simulated using fmincon interior-point in MATLAB. Using realistic and actual data for several case studies, the developed model has been successfully used to analyse the complex interaction between the daily non-linear load, the non-linear renewable resources as well as the battery dynamic, and their impact on the hybrid system’s daily operation cost minimization. The model developed, as well as the solver and algorithm used in this work, have low computational requirements for achieving results within a reasonable time, therefore this can be seen as a faster and more accurate optimization tool.

Thesis (MCom)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Worldwide, energy has been, and continues to be, key to economic development. However, the current global consensus is that energy-related carbon dioxide emissions would, at current rates, put the world onto a potentially catastrophic trajectory which could lead to global warming of 5 degree Celsius or more compared to pre-industrial times. There is a critical need for a low-carbon development or a move away from conventional fossil fuels energy sources. This study explores impacts of policies that South Africa developed in order to champion sustainable energy strategies based on energy efficiency and non-conventional energy sources, including renewable energy. The mining sector, because of its energy-intensive nature, was chosen. In order to achieve this objective three approaches were carried out: (i) a critical review of literature on energy efficiency (EE) and renewable energy (RE) ; (ii) two case-studies that demonstrate the impacts of the policies; and (iii) action research on a sample of mines using survey questionnaire and interviewing. The research results show that the need to have security in energy and the need to be competitive and grow revenue are significant in deciding to carry out EE and RE initiatives in the mining sector. The results also show that safety followed by production are the priorities and are accompanied by a range of other demands, such as cost reduction and legislative requirements. It is, therefore, within this context that EE and RE initiative will always be carried out in the mining sector. The research concludes that, under the current market framework, South African EE and RE policies are not as effective as hoped they would be. The research, therefore, recommends that a percentage of the mines’ revenue could be dedicated to EE and RE initiatives. In addition, South Africa needs to come up with a new type of productive endeavour that would lead to less extractive industries, including mines. / AFRIKAANSE OPSOMMING: Energie is, was en sal wereldwyd altyd die sleutel wees tot ekonomiese ontwikkeling. Nieteenstaande, word dit wereldwyd aanvaar dat die huidige energie opwekking se koolstofdioksied vrystelling moontlik kan lei tot aardverwarming van 5 grade Celsius of meer wanneer vergelyk met word met pre-industriële tye. Daar is ‘n kritiese behoefte aan lae koolstofdioksied vrystelling ontwikkelings of ‘n beperking van konvensionele fossielbrandstof energiebronne. Hierdie studie analiseer die impak van die Suid Afrikaanse beleid wat ontwikkel is om volhoubare energie te bevorder wat effektief en onkonvensioneel is, insluitend hernubare energie. Die mynsektor, as ‘n groot verbruiker van energie, vorm die kern van die studie. Die studie is voltooi in drie fases naamlik: (1) kritiese oorsig van die literatuur oor energiedoeltreffendheid (EE) en hernubare energie (RE); (2) twee gevallestudies wat die impak van die beleid bevestig; en (3) praktiese navorsing deur middel van vraelyste en persoonlike onderhoude met seker myne. Die navorsing bevestig dat die behoefte aan bestendige energie teen kompeterende pryse wat die mynsektor in staat stel om inkomste te groei ,‘n beduidende invloed het op die besluit om EE of RE inisiatiewe te onderneem. Die resultate bevestig verder dat beroepsveiligheid en produksie uitsette die eerste prioriteite vir die myne is. Dit word verder beinvloed deur kostebesparings en wetlike vereistes. Enige EE en RE inisiatiewe wat onderneem word sal in hierdie konteks plaasvind. Die navorsing kom tot die slotsom dat, onder huidige marktoestande, Suid Afrika se EE en RE beleid nie so effektief is as waarop daar gehoop is nie. Die navorsing beveel derhalwe aan dat ‘n persentasie van myne se inkomste geoormerk moet word vir EE en RE inisiatiewe. Verder meer , Suid Afrika moet strewe na tipes produksie wat minder natuurlike grondstowwe onttrek, insluitend die myne.