Keeping a contingency reserve in power systems is necessary to preserve the security of real-time operations. This work studies two different approaches to the optimal allocation of energy and reserves in the day-ahead generation scheduling process. Part I presents a stochastic security-constrained unit commitment model to co-optimize energy and the locational reserves required to respond to a set of uncertain generation contingencies, using a novel state-based formulation. The model is applied in an offer-based electricity market to allocate contingency reserves throughout the power grid, in order to comply with the N-1 security criterion under transmission congestion. The objective is to minimize expected dispatch and reserve costs, together with post contingency corrective redispatch costs, modeling the probability of generation failure and associated post contingency states. The characteristics of the scheduling problem are exploited to formulate a computationally efficient method, consistent with established operational practices. We simulated the distribution of locational contingency reserves on the IEEE RTS96 system and compared the results with the conventional deterministic method. We found that assigning locational spinning reserves can guarantee an N-1 secure dispatch accounting for transmission congestion at a reasonable extra cost. The simulations also showed little value of allocating downward reserves but sizable operating savings from co-optimizing locational nonspinning reserves. Overall, the results indicate the computational tractability of the proposed method. Part II presents a distributed generation scheduling model to optimally allocate energy and spinning reserves among competing generators in a day-ahead market. The model is based on the coordination between individual generators and a market entity. The proposed method uses forecasting, augmented pricing and locational signals to induce efficient commitment of generators based on firm posted prices. It is price-based but does not rely on multiple iterations, minimizes information exchange and simplifies the market clearing process. Simulations of the distributed method performed on a six-bus test system showed that, using an appropriate set of prices, it is possible to emulate the results of a conventional centralized solution, without need of providing make-whole payments to generators. Likewise, they showed that the distributed method can accommodate transactions with different products and complex security constraints.

No description available.

No description available.

Thesis (MBA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Although natural gas is utilised as a major source of energy in the world, in the past it has made a negligible contribution to the primary energy needs of Mozambique, Namibia and South Africa. This deviation from the rest of the world is in spite of known natural gas reserves in Mozambique, as well as off the coast of Namibia and South Africa. The reasons why natural gas is not a primary energy source of note in Southern Africa relate to the fact that cheap coal has always been available in abundance in South Africa, past exploration activities were focused on finding crude oil and regional conflicts prevented the development of the available natural reserves. The current interest in natural gas as a source of energy relates to the environmental advantages of natural gas over coal and crude oil, as well as the stated objective of the governments of Namibia and South Africa to diversify the energy supply to these countries The purpose of this study was to determine the economic impact of establishing a natural gasbased industry in Mozambique, Namibia and South Africa. To this end it was necessary to estimate the potential size of the natural gas reserves available in Southern Africa. It was also necessary to calculate the economic value to be added by utilising the few technologies applicable to Southern Africa to consume the natural gas. Based on the economic value added, it was recommended that initiatives to develop the available natural gas resources in Southern Africa should continue. When developing a natural gas-based industry, care must be taken to ensure that a balanced supply chain is established. The principle of a supply chain holds that there must be balanced growth through all the links of the supply chain. The principle of a supply chain highlights the balance to be played in developing the upstream segment as well as the downstream segment of a natural gas industry. Excessive rewards for risks taken by developers in the upstream segment of a natural gas supply chain will be to detriment of encouraging new consumers for natural gas. Significant efforts have been made to establish a regulatory framework in Mozambique, Namibia and South Africa to facilitate a balanced development of the available natural gas resources. There are however areas where the established regulatory framework does not adhere to these requirements and must therefore be reviewed. Several initiatives must also be launched to establish large volume anchor consumers for natural gas. These initiative include increased access to foreign capital as well as a pricing mechanism promoting the long-term development of natural gas resources Once large volume anchor consumers have been established, is will be a simple matter to grow the natural gas industry by adding smaller consumers to the established distribution infrastructure. / AFRIKAANSE OPSOMMING: Alhoewel natuurlike gas 'n belangrike bron van energie is vir die res van die wêreld, het natuurlike gas in die verlede 'n weglaatbare breukdeel van die primêre energiebehoeftes van Mosambiek, Namibië en Suid-Afrika voorsien. Hierdie verskil teenoor die res van die wêreld is ten spyte daarvan dat daar ontdekte natuurlike gasreserwes in Mosambiek sowel as in Namibiese en Suid-Afrikaanse gebiedswaters was. Die redes hoekom natuurlike gas nie 'n belangrike bron van primêre energie in Suidelike Afrika is nie, is te wyte aan die feit dat goedkoop steenkool nog altyd in oorvloed beskikbaar was in Suid-Afrika; dat eksplorasie aktiwiteite gefokus het op ruolie eerder as natuurlike gas en dat streekskonflikte verhoed het dat die beskikbare natuurlike gasbronne ontwikkel kon word. Die huidige belangstelling in natuurlike gas as 'n bron van energie is te wyte aan die omgewingsvoordele wat natuurlike gas inhou bo steenkool en ru-olie, sowel as die verklaarde beleid van die Namibiese en Suid-Afrikaanse regerings om die energieverskaffing aan hierdie lande te versprei tussen verskillende bronne. Die doel van hierdie studie was om die ekonomiese effek te bereken wat die onwikkeling van 'n natuurlike gasgebaseerde industrie in Mosambiek, Namibië en Suid-Afrika teweeg kan bring. Om die ekonomiese effek te bereken moes 'n skatting gemaak word van die verwagte grootte van beskibare natuurlike gasvelde in Suidelike Afrika. Dit was ook nodig om die ekonomiese toegevoegde waarde te bereken deur gebruik te maak van die beskikbare tegnologie, van toepassing op Suidelike Afrika, wat natuurlike gas kan verbruik. Gebaseer op die ekonomiese toegevoegde waarde is dit aanbeveel dat die pogings om die beskikbare natuurlike gasbronne in Suidelike Afrika te ontwikkel, moet voortgaan. Wanneer 'n natuurlike gas-gebaseerde industrie ontwikkel word, is dit belangrik dat 'n gebalanseerde verskaffingslyn geskep moet word. Die beginsel van 'n verskaffinglyn is dat daar eweredige groei in al die onderskeie komponente van die verskaffingslyn moet wees. Die beginsel van'n verskaffingslyn beklemtoon die balans wat gehandhaaf moet word tussen die stroom-op en stroom-af segmente van 'n natuurlike gas industrie. Oormatige beloning vir risiko's deur ontwikkelaars in the stroom-op segment van die natuurlike gasverskaffingslyn sal tot nadeel wees van nuwe verbruikers in die stroom-af segment. Daadwerlike pogings is aangewend om 'n regulatoriese raamwerk te skep binne Mosambiek, Namibië en Suid-Afrika sodat 'n gebalanseerde ontwikkeling van die beskikbare natuurlike gasbronne kan geskied. Daar is egter areas waar die regulatoriese raamwerk nie aan die vereistes voldoen nie en daarom sal dit hersien moet word. Verskeie aksies sal ook geloods moet word om hoë volume ankerkliënte van natuurlike gas te vestig. Hierdie aksies sluit verhoogde toegang tot buitelandse kapitaal, sowel as die ontwikkeling van 'n prysmeganisme wat die langtermynontwikkeling van die natuurlike gasbronne ten doel het. Sodra 'n hoë volume ankerkliënt gevestig is, is dit 'n eenvoudige aksie om groei in die natuurlike gas industrie te bewerkstellig deur kleiner kliënte by die bestaande verspreidingsinfrastruktuur te voeg.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Oil is the quintessential resource in the modern industrial economy. It accounts for a third of world primary energy, fuels 95% of global transport systems, sustains a highly mechanised agribusiness and food distribution industry, and provides the feedstock for a staggering array of petrochemical products. Historically, global economic growth has been closely coupled with consumption of energy in general and oil in particular. Yet oil is a finite resource subject to depletion, which has profound implications for the long-term sustainability of industrial civilisation. This dissertation addresses a serious dearth of attention given to this vital subject within South African energy, economic and policy discourses. The overarching aims are to understand the implications of global oil depletion for socioeconomic welfare in South Africa and to propose viable strategies and policies for mitigating and adapting to potential negative impacts. A comparative evaluation of three fields of study found that neoclassical economics is limited by its monistic and reductionist approach and its failure to adequately incorporate energy into its key theoretical models, whereas ecological economics and the socioecological systems approach together provide an appropriate, holistic lens for analysing the role of energy in socioeconomic systems. In this view, energy is the master resource: it is a pre-requisite for economic activity and societal complexity. A review of the literature on global oil depletion finds that a peak and decline in world oil production appears imminent, while world oil exports most likely peaked in 2005. Moreover, the energy return on (energy) investment (EROI) for global oil production is on a declining trend. The world oil peak thus marks the end of the era of cheap and abundant oil. Increasing oil scarcity will likely be reflected in oil prices following a rising trend with heightened volatility. While there are many potential substitutes for oil, all have significant limitations, most have lower EROI than oil, and it may take decades to scale them up sufficiently. Many aspects of the South African socioeconomic system are either directly or indirectly dependent on petroleum fuels, while structural features of the economy and society render them vulnerable to external shocks. Historical evidence and empirical models suggest that oil price and supply shocks will have debilitating socioeconomic impacts. Under business-as-usual policies and behaviours, future oil scarcity will likely lead at best to a gradual contraction in the economy with rising unemployment and inflation, and at worst to systemic collapse of interconnected critical infrastructure systems. A comprehensive range of mitigation measures are proposed, including accelerated investments in renewable energy and electrified mass transport, agro-ecological farming, greening the economy, monetary system reform, and rationing schemes to protect the most vulnerable members of society. Together these measures can build resilience to shocks and gradually decouple economic activity from petroleum consumption. A successful societal transition from a fossil fuel based industrial regime to a sustainable socioeconomic regime requires purposive government intervention, the promotion of sustainability-oriented innovations in technology and institutions, and the political will to surmount obstacles such as powerful vested interests and socio-technical lock-in. / AFRIKAANSE OPSOMMING: Olie is die kern-hulpmiddel in die moderne bedryfsgerigte ekonomie. Dit is verantwoordelik vir ’n derde van die wêreld se primêre energie, verskaf die aandrywing vir 95% van alle vervoerstelsels, onderhou ’n hoogs gemeganiseerde landboubedryf en voedselverspreidingsnywerheid, en voorsien die voerstof vir ’n verstommende reeks petrochemiese produkte. Histories beskou, is globale ekonomiese groei ten nouste gekoppel aan die verbruik van energie oor die algemeen en aan olie in die besonder. Tog is olie ’n beperkte hulpbron wat onderworpe is aan uitputting en lediging, en dit hou gevolglik onmeetlike implikasies vir die algemene langtermyn volhoubaarheid van nywerhede in. Dié verhandeling neem die ernstige gebrek aan aandag binne Suid-Afrikaanse diskoerse oor energie, ekonomie en beleidsrigtings wat betref hierdie lewensbelangrike onderwerp, in oënskou. Die oorkoepelende doelwitte is om die implikasies van globale olie-uitputting op sosio-ekonomiese welvaart in Suid-Afrika te begryp, en om lewensvatbare strategieë en beleidsrigtings voor te stel waarvolgens potensiële negatiewe invloede getemper en by aangepas kan word. ’n Vergelykende evaluering van drie studieterreine het bevind neoklassieke ekonomie is beperk weens sy monistiese en verlagingsbenadering en sy mislukking om energie doelmatig in te sluit by sy sleutel teoretiese modelle, terwyl die benaderings van die ekologiese ekonomie en die sosio-ekologiese stelsels saam ’n toepaslike holistiese lens bied vir die analisering van die rol van energie in sosio-ekonomiese stelsels. In dié opsig is energie die meester-hulpmiddel: dit is ’n voorvereiste vir ekonomiese bedrywigheid en gemeenskapsverbondenheid. ’n Oorsig van die literatuur oor globale olie-lediging toon dat ’n toppunt en daling in wêreldolieproduksie onvermydelik blyk te wees – globale olie-uitvoer het na alle waarskynlikheid sy toppunt in 2005 bereik. Voorts toon die energie-opbrengs op (energie) investering, ofte wel EROI, ten opsigte van wêreldolieproduksie ’n dalende tendens. Die wêreldolie-toppunt dui dus op die einde van die era van goedkoop en oorvloedige olie. Toenemende olieskaarste sal waarskynlik blyk uit oliepryse wat ’n stygende tendens volg gepaard met verskerpte veranderlikheid. Hoewel daar talle potensiële plaasvervangers vir olie bestaan, het almal beduidende beperkinge, die meeste se EROI is laer as olie s’n en dit kan dekades duur alvorens hulle genoegsaam opgegradeer sal kan word. Vele aspekte van die Suid-Afrikaanse sosio-ekonomiese stelsel is of direk of indirek afhanklik van petroleum-brandstowwe, terwyl strukturele kenmerke van die ekonomie en samelewing hulle kwesbaar vir eksterne skokke laat. Lesse uit die verlede en empiriese modelle dui daarop dat die olieprys en skokke rondom die voorsiening daarvan verlammende sosio-ekonomiese impakte en invloede tot gevolg sal hê. Onder ’n sake-soos-gewoonlik-beleid en optrede, sal toekomstige olieskaarste, optimisties beskou, waarskynlik aanleiding gee tot geleidelike inkrimping van die ekonomie met gepaardgaande stygende werkloosheid en inflasie – pessimisties beskou, kan dit die sistematiese ineenstorting van kritiesbelangrike en onderling verbonde infrastruktuurstelsels beteken. ’n Omvattende reeks verligtingsmaatreëls word voorgestel, insluitende versnelde investering in hernubare energie en geëlektrifiseerde massavervoer, agro-ekologiese landbou, vergroening van die ekonomie, monetêre stelselhervorming en rantsoeneringskemas om die mees kwesbare lede van die samelewing te beskerm. Saam kan dié maatreëls veerkragtigheid vestig teen skokke en ekonomiese bedrywigheid geleidelik van petroleumverbruik losmaak. ’n Geslaagde samelewingsoorgang van ’n fossielbrandstof-gebaseerde nywerheidsbestel na ’n volhoubare sosio-ekonomiese bestel vereis doelmatige regeringsintervensie, die bevordering van volhoubaar-georiënteerde innovasies in

Thesis (PhD (Forest and Wood Science))—University of Stellenbosch, 2007. / Developing sustainable mechanisms for use-management of forest products by user communities has been suggested as a possible solution to the often-observed conflict between forest use and the conservation of protected forests. In Zimbabwe, the use of forest products in protected forests by local communities has a long history, but few studies have explored both the socio-economic and ecological aspects of this use. This study was conducted in the Baikiaea plurijuga forests and woodlands in and around Fuller Forest in western Zimbabwe, protected since 1943. It explored the characteristics and dynamics of forest products use by communities surrounding this protected forest. Further, the demography and dynamics of commonly harvested woody species was examined in order to establish the present status of populations of these species. This examination, focusing on diameter class distributions, was aimed at informing whether species populations were expanding, stable or declining in view of their capacity to continue providing required goods and services. Results indicated that all households, rich and poor, were harvesting at least some forest resources from the protected forest, with the most frequently harvested resources being firewood, wood for curios, thatch grass, wild fruits, timber for construction and fencing and those who owned livestock used the forest for livestock grazing. The extraction and use of 23 different products was recorded across the villages. The top five harvested forest products in terms of the mean proportion of households using them were fuelwood, building poles, thatch grass, wild fruits and broom grass. Forest products were harvested both for own consumption and for sale. At present Baikiaea plurijuga, Colophospermum mopane, Brachystegia spiciformis, Diplorhynchus condylocarpon, Commiphora mocambicensis and Bauhinia petersiana out of 14 commonly harvested species appear to have relatively stable populations as indicated by their inverse J-shaped diameter class distribution profiles. Preliminary indications from this baseline information point towards the successful integration of local use of forest products and conservation objectives noting that there is need for caution until further studies as recommended in this study are taken.

Globally, there are significant quantities of natural gas reserves that lie economically or physically stranded from markets. Options to monetize such reserves include Gas to Liquids (GTL) and Liquefied Natural Gas (LNG) technologies. GTL is a unique monetization option that brings natural gas products to crude oil markets. This technology is commercially immature, appears to have attractive market potential, requires substantial capital investments, and has uncertain operating costs and revenue generation. LNG is a more established monetization option. Project economics for the two technologies are reviewed, as well as literature evaluating such for either or both. Discounted cash flow models are studied for two project scenarios, and results are discussed and compared. The modeling effort seeks to inform the decision to invest in GTL or LNG for the monetization of a stranded gas reserve. / text

Submitted to School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa 24 August 2016 / The recent significant discoveries of gas in Mozambique could provide a much needed solution to the South African electricity crisis, but at what cost? This research report seeks to determine the economic viability of utilising Mozambican Gas to produce electricity by using data from the Integrated Resource Plan 2010-2030 Update of 2013 in a levelised cost of electricity model. The Mozambican gas fields are yet to be developed and the final price at which gas will be available is unclear, but a price range determined by ICF international in a study for the World Bank is assumed for the purposes of the study, with the results yielding a range levelised cost of energy. The results of the levelised cost determine that Mozambican gas can be utilised to provide an economical solution to the south African electricity crisis, but the price at which gas is available will determine the type of generation, either peaking power, midmerit and or baseload generation. / MT2017

Cheung Ka-Kui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 111-117). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Figures --- p.viii / List of Tables --- p.x / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Objectives --- p.3 / Chapter 1.3 --- Significance --- p.4 / Chapter 1.4 --- Organization of the Thesis --- p.5 / Chapter Chapter 2. --- Literature Review --- p.7 / Chapter 2.1 --- Hong Kong Country Parks and Management Practices --- p.7 / Chapter 2.1.1 --- Establishment of Country Parks --- p.7 / Chapter 2.1.2 --- Country Park Management Practices --- p.8 / Chapter 2.1.3 --- Country Park Design --- p.9 / Chapter 2.2 --- Negative Impacts created from Visitors --- p.10 / Chapter 2.2.1 --- General Background --- p.10 / Chapter 2.2.2 --- Specific Impacts --- p.12 / Chapter 2.2.2.1 --- Noise --- p.12 / Chapter 2.2.2.2 --- Trampling --- p.13 / Chapter 2.2.2.3 --- Littering --- p.15 / Chapter 2.3 --- Wildlife Resources in Hong Kong Country Parks --- p.16 / Chapter 2.3.1 --- Wildlife Resources in Hong Kong --- p.17 / Chapter 2.3.2 --- Conservation Efforts in Hong Kong --- p.19 / Chapter 2.4 --- Technological Advancements in Park Management --- p.19 / Chapter 2.4.1 --- Remote Sensing and Vegetation Mapping --- p.20 / Chapter 2.4.2 --- GIS and Park Management --- p.22 / Chapter Chapter 3. --- Study Area and Methodology --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Study Site --- p.25 / Chapter 3.2.1 --- Park Settings --- p.25 / Chapter 3.2.2 --- Ecological Resources --- p.28 / Chapter 3.3 --- Field Measurement --- p.32 / Chapter 3.3.1 --- Sampling Strategy --- p.32 / Chapter 3.3.2 --- Impact Indicators --- p.34 / Chapter 3.3.2.1 --- Noise --- p.34 / Chapter 3.3.2.2 --- Trampling --- p.35 / Chapter 3.3.2.3 --- Litter Dispersal --- p.36 / Chapter 3.4 --- Laboratory Techniques --- p.36 / Chapter 3.4.1 --- Remote Sensing Application --- p.36 / Chapter 3.4.1.1 --- Image Pre-processing --- p.36 / Chapter 3.4.1.2 --- Vegetation Index --- p.38 / Chapter 3.4.1.3 --- Vegetation Class Map --- p.39 / Chapter 3.4.2 --- The Ecological Dataset --- p.40 / Chapter 3.4.3 --- GIS Application --- p.40 / Chapter 3.4.3.1 --- Basic Operations --- p.40 / Chapter 3.4.3.2 --- Composite Maps for Recreation Impacts and Conservation Importance --- p.41 / Chapter Chapter 4. --- Spatial Characteristics of Visitor Impact and Natural Resources --- p.44 / Chapter 4.1 --- General Situation of Visitor Impacts --- p.44 / Chapter 4.1.1 --- Patterns from Vector Data Format --- p.44 / Chapter 4.1.2 --- Patterns from Raster Data Transformation --- p.52 / Chapter 4.1.3 --- Composite Impact Level --- p.56 / Chapter 4.2 --- Ecological Attributes of Shing Mun Country Park --- p.59 / Chapter 4.2.1 --- Vegetation Cover --- p.59 / Chapter 4.2.2 --- Water Resources --- p.62 / Chapter 4.2.3 --- General Distribution of Wildlife --- p.62 / Chapter 4.2.4 --- Conservation Significance on the Number of Species found --- p.69 / Chapter 4.2.5 --- Conservation Significance on the Number of Class found --- p.69 / Chapter 4.2.6 --- Conservation Significance on the Number of Trophic Level with Ecosystem --- p.70 / Chapter 4.2.7 --- Composite Conservation Significance --- p.70 / Chapter Chapter 5. --- Discussion --- p.78 / Chapter 5.1 --- Potential Association between Recreation and Conservation --- p.78 / Chapter 5.2 --- Park Design --- p.86 / Chapter 5.2.1 --- Zoning and Site Location --- p.86 / Chapter 5.2.2 --- Road and Footpath Network --- p.88 / Chapter 5.3 --- Problems in Country Park Management --- p.96 / Chapter 5.3.1 --- Recreation Management --- p.96 / Chapter 5.3.2 --- Wildlife Conservation --- p.97 / Chapter 5.4 --- Implications from the Study --- p.98 / Chapter 5.4.1 --- Mode of Recreation --- p.98 / Chapter 5.4.2 --- Importance of Baseline Studies --- p.99 / Chapter 5.5 --- Recommendations for Country Park Management --- p.101 / Chapter Chapter 6. --- Conclusion --- p.104 / Chapter 6.1 --- Summary of Findings --- p.104 / Chapter 6.2 --- Limitations of the Study --- p.105 / Chapter 6.3 --- Recommendations for Further Studies --- p.107 / Reference --- p.111 / Appendices --- p.118 / Chapter 1. --- Descriptions and Basic Sensor Characteristics of IKONOS Satellite Image --- p.118 / Chapter 2. --- Mathematic Conversion in Radiometric Correction --- p.120 / Chapter 3. --- Details on Aerial Photo Interpretation --- p.121 / Chapter 4. --- Recreation Site Recording Sheet --- p.122 / Chapter 5. --- Trespassing Recording Sheet --- p.123

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2017. / The distribution of grazing herbivores is influenced by several factors, including spatial and temporal availability of resources. The Telperion and Ezemvelo Nature Reserves (TENR), located on the border between Gauteng and Mpumalanga Provinces, experienced a declining hartebeest (Alcelaphus buselaphus caama) distribution over the last years. Simultaneously, an increase in the density of plains zebra (Equus quagga) occurred in the reserves. In this study, I investigated the changes in the distribution of four herbivore species, namely red hartebeest, plains zebra, blue wildebeest and black wildebeest in TENR, and the possible influence that biotic and abiotic factors had on the distribution of hartebeest between 2010 and 2016. Data of aerial surveys conducted in the wet season of each year were used to assess the variation in herbivores distribution along the period. Furthermore, the influence of variables known to affect herbivore distribution (e.g. distance to water, slope gradient, spatial distribution of other herbivore species and vegetation greenness) was tested on hartebeest distribution in TENR. The results indicate that blue wildebeest (Connochaetes taurinus) had the highest distribution variation, while plains zebra presented the most spread distribution among the four species, and black wildebeest (Connochaetes gnou) concentrated their distribution almost entirely at the Ezemvelo nature reserve. Hartebeest avoided areas with the highest concentration of plains zebra, but did not show the same avoidance for areas with prevalence of wildebeest species. Further, high quality forage resources influenced the hartebeest distribution in TENR. Thus, competition for forage resources with bulk feeders may have affected the population and distribution of hartebeest between 2010-2016. / LG2018