One application for photovoltaic (PV) technology is in providing electricity for educational aids, in developing areas remote from grid supply. Technical, social and economic aspects of this option are investigated, in local context, by examining the use of small PV systems to power educational television and video in secondary schools in Bophuthatswana. Technical performance was assessed through monitoring PV system behaviour and climatic variables over an extended period, using remote data-capture techniques at a demonstration site. Modelling provided for further prediction of performance in nonobserved conditions. Social and educational aspects of the schools television project were investigated through interviews with educationists, planners, project administrators and a limited sample of teachers and pupils in Bophuthatswana. Overall conclusions are that PV systems can provide a reliable and technically appropriate solution to the problem of powering light electrical loads in off-grid schools. Levelised unit energy costs can be acceptable if PV systems are critically sized, and if there is close match between designed capacity and actual load energy demand. If this is not the case - as in Bophuthatswana school systems - unit energy costs may be very high. Organisational features of project implementation and inadequate central resources, particularly for delivering appropriate educational software to schools, have impaired the potential of the project, and the equipment in schools is under-utilised. Proceeding from an inductive performance analysis of the monitored system, a PV system performance model was developed, in order to assess the optimum sizing of components in small stand-alone photovoltaic systems in such applications, and to judge the sizing of the systems installed. The model is based upon critical runs of adverse weather, leading to-wards system loss of power to load. It predicts the minimum insolation required to avoid system loss of power to load over runs of days, and compares this with percentiles for plane-of-array insolation over runs of days, derived from long term · hourly weather station records. The approach allows development of a loss of power probability (LOPP) sizing methodology which preserves the run-length characteristics of local climatic data. Sizing predictions from this method are compared with other sizing methodologies, and are used to indicate design savings possible for the monitored systems. The proposed critical-run LOPP sizing method has potential for incorporation in a microcomputer-based sizing tool, suitable for more accurate design of photovoltaic systems with battery storage in local applications.

Coal combustion is recognized as the primary source of anthropogenic mercury emission in South Africa followed by gold mining. Coal is also known to contain trace concentrations of mercury which is released to the environment during coal mining, beneficiation or combustion. Therefore, determining the mercury speciation in coal is of importance in order to understand its behavior and fate in the environment. Mercury was also used, at a large extent, in the Witwatersrand Basin (South Africa) for gold recoveries until 1915 and is still used in illegal artisanal mining. Consequences of these activities are the release of mercury to the environment. Nowadays, gold (and uranium) is also recovered through the reprocessing of old waste dumps increasing the concern related to mercury pollution. While much effort has been put in the northern hemisphere to understand and control problems related to anthropogenic mercury release and its fate to the ecosystem, risk assessment of mercury pollution in South Africa was based, until very recently, on total element concentrations only or on non systematic fragmental studies. It is necessary to evaluate mercury speciation under the country’s semi arid conditions, which are different to environmental conditions that exist in the northern hemisphere, and characterize potential sources, pathways, receptors and sinks in order to implement mitigation strategies and minimize risk. In this study, analytical methods and procedures have been developed and/or optimized for the determination of total mercury and the speciation of inorganic and organic forms of mercury in different sample matrices such as air, coal, sediment, water and biota. The development of an efficient and cost effective method for total gaseous mercury (TGM) determination was achieved using nano-gold supported metal oxide (1% wt Au) sorbents and cold vapor atomic fluorescence spectrometry (CV-AFS). Analytical figures of merit and TGM concentrations obtained when using Au/TiO2, as a mercury trap, were similar to those obtained with traditional sorbents. The combination of isotope dilution with the hyphenated gas chromatography-inductively coupled plasma mass spectrometry (ID GC-ICP-MS) was also achieved and used successfully for the speciation analysis of mercury in solid, liquid and biological samples. The developed, or optimized, methodologies were used to estimate the average mercury content and characterize the speciation of mercury in South African coals, and also to study the speciation of mercury in selected South African environmental compartments impacted by gold mining activities. The obtained average mercury content in coals collected from the Highveld and Waterberg coalfields (0.20 ± 0.03 mg kg-1) was close to the reported United States Geological Survey (USGS) average for South African coals. Speciated isotope dilution analyses and sequential extraction procedures revealed the occurrence of elemental mercury, inorganic and organo-mercury species, and also the association of mercury mainly to organic compounds and pyrite. The environmental pollution assessment was conducted within the Witwatersrand Basin, at four gold mining sites selected mainly for their mining history and from geophysical information obtained through satellite images. This study showed a relatively important pollution in three of the four sites, namely the Vaal River west site near Klerksdorp, the West Wits site near Carletonville (both in the North-West Province) and the Randfontein site in the West Rand (Gauteng Province). Only one site, the closed Rietfontein landfill site in the East Rand (Gauteng Province) was found to be not impacted by mercury pollution. The methylation of mercury was characterized in all sites and factors governing the mercury methylation process at the different study sites were also investigated. Geochemical models were also used to explain the distribution, transport and fate of mercury in the study systems.

Includes bibliography. / A proposal to develop the Upper Tugela Location in KwaZulu, Natal, prompted this study. This study aims to investigate the means to enhance the availability of, and access to, affordable energy sources in the Upper Tugela Location. A further aim is to match appropriate energy sources with the socio-economic conditions prevailing there. The Upper Tugela Location is an ecologically sensitive area of the Upper Tugela catchment. Rural energy planning has been criticized for the development of energy-conversion technologies while there is insufficient understanding of energy procurement practices in rural subsistence economies in South Africa. Qualitative information gained from a questionnaire survey, informal group discussions and direct observations suggest that the inhabitants of the Upper Tugela Location are relatively poor. For this reason a basic rural energy needs approach, which attempts to address the needs of the poorest, has been adopted to provide a theoretical base for the study. Research has revealed the following. Wood is the dominant energy source in the Upper Tugela Location. It is estimated that the annual household consumption of fuelwood is 3000 kg which is below the average fuelwood consumption for a rural area in South Africa. This reflects that this resource is being depleted to the degree that the local inhabitants are supplementing their use of fuelwood with expensive commercial fuels such as coal and paraffin. Locally available wood is in short supply, particularly in densely populated areas of the Upper Tugela Location. Most people are buying fuelwood from Natal farmers living on the borders of the study area. This results in an economic leakage from the Upper Tugela Location and dependence on extralocally available sources of energy. There appear to be few attempts to establish woodlots at present in the Upper Tugela Location. Equitable access to local supplies of wood are curtailed. Renewable sources of energy such as thermal and photovoltaic solar energy, micro-hydro and wind generated power, and afforestation have been investigated as have non-renewable sources of energy such as grid electricity and commercial fuels. It is concluded that no single technical option adequately addresses the energy needs of the inhabitants of the Upper Tugela Location. Most of the renewable sources of energy, except wood, are too expensive for subsistence economies and can be unreliable as they are still at the developmental stage. It is recommended that electricity from the national grid should be made available to those who can afford it. The means to improving the distribution of commercial fuels in the Upper Tugela Location should be addressed. Woody biomass management and agroforestry programmes provide the best options for an energy strategy for the Upper Tugela Location as they are inexpensive, require little maintenance, are sustainable and reliable, and serve conservation requirements at the same time.

Thesis (MPhil)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: South Africa is one of the most energy-intensive economies in the world, with around 90 per cent of its electricity generated using coal as a primary resource. As such, the South African energy system remains on a highly unsustainable path, and the potential for long-term growth and prosperity of the economy is thwarted. The alternative to conventional energy, renewable energy, has unfortunately been relatively slow to take off in the South Africa market. This is disappointing considering the country’s wealth of natural resources required for renewable energy generation. The potential of renewable energy to contribute to the South African energy mix is thus significant. The transition to a green economy, and subsequently a more sustainable energy future, is therefore achievable and realistic. However, national policies aimed at promoting the deployment of renewable energy have been thwarted by inconsistencies, lack of coordination, and proved relatively ineffective at increasing the country’s renewable energy capacity to its full potential. The recent policy changes from a feed-in tariff to a competitive tender approach dented investor confidence in the South African renewable energy industry significantly. Nevertheless, renewable energy policy in South Africa is still in its infancy, and valuable lessons are still to be learnt and incorporated into future policies going forward. A critical analysis of the current policy identifies the need for amendment to the structure of the policy landscape. The current policy strongly favours larger, more established and mature renewable technologies, whilst completely neglecting smaller and less mature ones. This not only results in a highly undiversified renewable energy mix, which has considerable negatives in itself, but also reduces the ability of the policy to capture a host of significant opportunities and advantages associated with small-scale renewable energy projects. The importance of diversifying South Africa’s renewable energy mix was therefore ones of the principal stances of this study, and intervention that ensured diversification within the industry was therefore vital. This study fundamentally designs and proposes a revised policy system that makes use of both competitive tenders and feed-in tariffs within the policy framework. In essence, this would allow for greater diversification within the renewable energy industry. The competitive tender component should be used for larger, more established technologies and projects, while the feed-in tariff should be used to drastically stimulate investment in smaller technologies and projects. By making use of a dual-mechanism system, the benefits associated with small-scale renewable energy projects can be realized without any noteworthy opportunity costs foregone. These benefits include diversification of the renewable energy mix; stimulation of smaller technologies; increased job creation; and stabilisation of supply volatility. This study recommends that the current renewable energy policy in South Africa be reassessed for both its relevancy within the South African context as well as its ability to effectively promote the deployment of alternative energy technologies. In an ever-changing and globalising world, where exogenous influences on national policies are stronger than ever, it becomes necessary and of utmost importance that policies are evaluated constantly in order to ensure their effectiveness is at optimal level. / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse ekonomie is een van die energie-intensiefstes ter wêreld, met steenkool as hoofbron vir sowat 90 persent van die land se kragopwekking. Die Suid-Afrikaanse energiestelsel as sulks bly dus op 'n onstabiele pad, en die potensiaal vir langdurige ekonomiese groei en welvaart word geknel. As teenvoeter vir konvensionele krag het hernubare energie steeds stadig veld gewen in die plaaslike mark – wat teleurstellend is as die land se rykdom aan natuurlike bronne vir hernubare energie-opwekking in ag geneem word. Hernubare energie het dus 'n aansienlike potensiaal om tot die Suid-Afrikaanse energiemengsel by te dra. Die oorgang na 'n groen ekonomie, en gevolglik na 'n volhoubaarder energie-toekoms, is daarom bereikbaar en realisties. Nasionale beleide oor hoe die uitrol van hernubare energie bevorder word, is egter tot dusver gestrem deur ongereeldhede en 'n gebrek aan koördinasie, en was gevolglik relatief ondoeltreffend om die land se hernubare energiekapasiteit ten volle te verhoog. Die onlangse beleidsveranderinge vanaf 'n toevoertarief na 'n mededingende tenderbenadering het beleggersvertroue aansienlik geskaad. Suid-Afrika se hernubare energiebeleid is nietemin nog in sy kinderskoene, met kosbare lesse wat geleer kan word en vir die pad vorentoe in toekomsplanne ingewerk kan word. 'n Kritiese ontleding van die huidige beleid wys hoe nodig 'n aangepaste struktuur vir die beleidsraamwerk is. Die huidige beleid begunstig groter, meer gevestigde en ontwikkelde tegnologieë terwyl kleiner en minder ontwikkeldes heeltemal afgeskeep word. Dit het tot gevolg nie net 'n hoogs ongediversifiseerde mengsel van hernubare energie nie, wat op sigself 'n aantal nadele inhou, maar boonop verminder dit die beleid se vermoë om vele betekenisvolle geleenthede en voordele aan te gryp wat gepaard gaan met kleinskaalse projekte vir hernubare energie. Dat die diversifisering van Suid-Afrika se hernubare energiesamestelling belangrik is, was dus een van dié studie se hoofbenaderings, asook dat ingryping ter wille van diversifisering binne die bedryf onontbeerlik is. Hierdie studie bied 'n ingrypende ontwerp en voorstel vir 'n hersiene beleidstelsel, met mededingende tenders asook toevoertariewe binne die beleidsraamwerk. Dit sal in wese ruimte laat vir groter diversifikasie binne die hernubare energiebedryf. Die mededingende tendergedeelte behoort vir groter, meer gevestigde tegnologieë en projekte gebruik te word, terwyl die toevoertariewe kan dien om belegging in kleiner tegnologieë en projekte te stimuleer. Deur 'n stelsel van tweeledige meganismes kan die voordele van kleinskaalse hernubare energieprojekte realiseer sonder die inboet van noemenswaardige geleentheidskoste. Dié voordele sluit in, om enkeles te noem, die diversifikasie van die hernubare energie-toneel; die stimuleer van kleiner tegnologieë met gepaardgaande groter werkskepping; en toenemende plaaslike produkvervaardiging. Met dié studie word aanbeveel dat Suid-Afrika se huidige beleid oor hernubare energie heroorweeg word, rakende die relevansie daarvan binne die landskonteks asook die beleid se vermoë om die ontplooiing van alternatiewe energietegnologieë doeltreffend te bevorder. In 'n voortdurend veranderende en globaliserende wêreld, met buite-invloede op nasionale beleidsrigtings sterker as ooit, word dit noodsaaklik en uiters belangrik dat beleide voortdurend heroorweeg word om die doeltreffendheid daarvan op die gunstigste vlak te verseker.

Thesis (MBA (Business Management))--University of Stellenbosch, 2009.

Thesis (MDF)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Coal export mines in the Mpumalanga Highveld region of South Africa generate growing volumes of discard coal estimated to be in excess of a billion tonnes. It presents a significant pollution hazard. Discard coal has a usable carbon content that can be used in the generation of power through the application of fluidized bed combustion technology. The objective of this study was to evaluate its potential as an economically viable fuel source for generation of electricity at the Witbank coalfields. This study was motivated by advances in fluidized combustion technology and significant changes in the South African electricity market in recent years. A holistic approach was adopted considering regulatory policy, market, technical, environmental and economic factors in the use of discard coal as an alternative fuel source. The policy and regulatory environment was assessed from the perspective of the private sector as project developer and the most likely source of funding, given government’s funding constraints. An evaluation of the future pricing structure of electricity, energy resource mix, demand growth, future development of the coal market, production of discard coal and the cost of coal was conducted. Levelised cost of electricity methodology was used to conduct the economic feasibility for comparison with the cost of Eskom’s pulverised coal technology for its new power stations. The study found that generating electricity from discard coal presents a significant commercial opportunity as its levelised cost of electricity was found to be lower than Eskom’s levelised cost of electricity for its new power stations. Plant sizes of 125 MW to 1 000 MW were considered. For plant capacities of about 500 MW and larger, the cost of electricity was found to be competitive with the current average electricity price taking into account the cost of transmission/distribution and interest charges. This is on condition that the electricity is sold to Eskom or wheeled through Eskom’s grid and sold to third parties. Otherwise, plant capacity will be limited to the maximum demand from large local users, which is expected to be considerably less than 500 MW. Currently there is no regulatory certainty on wheeling mechanisms and charges and it is an area where major policy development is required. The development of a project could be hampered by policy uncertainty and because of Eskom’s monopoly position as single buyer. The favourable results and findings of the economic evaluation conducted during this study warrant further detailed feasibility studies.