Dissertations / Theses on the topic 'Biomass energy industries – South Africa'

The sugar beet (Beta vulgaris) plant has in recent years been added to the Biofuel Industrial Strategy (Department of Minerals and Energy, 2007) by the South African government as a crop grown for the production of bio-ethanol. Sugar beet is commonly grown in Europe for the production of sucrose and has recently been cultivated in Cradock and the surrounding areas (Engineering News, 2008). The biofuel industry usually ferments the sucrose with Saccharomyces cerevisiae to yield bio-ethanol. However, researchers are presented with a critical role to increase current yields as there are concerns over the process costs from industrial biotechnologists. The beet factories produce a pulp by-product removed of all sucrose. The hemicellulose-rich pulp can be degraded by microbial enzymes to simple sugars that can be subsequently fermented to bio-ethanol. Thus, the pulp represents a potential source for second generation biofuel. The process of utilising microbial hemicellulases requires an initial chemical pre-treatment step to delignify the sugar beet pulp (SBP). An alkaline pre-treatment with ‘slake lime’ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined were: lime load; temperature and time. The analysed results showed the highest release of reducing sugars at the pre-treatment conditions of: 0.4 g lime / g SBP; 40°C and 36 hours. A partial characterisation of the Clostridium cellulovorans hemicellulases was carried out to verify the optimal activity conditions stated in literature. The highest release of reducing sugars was measured at pH 6.5 – 7.0 and at 45°C for arabinofuranosidase A (ArfA); at pH 5.5 and 40°C for mannanase A (ManA) and pH 5.0 – 6.0 and 45°C for xylanase A (XynA). Temperature studies showed that a complete loss of enzymatic activity occurred after 11 hours for ManA; and 84-96 hours for ArfA. XynA was still active after 120 hours. The optimised lime pre-treated SBP was subsequently degraded using various combinations and percentages of C. cellulovorans ArfA, ManA and XynA to determine the maximal release of reducing sugars. Synergistically, the highest synergy was observed at 75% ArfA and 25% ManA, with a specific activity of 2.9 μmol/min/g protein. However, the highest release of sugars was observed at 4.2 μmol/min/g protein at 100% ArfA. This study has initiated the research within South Africa on SBP and its degradation by C. cellulovorans. Preliminary studies show that SBP has the potential to be utilised as a second generation biofuel source.

Bibliography: leaves 65-70.
Low access to electricity is a problem in Africa. Apart from South Africa and Mauritius access to electricity generally falls below 30% of the population. The situation is even worse in the rural areas which housed about 70% or more of the population and whose access to modern energy services in these areas is between 5%-10%. Hence, this work aims at providing means of increasing access to electricity for the larger portion of the continent. This work looked at the potential of using bagasse, a waste from sugar production, to produce electricity beyond the sugar factory to the national grid. It shows that bagasse generated electricity can contribute to increasing this access in Africa as a whole by as much as 9.4 TWh, using Condensing Extraction Steam Turbines. However, this increase varies among countries with the highest being Swaziland, 67%, and the lowest South Africa, 1.5%, due to the current capacity. The actualization of this technical potential, however, can only come about with proper application of relevant policies and measures that need to be in place for Africa in general and South Africa in particular as more detailed work was done on the latter. Due to limitation in scope, this work did not cover the social, financial and agronomic aspects and neither was optimization of sugar considered in evaluating electricity from bagasse.

The development of renewable energy has become increasingly important as countries strive to become less dependent on fossil-derived energy. Biomass accounts for a large part of energy derived from renewable energy sources in Africa. However, the biomass is used in primitive ways like cooking and heating, which is not at all effective at taking advantage of the biomass's true energy potential and contributes to premature death due to pollution. Scarce water supply and infrastructure built around an energy production from coal have hindered the development of bioenergy in South Africa. The Stated Policy scenario has developed energy targets for South Africa to reached by 2040 to streamline South Africa's use of available biomass. To find out if these goals can be achieved, data regarding biomass quantities for different biomass types have been collected to see how much biomass is available for energy production. Various types of technologies for converting biomass have been investigated to compare the efficiency of each technology and production costs to be able to analyze which technology is considered best for application in South Africa. Various scenarios have been developed where previous research and insights from interviews have been involved and influenced the type of technology used to convert the biomass and which end product is considered to have the highest potential. The different scenarios were modeled in Excel and then simulated in to optimize total production costs and energy production. The bioenergy produced has then been compared with the current energy production from fossil fuels to see how much can be replaced. The technologies that were considered to be applicable were combined heat and power together with hydroprocessing. These technologies contributed to efficient energy production and low production costs as well as lower transport costs. Due to drought and lack of water supply, the most optimal places for the implementation of this type of technology were in the northeastern parts of South Africa. These areas have better access to water and, therefore produces more biomass. Considering the current infrastructure in South Africa, transport by trucks was considered to be the most flexible choice of transport mode for transporting the biomass. With the available biomass and the selected technologies, bioenergy can replace up to 15% of the energy produced from coal in South Africa, and prices are competitive with today's electricity and fuel prices in South Africa. For this to happen, political support, public confidence, and investment are required. Increased bioenergy in South Africa would reduce dependence on energy from fossil fuels and also streamline the use of available renewable energy that would contribute to increased and safer energy supply. A more efficient use of bioenergy would also contribute with less premature deaths caused by primitive use of biomass, less emissions and a healthier environment.

Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018.
In Sub-Saharan Africa (SSA), there are several challenges that hinder development. One of these challenges is access to electricity. There are numerous benefits to having access to reliable electricity. These include less time spent fetching water from rivers and dams, as water purification systems for households could be used in villages; children in villages would be able to spend more time doing their schoolwork and not fetching wood for fire; and automated irrigation systems could be used for villagers to farm and make an income. Finding alternative ways to generate electricity would enable access to electricity for regions that currently do not have the electricity. This means that large organisations need to find alternative ways of generating electricity, as they have the means to do so. With the current renewable energy technologies available, there are now more ways in which electricity could be generated. The use of biomass is no exception to this. With constant developments in the renewable energy sector, waste-to-energy (WtE) is proving to be a viable method to generate electricity. The main aim of this research was to determine if a commercial food retailing organisation could use their food waste for generating electricity for their own use to reduce their demand from the central grid. A way of determining the viability of this type of technology is using a software that simulates renewable energy projects. In this research, an organisation was contacted for waste data. Systems for two of the stores will be simulated and results will be discussed. The organisation will remain anonymous. The software used in this research is System Advisor Model (SAM), which was developed by the National Renewable Energy Laboratory (NREL) in the United States. In the results, three results were discussed. These are the monthly energy, monthly heat rate and the monthly boiler efficiency for each of the stores for Store 1, the annual energy simulated was 138,509 kWh and 131,677 kWh for Store 2. Monthly energy averages for each store were 11,542 kWh for Store 1 and 10,973 kWh for Store 2, respectively. There are several opportunities for research based on the findings. These include researching other food sectors in the study; conducting a financial analysis of small-scale WtE systems; constructing a prototype of the system; and using three different softwares to simulate a system for the same project.

The production of biodiesel from vegetable oils is not a new technology; it has been around since the 1950’s and both the research in terms of the different feedstock that can be used and the production of biodiesel has since been gaining momentum as there needs to be a new, sustainable and domestic alternative to petroleum fuels. These petroleum fuels pose enormous threats to the environment and therefore need to be replaced as they are mostly contributing to climate change and global warming not to mention the frequent price hikes which are crippling the South African economy. Biodiesel production using vegetable oils seems to be and is the future and a law has recently been passed which sanctions the production of biofuel locally.[1] South African fuel producers will instigate obligatory blending of fossil fuel with biofuel as the country moves to encourage investment in its biofuels sector. The production of biodiesel locally and the blending of biodiesel with other petroleum products will reduce the country’s dependence on imported fuel. The already established petrochemical companies like BP, Sasol and Engine are therefore mandated to purchase these biofuels if and when the biofuels meet the required South African National Standard (SANS) 1935 requirements. This is then where the challenge comes as most of these growing biofuel companies cannot afford to purchase testing equipment.The growing companiesthen discover upon completion of the biofuel manufacturing process that their product does not meet the required standard specification. The failure translates to a financial loss as the final product can possibly not be reworked. The aim of the project is then to assist these companies who are manufacturing biofuel, by providing them with in-house biofuel process methods which will allow for early detection, should there be a need to redo a step in the process and not wait until the completion of the production process. These in-house process-testing methods will range from pH determination, titration tests which will determine the soap content and the percentage free fatty acid content, water determination, density and visual testing. It is not cost-effective for these biodiesel manufacturers to send their samples for outsource testing as evidently the results obtained would be out of specification hence the need to provide these biodiesel manufacturers with in-house analytical testing techniques that will aid in monitoring of the biodiesel production.

Thesis (MScAgric)--Stellenbosch University, 1994.
Some digitised pages may appear illegible due to the condition of the Microfiche
ENGLISH ABSTRACT: Many Proreaceae species indigenous to South Africa have potential as cutflower crops. Commercial production of proteas for expurt, mainly to Europe, must emphasise quality of flowers and time of production. Good export quality flowers have stems longer than 50cm and unblemished flowers. Cut-flower proteas are in greater demand and command better prices during the European winter (September to May, Southern hemisphere), when competition from flowers grown in Europe is less. Both quality and time of harvest can be manipulated by pruning techniques. Protea cv. Carnival (a natural hybrid, possibly between P. neriifolia and P. compacta) produces flowers in late summer, from February through to May. Picking flowers or pruning shoots of Proteo cv. Carnival entails removing the terminal portion of shoots with heading cuts to leave on the plant short stumps, known as bearers. Lateral shoots arising from axillary buds on bearers elongate by successive growth flushes until flowers are initiated terminally. The characteristics of the shoot determine whether or not flower initiation will take place, and will affect the quality of the resulting flower. Plants were pruned to produce bearers of different length and diameter. The characteristics of shoots arising from different bearers were recordea. Thick bearers of length 20-25cm produced the most shoots, and the longest shoots. Plants producing flowers biennially, rather than ann'Jally, produced thicker bearers, which, in turn, lead to production of better quality shoots arising from the bearers in the following season. Changing the time of pruning changed both the flowering cycle and the biomass allocation of Prorea cv. Carnival. Plants of Profea cv. Carnival were pruned on six different dates in 1991. Pruning in March, April or May, 1991, resulted in an annual flowering cycle. Less than 40% of the fresh mass produced in 1993 was reproductive, of which approximately 5% had stems long enough for export. The 1994 annual harvest was of s:milar size and quality as the 1993 annual harvest. Pruning in July, August or September, 1991, resulted in a biennial cycle of flowering. No flowers were produced in 1992, and a large crop was harvested in 1993. In 1993 lip to 70% of the fresh mass produced was reproductive, of which approximately 80% had stems long enough for export. Plants were pruned shortly after flowering in 1993, and the biennial cycle was replaced by an alternate flowering cycle, with a large crop being followed by a smaller crop. The large harvest in 1993 was significantly earlier than normal, but the small crop produced in 1994 was later. The harvest in 1994 from plants with an alternate flowering cycle was similar in size to the 1994 harvest from plants floweting annually, but flower stems were longer.
AFRIKAANSE OPSOMMING: Heelwat inheemse Proteaceae spesies besit die vereiste eienskappe om as snyblomr.-le verhanctci te wod. Indien proteas kommersieel verbou sou word vir uitvoer moet die klem val op gehalte van blomme en die tyd van produksie. Goeie gehalte uitvoer blomme moet steellengte van langer as 50cm en perfek gevormde blomme besit. Daar is 'n groter aanvraag na kommersieel verboude proteas gedurende die Europese winter (September tot Mei, suidelike halfrond) en beter pryse word derhalwe ook dan verkry. Beide gehalte en die oes periode kan gemanipuleer word deur snoeitegnieke. Wanneer blomme gepluk word of lote gesnoei word van Profea cv. Carnival (waarskynlik 'n kruising tussen P. compacta x P. neriifolia) word die terminale gedeelte van die loot teruggesny. Die oorblywende gedeelte bestaan uit kort stompe wat bekend staan as draers. Laterale lote afkomstig van okselknoppe op draers verleng totdat 'n blom terminaal ontwikkel. Die eienskappe van die loot bepaal of 'n blom inisieer sal word of nie, en sal ook die gehalte van die gevormde blom beinvloed. Protea plante was gesnoei om draers van verkillende lengtes en deursnee te produseer. Die eienkappe van lote afkomstig van die verskillende tipe draers was gemeet. Dik ..draers van lengte 20-25cm het die meeste asook die langste lote geproduseer. Plante wat twee-jaarliks, in teenstelling met jaarliks, geblom het, het dikker draers geproduseer en ook gelei tot produksie van beter gehalte lote in die opeenvolgende seisoen. Die verandering in die tyd van snoei het beide die blom siklus en die biomassa verspreiding beinvloed. Plante van Protea cv. Carnival was up 6 verskillende datums in 1991 gesnoei. Snoei in Maart, April of Mei, 1991, het 'n jaarlikse blom siklus veroorsaak. Minder as 40% van die vars massa geproduseer in 1993 was reproduktief, waarvan 5% steellengte lank genoeg vir uitvoer gehad hel. Die 1994 jaarlikse oes was van dieselfde grootte en gehalte as die van 1993. Snoei in Julie, Augustus of September, 1991, het egter 'n twee-jaarlikse blom siklus veroorsaak. Geen blomme was in 1992 geproduseer nie, maar die oes in 1993 was heelwat groter as die jaarlikse oeste. In 1993 was to 70% van die vars massa geproduseer, reproduktief, waarvan 80% steellengte lank genoeg vir uitvoer gehad het. Die twee-jaarlikse blom siklus het 'n vroeer oes in 1993 veroorsaak, maar 'n later oes in 1994. Die twee-jaarlikse oes in 1994 was van dieseifde grootte as die jaarlikse oes in 1994, maar die blomstele was langer.

Thesis ( MTech (Business Administration))--Cape Peninsula University of Technology, 2016.
Capital investment in bioethanol production requires sound economic feasibility studies. This study investigated the economic feasibility of using maize as a feedstock to produce bioethanol in South Africa. There is a huge opportunity to use dedicated underutilised arable land to grow maize which can be used for both consumption and bioethanol production. The study used 200 000 ton/year of maize that could have been exported to SADC countries to size a plant that produces 80 million litres per year of bioethanol. An advanced bioethanol processing technology that separates the fibre/bran which is burnt in a steam boiler to produce process steam was selected owing to advantages such as low energy consumption and capital expenditure on fermentation and distillation equipment. This study employed a combination of qualitative and quantitative methods to gather data. The findings from a qualitative instrument indicated that a majority of respondents were in favour of the decision of excluding maize made by the South African government. Putting security of food at risk and uncertainty in the profitability of a maize-fed bioethanol plant in the South African context, were two of the primary reasons the respondents opted for an explicit exclusion of maize as a feedstock. Findings from quantitative analysis revealed that the profitability of the bioethanol plant was largely influenced by the prices of feedstock and bioethanol. The 2016 fiscal year indicated the worst case scenario in terms of economic viability of the bioethanol. The astronomically high price of maize due to drought (R5000/ton) rendered the project unprofitable as all of the economic indicators were negative. In the same marketing year, however, the trade balance of maize was positive, indicating a surplus. The study recommended that all of the surplus maize should be exported because it is not economically viable to build a bioethanol plant. The 2011 fiscal year indicated the best case scenario in terms of the economics of the project. This was due to the decrease in price of maize (R1726/ton) and a slight increase in the price of bioethanol. All of the economic indicators were positive, suggesting the benefits of investing in bioethanol production. It was recommended that under normal conditions of maize production in South Africa, a bioethanol plant can be operated simultaneous to maize exportation to other countries without compromising food security, because a maize-fed bioethanol plant uses only a small proportion of maize (14.3%) from the total volume of maize that is exported. Furthermore, it generates more revenue (99.9%) compared to the maize export revenue. It was recommended that sensitivity analysis should be conducted in a holistic manner whereby all variables in the economic model must be adjusted to assess the impact of each on the overall project profitability.

Thesis (MBA)--Stellenbosch University, 2011.
The global energy industry is actively moving toward renewable energy sources in order to meet the ever-increasing demand for energy in a sustainable manner. The South African government, however, has only recently begun creating an environment which is truly conducive to investment into the renewable energy industry. Metso, a Finnish multi-national corporation, has a strong global position in the field of biomass-based power generation for heat, power or combined heat and power applications. The corporation has developed a modular biomass-based power generation solution for power generation in the 3MW to 10MW range, which is highly automated and can essentially operate without the need for extensive human intervention and is known as the Metso Bio-energy Solution. Considering the current state of the South African energy environment, Metso management requested the researcher to investigate the opportunities that exist in the South African market for Metso’s Bio-energy Solution, and to propose a market entry strategy which Metso should follow in order to enter the South African market. In the findings, the researcher observed that South Africa has a clear potential for the development of a bio-energy industry for power generation, although the limited availability of biomass in certain regions and the various harvesting methods in industries such as the forestry and sugar industries do restrict the access to this resource. The municipal solid waste industry appears to be an area of interest as well, although very little information exists regarding the volumes of waste available and sorting practices, which may be required in order to access these resources. Interviews were held with experts in the field of energy, renewable energy and energy policy in order to obtain opinions on the market potential for Metso’s Bio-energy Solution. The general perception of all interviewees was that the technology has its place within the South African energy mix. The interviewees, however, did confirm that there currently appears to be a major focus on wind and solar energy in the country, although biomass technology may well be a better solution due to its baseload capabilities. It was found that the local policy environment, the lack of government initiative on renewable energy licensing and unclear tariff structures have all inhibited the proliferation of the renewable energy industry. In many cases, frustration with power outages and policy delays has caused companies to invest in biomass co-firing facilities for their own consumption. The factors for success for biomass-based technologies in the South African market would appear to be directly linked to job creation potential, access to reliable and sustainable biomass resources and access to investment capital, from both private equity and the state. It is the recommendation of the researcher that Metso enters into a joint venture with a large international environmental finance company, which would base their business model on the technology provided by Metso, whilst securing the political and financial support for projects of this nature in the country.

Biomass gasification has attracted the interest of researchers because it produces zero carbon to the atmosphere. This technology does not only produce syngas but also the byproducts which can be used for various application depending on quality.The study conducted at Melani village in Alice in the Eastern Cape of South Africa was aimed at investigating the possible applications of the gasification byproducts instead of being thrown away. Pine wood was employed as the parent feedstock material for the gasifier. Biomass gasification by-products were then collected for further analysis. The studied by-products included tar(condensate), char, soot and resin. These materials were also blended to produce strong materials.The essence of the blending was to generate ideal material that is strong but light at the same time.The elemental analysis of the samples performed by CHNS analyser revealed that carbon element is in large quantities in all samples. The FTIR spectra showed almost similar results for all the studied samples, since the samples are end products of lignocellulosegasification. SEM gave the sticky images of resin as well as porous char structures. Char showed a higher heating value of 35.37MJ/Kg when compared to other by-products samples.

Thesis (MDF)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: In 2007, Bürer and Wüstenhagen (2009) conducted a survey amongst European and United States venture capital and private equity investors (VC/PE) to ascertain their public clean energy policy preference and concluded that VC/PE investors view the feed-in tariff (FIT) scheme to be the most preferred policy option. In this research study, the author re-conducted part of the Bürer and Wüstenhagen (2009) survey with thirty South African VC/PE investors to determine their perceptions on clean energy public policy preference. It is evident from the survey, that opinions are varied and at times even contradictory. This in itself demonstrates an important feature of the South African VC/PE and clean energy industry: it is young, dynamic, changing rapidly and can look very different, depending on the vantage point. The investors surveyed were mainly optimistic about the long-term development of the South African renewable energy industry led by private investors. VC/PE investors in South Africa have mixed views on various investment options, and are concerned about both the regulatory and macro-economic trends. The interviews and survey results show a number of recurring issues. Altogether, the survey results indicate that VC/PE investors consider FITs to be the best public clean energy policy instrument in leveraging private investment and finance for renewable energy in South Africa. This study serves to illustrate and confirm, in line with empirical studies, that VC/PE investors in South Africa believe that clean energy market-pull policies provide an impetus and indeed spur private investor participation in clean energy in developing countries. While it is true that most VC/PE investors would prefer the price certainty associated with a FIT regime, this is almost an irrelevant question in South Africa since constitutionally the state is bound to procure through competitive tendering. This study also serves to highlight the need for more active research and attention in this field.

The cellulosome is a multimeric enzyme complex that has the ability to metabolise a wide variety of carbonaceous compounds. Cellulosomal composition may vary according to the microbe’s nutritional requirement and allows for the anaerobic degradation of complex substrates. The complex substrates of interest in this research study were sugarcane bagasse and pineapple fibre waste, as they represent two important lignocellulosic, South African agricultural crops. The effective degradation of complex plant biomass wastes may present a valuable source of renewable compounds for the production of a variety of biofuels, for example bioethanol, and a variety of biocomposites of industrial importance. The identification of renewable energy sources for the production of biofuels is becoming increasingly important, as a result of the rapid depletion of the fossil fuels that are traditionally used as energy sources. An effective means of completely degrading lignocellulose biomass still remains elusive due to the complex heterogeneity of the substrate structure, and the fact that the effective degradation of the substrate requires a consortium of enzymes. The cellulosome not only provides a variety of enzymes with varying specificities, but also promote a close proximity between the catalytic components (enzymes). The close proximity between the enzymes promotes the synergistic degradation of complex plant biomass for the production of valuable energy products. Previous synergy studies have focused predominantly on the synergistic associations between cellulases; however, the synergy between hemicellulases has occasionally been documented. This research project established the synergistic associations between two Clostridium cellulovorans hemicellulases that may be incorporated into the cellulosome and a cellulosomal endoglucanase that is conserved in all cellulosomes. This research study indicated that there was indeed a synergistic degradation of the complex plant biomass (sugarcane bagasse and pineapple fibre). The degrees of synergy and the ratio of the enzymes varied between the two complex substrates. The initial degradation of the bagasse required the presence of all the enzymes and proceeded at an enhanced rate under sulphidogenic conditions; however, there was a low production of fermentable sugars. The low quantity of fermentable sugars produced by the degradation of the bagasse may be related to the chemical composition of the substrate. The sugarcane contains a high percentage of lignin forming a protective layer around the holocellulose, thus the glycosidic bonds are shielded extensively from enzymatic attack. In comparison, the initial degradation of the pineapple fibre required the action of hemicellulases, and proceeded at an enhanced rate under sulphidogenic conditions. The initial degradation of the pineapple fibre produced a substantially larger quantity of fermentable sugars in comparison to the bagasse. The higher production of fermentable sugars from the degradation of the pineapple fibre may be explained by the fact that this substrate may have a lower percentage of lignin than the bagasse, thus allowing a larger percentage of the glycosidic bonds to be exposed to enzymatic attack. The data obtained also indicated that the glycosidic bonds from the hemicellulosic components of the pineapple fibre shielded the glycosidic bonds of the cellulose component. The identification of the chemical components of the different substrates may allow for the initial development of an ideal enzyme complex (designer cellulosome) with enzymes in an ideal ratio with optimal synergy that will effectively degrade the complex plant biomass substrate.

Thesis (MBA (Business Management))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The objective of the study was to establish whether a small-scale biomass renewable energy project that uses waste fruit and pomace as the predominant feedstock could be a feasible clean development mechanism (CDM) project. The study was based on the solid waste streams of a pome fruit processor. Renewable energy technologies that convert biomass into a methane rich gas were evaluated. These included the various anaerobic digestion technologies that yield biogas and gasification technologies that yield syngas. Gasification was not found to be a feasible technology due to the moisture content requirement of less than 20% against that of the biomass of 70-80% and due to the low bulk density of the biomass of 250 kg/m3 versus the required minimum of 500kg/m3. The biogas could either be fired in a combined heat and power (CHP) unit or in a dual fired burner with heavy furnace oil (HFO). Feeding the thermal energy and electricity from the CHP unit back to the processor or supplying the electricity to the national electricity grid was considered. The plant would supply electricity to the national electricity grid as an Independent Power Producer (IPP). Eskom would be the renewable energy purchasing agent (REPA) that purchases the electricity at an anticipated R0.96/kWh under a power purchase agreement (PPA) in terms of the renewable energy feed-in tariff phase II (REFIT) guidelines. The anticipated revenue for electricity was six fold the coal offset cost of R0.16/kWh, while there was no demand for the heat energy after the processing season, thus firing biogas in a dual fired burner was not feasible. The most feasible technology was the anaerobic digestion of the biomass using a continuous stirred tank reactor (CSTR) process followed by a CHP unit that feeds the heat to the processing facility and the electricity into the national electricity grid. Waste fruit and wet pomace would be codigested with abattoir waste during the operating season. Dried pomace, abattoir waste, waste fruit and any other non-woody material from the surrounding farms and packhouses would be digested after the season to optimize the utilisation of the plant capacity. A capacity of 11 dry tons per day for the case study at a cost of R13 138 889 yielded an IRR of 15.2% and a net present value (NPV) of - R1 498 616 based on a discount rate of 18%, when excluding revenue from the sale of carbon emission reductions (CERs). Therefore, without the sale of CERs, this project would be rejected as a non-feasible investment. The project is eligible for CDM registration as a small-scale renewable energy project activity. No barriers were identified that would prevent the registration of this project activity as a CDM project in South Africa. The sale of CERs increased the NPV of the optimum solution to R156 483 and the IRR to 18.3%. Registering the project as a CDM project activity improved the feasibility of the project to the extent that it was marginally feasible. The fermentation and hydrolysis of the biomass into bioethanol was investigated as an alternative to the generation of heat and electricity. Although the technology is proven, no facilities were identified that use spoilt apples or apple pomace as the substrate. This increased the risk of the project and a discount rate of 24% was set when calculating the project NPV. This project activity yielded an NPV of - R1 296 057 when excluding CDM revenue. The feasibility improved to an NPV of - R263 507 and an IRR of 23.4% when taking the additional revenue from the sale of CERs into account. This project alternative was only marginally out of the money. With the development of newer technology, this alternative could prove to be more attractive in the future.

Low cover crop biomass production is a major obstacle to the success of conservation agriculture currently promoted as panacea to the inherent problem of soil erosion and loss of soil productivity in the Eastern Cape (EC). Therefore, this study evaluated cover crop management strategies for optimizing biomass production for better soil cover, soil nitrogen (N) and phosphorus (P) fertility, weed control and maize yields. The strategies tested are cover crop bicultures, selection of an adapted lupin cultivar and seeding rate, and the feasibility of rain fed winter cover cropping. The cover crop experiments were carried in rotation with summer maize between the winter of 2009 and summer of 2010/2011. Biculture trial was carried out by seeding oat (Avena sativa) and vetch (Vicia dasycarpa) at three mixture ratios and as sole crops under irrigation. On a separate irrigated trial, two lupin cultivars (Lupinus angustifolius var Mandelup & Qualinock) were seeded to a range of seeding rate, 40 to 220 kg ha-1. To study the feasibility of rain fed winter cover cropping, oat, vetch, rye (Lolium multiflorum), barley (Hordeum vulgare), radish (Raphanus sativa) and triticale (Triticale secale) were relayed into a maize crop in February, March and April of 2010. The irrigated trials were followed with SC701 maize cultivar, whilst the rain fed trial was followed with DKC61-25 maize cultivar. Bicultures gave higher cover crop biomass than sole vetch, increasing with an increase in the oat component of the mixture. Increased N and P uptake was observed with bicultures compared to sole oat, however, the levels were comparable to sole vetch. Sole vetch increased soil inorganic N and P at maize planting, whilst the slow decomposition by sole oat residue resulted in mineral lock up. Bicultured cover crop residues had intermediate decomposition rates and resulted in optimum levels of inorganic N and P for prolonged periods compared to sole crops. Weed suppression by the bicultures was comparable to sole cover crops. Biculturing technology significantly (P<0.05) increased maize grain yield compared to sole oat and the yields were comparable to those from sole vetch. For lupins, 206 kg ha-1 seeding rate gave the optimum biomass yield. Weed dry weights in both cover crop and maize crop decreased with an increase in lupin biomass. Comparable soil total N and inorganic P values at maize planting, were observed from plots planted to 120, 180 and 220 kg ha-1. Maize grain yield increased with an increase in lupin seeding rate. The study on rain fed winter cover cropping had most cover crop species’ biomass decreasing with each delay in planting except for radish, which increased. Vetch produced the highest amounts of biomass from February and March planting whilst radish had the highest biomass in April planting. The two species resulted in the greatest N improvement compared to the other species. Regardless of the grazing, the grass specie residues managed to persist to the next cropping season and the residue remaining were comparable to that of radish and vetch. Late-planted cover crops had the greatest residue remaining than early-planted, as a result, April planted cover crops provided better weed suppression than March and April planted. Vetch provided the highest maize grain yield (4005 kg ha-1) whilst all other species tested had comparable grain yields. The results suggested that bicultures could be grown to give sufficient biomass for both weed suppression and soil fertility improvement. Furthermore, increasing lupin plant densities improve its function as a cover crop with respect to weed suppression, soil fertility improvement and maize yields. The study also showed that for dry land systems, February and March planted vetch and April planted radish can provide the greatest biomass and maize yield improvement.

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.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The discussion on climate change is leading to a re-evaluation of tree plantations in South Africa; prompting the adoption of forest bioenergy system as one of the cost effective ‘carbon mitigation options’. In an analysis of this changing paradigm, emphasis was placed on the socio-economic aspects of integrated commercial tree plantations and forest bioenergy systems with special attention to harvest residues recovery for bioelectricity production and construction and operation of a bioelectricity plant. The study also explored the direct and indirect benefits that adjacent communities derive from tree plantations in South Africa in order to determine the potential impact of integrated timber and bioelectricity production on rural livelihood and conventional forestry operations. Structured questionnaires and in-depth interviews were used in randomly sampling twelve villages on Mondi tree plantations in the Piet Retief and Iswepe areas of South Africa. Six villages from each area were selected; and a systematic random sampling of ten households per village was carried out. The possibility of using harvest residues from final clear felling from these plantations for bioelectricity production was examined. The study developed and described a scenario for a five megawatt bioelectricity generation facility, requiring an annual volume of 19,569.85 dry tonnes of residues as feedstock for its operation. The study revealed that adjacent rural communities to Mondi plantations in Piet Retief and Iswepe areas enjoy direct benefits such as employment opportunities, utilization of harvest residues, utilization of non-timber resources, and free accommodation. Indirect benefits that these communities enjoy include: free farmland and graze-land and various social benefits. Issues of concern and dislike such as: lack of electricity; poor health and sanitation and transportation problems were also identified. Using NPV and IRR, the study estimated the economic impacts of integrated pulpwood and bioelectricity production, compared to conventional pulpwood production operation. The study concluded that integrated pulpwood and harvest residue recovery for bioelectricity production is a profitable means of producing renewable energy. The approach was found to increase the profitability of conventional forest operations.
AFRIKAANSE OPSOMMING: Besprekings rondom klimaatsverandering lei tot ‘n her-evaluasie van boom plantasies in Suid Afrika wat aanleiding gee tot die aanvaarding van bio-energie stelsels as een van die koste effektiewe “koolstof versagtende opsies”. In ‘n ontleding van hierdie paradigma verandering, is klem geplaas op die sosio-ekonomiese aspekte van die integrasie van boom plantasies en bos bio-energie stelsels. Spesiale aandag is gegee aan onginningsafval herwinning vir bio-energie produksie en die konstruksie en werking van ‘n bio-elektriese kragsentrale. Die studie ondersoek ook die direkte en indirekte voordele wat gemeenskappe, aangrensend aan boom plantasies in Suid Afrika verkry, om sodoende die potensiële effek van geintegreerde hout en bio-elektriese produksie op landelike lewensbestaan en konvensionele bosbou operasies te bepaal. Gestruktureerde vraelyste en indiepte onderhoude is gebruik om ‘n lukraakte steekproef van twaalf dorpies op Mondi boom plantasies in die Piet Retief en Iswepe areas van Suid Afrika uit te voer. Ses dorpies in elke area is gekies en ‘n sistematiese lukraakte steekproef van tien huishoudings per dorpie is uitgevoer. Die moontlikheid om ontginningsafval van finale kaalkap van hierdie plantasies vir bio-elektrisiteit te gebruik is ook ondersoek. Die studie het ‘n senario ontwikkel en beskryf van ‘n vyf megawatt bio-elektriese kragsentrale wat ‘n jaarlikse volume van 11,708 droë ton ontginningsafval benodig as voermateriaal vir kragopwekking. Die studie het getoon dat aangrensende landelike gemeenskappe langs Mondi plantasies in die Piet Retief en Iswepe areas direkte voordele soos werksgeleenthede, gebruik van ontginningsafval, gebruik van nie-hout hulpbronne en gratis akkommodasie geniet. Indirekte voordele wat gemeenskappe geniet sluit in gratis toegang to landbou grond en weiding, sowel as sosiale voordele. Probleemfaktore waarmee hulle saamleef is ‘n gebrek aan elektrisiteit, swak gesondheids en sanitasie dienste en vervoerprobleme. Deur die gebruik van NPV en IRR analitiese metodes is die ekonomiese impak van geintegreerde pulphout en bio-elektrisiteits produksie bepaal en vergelyk met konfensionele pulphout produksie. Die gevolgtrekking is dat geintegreerde pulphout en ontginningsafval herwinning vir bio-elektrisiteit produksie ‘n winsgewende manier van hernubare energie produksie is. Die benadering kan die winsgewendheid van konfensionele bosbou operasies verbeter.

Rural development efforts to reduce poverty and enhance food security and generally improve livelihoods in developing countries continue to be constrained by high energy cost. For that reason, renewable energy has been identified as a possible panacea to fill this gap. Renewable energy is cheaper, more accessible and environmentally sustainable and promotes inclusivity. Biogas is a renewable energy that is readily available and easy to use by poor rural households. The use of biogas digesters among households in rural areas of developing countries is a well-known technology. The potential for biogas in these areas has been demonstrated and a strong economic case has been made. However, its adoption and use have been lower than expectations possibly as result of non-economic considerations, including social issues about which rural people hold different perceptions. Perceptions of rural households are important because they influence the behaviour to a large extent. Since limited access to affordable energy in rural areas has encouraged government and private organisations to initiate biogas projects to overcome the challenge, it is important to ascertain the factors that affect attitudes towards the technology. The present study sought to explore perceptions of rural households about biogas production towards rural household income in the Raymond Mhlaba Local Municipality. Specifically, this research investigated the state of biogas project being implemented by the University of Fort Hare’s Institute of Technology (FHIT), the perceptions of respondents towards biogas production and determine the contribution of biogas consumption to rural income. The study also aimed to identify the factors affecting the adoption of biogas production in the study area. The study was carried out in Melani village in Raymond Mhlaba Local Municipality in the Eastern Cape Province of South Africa and employed survey data obtained from 48 households who were enumerated to identify their perceptions on biogas production, with special emphasis on the role and effect contributed to rural income of Melani village. The study employed a cross-sectional research design and purposive sampling technique was used in data collection. Data were collected and captured in Excel and then analysed using the statistical package for social sciences (SPSS) Version 24 Descriptive statistics was used to examine socio-economic characteristics of households and state of biogas production in the area, Bivariate correlation analysis was used to determine the relationships among the key elements of perceptions of household towards biogas adoption, binary logistic model was used to estimate factors influencing adoption of biogas technology by households. The results show that women were dominant for both adopters and non-adopters of biogas. The majority of households were young with mean age of 40 years while for non-adopters were 65 years old on average. The results showed high levels of literacy amongst household adopters. Majority of the households for both adopters and non-adopters of biogas technology were married and unemployed and household size ranged from one to five persons, with social grants being dominant source of income. The bivariate correlation analysis suggests a positive effect of green pepper production and livestock ownership on biogas technology adoption. Age and level of education were negatively correlated with adoption of biogas. The cross tabulation analysis suggests that water scarcity, lack of knowledge about biogas technology, cattle ownership, lack of maintenance and repairing, flooded biogas digesters during rainy season are negatively associated with the uptake of biogas technology. The empirical results from binary logistic model suggest that land size was the key determinant of adoption behaviour towards biogas technology while age of the household head, source of income and level of education may have a negative influence on adoption of biogas technology. Based on the findings highlighted above, the study recommends strategies to encourage households to adopt biogas technology.

Thesis (MBA (Business Management))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: It has been established worldwide that energy efficiency undertakings are the fastest, most cost-effective and cleanest way to extend energy supplies. When the energy supply made available through energy efficiency projects are compared with increasing primary supply through building new conventional generation facilities, the former is in most cases also safer, more reliable and a more secure form of investment. Energy service companies (ESCOs) are the recognised implementation vehicles of energy efficiency projects and have been in use internationally for many years for this purpose. Globally, however, ESCOs do not have a good history of being viable business enterprises. The most important barriers identified internationally hindering ESCOs’ growth and sustainability were the potential customers’ lack of awareness, information and understanding regarding energy efficiency projects, the financing of these projects, as well as the support of government on energy efficiency policies and regulations. The urgency of implementing energy efficiency measures in South Africa is critical based on the precarious situation of the national electrical suppliers’ ability to provide electricity unfailingly to all its current and future customers. The South African electrical energy situation should therefore provide tremendous opportunities to the local ESCO industry. The aim of this study was therefore to reiterate the importance of energy efficiency projects and to describe the barriers to growth and sustainability experienced by ESCOs in South Africa against the international backdrop. This was done by way of a survey sent out to all registered ESCOs in South Africa. Based on the responses to the survey, the South African industry is in dire straits and is hindered by various barriers to their growth and sustainability. The study identified eight major barriers in the South African ESCO industry which are similar to those experienced by ESCOs internationally. The uniqueness of the local barriers however, is that the industry operates in a highly regulated environment and that these regulators, being the government and Eskom, are recognised as the main perpetrators responsible for most of these barriers, largely due to a lack of dedicated action. Furthermore, the study shows that it is critical for all role players in the South African energy efficiency industry, and specifically the South African government and Eskom, to recognise these barriers and to assist in solving them to improve the growth opportunities in the ESCO industry. Removal of these barriers will not only improve the electricity situation, but will also have a number of positive effects on the micro and macro-economic levels of South Africa, as well as the environment. Finally, the study makes suggestions about the way forward through a number of actions to be taken to lower or remove the most important of these barriers.
AFRIKAANSE OPSOMMING: Dit is reeds wêreldwyd bevestig dat energie-effektiwiteitsprojekte die vinnigste, kostedoeltreffendste en omgewingsvriendelikste manier is om energiebronne uit te brei. Wanneer die energieverskaffing wat beskikbaar gestel word deur energieeffektiwiteitsprojekte vergelyk word met die vermeerdering van primêre energie deur die bou van nuwe konvensionele opwekkingsfasiliteite, is eersgenoemde in die meeste gevalle ook veiliger en ’n meer betroubare en stabiele beleggingsvorm. Energie-diensmaatskappye (energy service companies (ESCOs)) is die erkende implementeringsmediums vir energie-effektiwiteitsprojekte en word reeds baie jare lank internasionaal vir hierdie doel aangewend. ESCOs het egter wêreldwyd nie ’n goeie rekord as lewensvatbare sake-ondernemings nie. Die vernaamste hindernisse wat ESCOs se groei en welvaart stuit is internasionaal geïdentifiseer as voornemende kliënte se gebrek aan bewustheid, inligting en begrip rakende energie-effektiwiteitsprojekte, die finansiering van sodanige projekte, asook die ondersteuning van die regering ten opsigte van energieeffektiewiteitsbeleide en -regulasies. Daar is groot dringendheid om energie-effektiewe projekte en maatreëls in Suid Afrika te implementeer, gebaseer op die huidige onsekerheid of die nasionale elektrisiteitsverskaffer wel in staat is om ’n betroubare bron van elektrisiteit aan sy huidige en voornemende kliënte te voorsien. Die Suid Afrikaanse elektriese energie situasie behoort daarom heelwat geleenthede te skep vir die plaaslike ESCO-industrie. Die doel van hierdie studie was dus om die belangrikheid van energie-effektiwiteitsprojekte te beklemtoon en om die hindernisse te omskryf wat ESCOs in Suid Afrika se groei en welvaart stuit, gesien vanuit ‘n internasionale perspektief. Dit was gedoen deur ‘n vraelys aan alle geregistreerde ESCOs te stuur. Na aanleiding van die terugvoering op die vraelyste, sukkel hierdie industrie om kop bo water te hou weens verskeie hindernisse wat hulle groei en welvaart stuit. Hierdie studie identifiseer agt belangrike hindernisse in die Suid-Afrikaanse ESCO industrie wat ooreenstem met die wat deur internasionale ESCOs ondervind word. Die uniekheid van die plaaslike hindernisse is egter dat die industrie werksaam is in ‘n streng gereguleerde omgewing en dat die reguleerders, die regering en Eskom, ook uitgewys word as die vernaamste skuldiges wat verantwoordelik is vir meeste van die hindernisse, hoofsaaklik as gevolg van hulle gebrek aan toegewyde uitvoering van take. Die bevindinge van hierdie studie toon verder dat dit krities is vir al die rolspelers in die Suid-Afrikaanse energie-effektiwiteitsindustrie, spesifiek die Suid-Afrikaanse regering en Eskom, om hierdie hindernisse te erken en om saam te werk om hulle te oorkom en sodoende die groeigeleenthede in die ESCO-bedryf te verbeter. Die verwydering van hierdie hindernisse sal nie alleen die elektrisiteitsituasie verbeter nie, maar sal ook ’n aantal positiewe invloede hê op die mikro- en makro-ekonomiese vlak van Suid-Afrika, sowel as die omgewing. Die studie sluit af met voorstelle rakende die uitvoering van verskeie aksies wat die verwydering van die vernaamste hindernisse tot gevolg sal hê, of die hindernisse se impak op die industrie sal verminder.

Thesis (MBA)--Stellenbosch University, 2012.
Bioethanol and biodiesel are currently the main biofuels. The United States of America and Brazil are the major bioethanol producers from maize and sugar cane respectively. European and Asian countries produce and consume biodiesel as transportation fuel. Generally, governments want to avoid importing biofuels, since this erodes the advantage of fuel security from growing fuel locally. There are however opportunities for many African countries to export to Europe and the United States of America, since they have preferential import tax exemption agreements with African countries. Sub-Saharan Africa has large potential to produce biomass. Inherently, South Africa has poor potential to produce biomass, due to the climatic conditions and water scarcity. However, South Africa has infrastructure, skills, commercial farmers and, importantly, government policy on biofuels. These advantages should be leveraged to optimise gains from a biofuel industry. A biofuels industry holds potential in terms of job creation and rural development gains, apart from the advantages of fuel security, greenhouse gas (GHG) emission reductions, stimulation of the agricultural sector, and reduced fuel imports with the balance of payment advantages. The South African government aims to develop rural communities in former homeland areas. If degraded land in these areas is recovered and used for production of biofuels, the environmental benefits are immediate and substantial. Fuel crop production in these areas does not compromise food security nor does it result in further deforestation. Creating jobs in rural areas can contribute to reduction of poverty. The Department of Minerals and Energy (DME) published its strategy in 2007. This excluded maize as permitted bioethanol feedstock, it sets a two per cent liquid fuels penetration target, and gave fuel tax exemptions for biodiesel and bioethanol. The biofuels would be distributed through voluntary low concentration blending into petroleum products by oil companies. The industry would be regulated and producers require licensing through the South African Revenue Service (SARS). The license conditions were mainly related to the type of feedstock, where it was produced, volumes produced, local consumption, environmentally friendliness, compliance with broad based black economic empowerment requirements and it should not compete with food sources. The strategy is up for review after the initial five years phase. Currently there are no commercial bioethanol fuel production plants in South Africa and only some small scale biodiesel production plants with very limited outlets to consumers. With all the apparent advantages, why is nothing happening in the industry? Business is not showing interest, proving that the economic conditions are not favourable. The government wants to control the production side to maximise the gains from it, but instead of assisting the industry, it has practically inhibited it from getting started. The consumers must also be prepared to accept the new fuels. Awareness, education and a culture of sustainable use are vital to create the required market. This is an exciting industry with potential benefits to South Africa and its society as a whole, but the fundamental elements of business must be in place in order for it to become self-sustainable.

Thesis (MScAgric (Agricultural Economics)--University of Stellenbosch, 2009.
The growing scarcity of fossil energy, expressed by rising real prices, justifies an investigation into the viability of utilising alternative, sustainable energy sources. Another motivation is to mitigate CO2 pollution resulting from using fossil fuels, causing climate change. Biomass has the potential to become a major global primary energy source during the next century. In South Africa, a limited amount of land is suitable for high‐potential biomass energy sources like sugar cane or grain. Large areas of South Africa are, however, dry and more suitable for woody biomass production. Cultivating trees in short‐rotation‐system plantations provides a sustainable and effective way of producing biomass. The first part of this study investigated the physical capacity of the Cape Winelands District Municipality (CWDM) for woody biomass production in short‐rotation systems, based on a land availability assessment using Geographic Information Systems (GIS). The CWDM comprises about 2.3 million hectares, of which about 175 000 ha with a slope of less than 35% have been identified as suitable for woody biomass production. Within the CWDM, the following land use classes were excluded: nonagricultural land, such as urban areas, bare rock and mines; ecologically sensitive areas; as well as areas with slope gradients that are too steep for biomass production, due to limited accessibility and trafficability. This was followed by an assessment of suitable tree species and their productivity rates – also using GIS with climate data (i.e. temperature extremes, frost and mean annual precipitation) and terrain data. By combining the identified biomass production sites with the productivity rates of the identified species, an annual supply of woody biomass for energy generation at a medium productivity of about 1 412 000 tonnes of fresh biomass is expected, using exotic species like Eucalyptus claducalyx ( and about 1 306 000 tonnes, using indigenous species like Acacia karoo).

Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2003.
108 leaves printed on single pages, preliminary pages i-vi and numbered pages 1-1 to 1-5 to 9-1 to 9-3. Includes bibliography, list of abbreviations and 22 figures in color. Digitized at 300 dpi grayscale and 300 dpi 24-bit Color to pdf format (OCR), using an HP Scanjet 8250 Scanner.
ENGLISH ABSTRACT: A long term experiment was conducted at the Langgewens Experimental Farm, near Malmesbury in the Western Cape province of the Republic of South Africa. The effect of soil tillage, crop rotation and nitrogen fertiliser rates on mineral-N levels in the soil, nitrogen levels in plants, wheat growth and yield components, grain yield as well as quality parameters of spring wheat were determined. Although the tillage treatments tested were initiated in 1976, present crop rotations and nitrogen application rates were only applied since 1990. Most of the data that are discussed however was recorded during the 1997 to 2001 period. The trial was designed as a randomised complete block with a split-plot arrangement and four replicates. Main plots were tillage methods namely conventional tillage (CT), tine tillage (TT), minimum tillage (MT) and no tillage (NT). Crop rotations used were continuous wheat (WW) and wheatl lupin/wheat/canola (WLWC). Both soil and crop data were recorded. The results of this study showed the differences in total mineral-N content of the soil. N-contents of wheat, wheat growth and yield components as well as wheat quality parameters were found between tillage treatments, crop rotations used as well as N- fertiliser rates applied. Response however, varied largely between years due to annual variation in especially total precipitation and distribution of rainfall. The inclusion of a legume crop (lupin) and canola in the rotation with wheat was found to have only a small effect probably due to the fact that lupins were grown once in a four year cycle only. Application of different nitrogen rates did increase the mineral-N in the soil, but the effect did not last very long in most years due to either N-leaching or plant uptake. To ensure sufficient mineral-N levels, late application of N-fertiliser will therefore be needed. Minimum tillage or reduced tillage performs better than conventional tillage in low rainfall years. In general these tillage systems should be combined with crop rotation to ensure that yields are comparable to that obtained with conventional tillage.
AFRIKAANSE OPSOMMING: Die ontwikkeling, graanopbrengs en bakkwaliteit van koring (Tritium aestivum L.) in reaksie teenoor gewasratasie, metode van grondbewerking en N-bemestingspeil is in 'n lang tennyn sllldie op Langgewens Proefplaas, naby Malmesbury in die Weskaap provinsie van die Republiek van Suid-Afrika, bepaal. Hoewel die verskillende grand bewcrkingsmetodes sedert 1976, en gewasrotasies en slikstofpeile sedert 1990 toegepas is, is daar in hierdie studie gekonsentreer op data wal gcdurcnde die periode 1997-2001 ingesamel is. Die eksperiment is as 'n randomiseerde blok ontwerp met vier bewerkingsmetodes nl. konvcnsionele bewerking (CT), tand bewerking (TT). minimum bewerking (MT) en geen bewerking (NT), twee gewasratasies nl. monokuhuur koring (WW) en koring/lupienelkoringiCanola (WLWC) en drie N-peie (60 kg N ha- ', 100 kg N ha- 1 , 140 kg N ha- I uitgevoer. Aile stikstof is in die vorm van kalksteen-ammoniumnitraat toegedien. Die reaksie van beide grondfaktore soos die minerale N inhoud en gewaskomponente 5005 biomassa produksie, opbrengs en kwaliteit teenoor bogenoemde faktore het '0 goeie korrelasie getoon met die heersende klimaatstoestande. Lae reenval jare (gebiede) sal volgens hierdie stlldie die grootste voordeel verkry met minder intensiewe grand bewerkingstelsels. terwyl 'n frekwensie van meer as een peulgewas per siklus van 4 jaar nodig sal wees om grondvrllgbaarhcidsvlakke betekenisvol te verhoog. Stelsels van rninder intensiewe grondbewerking is ook tot 'n grater mate deur gewaswisseling bevoordeel as konvensionele melOdes van grondbewerking. Hocwel minerale-N vlakke in grond deur verskillende N-peile be'lnvloed is, was die efTektiwiteit van toedienings laag en het verdeelde tocdienings groat voordele ingehou.

One of the greatest challenges facing the world today is integrating industrial activities such as mining with environmental integrity and social concerns. Monitoring is fundamental to environmental management, both to assess the adherence to standards and to allow environmental managers to learn from practical experiences. However, a problem arises when the regulatory authorities cannot keep up with their mandate of enforcement and compliance monitoring. This research examined how the Department of Minerals and Energy (DME) implements the concept of sustainable development in the mining sector of the Eastern Cape (EC) and, more specifically, the extent to which the Mine Environmental Management (MEM) section is able to effectively monitor compliance of mining operations with environmental legislation. This was the first systematic compilation of statistical data for the DME, and presents the first study in the EC regional office in terms of environmental sustainability. Results indicate that there has been a sustained increase in mining activity over the past three years, possibly as a result of the boom in the construction industry and the accelerated road maintenance and improvement programmes in the Eastern Cape. Mining applications received by the DME have increased by 47% from 2006 to 2007 (January-May) and by a further 100% from 2007 to 2008. In addition to the increasing number of mining concerns being established, 98 mining concerns will need to apply for the conversion of their old order rights to new order rights by the 1st May 2009. Mining in the province is predominantly small scale with mining permits (mined areas less than 1.5Ha) making up 52.3% of all applications, with larger mining concerns contributing 29.3% and prospecting contributing the remaining 18.4%. In terms of compliance inspections, the EC regional office is required to conduct 120 environmental compliance inspections annually in terms of contributing to sustainable development. The MEM section exceeded this target since 2003. However, when the number of operational mines is considered, 120 inspections per year equates to one mine being visited, on average once every four years (based on 2008 data). Based on projected figures (number of compliance audits and number of operational mines) for 2009, the DME’s target of 150 inspections for 2009/10 combined with the limited staff D. Watkins – MBA Dissertation 2008 capacity will, at best, mean that mines would be inspected once in seven years. However, the target of 150 inspections will not actually even cover the expected number of EMP evaluation inspections. This has serious implications in terms of regulating the compliance of the mining concerns with their EMPR’s. The low level of compliance monitoring can be directly related to staff capacity and logistics problems at the regional office as well as provincial targets being based on staff capacity rather than the number of operational mines. Thus, considering potential environmental damage associated with mining operations and the capacity constraints of the MEM to conduct frequent compliance audits, it is likely that mining operations will have negative implications for sustainable development in the region. Currently there are many challenges facing the DME in terms of contributing positively to sustainability in the mining sector and there is a need to base future actions on the idea of continuous improvement and ultimately progress.

The study aims to evaluate the biomass production and nutrient content and silage quality of perennial ryegrass (Lolium perenne (L)), cocksfoot (Dactylis glomerata (L)) and tall fescue (Festuca arundinacea (Schreb)). Six varieties were used, two for each species. A completely randomized block designed replicated three times was conducted at University of Fort Hare Research Farm during 2014-2015 growing season. The plots were harvested at four-week interval (post emergency) for one year. Biomass yields were measured for fresh forage and dry matter yield. Duplicated samples were then dried, milled and analyzed for chemical and mineral composition (CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe) for only winter season. In addition the grasses were ensiled and the silage was analyzed for its fermentation parameters and nutrient content (lactic acid, pH, DM, CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe). Biomass results showed significant differences (P < 0.05) between season and varieties. On average Tall fescue varieties Jessup (13741.67 FM kg/ha), Alix (12007.78 FM kg/ ha) and Ryegrass varieties Samson (11597.22 FM kg/ha) and Nui (10591.67 FM kg/ha) had the highest fresh biomass yield. Similarly, Tall fescue varieties Jessup (2833.06 DM kg/ha) and Alix (2708.3 DM kg/ ha) and Ryegrass varieties Samson (2169.44 DM kg/ha) and Nui (2169.67 kg/ha) had the highest dry biomass yield. Throughout the year the average biomass yield was significantly different among species (P< 0.05). During summer and autumn Tall fescue varieties Jessup and Alix gave the highest dry matter yields of 3855.5 to 1977.8 DM kg/ha, and 3877.8 to 1900 DM kg/ha, respectively, and followed by Cocksfoot 2400 DM kg/ha. Ryegrass had the highest dry matter biomass yield in winter (2975 DM kg/ha) and the least in summer (977.75 DM kg/ha). There were no significant (P>0.05) differences on the chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe) of the six varieties. The grass silage results showed significant differences (P< 0.05) among the six varieties for moisture content. Perennial ryegrass variety Nui (66.76 percent) had low moisture content than the other grass silages. The different varieties had no significant effects (P>0.05) on chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe). It is concluded that the biomass production of the six varieties of three grass species was different throughout the year under irrigation hence Ryegrass and Tall fescue are recommended for dairy farmers in the region for all seasons. It can be concluded that there is no difference with respect to fermentation characteristics and nutrient content among the varieties of the grass species.

Thesis (MBA (Business Management))--Stellenbosch University, 2008.
ENGLISH ABSTRACT: The world today is facing many energy challenges such as power outages experienced internationally and in South Africa. The demand for energy is constantly increasing and is creating environmental problems such as climate change, which is presently a major concern to society. This study is an attempt to establish how energy saving mechanisms such as the elimination of non-essential power can add economic value within the mining industry. This paper examines the effect of non-essential power and how it could assist companies to reduce their energy consumption, aid local power utilities in a crisis and maintain normal production levels. This research report was based on an investigation for power saving opportunities at a mining company during a power crisis. The paper looks at energy efficiency and the barriers to the adoption of energy savings. Companies in general do not have a structured way of addressing non-essential power saving. Companies are not aware of the value such initiatives could have on corporate responsibility and sustainable reporting. The benefits of energy efficiency and nonessential power on the triple bottom line are not clearly documented in literature. When comparing the impact of non-essential power on the triple bottom line, it became obvious that further research is required in order to prove whether it influences the social aspect. The impact of power generation on the global environment has not been clearly calculated and linked to the value of saving power. The literature review highlighted that companies are focusing on long-term initiatives instead of smaller initiatives, which requires less effort. During the investigation of the mining company, it was found that not much effort was made during the design stages in separating the electrical circuits from non-essential and essential power. The author concludes that switching off non-essential power held economic and environmental benefits for the mining company. The author therefore concludes that switching off non-essential power impacts positively on the economic and environmental part of the triple bottom line. It was found that the elimination of non-essential power is easy to implement with minimum investment and effort. Furthermore, the savings from these initiatives could easily be measured to calculate the return on the investment.
AFRIKAANSE OPSOMMING: Ons kry deesdae al meer te doen met uitdagings soos internasionale en plaaslike kragonderbrekings in die energiebedryf. Die aanvraag vir energie verhoog deurlopend en veroorsaak omgewingsprobleme soos klimaatsveranderinge, wat ‘n groot bekommernis is vir die samelewing. In hierdie studie word gepoog om vas te stel hoe energie besparings meganismes soos die eliminering van nie-noodsaaklike krag ekonomiese waarde kan voeg tot die mynboubedryf. Die uitwerking wat nie-noodsaaklike krag het en hoe dit maatskappye kan help om kragverbruik te verlaag terwyl produksievlakke steeds gehandhaaf word, is hier ondersoek. Plaaslike kragvoorsieners kan ook baat vind hierby in krisistye. Hierdie navorsingsverslag is gebaseer op ‘n ondersoek van krag besparings geleenthede by ‘n mynmaatskappy gedurende ‘n krisistydperk van kragonderbrekings. Die verslag kyk na die doetreffendheid van energieverbruik, asook na die hindernisse wat ondervind word in die inwerkingstelling van energie besparings inisiatiewe. Maatskappye het in die algemeen nie ‘n gestruktureerde metode om die probleem rakende nie-noodsaaklike krag aan te spreek nie. Hulle is nie bewus van die nut wat sulke inisiatiewe kan hê op korporatiewe verantwoordelikheid en volhoubare verslaggewing nie. Die voordele wat energiebesparing en die eliminering van nie-noodsaaklike krag op die ekonomie, gemeenskap en omgewing het, word nie duidelik geboekstaaf nie. Verdere navorsing moet gedoen word om die impak van energiedoeltreffendheid en nie-noodsaaklike krag op die sosiale aspek te bewys. Die uitwerking wat kragopwekking op die globale omgewing het is nog nie bereken en verbind met die waarde daarvan op kragbesparing nie. Die verslag beklemtoon dat maatskappye fokus op langtermyn inisiatiewe in plaas daarvan om te kyk na kleiner inisiatiewe wat minder moeite en tyd sal verg. Die ondersoek by die mynmaatskappy het getoon dat daar nie klem geplaas is op die onderskeiding tussen nie-noodsaaklike en noodsaaklike krag met die installering van die elektriese stroombane tydens die ontwerpstadium nie. Daar is gevind dat die afskakeling van nie-noodsaaklike krag ekonomiese en omgewingsvoordele vir die maatskappy inhou. Daar is tot die slotsom gekom dat die afskakeling van nie-noodsaaklike krag in die algemeen dus ‘n voordelige uitwerking het op die ekonomie en omgewing. Dit is maklik om te implementeer met minimum moeite en belegging. Die besparings deur middel van hierdie inisiatiewe kan ook maklik gemeet word om die opbrengs op die belegging te bereken.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: Access to secure energy supplies is widely acknowledged as a critical foundation for sustainable development. Rural households are highly dependent on forest resources for their livelihoods including energy needs. Fuelwood is a non-timber forest product (NTFP) that accounts for one of the main uses of forests and woodlands. Despite substantial household electrification programmes in South Africa, the use of fuelwood as a source of energy continues. This study aimed to analyze fuelwood use patterns of two rural villages situated in Keiskammahoek in the Eastern Cape Province of South Africa in order to understand the perceptions of the community members regarding communal tree planting. The study was conducted in two rural villages, namely, Cata and Tshoxa. A total of 120 respondents from both villages were interviewed using semi-structured questionnaires to collect data on the use of fuelwood and evaluate their perception on tree planting. The study revealed that up to 77% of the people living in Keiskammahoek used fuelwood as a major source of energy and that women were the main collectors and users of fuelwood. In the rural Cata, food is cooked in three-legged pots over open fires while in Tshoxa food is mainly cooked over paraffin and electric stoves. The respondents from both villages did not have energy conservation measures in place and improved wood stoves have not been introduced in this region. The local community of Cata was also involved in tree planting on a community level, while both villages were also involved in tree planting at a household level. The study concluded that fuelwood was the most important product from the forests in both rural areas and natural forests were a valuable source of other NTFPs; most notably indigenous fruit products. In addition most of the fuelwood was used for cooking and heating purposes but that there was no deliberate use of energy efficient methods. On tree planting, the study showed that communities from both rural villages have an interest in planting trees around their households; with preference for fruit and shade trees.
AFRIKAANSE OPSOMMING: Toegang tot betroubare energieverskaffing word algemeen erken as 'n uiters belangrike grondslag vir volhoubare ontwikkeling. Plattelandse huishoudings is hoogs afhanklik van bosbronne vir hul bestaan, met inbegrip van energiebehoeftes. Brandhout is 'n nie-hout bosproduk (NHBP) wat beskou word as een van die hoofgebruike van woude en boslande. Nieteenstaande wesenlike elektrifiseringsprogramme vir huishoudings in Suid-Afrika, duur die gebruik van brandhout as 'n bron van energie voort. Hierdie studie het beoog om die gebruikspatrone van brandhout van twee plattelandse dorpe in Keiskammahoek in die Oos-Kaapse Provinsie van Suid-Afrika te ontleed en om die begrip van die gemeenskap aangaande die gemeenskaplike plant van bome te verstaan. Die studie is in twee plattelandse dorpe, naamlik Cata en Tshoxa, uitgevoer. Onderhoude is gevoer met 'n totaal van 120 respondente van beide dorpe deur die gebruik van halfgestruktureerde vraelyste om gegewens oor die gebruik van brandhout in te samel en die respondente se begrip van die plant van bome te evalueer. Die studie het aan die lig gebring dat tot 77% van die mense wat in Keiskammahoek woon, brandhout as 'n hoofbron van energie gebruik en dat vrouens die hoofgaarders en gebruikers van brandhout is. In die landelike Cata word kos in driepootpotte op oop vure gekook terwyl kos in Tshoxa hoofsaaklik op paraffien- en elektriese stowe gekook word. Die respondente van beide dorpe het nie energiebesparingsmaatreëls in plek gehad nie en verbeterde houtstowe is nog nie in hierdie streek ingebring nie. Die plaaslike gemeenskap van Cata was ook betrokke by die plant van bome op 'n gemeenskapsvlak, terwyl beide dorpe ook betrokke was by die plant van bome op 'n huishoudelike vlak. Die studie het tot ’n gevolgtrekking gekom dat brandhout die belangrikste produk van die woude in beide plattelandse gebiede is en dat die natuurlike woude 'n belangrike bron van ander NHBP’s is; veral inheemse vrugteprodukte. Daarbenewens is meeste van die brandhout gebruik vir kook- en verhittingsdoeleindes, maar daar was geen doelbewuste gebruik van energiedoeltreffende metodes nie. Op die gebied van die plant van bome het die studie getoon dat die gemeenskappe van beide plattelandse dorpe belange het in die plant van bome rondom hulle huishoudings; met voorkeur aan vrugte- en skadubome.

Achieving high biomass yields of cover crops has been a challenge to the success of Conservation Agriculture (CA) practices in the Eastern Cape (EC). A study was conducted to evaluate strategies for optimizing cover crop biomass production. Trials were carried out to screen summer and winter cover crops, as well as evaluate intercropping patterns and planting dates for biomass, weed suppression and subsequent maize yield under irrigation. Four summer legume cover crop species were evaluated under a Randomised Complete Block Design (RCBD) design. The cover crops were fertilized with 13.34 kg ha-1 of N, 20 kg ha-1 P and 26.66 kg ha-1 K. In the 2008/09 summer season a maize crop was superimposed on the 2007/08 screening trial under no-till. The crop was fertilized with 60 kg ha-1 of N. An intercropping trial was conducted over two seasons as a way of investigating the best way of incorporating cover crops into farmers cropping systems. This was done bearing in mind the limitation of resources such as land. The trial evaluated 3 factors laid as a 2 x 2 x 3 factorial arranged in a split-plot design. The main factor was cover crop planting date (planting at maize planting or 2 weeks after maize planting). The sub plot factor was intercropping pattern (strip intercropping and between row intercropping). A trial was also conducted to evaluate the effect of planting date (End of April and mid May) and four winter legume cover crop species on cover crop biomass, weed suppression and maize grain yield. The experiment was laid out as a Randomised Complete Block Design (RCBD) replicated 3 times. In the subsequent summer season a maize crop was superimposed on the winter trial to test the residual effects of the cover crop species. Another study was conducted to evaluate winter cereal cover crop species for biomass accumulation, weed suppression and subsequent maize grain yield. The cover crops as well as a weedy fallow control plot treatments were laid out as a Randomised Complete Block Design replicated 3 times. In the subsequent summer season a maize crop was superimposed on the site under no-till to evaluate the residual effect of the cover crops on maize. The results showed sunhemp, cowpea and lablab as the best cover crops with high biomass and weed suppression whilst mucuna was the least. Sunhemp consistently yielded higher cover biomass averaging 11200 kg ha-1 over the two seasons whilst mucuna had a consistently lowest average biomass yield of 4050 kg ha-1. These cover crops were above the critical 6 t ha-1 for effective weed suppression. There was a significant (p<0.01) relationship of cover crop dry weight and weed dry weight in both seasons. Subsequent maize grain yield was significantly higher in the sunhemp plots (64.2 %) than the weedy fallow plot. Mucuna, lablab and cowpea had maize grain yield increases of 16.6%, 33% and 43.2% respectively. Intercropping cover crops at maize planting yielded higher cover crop dry weights than a delay in intercropping cover crops. A delay in intercropping resulted in significantly higher average maize grain yield of 4700 kg ha-1 compared to intercropping at maize planting (3800 kg ha-1) and sole maize (4300 kg ha-1) over the two seasons. Strip intercropping also yielded higher (5000 kg ha- 1) average maize grain yield compared to row intercropping (3600 kg ha-1) and sole maize (4300 kg ha-1). There was a significant (p<0.05) relationship between cover crop dry weight in the 2007/08 season and maize grain yield in the 2008/09 season. Early planting grazing vetch gave the highest biomass yield of 8100 kg ha-1 whilst early planted red clover had the lowest biomass of 635 kg ha-1. Low weed dry weights were also obtained from the early planted grazing vetch as opposed to the other treatments. There was a significant (p<0.001) relationship of cover crop dry weight and weed dry weight. In the subsequent 2008/09 summer season early planted grazing vetch had the highest maize yield of 7500 kg ha-1 which was 56.3 % more than the weedy fallow plot had 4800 kg ha-1. The weedy fallow plot also had high weed infestation than the cover crop plots. There were significant (p<0.01) relationships between cover crop dry weight and maize grain yield, winter weed dry weight and maize grain yield and summer weed dry weight and maize grain yield. The results also showed triticale (13900 kg ha-1) as the best winter cover crop for biomass production. Italian ryegrass (6500 kg ha-1) produced the least amount of biomass. In The subsequent maize crop white oats gave highest maize grain yield (6369 kg ha-1) which was 33 % more than the weedy fallow plot (4784 kg ha- 1). There were also significant (p< 0.01) relationships of maize grain yield and winter weed dry weight, maize grain yield and summer growing weeds. The various studies demonstrated that there is opportunity for high biomass production under small scale farmers irrigated conditions using cover crops both in winter and summer. Best bet cover crops were sunhemp, cowpea and lablab for summer and triticale, white oats, barley, Italian ryegrass and grazing vetch for winter. Cover crops can also be incorporated into farmers cropping systems as sole crops or intercrops within the maize based cropping systems. Strip intercropping can be used by farmers as a way of introducing cover crops. Critical to achievement of high biomass is the time of planting cover crops with high biomass when planting is done early. A 2 week delay in strip intercropping cover crop into maize can be used as a way of incorporating cover crops into farmers cropping systems with minimal maize yield reduction.

There is consensus that Eskom, South Africa’s main energy supplier, needs to expand its energy generating capacity in order to satisfy the growing demand for electricity, but there is less agreement on how it should do this. The existing supply is heavily reliant on thermal generation using coal, but the combustion of fossil fuels for electricity generation may contribute to climate change because it causes harmful greenhouse gases to be emitted into the atmosphere. This emission is something South Africa has committed itself to reducing. One way of achieving this is by the adoption of cleaner technologies for energy generation. One of these technologies is harnessing wind energy. The problem with harnessing wind energy is where to locate the turbines to harness the wind because these turbines ‘industrialise’ the environment in which they are located. They are a source of increased noise, a visual disturbance, cause increased instances of bird and bat mortality and the destruction of flora or the naturalness of the landscape in the areas in which they are located. The residents located near wind farm developments are most negatively affected and bear the greatest cost in this regard. A proper social appraisal of wind turbine projects would have to take this cost into account. Before such developments are approved there should be an assessment made of the impact on the residents, these impacts should be incorporated into the cost-benefit analysis. The negatively affected residents should also be compensated. The objective of this study was not to undertake a cost-benefit analysis of such a wind farm proposal, but to estimate the negative external cost imposed on nearby residents of such an industry, and thereby calculate appropriate compensation to be paid to these residents. Quantifying preferences for proposed, but not-yet developed, wind farms may be done by applying non-market valuation techniques, e.g. through one of the stated preference methodologies, such as a discrete choice experiment. The selected study site for providing guidance was one where Red Cap Investments Pty (Ltd) has proposed the development of a wind farm - in the Kouga local municipality. The basis for drawing conclusions was the analysis of the response samples of two groups of Kouga residents, distinguished by socio economic status; 270 from each group, 540 in total. The methodology applied to analyse the responses was a discrete choice experiment. The questionnaire administered included attitude, knowledge and demographic questions as well as a choice experiment section. The choice experiment section of the questionnaire required that the respondents choose between two different hypothetical onshore wind energy development scenarios and a status quo option. The hypothetical scenarios comprised different levels of wind farm attributes. The attributes included in the experiment were determined by international studies and focus group meetings. These attributes were: distance between the wind turbines and residential area, clustering of the turbines (job opportunities created by the wind farm development for underprivileged respondent group), number of turbines and subsidy allocated to each household. Three different choice experiment models were estimated for each socio-economic group: a conditional logit (CL), nested logit (NL) and a random parameters logit (RPL) model. It was found that, in the affluent respondent group, the simpler CL model provided the best fit. In the underprivileged respondent group, the RPL model, with the number of jobs created by the wind farm project as a random parameter1, explained by the gender of the respondent, provided the best fit. The estimated models identified distance as an important factor in both sampled respondent groups. Both respondent groups preferred that the wind farm be located further away from their residential areas. In addition to distance, the underprivileged respondent group also valued new job opportunities as an important determinant of choice. The affluent respondent group were very sensitive to densely clustered turbines but were almost indifferent between two of the effects coded levels of the clustering attribute “moderately close together” and “widely spaced apart”. Welfare estimates for the significant attributes in each socio-economic group were computed from the best fit models. Table 1 shows the resulting willingness to accept (WTA) compensation measures for distance in both socio-economic respondent groups.

Thesis (MFor)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: This study is aimed at testing the possibility of using woody biomass from three invasive woody vegetation types (Spider Gum, Myrtle and Acacia) for production of bioenergy in the Cape Agulhas Plain. Physical recoverability of the woody biomass was studied by means of a semi-mechanized harvesting system to evaluate potential productivity, operational costs and the estimated yield energy gain. The system consisted of five components: manual harvesting, motor-manual harvesting, extraction, chipping and road transport. Data on the system productivity was obtained using activity sampling and time study techniques. Activity sampling was applied on manual and motor-manual harvesting in order to record harvesting time and standard time study techniques were used to obtain time data for extraction, chipping and road transport operations. Findings revealed benefits associated with the utilisation of invasive woody vegetation as energy feedstock. Therefore, the problem of exotic tree species can be dealt with by transforming them into energy feedstock, thus minimising the effect of invasive plants. At the same time essential biomass energy can be produced, while some of the cost of production could be offset by the benefits accruing from the biomass energy. The Acacia site, characterized by larger mature dense trees, had the highest amount of harvested biomass compared to the rest of the vegetation types (i.e. Myrtle and Spider Gum). The overall system productivity was found to be significantly influenced by a low equipment utilisation rate, estimated at 50%. This resulted in low production rates in general. The low supply rate of material to the chipper by the three-wheeled loader (1.5 – 5.3 oven-dry tonne per production machine hour) was found to be a major constraint in the chipping process, especially when considering that the chipper is potentially capable of chipping 4 – 9.4 ODT PMH-1 at the harvesting sites. This resulted in a significant energy balance of 463 GJ between output and input energy of the system. The overall total supply chain system costs based various road transport distances of species ranged from R 322.77 ODT-1 to R 689.76 ODT-1 with an average of R 509 ODT-1. This was found to be costly compare to the case where high machine utilisation rate and optimal productivity are used (average of R 410 ODT-1), biomass recoverability in this field trial had a higher total system cost due to low productivity, resulting from the low equipment utilisation rate applied.
AFRIKAANSE OPSOMMING: Hierdie studie was gemik daarop om die moontlikheid van die gebruik van houtagtige biomassa, afkomstig van uitheemse plantegroei (Bloekom, Mirte en Akasias) op die Agulhasvlakte vir bio-energie te ondersoek. Potensiële produktiwiteit, bedryfskostes en die geskatte energie opbrengs toename is gebruik, om die fisiese opbrengs van houtagtige biomassa van ʼn semi-gemeganiseerde ontginningstelsel te evalueer. Die stelsel het uit vyf komponente bestaan: Handontginning, motor-handontginning, uitsleep, verspandering en padvervoer. Data oor die stelselproduktiwiteit is uit tydstudie en aktiwiteit steekproewe verkry. Aktiwiteit steekproewe is toegepas op hand- en motorhandontgining om ontginingstyd te verkry, terwyl tydstudie standaardtegnieke gebruik is om tyd data vir uitsleep, verspandering en padvervoer werksaamhede te verkry. Bevindings het die voordele met bettrekking tot die gebruik van uitheemse plantegroei as energiebron bevestig. Die uitdaging rondom die verspreiding van uitheemse plantegroei kan dus aangespreek word deur dit as energiebron te benut. Die produksiekoste vir die toegang tot die bruikbare biomassa kan moontlik voorsien word uit die voordele van die gebruik van die energie wat uit die benutting van die biomassa verkry word. Die groter meer volwasse en digte Akasia opstand het die meeste ontginde biomassa gelewer vergeleke met die ander opstande in die studie (d.i. Mirte en Bloekom). Die stelselproduktiwiteit is beduidend beïnvloed deur die lae toerustinggebruik wat minder as 50% beloop het. Dit het ook laer produksievermoë in die algemeen tot gevolg gehad. In die verspandering werksaamheid blyk die lae invoer tempo (1.5 – 5.3 oonddroog ton per produktiewe masjienuur) van die driewiellaaier die beperking op die proses te wees, veral as in ag geneem word dat die verspandering teen 4-9.4 ODT PMH-1 kan geskied. Die resultaat was ʼn beduidende energie balans van 463 GJ tussen uitset- en invoerenergie van die stelsel. Die totale toevoerketting kostes gegrond op verskeie padvervoer afstande van die spesies was tussen R 322.77 ODT-1 tot R 689.76 ODT-1, met ʼn gemiddelde rondom R 509 ODT-1. Die resultaat is duur gevind in vergeleke met gevalle waar hoë masjiengebruik en optimale produktiwiteit (gemiddeld van R 410 ODT-1), moontlik was. Die biomassaherwinning in die studie het ʼn hoër totale stelselkoste gehad veroorsaak deur lae produktiwiteit, wat verwant is aan die laer toerusting gebruikstempo wat verkry is.

Thesis (MBA)--Stellenbosch University, 2006.
ENGLISH ABSTRACT: The adoption of the White Paper on the promotion of Renewable Energy and clean fuels in 2003, opened the playing field for participants from other industries than the conventional petroleum, to participate in the fuel industry in South Africa. South Africa is a net importer of crude oil, which accounts for 92% of liquid fuels supply in South Africa. Although the country has significant coal reserves which can supply the country's demand for approximately 200 years, this energy source contributes significantly to CO, emissions. South Africa's participation in the Kyoto Protocol compels it to abide by its commitments to reduce these emissions between 2008 and 2012. The country's dependence on energy to fuel its growing economy, and the infiationary impact that oil imports has had on the country's economy, has prompted government to explore alternative sources of energy to reduce its dependence on fossil fuels and especially importing crude oil. As a result of this, and in an attempt to increase the potential for the successful implementation of ASGISA, government is exploring the feasibility of introducing an E10 fuel blend to the South African petrol blend. In view of th is, government has in it Accelerated and Sustainable Growth Initiative (ASGISA) targeted the development of the bio-fuels industry as an industrial sector that presents opportunities to create opportunities for sustainable growth and development. In view of this, the fiedgling fuel-ethanol industry (which is in its construction phase at the t ime of writing this report), faces lucrative prospects for the agricultural industry, especially maize- and ethanol producers. It is anticipated that the fuel-ethanol industry will create between 8000 and 10000 direct and indirect employment opportunities per plant. This will result in significant investment in rural areas as well. The creation of employment in the rural areas will prevent the large-scale urbanisation that has become a phenomenon in the past decade, as a result of dwindling agricultural industries. The production of ethanol presents the opportunity to earn foreign exchange, especially if the industry embarks on large scale export strategies. In addition to the export market, the local market for ethanol consist of the possible E10 petrol-blend and to supply Eskom with ethanol to fuel its gas turbine electricity generators at Acacia, Port Rex, as well as the anticipated generators at Atlantis and Mossel Bay. This document is a report on the investigation of the economic evaluation of a bio-fuel industry in South Africa. It will explore the current outlook for fossil fuel reserves, supplies and demand, both internationally and locally. It will report on the phenomenon of peak oil production and some opinions thereon . An investigation into the most probable biomass that can be used as feedstock for bio-fuel production will conducted. In this regard, specific investigation into maize, sugar cane (for fuelethanol) and Jatropha eureas (for bio-diesel) will be conducted. The report will explore the most efficient ethanol production processes, for both maize- and sugar-to-ethanol production, with the weight of the document to be attributed to the economic impact that the adoption of the fuel-ethanol programme
AFRIKAANSE OPSOMMING: Die publisering van die Witskrif oor die promosie van hernieubare energiebronne en skoon brandstowwe in 2003, het die speelveld vir deelname aan die brandstof industrie oopgemaak vir rolspelers buiten die konvensionele petroleum maatskappye. Suid-Afrika is 'n netto invoerder van ru-olie en het in 2004 ongeveer 92% van die totale vloeibare brandstowwe ingevoer. Alhoewel die land aansienlike steenkool reserwes het om te voorsien in die aanvraag vir die volgende ongeveer 200 jaar, dra hierdie energiebron aansienlik by tot die koolstofdioksied vrystellings. Suid-Afrika se deelname aan die Kyoto Protokol van 1998, dwing die land om te voldoen aan die ondernemings wat gemaak is om hierdie koolstofdioksied vrystellings te verminder tussen 2008 en 2012. Die land se afhanklikheid van energiebronne om groei te stimuleer, asook die inflasionistiese effek van olie invoere op die ekonomie, het die regering genoop om alternatiewe bronne van energie te ondersoek sodat die afhanklikheid van olie verminder kan word. Uiteenlopend hiervan en om die implementering van ASGISA te stimuleer, ondersoek die regering tans die moontlikheid om 'n E10 petrol vermenging in die petrol formule te spesifiseer. Uit die oogpunt van ASGISA (Accelerated and Sustainable Growth Initiative) van Suid-Afrika, het die regering die ontwikkeling van die bio-brandstowwe industrie geoormerk om geleenthede te skep vir volhoubare ontwikkeling en groei. Met die oog hierop, voorspel die etanol bedryf, wat ten tyde van die skryf van hierdie verslag nog in kontruksie was, winsgewende potensiaal vir die landboubedryf, veral mielie produsente. Dit word verwag dat die etanol bedryf tussen ongeveer 8000 en 10000 direkte en indirekte werksgeleenthede sal skep, veral in die landelike gebiede. Dit sal grotendeels bydra tot die voorkoming van die voortslepende ontvolking van die platteland wat oor die afgelope jare 'n verlammende effek op plattelandse gebiede gehad het. Dit word ook voorsien dat daar aansienlike belegging in die platteland sal plaasvind en al hierdie faktore sal bydra tot die voorkoming van verstedeliking . Die etanol bedryf skep die geleentheid om buitelandse valuta te genereer, veral as die industrie op uitvoere gaan konsentreer. Indien 'n plaaslike mark beoog word , sal die implementering van die E10 vermenging 'n besliste mark skep. 'n Alternatiewe mark wat ondersoek kan word, en wat groot geleentheid skep, is Eskom, wat tans ingevoerde diesel verbruik om hul gas turbine krag opwekkers by Acacia en Port Rex van brandstof te voorsien . Indien die beoogde turbines by Atlantis en Mosselbaai gebou word, sal die mark vir plaaslike etanol verdubbel. Hierdie dokument is 'n verslag oor die ondersoek wat gedoen is na die lewensvatbaarheid van 'n brandstof etanol bedryf in Suid-Afrika. Dit berig oor die huidige uitkyk oor die fossiel brandstof reserwes in die wereld en plaaslik. Dit opper die vraagstuk oor piek olie produksie fenomeen wat uiteenlopende debate ontketen het. Die verslag dek die waarskynlike bronne van biomassa wat aangewend kan word in die produksie van etanol, met spesifieke verwysing na mielies, suikerriet en Jatropha curcas. Die mees effektiewe produksie metodes word verder ondersoek wat van toepassing is op beide mielies en suikerriet. Die mees relevante deeI van die verslag is die ondersoek na die ekonomiese impak wat die industrie op die Suid-Afrikaanse ekonomie mag hê, waarna die nodige gevolgtrekkings en aanbevelings gemaak sal word.

Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: In the developed and developing world, the use of lipids for the production of alkyl esters, also known as biodiesel, showed phenomenal growth during the ten year period up to the end of 2007. The main sources for these lipids are the oils extracted from oil seeds such as soya-, palm-, and rape seed, but other products in the food chain such as waste cooking oil (yellow grease) and animal fats are also used. In Africa and Asia vast tracks of land not previously tilled, are now being cultivated to yield oils which are not edible and in a number of countries intensive research is focused on lipid producing species such as algae. Meanwhile more evidence is coming to the fore pronouncing biodiesel and other first generation biofuels not to be the panacea for the predicament the world is facing on unbridled population growth, energy security concerns and environmental issues such as indirect land use changes, global warming and climate changes. The acceptance of the National Biofuels Industrial Strategy at Cabinet level has not yet resulted in significant commensurate activity in South Africa. The availability, other uses and volumes of selected feed stocks for biodiesel production invite debate on the choice between food- and energy security and the appropriateness of some identified socio-economical and socio-political drivers for a viable industry. Somehow the unique characteristics of South Africa and its resources seem not to feature in debate and constraints on the production of biodiesel, as described in this dissertation. The conventional process routes for commercial biodiesel production are based on a mature technology which has inherent pollution and economical limitations. This called for a detailed critical evaluation on process routes more environmentally friendly or involving fewer unit processes generating more desirable products, albeit with more severe process conditions. By comparison, the homogeneous alkali catalyst alcoholysis (HACA), the enzymatic catalyst alcoholysis (ECA) and the super critical alcoholysis (SCA) process routes as developed in this study, are found to be competitive on total manucturing costs as assessed, if results emanating from selected sensitivity analyses and optimisation studies, are accepted. The total manufacturing and operating costs in the selected process routes as estimated, assuming the same capacities for commercial biodiesel production, are dominated by feed stock costs. Incentives on depreciation and fuel levies are deemed not effective, if costs are compared to the price of fossil diesel at the retail level – October 2011. It is concluded that using the feed stocks indicated in the Strategy, commercial biodiesel production is not economically feasible in South Africa at present. In this study process routes and feed stocks were identified that can change this position. Note should be taken of the intensive research activities being conducted on second generation technologies and biorefineries in the developed world, as discussed in this dissertation.
AFRIKAANSE OPSOMMING: In die ontwikkelde en ontwikkelende wêreld het die gebruik van vette vir die produksie van alkielesters, ook bekend as biodiesel, in die tienjaarperiode tot die einde van 2007 fenomenale groei getoon. Die hoofbronne vir hierdie lipiede is die olies onttrek van oliesade soos soja-, palm-, en raapsaad, maar ander produkte in die voedselketting soos gebruikte kookolie en dierevette word ook gebruik. In Afrika en Asië word uitgestrekte stukke grond voorheen onbewerk, nou bewerk om olies wat nie eetbaar is nie, op te lewer, en in verskeie lande word intensiewe navorsing op vetproduserende spesies soos alge gedoen. Intussen kom meer bewyse na vore wat verklaar dat biodiesel en ander eerste-generasie biobrandstowwe nie die wondermiddel is vir die moeilike posisie wat die wêreld in die gesig staar oor onbeteuelde bevolkingsaanwas, kwellings oor energiesekuriteit en omgewingskwessies soos indirekte grondverbruike, aardverwarming en klimaatsveranderings nie . Die aanvaarding van die Nasionale Biobrandstowwe Industriële Strategie op kabinetsvlak het nog nie verhoogde soortgelyke aktiwiteite in Suid-Afrika tot gevolg gehad nie. Die beskikbaarheid, gebruike en volumes van gekose grondstowwe, lok debatte uit oor die keuse tussen voedsel- en energiesekuriteit en die toepaslikheid van sekere geïndentifiseerde sosio-ekonomiese en sosio-politieke stimulante vir ‘n lewensvatbare nywerheid. Op een of ander manier is die unieke kenmerke van Suid- Afrika en sy bronne nog nie in die debat op die knelpunte van biodiesel nie, soos beskryf in hierdie proefskrif. Die gewone prosesroetes vir kommersiële produksie van biodiesel is gebaseer op ‘n beproefde tegnologie met inherente besoedelings- en ekonomiese beperkings. Dit het gevra vir ‘n uitvoerige kritiese evaluasie van meer omgewingsvriendelike- en minder eenheidsprosesse wat meer gewensde produkte genereer, al is dit met erger prosesbepalings. By vergelyking, is dit bevind dat die homogene alkali-katalisator- alkoholisis (HAKA), ensiem-katalisator-alkoholisis (EKA) en die superkritiese-alkoholisis (SKA) prosesroetes soos in hierdie studie ontwikkel, mededingend is op ‘n totale vervaardigingskoste-vlak, as die resultate wat spruit uit geselekteerde sensiwiteitsanalises en optimiseringsstudies, aanvaar word. Die totale vervaardigings- en bedryfskostes soos beraam vir die gekose prosesroetes vir kommersiële biodieselvervaardiging vir dieselfde deursette, word oorheers deur grondstofkostes. Aansporings op afskrywings en brandstofheffings word gesien as nie effektief nie, as kostes vergelyk word met die prys van fossieldiesel op kleinhandelsvlak – Oktober 2011. Die gevolgtrekking word gemaak dat met die grondstowwe aangedui in die Strategie, kommersiële biodieselvervaardiging tans nie ekonomies gangbaar is vir Suid-Afrika nie. In hierdie studie is prosesroetes en grondstowwe geïdentifiseer wat die posisie kan verander. Kennis moet geneem word van die intensiewe navorsingsaktiwiteite op tweede-geslag tegnologieë en bioraffinaderye in die ontwikkelde wereld, soos in hierdie proefskrif bespreek.

Thesis (MBA)--University of Stellenbosch, 2010.
Climate change is one of the most serious issues the world is facing today. With an economic slowdown globally, huge food shortages and record-high fuel prices, it has never been so important for countries to guard their natural resources to ensure future sustainability. The South African energy generation industry, of approximately 40 000 Mega Watt (MW), consists largely (90%) of coal-fired power stations, with the remainder comprising of nuclear and pumped storage schemes which are regarded as environmentally neutral. It is only recently that Eskom and independent power producers (e.g. Darling Independent Power Producer Wind farm with an estimated 10 MW) embarked on utilising South Africa's natural resources to generate electrical power. South Africa's access to inexpensive coal and paid off coal-fired power stations has made it difficult to justify the investment in renewable energy. However, on 31 March 2009 South Africa became the first African country to introduce a feed-in-tariff for renewable energy (Gipe, 2009). The hope is that this initiative would stimulate the investment in green energy generation. Eskom and municipalities are currently the only entities that have licences from the National Energy Regulator of South Africa (NERSA) to buy bulk electricity from power producers. The question therefore arises: if green electricity is more expensive to generate and is sold at a price premium to Eskom and municipalities, would they pass the premium on to consumers; can they differentiate the green electricity product and will consumers be willing to buy at a premium price? This research study aims to answer if businesses would be willing to pay a premium for green electricity, why they would be willing to buy it, which factors influence the purchasing decision and what barriers exist that will deter a purchase. A survey was conducted on businesses in the Western and Northern Cape of South Africa. The businesses sampled have a notified maximum demand of 50kVA or higher and excludes the re-distributor (City of Cape Town) customers. Approximately ten per cent of businesses would be willing buy green electricity. Most of these businesses have indicated that they are willing to pay a premium of five to nine per cent for green electricity. The businesses that are willing to pay the largest premiums (>10%) are in the electricity, gas, water, finance, insurance, real estate, business services, manufacturing, transport, storage and communications sector. Businesses that are willing to buy green electricity: • Have a strategy to reduce their carbon footprint; • Want to be community leaders (altruistic motivators); • Have as their biggest barrier the additional cost of green electricity; and • Feel that power utilities should be required to include a minimum percentage of green energy in their energy mix.

The overall objective of the whole study was to assess whether conservation agriculture (CA) systems can work in the Eastern Cape Province (EC). The CA systems were engaged through cover cropping to address land degradation problems by emphasizing high biomass production in order to realize short term benefits such as moisture conservation, weed suppression and soil fertility benefits under rainfed conditions in the central region of the Eastern Cape province. Since rainfall is the most limiting factor to crop production in the EC, a within season rainfall distribution analysis was conducted to expose the quality of the season (onset, end and duration) and hence the feasibility of CA systems to guide agronomic decisions by farmers in EC. To assess season parameters, thirty four years of daily rainfall was collected from the University of Fort Hare Research station and used to conduct the rainy pentad (5 day rainfall totals) analysis and the daily rainfall analysis using INSTAT software programme. Based on the pentad analysis, results showed that Alice does not have a rainy season in 1 out of 2 years (50% probability) but has one in 1 out of 4 years (25% probability level). This criterion proved to be harsher and conservative when compared to the daily rainfall approach which is more precise in measuring trends on season parameters. The daily rainfall analysis indicated a 65% feasibility for the dry land cropping systems in the EC. The pentad analysis however was effective in illustrating seasonality and it showed that the wet season begins on the 1st of November, ending on the 22nd of March lasting for 140 days. Though the season duration appeared too long, the existence of dry spells during critical growth stages adversely affects the quality of the season. The daily rainfall analysis also managed to derive a signal which can guide planting decisions. For planting to be successful, this analysis determined that 20 mm of rain should be received in two consecutive days after the 1st of November. A screening trial for cover crop biomass production and weed suppression was conducted on-station Fort Hare Research Farm (32°46' S and 26° 50' E), and Msobombvu village (MSBV) (32°44' S, and 26° 55' E) over two seasons (2007/08 and 2008/09). Six summer cover crops i.e. cowpea (Vigna unguiculata), dolichos lablab (Dolichos argenteus), sunnhemp (Crotalaria juncea), buckwheat (Fagopyrum sagittatum), forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were evaluated for biomass yield, and weed suppression. Decomposition rates, moisture conservation and residual effects of these cover crops on the succeeding main crop were also evaluated under dryland conditions. The screening trial was laid in randomized complete block design replicated three times. Forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were identified as high biomass producers and their dry matter yields ranged from 8 -12 t ha-1. These cover crops can be useful in generating high biomass in rainfed cropping systems in the EC. Other cover crops produced 3 - 4 t ha-1 of biomass which fell short of the 6 t ha-1 expected benchmark. However, these biomass yields were important in weed management since all cover crop species showed a similar degree of weed suppression which surpassed the weed fallow treatment. As dead mulches, the cover crops failed to show residual moisture conservation and weed control benefits for the succeeding maize crop mainly because of poor residue persistence, and low harvestable fallow rainfall. Buckwheat (Fagopyrum esculentum), was selected for further investigations in a follow up trial on station in 2008/09 season because of its weed smothering qualities, suitability to short cycle rotations, and possible allelopathic properties. The trial aimed at finding weed and cost effective management options of buckwheat that are none detrimental to the succeeding maize crop. Results showed that cropping systems where buckwheat is followed by a main crop may not work as they are unprofitable with respect to R100 rand invested. Though perceived to have allelopathic properties, buckwheat failed to demonstrate the possibilities of allelopathic action against weeds. Intercropping trial was conducted on-station in 2007/8-2008/09 seasons to try and find better ways of fitting legume cover crops into maize based cropping systems without compromising production of staple cereals on limited landholdings. The trials evaluated three factors in factorial combination, cover crop planting date, intercropping strategy, and cover crop species. The trial was laid as 2 x 2 x 3 factorial arranged in a split-split plot design. The main plot factor was cover crop planting date, cover crops simultaneously planted with maize and cover crop planted two weeks after planting maize (DKC 61-25). The sub-plot factor was intercropping strategy, strip intercropping and betweenrow intercropping. The sub-sub-plot factor was cover crop species, Dolichos lablab (Dolichos argenteus (Highworth), and Cowpea Vigna ungiculata (Agrinawa) plus control plots of sole maize. Results showed that same time planting of leguminous cover crops with maize using the in-between row intercropping patterns can derive appreciable system biomass (maize/cover crop) yields, utilize land efficiently whilst getting favourable maize grain yield. Based on the rainfall analysis, results showed that the probability of success when relay seeding cover crops after two weeks into standing maize is low (15% chances of success). This suggests that relay intercropping strategies would not work due to the unavailability of a good quality season.

Thesis (PhD(Agric))--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The energy paradigm shift from fossil fuels to renewable energy sources is driven, among others, by a growing sustainability awareness, necessitating more sophisticated measurements in terms of a wider range of criteria. Technical efficiency, financial profitability, environmental friendliness and social acceptance are some of the factors determining the sustainability of renewable energy systems. The resulting complexity and conflicting decision criteria, however, constitute major barriers to processing the information and decision-making based on the information. Seeking to implement local bioenergy systems, policymakers of the Cape Winelands District Municipality (CWDM), South Africa, are confronted with such a problem. Following a case study approach, this study illustrates how life-cycle assessment (LCA), multi-period budgeting (MPB) and geographic information systems (GIS) can aid the decision-making process by providing financial-economic, socio-economic and environmental friendliness performance data in a structured and transparent manner, allowing for a comparison of the magnitude of each considered criterion along the life-cycle. However, as the environmental impacts cannot readily be expressed in monetary terms on a cardinal scale, these considerations are given less attention or are omitted completely in a market economy. By measuring the various considerations on an ordinal scale and by attaching weights to them using the multi-criteria decision analysis (MCDA) approach, this study, illustrates how to internalise externalities as typical market failures, aiding policymakers of the CWDM to choose the most sustainable bioenergy system. Following the LCA approach, 37 lignocellulosic bioenergy systems, encompassing different combinations of type of harvesting and primary transport, type of pretreatment (comminution, drying, and fast pyrolysis) and location thereof (roadside or landing of the central conversion plant), type of secondary transport from the roadside to the central conversion plant, and type of biomass upgrading and conversion into electricity, were assessed against five financial-economic viability criteria, three socio-economic potential criteria and five environmental impact criteria. The quantitative performance data were then, as part of the MCDA process, translated into a standardised ‘common language’ of relative performance. An expert group attached weights to the considered criteria using the analytical hierarchy process (AHP). The ‘financial-economic viability’ main criterion received a weight of almost 60%, ‘socio-economic potential’, nearly 25% and ‘lowest environmental impact’, the remainder of around 16%. Taking the prerequisite of financial-economic viability into consideration, the preferred option across all areas of the CWDM (despite various levels of productivity) comprises a feller-buncher for harvesting, a forwarder for primary transportation, mobile comminution at the roadside, secondary transport in truck-container-trailer combinations and an integrated gasification system for the conversion into electricity.
AFRIKAANSE OPSOMMING: Die energie paradigma verandering van fossielbrandstowwe na hernubare energiebronne word gedryf deur ‘n groeiende klem op volhoubaarheid, wat ook meer gesofistikeerde meting in terme van ‘n wyer verskeidenheid maatstawwe vereis. Tegniese doeltreffendheid, finansiële winsgewendheid, omgewingsvriendelikheid en sosiale aanvaarbaarheid is sommige van die faktore wat die volhoubaarheid van hernubare energie stelsels bepaal. Die verskeidenheid oorwegings bring egter kompleksiteit en konflik mee by die verwerking van inligting en die besluitneming wat daarop berus. Beleidmakers van die Kaapse Wynland Distriksmunisipaliteit wat ten doel het om plaaslik bio-energie stelsels te implementeer, word met hierdie probleem gekonfronteer. Hierdie ondersoek illustreer aan die hand van ‘n gevallestudie benadering hoe lewensiklus analise, multiperiode begroting en geografiese inligtingstelsels besluitneming kan ondersteun deur die voorsiening van finansieel-ekonomiese, sosio-ekonomiese (indiensneming) en omgewingsvriendelikheid prestasie data op ‘n gestruktureerde en deursigtige wyse. Dit maak die vergelyking van die waardes van al die kriteria by elke fase van die lewensiklus moontlik. Aangesien die omgewingseffekte nie geredelik in monetêre terme op ‘n kardinale skaal gemeet kan word nie, kry hulle binne die markekonomie minder aandag of word selfs buite rekening gelaat. Deur hierdie verskeidenheid kriteria op ‘n ordinale skaal te meet en gewigte met behulp van multikriteria besluitneming aan hulle toe te ken, toon hierdie ondersoek hoe om eksternaliteite as tipiese markmislukkings te internaliseer om beleidmakers van die Kaapse Wynland Distriksmunisipaliteit in staat te stel om die mees volhoubare bio-energie stelsel te kies. Met behulp van lewensiklus analise is 37 lignosellulose bio-energie stelsels geïdentifiseer as verskillende kombinasies van oes van die bome, primêre vervoer van houtstompe, vooraf verwerking (verspaandering, droging, vinnige pirolise), die ligging van hierdie aktiwiteite (langs ‘n plantasie of by ‘n sentrale omsettingsaanleg), tipe sekondêre vervoer van houtspaanders vanaf die plantasie na die sentrale omsettingsaanleg en tipe biomassa opgradering en omsetting van die houtspaanders na elektrisiteit. Die verskillende stelsels is gemeet aan die hand van vyf finansieel-ekonomiese kriteria, drie indiensneming potensiaal kriteria en vyf omgewingsimpak kriteria. Die kwantitatiewe metings is deur middel van multikriteria besluitneming omgeskakel na ’n gestandaardiseerde “gemeenskaplike taal” van relatiewe prestasie. Lede van ‘n ekspertgroep het gewigte is aan die onderskeie kriteria met behulp van die analitiese hierargie proses toegeken. Aan die finansieel-ekonomiese lewensvatbaarheid hoof kriterium is ‘n gewig van by die 60% toegeken, aan die indiensnemingspotensiaal bykans 25% en aan omgewingsvriendelikheid sowat 16%. Die voorkeur kombinasie vir al die areas van die Kaapse Wynland Distriksmunisipaliteit sluit in ‘n saag-bondelaar vir die oesproses, ‘n plantasie-vragmotor vir primêre vervoer, mobiele verspaandering langs die plantasie, ‘n vragmotor-skeepshouer-treiler kombinasies vir die sekondêre vervoer van houtspaanders en ‘n geïntegreerde vergassingstelsel vir die omsetting van houtspaanders na elektrisiteit.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The purpose of the study was to investigate the potential tree taxa that could be grown as a source of biomass in the Cape Winelands region. The trials comprises of two different aspects. The first being the estimation of potential volume, density and biomass of a pair of six year-old stands of E. gomphocephala and E. cladocalyx families at two climatically different sites within the study region. The second part of the study was the early growth assessment of alternative taxa that could be planted in the region compared to the regional mainstay E. cladocalyx. The volume of families was estimated using appropriate volume equations and using the form height were none were available. The best volume yield varied from 4.6 to 11.2 m3 ha-1a-1, at the dry and sub-humid sites, respectively. Wood density, estimated from non-destructive samples at both sites, varied from 620 (sub-humid) to 588 kg m-3 (dry site). The estimated biomass production rate of the top producing families yielded 2.7 and 6.9 t ha -1a -1 at the dry and sub-humid sites, respectively. In terms of estimated biomass and survival, E. gomphocephala was more suited to the dry site, while E. cladocalyx displayed superior yield than E. gomphocephala on the sub-humid site, but not significantly so. Early growth assessment of the trial of alternative taxa found that the hybrid E. grandis × camldulensis and E. grandis × urophylla had superior biomass indices, but were more susceptible to infestation by Thaumastocoris peregrinus and Gonipterus scuttelatus.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om potensiële boom taksa vir gebruik as ’n bron van biomassa in die Kaapse Wynlandstreek te ondersoek. Die proewe behels twee aspekte: eerstens die beraming van die potensiële volume, digtheid en biomassa van sesjaaroue opstande met families van E. gomphocephala en E. cladocalyx by twee klimatologies verskillende groeiplekke in die studiegebied; tweedens die beoordeling van die vroeë groei van alternatiewe taksa wat in die streek geplant kan word in vergelyking met die streek se historiese staatmaker-spesie E. cladocalyx. Die volume van die families is beraam deur gebruik te maak van toepaslike volumevergelykings, en met behulp van ’n vormfaktor waar vergelykings nie beskikbaar was nie. Die volume aanwas by die droë en sub-humiede groeiplekke was onderskeidelik 4.6 en 11.2 m3 ha-1j-1. Houtdigtheid is beraam deur nie-destruktiewe monsters uit die opstand te neem. Gemiddelde digthede het variëer van 588 (sub-humied) tot 620 kg m-3 (droë groeiplek). Die beraamde biomassaproduksie van die top-families beloop onderskeidelik 2.7 en 6.9 t ha -1j -1 vir die droë en sub-humiede groeiplekke. In terme van beraamde biomassa en oorlewing, is E. gomphocephala meer geskik vir droër groeiplekke , terwyl E. cladocalyx by die sub-humiede groeiplek ’n hoër opbrengs as E. gomphocephala getoon het, hoewel nie betekenisvol nie. Beramings van die vroeë groei by die proef met alternatiewe taksa het getoon dat die basters E. grandis × camldulensis en E. grandis × urophylla hoër biomassa-indekse het, maar meer vatbaar is vir besmetting deur Thaumastocoris peregrinus en Gonipterus scuttelatus.
Centre for Renewable and Sustainable Energy Studies

Thesis (MScEng)-- Stellenbosch University, 2013.
ENGLISH ABSTRACT: Climate change that results from greenhouse gases (GHG’s) released from the burning of fossil fuels, together with the rising price of oil, have sparked interest in renewable biofuels. The production of biofuels also presents potential socio-economic benefits. There are two types of technologies for bioethanol production: · First generation bioethanol is produced from food feedstocks such as juice of sugarcane. · Second generation bioethanol is produced from non-food feedstocks (lignocellulosic materials). This project is concerned with 1st and 2nd generation bioethanol production from sugarcane juice and bagasse and the integration of these technologies. This project comprises a combination of experimental and process modelling work to assess energy efficiencies and the economic viability of integrated and stand-alone processes in the sub-Saharan African context. First generation fermentation experiments were conducted and high ethanol concentrations of up to 113.7 g/L were obtained. It was concluded that a recombinant yeast strain may be able to replace a natural hexose fermenting yeast for 1st generation fermentations to reduce costs. 2nd generation fermentation experiments were performed and ethanol concentrations of close to 40 g/L were obtained. Combinations of 1st and 2nd generation fermentation experiments were performed to improve the 2nd generation fermentation. In one of the experiments it was concluded that the combination of 1st and 2nd generation fermentations significantly improved the 2nd generation fermentation with an overall ethanol concentration of 57.6 g/L in a shorter time than for the pure 2nd generation experiments. It was determined from washing and pressing experiments that pressing the pre-hydrolysate liquor out of the pre-treated bagasse will sufficiently lower the levels of inhibitors in a 2nd generation fermentation when using a hardened yeast. Some of the data from the 1st generation experiments were used along with literature data to model a first generation process in Aspen Plus® which processes 493 tons of cane per hour (tc/hr). Pinch heat integration was used to reduce the utility requirements. The process used the bagasse that was generated to co-produce steam and electricity. The excess electricity was sold for additional revenue. In one scenario the excess bagasse was determined at 57.5%. This bagasse was sold to a stand-alone 2nd generation plant. The first generation process produced 85.5 litres of ethanol per ton of cane (L/tc), the integrated process produced 128 L/tc while the stand-alone 2nd generation process produced 185 litres of ethanol per ton of bagasse (50% moisture) or 25.5 L/tc. The amount of excess electricity that was produced ranged from 14.3 to 70.2 kWh/tc. Economic analyses were performed using South African economic parameters to resemble the sub- Saharan African context. Data from the 1st generation process model and literature data for integrated 1st and 2nd generation and stand-alone 2nd generation processes were used for the analyses. It was found that the integrated plant is the most economically viable (IRR = 11.66%) while the 1st generation process basically broke even (IRR = 1.62%) and the 2nd generation process is unviable. This was as a result of high sugarcane prices and too few incentives for 2nd generation ethanol.
AFRIKAANSE OPSOMMING: Klimaatsverandering wat veroorsaak word deur kweekhuisgasse wat vrygestel word deur die verbranding van fossielbrandstowwe en die stygenede olieprys het belangstelling in hernubare biobrandstowwe laat opvlam. Die produksie van biobrandstowwe hou ook potensiële sosioekonomiese voordele in. Daar is twee tegnologieë vir bioetanol produksie: · Eerste generasie bioetanol word vanaf voedsel bronne soos suikersap geproduseer. · Tweede generasie bioetanol word van nie-voedsel bronne (lignosellulose materiaal) geproduseer. Hierdie projek handel oor 1ste en 2de generasie bioetanol produksie van suikersap en suikerriet bagasse en die integrasie van hierdie tegnologieë. Hierdie projek bestaan uit ‘n kombinasie van eksperimentele- en prosesmodellering werk om die energiedoeltreffendheid en ekonomise vatbaarheid van geïntegreerde en alleenstaande prosesse in die sub-Sahara konteks te ondersoek. Eerste generasie fermentasie eksperimente is uitgevoer en hoë etanol konsentrasies van tot 113.7 g/L is gekry. Dit was bepaal dat ‘n rekombinante gisras ‘n natuurilke heksose fermenterende gisras kan vervang vir 1ste generasie fermentasies om kostes te bespaar. 2de generasie fermentasie eksperimente is gedoen en etanol konsentrasies van amper 40 g/L is behaal. Kombinasies van 1ste en 2de generasie fermentasie-eksperimente was uitgevoer om die 2de generasie fermentasie te verbeter. In een van die eksperimente is dit bepaal dat die kombinasie van 1ste en 2de generasie fermentasie die 2de generasie fermentasie beduidend verbeter het met ‘n etanol konsentrasie van 57.6 g/L en dít in ‘n korter tyd as vir die suiwer 2de generasie eksperimente. Dit was bepaal vanuit pers- en was eksperimente dat om die pre-hidrolisaat vloeistof uit die stoombehandelde bagasse te pers, die vlak van inhibitore in ‘n 2de generasie fermentasie voldoende verlaag vir die gebruik van ‘n verharde gis. Van die data van die 1ste generasie eksperimente was saam met literatuurdata gebruik om ‘n 1ste generasie proses in Aspen Plus® te modelleer wat 493 ton suikerriet per uur prosesseer (tc/hr). Pinch hitte integrasie was gebruik om die dienste vereistes te verminder. In die proses word die bagasse gebruik om stoom en elektrisiteit te genereer. In een geval was die oortillge bagasse bepaal as 57.5%. Hierdie bagasse was verkoop aan ‘n alleenstaande 2de generasie aanleg. Die eerste generasie proses het 85.5 liter etanol per ton suikerriet geproduseer (L/tc), die geïntegreerde proses het 128 L/tc geproduseer terwyl die 2de generasie proses 185 liter etanol etanol per ton bagasse (50% vog) of 25.5 L/tc geproduseer het. Die hoeveelhede oortillige elektrisiteit wat geproduseer is wissel van 14.3 tot 70.2 kWh/tc. Ekonomiese analieses is gedoen met Suid-Afrikaanse ekonomiese parameters om die sub-Sahara Afrika-konteks uit te beeld. Data van die 1ste generasie prosesmodel en literatuurdata van geïntegreerde 1ste en 2de generasie en alleenstaande 2de generasie prosesse was vir die analieses gebruik. Dit is bepaal dat die geïntegreerde model die mees ekonomies vatbare model is (IRR = 11.66%) terwyl die 1ste generasie proses basies gelyk gebreek het (IRR = 1.62%) en die 2de generasie proses is ekonomies onvatbaar. Hierdie bevindinge is as gevolg van hoë suikerrietpryse en te min aansporings vir 2de generasie etanol.

Thesis (MEng)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: The complexity of adopting a new crop-based biodiesel feedstock into South Africa given the prevailing environmental, economic and social concerns facing the country are addressed in this study by utilising a Systems Thinking approach. Solaris is a new variety of Tobacco developed specifically as an energy crop over the last twelve years by Italian companies Plantechno and Sunchem. Small-scale trials have been underway over the last year in the Loskop Valley farming community in the Limpopo Province of South Africa. These trials have been managed by the newly-formed local entity, Toboil (Pty) Ltd. In order to assess the viability of introducing Solaris into Loskop in terms of addressing the current diesel and electricity needs of the community and larger over-arching biofuel goals of South Africa, the full System Dynamic Modelling process was employed. This included significant research, stakeholder engagement, a Systems Thinking workshop as well as model development and simulation using the System Dynamics programming tool, Vensim. Following the simulation of various scenarios, it was determined that in order for Solaris implementation to have the greatest impact on the diesel and electricity independence desires of the community, as well as maximising job creation and avoided greenhouse gas emissions, the first five to ten years of implementation may only achieve low to moderate profitability. It was further concluded that if crop-based biofuels are to help meet the rural development goals of South Africa then significant investment and skills transfer is required. In order to address both of these, a modular development process is advocated and should be aided and mentored by members of the commercial farming industry.
AFRIKAANSE OPSOMMING: Die kompleksiteit van die aanvaarding van ‘n nuwe oes-gebaseerde bio diesel roumateriaal in Suid-Afrika in die heersende omgewings-, ekonomiese- en sosiale kommer wat die land ervaar, word in hierdie studie aangespreek deur gebruik te maak van ‘n Sistemiese Denke Benadering (Systems Thinking approach) Solaris is ‘n nuwe variasie Tabak wat deur twee Italiaanse maatskappye Plantechno en Sunchem oor die afgelope twaalf jaar spesifiek as ‘n bron van energie ontwikkel is. Kleinskaalse proewe is gedurende die afgelope jaar in die Loskop Vallei Landbougemeenskap in die Limpopo-provinsie van Suid-Afrika gedoen. Hierdie proewe word onder die toesig van die nuut gevormde plaaslike entiteit, Toboil (Pty) Ltd uitgevoer. Aansienlike navorsing, die aktiewe deelname van die onderskeie belanghebbende partye, ‘n Sistemiese Denke werkswinkel sowel as die ontwerp van ‘n simulasie model deur die gebruik van Sisteem Dinamieke Programerings program, naamlik Vensim, is ingespan om die lewensvatbaarheid van die moontlike aanplanting van Solaris te beoordeel. Die spesifieke gemeenskap se huidige behoeftes aan diesel en elektrisiteit sowel as Suid-Afrika se breër doelwitte aangaande bio-brandstowwe was as die grondslag gebruik waarop die volle Sistemiese Denke Benadering toegepas is. In Loskop omgewing was verskeie moontlike scenarios beproef en daar is op grond daarvan vasgestel dat ten einde die grootste moontlike inpak te maak op die afhanlikheid van diesel en elektrisiteit behoeftes van die gemeenskap, sowel as om die grootste moontlik werkskepping potensiaal te verwesenlik – terwyl die afskeiding van kweekhuis gasse verhoed word - die eerste vyf tot tien jaar van implementering baie lae winsgrens tot gevolg sal hê. Daar is ook verder afgelei dat afsienbare beleggings en opleiding benodig gaan word indien aangeplante bio-brandstowwe aangewend sou word om die landelike ontwikkelingsdoelwitte in Suid-Afrika te verwesenlik. Ten einde beide hierdie doelwitte aan te spreek, word ‘n modulêre ontwikkelings proses aanbeveel waar gevestigde lede van die kommersiële lanbou industrie, bystand en leierskap voorsien.

Thesis (MScEng)--Stellenbosch University, 2012
ENGLISH ABSTRACT: Through many years of research, a number of production schemes have been developed for converting lignocellulosic biomass into transport fuels. These technologies have been assessed through a number of techno-economic studies for application in a particular context in terms of the technical and economic feasibility. However, previous studies using these methods have tended to lack vigour in various aspects. Either the energy efficiency of the processes were not maximised through adequate heat integration, or a competing technology which existed was not considered. From an economic perspective, the financial models would often lack the vigour to account for the risk and uncertainty that is inherent in the market prices of the commodities. This phenomenon is especially relevant for the biofuel industry that faces the full fledge of uncertainties experienced by the agricultural sector and the energy sector. Furthermore, from an environmental perspective, the techno-economic studies had often ignored the environmental impacts that are associated with biofuel production. Thus, a comparative study could have favoured an option due to its economic feasibility, while it could have had serious environmental consequences. The aim of this study was to address these issues in a South African context, where biofuels could be produced from sugarcane bagasse. The first step would be to modify an existing simulation model for a bioethanol scenario that operates with a Separate Hydrolysis and Fermentation (SHF process) configuration into a second processing scenario that operates with a Simultaneous Saccharification and Fermentation (SSF process) configuration using reliable experimental data. The second step was to ensure that the maximum energy efficiency of each scenario was realised by carrying out pinch point analysis as a heat integration step. In contrast to these biological models is the thermochemical model that converts bagasse to gasoline and diesel via gasification, Fischer-Tropsch synthesis and refining (GFT process). While there were no significant advances in technology concerning this type of process, the energy efficiency was to be maximised with pinch point analysis. The GFT process obtained the highest energy efficiency of 50.6%. Without the affects of pinch point technology, the efficiency dropped to 46%, which thus emphasises the importance of heat integration. The SSF had an efficiency of 42.8%, which was superior to that of the SHF at 39.3%. This resulted from a higher conversion of biomass to ethanol in the SSF scenario. Comparing the SHF model to an identical model found in literature that did not have pinch point retrofits, this study showed lower efficiency. This arose because the previous study did not account for the energy demands of the cold utility systems such as the cooling tower operation, which has been shown in this study to account for 40% of the electrical energy needs. The economic viability of all three processes was assessed with Monte Carlo Simulations to account for the risks that the fluctuations in commodity prices and financial indices pose. This was accomplished by projecting the fluctuations of these parameters from samples of a historical database that has been transformed into a probability distribution function. The consequences were measured in terms of the Net Present Value (NPV) and Internal Rate of Return (IRR) for a large number of simulations. The results of these variables were aggregated and were then assessed by testing the probability that the NPV<0, and that the IRR recedes below the interest rate of 12.64%. The investment was thus deemed unfeasible if these probabilities were greater than 20%. Both biological models were deemed profitable in terms of this standard. The probabilities were 13% for the SSF and 14% for the SHF. The GFT process however was deemed completely unfeasible because the probability that the NPV<0 was 78%. Given that the GFT process had the highest energy efficiency, this result arises mainly because the capital investment of 140,000USD/MWHHV of biomass energy input is to enormous for any payback to be expected. The environmental footprint of each process was measured using Life Cycle Assessments (LCAs). LCAs are a scientifically intricate way of quantifying and qualifying the effects of a product or process within a specified boundary. The impacts are assessed on a range of environmental issues, such as Global Warming, Acidification, Eutrophication and Human toxicity. Furthermore, if the project under concern has multiple output products, then the impacts are distributed between the output products in proportion to the revenue that each generates. The impacts were either relative to the flow of feedstock, which was 600MW of bagasse, or to the functional unit, which was the amount of fuel required to power a standard vehicle for a distance of 1 kilometre. In either case, the GFT scenario was the least burdening on the environmental. This was expected because the GFT process had the highest energy efficiency and the process itself lacked the use of processing chemicals. Relative to the feedstock flow, the SSF was the most environmentally burdening scenario due to the intensive use of processing chemicals. Relative to the functional unit, the SHF was the most severe due to its low energy efficiency. Thus, the following conclusions were drawn from the study:  The GFT is the most energy and environmentally efficient process, but it showed no sign of economic feasibility. iv  There is no significant difference in the economic and environmental evaluation of the SSF and SHF process, even though the SSF is considered to be a newer and more efficient process. The major cause of this is because the setup of the SSF model was not optimised.
AFRIKAANSE OPSOMMING: Deur baie jare van navorsing is ‘n aantal produksie-skemas vir die omskakeling van lignosellulose biomassa na vloeibarebrandstof ontwikkel. Hierdie tegnologië is geassesseer ten opsigte van die tegniese en ekonomiese haalbaarheid deur middel van tegno-ekonomiese studies in bepaalde tekste. Tog het hierdie vorige studies besliste beperkings gehad. Of die energie-doeltreffendheid van die proses is nie gemaksimeer deur voldoende hitte-integrasie nie, of 'n mededingende tegnologie wat bestaan is nie oorweeg nie. Vanuit 'n ekonomiese perspektief, was die finansiële modelle dikwels nie die omvattend genoeg om rekening te hou met die risiko en onsekerheid wat inherent is in die markpryse van die kommoditeite nie. Hierdie verskynsel is veral relevant vir die biobrandstof bedryf wat die volle omvang van onsekerhede ervaar waaraan die landbousektor en die energiesektoronderhewig is. Verder het die tegno-ekonomiese studies dikwels die omgewingsimpakte wat verband hou met biobrandstofproduksie geïgnoreer. Dus kon ‘n opsie deur die ekonomiese haalbaarheid bevoordeel word, ten spyte van die ernstige omgewingsimpakte wat dit kon inhou. Die doel van hierdie studie was om hierdie kwessies aan te spreek in 'n Suid-Afrikaanse konteks, waar biobrandstof uit suikerriet bagasse geproduseer kan word. Die eerste stap was om 'n bestaande simulasiemodel vir 'n bio-scenario wat met Afsonderlike Hidroliese en Fermentasie (SHF proses) stappe werk, te modifiseer vir 'n tweede verwerking scenario wat met 'n gelyktydige Versuikering en Fermentasie (SSF proses) konfigurasie werk. Die verandering is gedoen deur die gebruik van betroubare eksperimentele data. Die tweede stap was om te verseker dat elke scenario die maksimum energie-doeltreffendheid het, deur 'n hitte-integrasie stap, wat gebruik maak van “pinch-point” analise. In teenstelling met hierdie biologiese modelle, is daar die thermochemiese roete waar petrol en diesel van bagasse vervaardig word via vergassing, Fischer-Tropsch-sintese en rafinering (GFT proses). Daar was geen betekenisvolle vooruitgang in tegnologie vir hierdie proses nie, maar die energie-doeltreffendheid is gemaksimeer word deur energie-integrasie. Die GFT proses toon die hoogste energie-doeltreffendheid van 50,6%. Sonder die invloed van energie-integrasie het die doeltreffendheid gedaal tot 46%, wat dus die belangrikheid van hitte-integrasie beklemtoon. Die SSF het 'n effektiwiteit van 42,8% gehad, wat beter was as dié 39,3% van die SHF opsie. Hierdie hoër effektiwiteit wasas gevolg van die hoër omskakeling van biomassa na etanol in die SSF scenario. Die energie doeltreffendheid vir die SHF-model was laer as met 'n identiese model (sonder energie-integrasie) wat in die literatuur gevind wat is. Dit het ontstaan omdat die vorige studie nie 'n volledig voorsiening gemaak het met die energie-eise van die verkillingstelselsnie, wat tot 40% van die elektriese energie behoeftes kan uitmaak. Die ekonomiese lewensvatbaarheid van al drie prosesse is bepaal met Monte Carlo simulasies om die risiko's wat die fluktuasies in kommoditeitspryse en finansiële indekse inhou, in berekening te bring. Hierdie is bereik deur die projeksie van die fluktuasies van hierdie parameters aan die hand van 'n historiese databasis wat omskep is in 'n waarskynlikheid verspreiding funksie. Die gevolge is gemeet in terme van die netto huidige waarde (NHW) en Interne Opbrengskoers (IOK) vir 'n groot aantal simulasies. Die resultate van hierdie veranderlikes is saamgevoeg en daarna, deur die toets van die waarskynlikheid dat die NPV <0, en dat die IRR laer as die rentekoers van 12,64% daal, beoordeel. Die belegging is dus nie realiseerbaar geag as die waarskynlikhede meer as 20% was nie. Beide biologieseprosesse kan as winsgewend beskou word in terme van bostaande norme. Die waarskynlikhede was 13% vir die SSF en 14% vir die SHF. Aangesien die NHW van die GFT-proses onder 0 met ‘n waarskynlikheid van 78% is, is die opsie as nie-winsgewend beskou. Gegewe dat die GFT-proses die hoogste energie-doeltreffendheid het, is die resultaat hoofsaaklik omdat die kapitale belegging van 140,000 USD / MWHHV-biomassa energie-inset te groot is, om enige terugbetaling te verwag. Die omgewingsvoetspoor van elke proses is bepaal deur die gebruik van Lewens Siklus Analises (“Life Cycle Assessments”) (LCAS). LCAS is 'n wetenskaplike metodeom die effek van ‘n produk of proses binne bepaalde grense beide kwalitatief en kwantitatief te bepaal. Die impakte word beoordeel vir 'n verskeidenheid van omgewingskwessies, soos aardverwarming, versuring, eutrofikasie en menslike toksisiteit. Voorts, indien die projek onder die saak verskeie afvoer produkte het, word die impakte tussen die afvoer produkte verdeel, in verhouding tot die inkomste wat elkeen genereer. Die impak was met of relatief tot die vloei van roumateriaal (600MW van bagasse), of tot die funksionele eenheid, wat die hoeveelheid van brandstof is om 'n standaard voertuig aan te dryf oor 'n afstand van 1 kilometer. In al die gevalle het die GFT scenario die laagste belading op die omgewing geplaas. Hierdie is te verwagte omdat die GFT proses die hoogste energie-doeltreffendheid het en die proses self nie enige addisionele chemikalieë vereis nie. Relatief tot die roumateriaal vloei, het die SSF die grootse belading op die omgewing geplaas as gevolg van die intensiewe gebruik van verwerkte chemikalieë. Relatief tot die funksionele eenheid, was die SHF die swakste as gevolg van sy lae energie-doeltreffendheid.

M.Phil.
The aim of this study is to achieve a greater output by scrutinizing the present way of coordinating the efforts Qf Steam Industries in South Africa to achieve a sustainable industrial development by using energy source efficiently and effectively. Furthermore into the study we look at obstacles that prevents and those that leads to maximum utilization of energy management measures, and also highlights the effects of implementing cheap available energy source in South Africa...

Interest in the biofuels industry in South Africa is driven largely by high oil prices and a strain on energy resources and logistics. This report considers the development of the biofuels industry in its infancy in South Africa and the factors that need to be taken into account by the potential entrants into the market. It also considers the factors which will continue to affect the sustainability of the biofuels industry.A total of fifteen experts across the biofuels value chain as well as stakeholders, who are considered experts in their field, were approached directly to provide input into this research. Further information was gathered from three focus groups involving thirty five people, all of whom are involved in the evolving biofuels sector.The research has shown that out of a number of production factors and consumption factors identified, there a few key factors that can be seen to be largely influencing the further development of the biofuels industry. Similarly a few key factors which will influence the sustainability of the biofuels industry have been identified.
Dissertation (MBA)--University of Pretoria, 2010.
Gordon Institute of Business Science (GIBS)
unrestricted

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering, October 2017
The dwindling fossil reserves coupled with environmental pollution necessitate the search for clean and sustainable energy resources. Biohydrogen is emerging as a suitable alternative to fossil fuels and has received considerable attention in recent years due to its economic, social, and environmental benefits. However, the industrial application of biohydrogen has been hindered by low yield. Therefore, development of novel techniques to enhance the yield is of immense importance towards large-scale production of biohydrogen. Thus, this research effort explored various options to enhance the yield of biohydrogen during dark fermentation process. Some options explored included (i) the utilization of feedstocks from the agricultural, industrial and municipal sectors, (ii) parametric optimization of biohydrogen production, (iii) investigation of biohydrogen production using metal ions and nitrogen gas sparging, and (iv) assessing the feasibility of biohydrogen scale-up study to pave the way for pilot-scale development. Solid biowaste feedstocks consisting of apple, bread, brewery residue, cabbage, corn-cob, mango, mealie-pap, pear, potato, and sugarcane were investigated for dark fermentative biohydrogen production using anaerobic mixed sludge. The experimental results showed that substrates which are rich in carbohydrates are suitable for dark fermentative biohydrogen-producing bacteria. Consequently, a maximum biohydrogen fraction of 43.98, 40.32 and 38.12% with a corresponding cumulative biohydrogen yield of 278.36, 238.32 and 215.69 mL H2/g total volatile solids (TVS) was obtained using potato, cabbage, and brewery wastes, respectively. Based on these results, potato waste was chosen as a suitable substrate for subsequent biohydrogen production studies. Parametric optimization was carried out on biohydrogen production via dark fermentation using potato waste as the substrate. Effects of operating variables such as pH, temperature, fermentation time, and substrate concentration were investigated via response surface methodology (RSM) approach using a two-level-four factor (24) central composite design (CCD). The obtained predictive model (statistical model) was used to explain the main and interaction effects of the considered variables on biohydrogen production. In addition, the model was employed in the optimization of the operating conditions. Consequently, a secondorder polynomial regression with a coefficient of determination (R2) of 0.99 was obtained and used in the explanation and optimization of operating variables. The optimum operating conditions for biohydrogen production were 39.56 g/L, 5.56, 37.87 oC and 82.58 h for potato waste concentration, pH, temperature and fermentation time, respectively, with a corresponding biohydrogen yield of 68.54 mL H2/g TVS. These results were then validated experimentally and a high biohydrogen yield of 79.43 mL H2/g TVS indicating a 15.9% increase was obtained. Furthermore, the optimized fermentation conditions were applied in the scale-up study of biohydrogen production that employed anaerobic mixed bacteria (sludge) which was immobilized in calcium alginate beads. A biohydrogen fraction of 56.38% with a concomitant yield of 298.11 mL H2/g TVS was achieved from the scale-up study. The research also investigated the influence of metal ions (Fe2+, Ca2+, Mg2+ and Ni2+) on biohydrogen production from suspended and immobilized cells of anaerobic mixed sludge using the established optimal operating conditions. A maximum biohydrogen fraction of 45.21% and a corresponding yield of 292.8 mL H2/g TVS was achieved in fermentation using Fe2+ (1000 mg/L) and immobilized cells. The yield was 1.3 times higher than that of suspended cultures. The effect of nitrogen gas sparging on biohydrogen conversion efficiency (via suspended and immobilized cells) was studied as well. Cell immobilization and nitrogen gas sparging were effective for biohydrogen production enhancement. A maximum biohydrogen fraction of 56.98% corresponding to a biohydrogen yield of 294.83 mL H2/g TVS was obtained in a batch process using nitrogen gas sparging with immobilized cultures. The yield was 1.8 and 2.5 times higher than that of nitrogen gas sparged and non-sparged suspended cell system, respectively. Understanding the functional role of microorganisms that actively participate in dark fermentation process could provide in-depth information for the metabolic enhancement of biohydrogen-producing pathways. Therefore, the microbial composition in the fermentation medium of the optimal substrate (potato waste) was examined using PCR-based 16S rRNA approach. Microbial inventory analysis confirmed the presence of Clostridium species which are the dominant biohydrogen-producing bacteria. The results obtained from this research demonstrated the potential of producing biohydrogen using South African solid biowaste effluents. These feedstocks are advantageous in biohydrogen production because they are highly accessible, rich in nutritional content, and cause huge environmental concerns. Furthermore, optimization techniques using these feedstocks will play a pivotal role towards large-scale production of biohydrogen by increasing throughput and reducing the substrate costs which accounts for approximately 60% of the overall costs. The findings from this research also provide a solid basis for further scale-up and techno-economic studies. Such studies are necessary to evaluate the competitiveness of this technology with the traditional processes of hydrogen production. In summary, the findings from this research effort have been communicated to researchers in the area of biohydrogen process development in the form of peer-reviewed international scientific publications and conference proceedings, and could provide a platform for developing an economic biohydrogen scaled-up process.
CK2018

M. Tech. Civil Engineering
Rural communities in South Africa and Africa as a whole are faced with a problem of the lack of reliable, efficient, sustainable and affordable energy sources. This problem serves as a catalyst to the slow economic development of the rural communities. In order to eradicate the problem and expedite economic development, a need exists to expand energy supply from the national grid or introduce alternative clean, sustainable, environmentally friendly and affordable energy sources to rural areas. However, expanding the national grid would not be sustainable in the long term because 80% of the national grid energy in South Africa is generated from burning fossil fuels, which is neither environmentally friendly nor renewable. The aim of this study was to address the above challenge through scientific investigation of the feasibility of introducing biogas as an alternative source of energy in rural areas. The investigation was to establish a mix ratio of the three types of domestic animal waste namely cow dung, pig dung and chicken droppings, which would optimise biogas production. Biogas, which is a mixture of mainly methane and carbon dioxide gases would in turn be used for cooking. Therefore, the broad objective of the study was to optimise methane gas production through the anaerobic digestion of domestic animal waste.

M.A.
Although South Africa is a country endowed with abundant energy resources (fuels such as coal, uranium and gas), biomass is the prime source of energy for cooking and heating in the rural domestic sector. Fuelwood is the common biomass used, followed by crop residues and animal dung. This research examines the environmental and socio-economic impacts of biomass energy consumption in the Mbhokota village in the Northern Province. The research was conducted by means of a field survey. Data collection methods included administering questionnaires to those who are involved in fuelwood collection (mostly women), interviews with various interested groups and personal observation of the affected sites, and a review of literature relevant to this study. The use of biomass as a source of fuel has much wider implications for the social and biophysical environments. The excessive cutting of trees for fuel leads to a reduction in the diversity of plant species and destruction of habitat for wildlife. Loss of soil cover through the use of crop residues increases soil erosion and thus reduces the agricultural production. The use of biomass fuels gives rise to high levels of indoor air pollution which affects the health of people. As fuelwood supplies diminish, people must travel further and hence spend more time collecting wood. Greater time spent collecting wood means that less time is spent on food production and other household activities (farming, childcare, housekeeping, socialising and educating themselves). Other issues of concern include the high cost of purchasing wood from vendors and personal security in places where wood is collected. The above factors do not only entrench poverty, but also have dire implications for the rural economy. This study has shown that the present patterns of fuelwood collection inflict permanent damage on the environment, reducing its ability to provide further fuel in the future. The implication is that the supply of fuelwood can no longer be guaranteed in some parts of the study area, leading to the use of crop residues and animal dung. This report also highlights the recommendations and management measures (based on the results of the study) that can be used in mitigating the impacts of biomass energy use. These include the introduction of improved stoves, use of solar energy as an alternative energy source, empowerment of women, establishment of community based projects and integrating energy with rural development

Thesis submitted in fulfilment of the requirements for the degree of Master of Management in Finance & Investment in the Faculty of Commerce Law and Management Wits Business School, Johannesburg 2016
This thesis reviewed research papers, reports, conference documents and policy documents that looked at financial models used to finance RE projects in Brazil, China, India and South Africa.The comparison between the financing models revealed the following; Both Brazil and China’s financing model is a centralised government led model which might not necessarily work in the South African context. The India decentralised model is similar to the South African model, with the exception that corporate finance is widely used in India and Project Finance in South Africa. Thus there are lessons to be learnt from each country, however no single country financing model was found to be suitable for South Africa. Accordingly, this paper therefore recommends that South Africa’s model be altered to incorporate project bonds. The use of these bonds in the current financial model will ensure that banks are able to lend to projects on short term basis; thus, managing their liquidity and their asset--liability effectively. Further, some institutional investors have shown an interest in funding projects at the construction stage, and the inclusion of project bonds would ensure that more of these investors play a role in financing projects. Key Words GDP-Gross Domestic Product; GW- Gigawatts; DoE-Department of Energy; REIPPPP- Renewable Energy Independent Power Producer Procurement Programme; BEE-Black Economic Empowerment; RE-Renewable Energy; SSA-Sub Saharan Africa; PPA-Power Purchase Agreement; FIT-Feed In Tariff; DFIDevelopment Finance Institution; MDB-Multilateral Development Bank
GR2018

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science 17th August 2015 in Johannesburg, South Africa
Ecosystem services provide a vital lifeline to millions of people living in rural areas. The poorest people in these areas depend upon the natural resource base in their surroundings to provide these services. With growing populations in rural areas of South Africa, the natural resource base is under considerable pressure; however, uncovering the dynamics of vegetation in these systems has proven difficult. While much attention has been given to savanna ecology, long term studies on the patterns and drivers of woody biomass are few. We used 65 years of aerial imagery (from 1944 to 2009) over 31 953 ha of rural savanna in a communal rangeland in South Africa to determine the abundance of woody canopy cover. This data were captured at hectare resolution, giving a fine enough level of detail for local level analysis. We also captured data for five potential drivers for change at this resolution, in order to analyse these drivers for their relative importance in determining woody canopy cover throughout the study period. Surprisingly, while individual sites showed varied trends in the amounts of woody canopy cover through time, when pooled across all sites the total woody canopy cover increased over the 65 year period. Disturbance gradients were found around some of the villages, but only in 2009, suggesting that the drivers of disturbance gradients in these systems may have only operated sufficiently to produce disturbance gradients in recent years. A hot spot analysis (hot spots indicate cells that have similarly high values beyond what would be expected in a random distribution, with cold spots indicating the inverse) revealed an increase in both hot and cold spots through time, but with a low persistence of both through time. High canopy cover cells are presumed to be the result of bush encroachment, while low canopy cover cells are presumed to be the result of harvesting of trees for fuelwood or clearing for fields. The low persistence of hot and cold spots points to a system in continual change, with patches of hot and cold spots appearing and disappearing, and therefore drivers of change operating in short periods of time. MAP (Mean Annual Precipitation), and not an anthropogenic driver, was found to be the most important driver for woody canopy cover throughout the study period, with MAP up to 670 mm having a predictable pattern of hot and cold spots through time. Higher MAP was shown to have a non-linear and unpredictable pattern of hot and cold spots through time, indicating that low precipitation may produce a system where woody canopy cover is less influenced by other drivers and is more stable when acted upon by other drivers. This research demonstrates the value of a long term dataset, and the applicability of our methods for monitoring woody canopy cover. As such, it may well serve as a baseline for woody canopy cover in communal savanna rangeland systems, with the methodology employed here suitable for an early warning detection system for sudden changes in the woody canopy cover.

Submitted in fulfillment of the requirements of the degree of Master of Applied Science in Biotechnology, Durban University of Technology, 2015.
In light of the world’s declining fossil fuel reserves, the use of microalgal biodiesel has come to the forefront as a potentially viable alternative liquid fuel. The depleting freshwater reserves make the feasibility of this concept questionable. The use of wastewater reduces the requirement for depleting freshwater supplies. This project aimed to determine the viability of municipal domestic wastewater effluent as a substrate for microalgal growth, in order to generate an economical and environmentally friendly source of biofuel. Wastewater effluents from three domestic wastewater treatment plants were characterized in terms of known microalgal nutrients viz., ammonia, phosphate and nitrates. Phosphate concentrations varied throughout the year and were found to be low (< 3 mgL-1) whilst ammonia and nitrate concentrations ranged from 0 to 10 mgL-1 throughout the experimental period. These wastewaters were found to be suitable for cultivating microalgae. The study explored the cultivation of Chlorella sorokiniana on pre- and post-chlorinated domestic wastewater effluent to assess their potential as a medium for high microalgal culture density and lipid production. Post-chlorinated wastewater effluent was found to be superior to pre-chlorinated wastewater effluent, as evident by the higher biomass concentration. This wastewater stream did not contain high concentrations of bacteria when compared to pre-chlorinated wastewater effluent. Nitrogen is an essential nutrient required for regulating the growth and lipid accumulation in microalgae. Cultures growing in post-chlorinated effluent had a lifespan of 18 d. Residual nitrogen in wastewater effluent supported microalgal growth for limited periods. Supplementation using cheap, readily available nitrogen sources was required for optimal biomass and lipid production. Urea, potassium nitrate, sodium nitrate and ammonium nitrate were evaluated in terms of biomass and lipid production of C. sorokiniana. Urea showed the highest biomass yield of 0.216 gL-1 and was selected for further experimentation. Urea concentrations (0–10 gL-1) were assessed for their effect on growth and microalgal physiology using pulse amplitude modulated fluorometry. A concentration of 1.5 gL-1 urea produced 0.218 gL-1 biomass and 61.52 % lipid by relative fluorescence. Physiological stress was evident by the decrease in relative Electron Transport Rate from 10.45 to 6.77 and quantum efficiency of photosystem II charge separation from 0.665 to 0.131. Gas chromatography analysis revealed that C16:0, C18:0, C18:1, C18:2 and C18:3 were the major fatty acids produced by C. sorokiniana. Wastewater effluent has been considered an important resource for economical and sustainable microalgal biomass/lipid production. The study showed that C. sorokiniana was sufficiently robust to be cultivated on wastewater effluent supplemented with urea. The results indicate that supplemented wastewater effluent was an acceptable alternative to conventional media. Using a relatively cheap nitrogen source like urea can certainly improve the techno-economics of large scale biodiesel production.

M.Sc.
Biofuels have the potential to reduce a country’s dependence on imported oil, to ensure diversity of energy sources, to increase the availability of renewable energy sources and to address global environmental issues. In recognition of the potential benefits of the production and use of biofuels, the Department of Minerals and Energy released the Draft Biofuels Industrial Strategy in December 2006 with the aim to increase the use of biofuels in South Africa to replace 4.5% of conventional transport fuels by 2013. However, there are several barriers that need to be overcome before South Africa can establish a large-scale biofuel industry to achieve the DME’s biofuel target. This includes environmental barriers, such as the availability of land for the cultivation of biofuel feedstocks and potential threats to food security. This study focuses on these environmental barriers and aims to determine the potential for bioethanol production from maize in South Africa to 2013. To this purpose, a bioethanol potential model is developed to simulate the potential for bioethanol production from maize in South Africa between 2008 and 2013. The model incorporates four key elements that all impact on the availability of maize for bioethanol production, namely: maize demand; maize supply; the demand for maize as biomaterial; and the available land area for the cultivation of maize. The study makes further use of the scenario planning method to determine the potential for bioethanol production from maize in South Africa. Four unique bioethanol potential scenarios are designed and simulated within the bioethanol potential model developed for this purpose. Each scenario plays out a differentstoryline for the future social, economic and natural environment that will impact on the availability of maize for bioethanol production. The results of the bioethanol potential scenario simulations show that South Africa will be able to produce enough maize to meet the DME’s biofuel target of 1.2 billion liters of bioethanol for all scenarios between 2009 and 2010. From 2011 onwards, the bioethanol potential decreases below the DME’s target value in both the worst case and rapid change scenarios. The study concludes that the production of bioethanol from maize in South Africa will have various social, economic and environmental consequences for the country’s agricultural sector. The depletion of domestic maize supplies will seriously threaten food security and consequently, increase the country’s dependence on maize imports. This will not only affect the country’s maize producing regions, but spread throughout South Africa as the demand for agriculturally productive land for maize production increases. Domestic food security is therefore at risk and South Africa will have to resort to other energy technologies to achieve a sustainable and renewable energy future for road transport.

thesis submitted in fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY (PhD) in the School of Law at the University of the Witwatersrand
Many countries are under pressure to transition from fossil to renewable sources of energy. This pressure comes from multiple points including sustainable energy and climate change imperatives. The energy industry, especially electricity generation, is the main source of greenhouse gases, hence the significance of reductions in this industry. The purpose of this study was to conduct a legal analysis of the renewable energy law in the context of energy law generally in South Africa, to understand the regulatory function of law in promoting renewable energy. The study analysed government legal and policy positions, and the response by non-state actors to such policy positions and laws. Through a qualitative analysis of primary and secondary sources of law and public participation documents, the study found that; while South Africa is committed to renewable energy, its socio-economic, cultural, and environmental context superimposes other priorities that impede progress towards renewable energy. Several obstacles to renewable energy were identified, some internal to energy law and others external to it, coming from other areas such as environmental law, governance, economics, and behavioural sciences. Analysis at the convergence of environmental and energy law revealed misalignment and fragmentation as major obstacles to renewable energy. While barriers are common across the globe, countries cannot apply the same responses with the same results. Regulatory responses, beyond the traditional ‘command and control’ tools are context specific and tools that have worked, in other countries, may not be as effective in South Africa. Socio-economic dynamics determine the legal responses to the barriers to renewable energy or the efficacy of economic incentives to promote renewable energy. However, overall, law and regulation can, and must, play a crucial enabling role by removing barriers to renewable energy. Nevertheless, there are limits to the use law ‘as regulation.’ Renewables will not replace fossil sources yet; rather in the long-term, renewables should become a big part of the energy mix. Despite gaining price competitiveness, it is too early for renewables to displace conventional fossil sources in a context of entrenched structural and institutional obstacles. Concomitant technical, market, economic, and environmental and resource governance interventions are necessary to effectively promote an energy mix substantially composed of renewables. The study recommends that law should create an enabling regulatory environment for renewable energy. South Africa has not used law effectively enough to create this environment, thereby impeding the integration of renewable energy into its energy mix. Aligning energy and environmental law, among other incentives, can enhance this role of law. Legal reforms are necessary to remove the regulatory advantage afforded to conventional sources of electricity and level the playing field.
MT2017