Masters Degrees (Industrial Engineering)

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Agriculture sector implications of a green economy transition in the Western Cape Province of South Africa : a system dynamics modelling approach to food crop production
(Stellenbosch : Stellenbosch University, 2015-12) Van Niekerk, Jacobus Bosman Smit; Brent, Alan C.; Musango, J. K.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: The Western Cape Province of South Africa has introduced a green economy plan called "Green is Smart". This initiative has the envisaged possibility of providing the Province with a sustainable economy. The transition towards a green economy will, however, have implications on the food crop production in the Province. Agriculture is a vital part of the Province's economy and a "systems thinking" approach is required to better understand how this transition will influence food crop production. The aim of this study is then to better understand systems thinking, identify different system modelling approaches, and to better understand how the Western Cape's agriculture acts as a complex system. By achieving this, the green economy transition can be better managed within the Province's food crop production. After reviewing the literature, system dynamics modelling was identified as the preferred modelling technique to better understand the implications of a green economy transition of the Western Cape's food crop production. The model simulates the production for ten different food crops from 2001 until 2040. Food crops are produced with a combination of different framing practices, namely conventional, organic and conservation farming. There are three different green economy scenarios (pessimistic, realistic and optimistic), and one scenario where current practices are continued (business as usual). The model results indicate that all three green economy scenarios will require significant financial investment. The results also indicate that only the optimistic green scenario might be worth the financial investment when considering the potential benefits. The study further provides recommendations for stakeholders in order to help this transition to a green economy within the Western Cape food crop sector. The study highlights the usefulness of using system dynamics to model and better comprehend complex systems. The limitations of system dynamics modelling are also discussed in this study. Difficulties with obtaining historical data and modelling sporadic events are the two most noteworthy limitations.
Biofuel implications of a green economy transition in the Western Cape Province of South Africa : a system dynamics modelling approach to biofuel
(Stellenbosch : Stellenbosch University, 2015-12) Jonker, Willem Daniel; Brent, Alan C.; Musango, J. K.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: This study investigates the implications of producing biofuel as part of a green economy transition in the Western Cape Province of South-Africa. Biofuel production was identified as a complex system and different methodologies were reviewed to find the most appropriate technique to analyse complex systems. Systemynamics was identified and used to build a model simulating the effects and potential of biofuel production within the Province, under certain project and policy onsiderations. The biofuel model was built with a generic structure that can simulate both bioethanol and biodiesel with different parameters. The model assumes a bioethanol plant, capable of producing 160 million litres per annum to be completed in 2018, using triticale as feedstock. A biodiesel plant with a capacity of 35 million litres per annum will also completed in 2018, using canola as production feedstock. Different scenarios regarding the energy use of biofuel production were simulated in order to evaluate the feasibility and identify the strategic intervention points, which could strengthen the business case of biofuel production. The national mandatory biofuel blending policy leads to alternative scenarios being simulated, in which the Western Cape Province is externally supplied with biofuel. Recommendations are made on the best approach to follow for the Province to form part of the blending policy, based on pre-determined indicators within the three pillars of sustainability, namely: the economy, environment and social considerations. From the model, it was deduced that feedstock availability and the high capital and operating costs are the major constraining factors in biofuel production. Recommendations are made to mitigate and improve the identified constraints. A feasible business case (operating without subsidy) was established for bioethanol production within the Province. Under the model assumptions for locally producing bioethanol (using biomass as energy source), an internal rate of return of 23% is estimated, while emissions are reduced by 63% when compared to using coal as the energy source. A medium-large scale biodiesel production facility was not feasible (subsidy of R4.30 per litre) as the adverse effects of emissions and employment creation does not justify the high costs involved. Alternative biodiesel solutions are then proposed, like encouraging the establishment of numerous small-scale on-site biodiesel production facilities. In conclusion, the study limitations and recommendations for future research are discussed. The applicability and effectiveness of using system dynamics for this study is discussed and some recommendations are made to indicate the context in which system dynamics would best be applied.
Calculating the energy potential of solar PV located on Northern Cape mining properties using R
(Stellenbosch : Stellenbosch University, 2019-04) Van der Merwe, Waldo; Brent, Alan C.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: South-Africa, as a sovereign member of various international treaties and agreements, is bound to agreed-upon objectives set to limit the proliferation of global climate change. The ramifications of these objectives have the potential to be particularly severe in a country where the social-, political- and economic structures have been intertwined in what has become known as the minerals-energy complex. Electricity generation, as a significant representative of the energy sector, is a key sector targeted for change by policymakers. Rightly so, as coal-based electricity generation constitutes the vast majority of all generation types and this has earned the country a precariously high position as a greenhouse gas emitter compared to other countries with similar levels of gross domestic product output. The policy arena, past and present, is analyzed in conjunction with other research results obtained by combining the same policy and technical aspects, with the aim of revealing a growth path for the renewable, and iii specifically solar photovoltaic, energy market. A Multi-criteria decision-making system is identified during the literature study as the most applied technique when used in conjunction with geospatial information systems. A customized version of such a system is applied to the relevant sourced datasets in order to quantify the solar potential on mining land which currently holds mineral rights within the borders of the Northern Cape province. In contrast with the literature study, these areas were pre-selected based on known technical and current policy requirements. The entire quantification process was completed with the use of R and publicly available data in order to promote repeatability and prove the use of R as a cost-effective alternative in geospatial analyses. The results of the quantitively performed analysis revealed that mining land in the Northern Cape province has enough solar photovoltaic potential to, at least, satisfy the entire country’s electricity consumption on an annual basis. To be able to extract this potential, recommendations are made to stakeholders with future policy amendments in mind. Currently, the model of own-consumption is still the easiest to access in the current policy climate, given profitability can be proven. However, given the restrictions in terms of timeframe imposed on mines, using rehabilitated mining land as a long-term solution is proposed as another alternative, given the envisaged policy scope can be utilized as envisaged.
Determining an appropriate electricity supply mix for the Hessequa Municipality: A system dynamics approach
(Stellenbosch : Stellenbosch University, 2018-03) Janse van Rensburg, Johannes Gerhard; Brent, Alan C.; Musango, Josephine Kaviti; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: South Africa has a highly centralised, monopolistic and regulated electricity sector. Eskom is the country’s national electricity utility and a state owned enterprise. Steep electricity tariff hikes have caused many consumers to invest in embedded generation technologies such as rooftop PV systems to reduce their dependence on grid-based electricity. Most of the defecting electricity consumers purchased electricity from a local government entity, who in turn purchased electricity directly from Eskom. Local governments often use profits from electricity sales to subsidise its various service delivery functions. A shrinking customer base on the local government level can thus threaten the financial viability of a municipality. Increases in electricity tariffs result in more customers investing in embedded generation causing the municipal customer base to shrink even more. This complex municipal system and its internal interactions are commonly referred to as the municipal dilemma. The Hessequa local municipality, located in the Eden district of the Western Cape, is used as a case study to explore the possible impacts of the municipal dilemma on its electricity sector. In order to limit the potential negative impacts, local government wants to investigate the option of supplying a third of local electricity demand with renewable energy technology. This study estimates the current and future demand for electricity in the Hessequa area based on population growth and economic growth. Various renewable energy technologies are evaluated along with renewable resource availability. A system dynamics model is used for simulating scenarios that test policies relating to renewable energy technology investment. The impacts of expanding the renewable energy generation capacity on the environment, socio-economic conditions and local government are investigated. This study shows that both biomass (in the form of invasive alien plants) and solar resources are in sufficient supply to meet the municipality’s goal of supplying its electricity demand through renewable electricity generation. Simulation results indicate that solar photo-voltaic (PV) energy is the most attractive renewable energy option in terms of capital cost and the cost of generated electricity. Biomass power is more expensive than solar PV in terms of capital cost and cost of generated electricity, but has better job creation potential and positive environmental impact due to invasive alien clearing. Simulation results further suggest that an appropriate renewable electricity supply mix would consist of a large portion solar PV and biomass power. The recommended electricity supply mix will require an estimated cumulative investment of R 679 million by 2040. The model also indicates that significant 𝐶𝑂2 emission reductions up to 37% can be expected by the year 2040 relative to the case where no commercial scale renewable energy generation is established.
Determining shelve placement in a chain store for optimal customer interaction
(Stellenbosch : Stellenbosch University, 2017-03) Olivier, Zen-Mari; Van Rensburg, Antonie; Brent, Alan C.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Pedestrian interactions in any setting have a large impact on the pedestrians in this setting. The field of research behind these pedestrian interactions is rather young, with little research done on pedestrian interactions in a specific store. This study investigates two case studies in specific stores, in which the area covered by pedestrian foot traffic is attempted to be minimized. For each case study, there are three scenarios presented. The first scenario is the store as it currently is, the second scenario is how the pedestrian traffic would change if the amount of pedestrians that enter the store should double. The final scenario is how the pedestrian traffic would change if the layout of the shelves, and the placement of the products on the shelves should change from the layout in scenario one. The layout is changed by moving the shelves around the high pedestrian traffic areas in scenario one. The investigation of the case studies is done by gathering and analysing data, and placing all the pedestrians in different customer segments, to create a realistic simulation model in Pedestrian Dynamics. It is determined how many simulation runs are necessary to obtain statistically significant results, and the simulations are run for this number of runs. The area of high pedestrian densities is measured, and the average over all of the simulation runs is taken, to have a single value to compare to the other scenarios. All of the values for the three scenarios is then taken into comparison with one another, and the results of the simulations are discussed.
Developing a behaviour change intervention to improve the adoption and implementation of sustainable construction practices by stakeholders in the South African construction industry
(Stellenbosch : Stellenbosch University, 2020-12) Marsh, Ralmar Juanita; Brent, Alan C.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: While sustainable construction has gained increasing attention internationally, there are still only limited studies thataddress the issue of sustainable construction in South Africa. Furthermore, the adoption and implementation of sustainable solutions in the South African construction industry is not apparent. The objective of this research study isto understand the current behaviour of construction industry stakeholders with respect to sustainable construction practices and to identifyand examinethebarriers and drivers of sustainable construction in the context of South Africa. This isachieved by adopting a theoretical behaviour change approach to develop an intervention strategy for improvingand facilitatingthe shift towards adopting sustainableconstruction practices and principles,thereby reducingthe negative impact of the development of the construction industry on the environment. Athree-phased, explanatory sequential mixed methods research design approach,guided by the Behaviour ChangeWheel(BCW),was adopted in this study. In Phase Oneof the three-phaseprocess to intervention design, an integrative reviewwas conducted,and a descriptive and content analysis of the barriers and drivers of sustainable construction is presented.A total of 37 articles werereviewed, identifying 56 barriers and drivers from the integrative review,and coded against the Capability, Opportunity, Motivation –Behaviour (COM-B) model components andtheTheoretical Domains Framework (TDF)domains. The barriers and drivers include: capability (knowledge, cognitive and interpersonal skills, behavioural regulation); opportunity (environmental context andresources); motivation (reinforcement, social/ professional role and identity, beliefs about consequences). This provided a theoretical basis for developinga survey questionnaire in phase two of theintervention design. Phase Twoincludeda statistical analysis of the relevant barriers to and drivers of sustainable construction that emergedthrough a survey questionnaire distributed to construction industry stakeholders. Phase Three presentsthe three stages of the BCW design and the development of the intervention components for the intervention toolbox.Five intervention functions and 12 behaviour change techniques (BCTs)wereidentified as relevant to include in the intervention toolbox design to improve the engagement of sustainable construction amongst construction industry stakeholders.Semi-structured interviews wereconducted with subject matter expertsinthe construction industry in order to evaluatethe findings from Phase One and Phase Two, assess the intervention content identifiedwhich consists of the intervention functionsand theBCTs,evaluate the intervention componentsand discuss the quality and applicability of the behaviour change interventiontoolbox.This research study provides an understanding and overviewof the use of the BCWto develop abehaviour changeintervention toolboxaimed at facilitating the adoption and implementation of sustainable construction practices amongst construction industry stakeholders. The BCW presentsa useful framework and systematic approach to integrate multiple sources of data to inform the selection of a theory-based behaviour change intervention strategy.Construction industry stakeholders mayuse thesestrategies to design, implement and evaluate sustainable construction interventions that are feasible within the context of the built environmentin South Africa.
Developing sustainable product-service system business models for energy provision in South African urban informal settlements
(Stellenbosch : Stellenbosch University, 2020-03) Cronje, George Frederick; De Kock, Imke; Brent, Alan C.; Musango, Josephine Kaviti; Stellenbosch University. Faculty of Industrial Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Deep socio-economic inequalities are still a reality in spite of South Africa being regarded as an upper-middle-income country. Informal settlements, in particular, reflect these inequalities. It is estimated that 10 per cent of the population live in rural or urban informal settlements. Urban informal settlements are the fastest-growing household sector in South African cities, accommodating more than 4 million people. Although these dwellers might have secured a living space in urban society, they are still excluded from city amenities and suffer tremendous hardships. Providing sustainable energy services to these communities is a complex and challenging undertaking. Blanket, national grid electrification policies are incapable of adequately serving the various types of informal settlements, each offering unique challenges. A singular inflexible technology supply response does not consider the dynamic and highly unpredictable nature of the urban informal community fraught with challenges and market barriers. To address this challenge, both governmental and non-governmental enterprises started operating in this space by providing energy through alternative means than that of the grid. Product-service system business models offer a promising solution to the market barriers existing in the informal context, due to the consideration of sustainability, multi-stakeholder collaboration and end-user desirability. This study set out to develop a tool to consider the multiple trade-offs in the urban informal context for developing a sustainable product-service system business model. A framework (manifesting as a tool) was developed using an adapted grounded theory methodology – the conceptual framework analysis technique. The usefulness of the developed tool was tested during a focus group with experts in the energy sector. Within the focus group environment, the tool successfully achieved the development of a sustainable product-service system business models by allowing the experts to visually map out the various trade-offs. Considered among the multiple trade-offs were the energy needs and desires of an informal community. The information was gathered by distributing a questionnaire to 100 participants living in an urban informal settlement. These were collected using a questionnaire administrated by three field researchers. A post-focus group evaluation survey revealed experts see much potential in the developed framework. Thus, using the framework developed in this study, new and existing energy provision enterprises can be assisted to provide sustainable energy services to the urban poor.
The development of a framework to align the use of technologies in industries to the sustainable development goals
(Stellenbosch : Stellenbosch University, 2019-04) Spies, Joubert; De Kock, Imke; Brent, Alan C.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: It is acknowledged that South Africa, and the rest of the world, faces sustainability challenges. Ideally, and in order to contribute towards sustainability, industries should continuously improve their activities through technological innovation and advancements. However, not all technological advancements contribute positively towards sustainability. Technology and technological innovation are seen by many as a major factor that can contribute towards sustainable development and the Sustainable Development Goals (SDGs). It is thus argued that sustainable development could be signi cantly in uenced by technological innovation, and it is evident in literature that society and technology co-evolve and exert in uence on one another. Therefore, one can infer that by aligning the objectives of industries with those of the technologies by means of SDGs, industries can positively in uence the SDGs, and therefore also sustainable development, with the help of technology. The present study investigates the role of technology (existing and emerging) in fostering sustainable development, and aims to highlight how sustainable development and SDGs are fostered within South Africa. The study further investigates how current frameworks guide industries towards choosing technologies within the context of sustainable development and to evaluate the applicability of such frameworks to the aim of aligning the objectives of industries with those of the technology by means of SDGs. Ultimately, the key objective of this study is to developed and e ective framework to decision makers within industries that will ultimately provide guidance in choosing between technologies; the aim being to select technologies that contributes towards SDGs. A systematic literature review is conducted to identify technologies that are used to support sustainable development within a South African context. Several technologies are identi ed, and emerging technologies, that holds potential to contribute towards sustainable developments, are identi ed and discussed. There are various bodies in existence exist within South Africa that aim to ensure that positive progress is being made regarding planning and implementation of sustainable development, and given the focus of this research, the processes, focus areas and actions relating to how sustainable development is fostered in South Africa is identi ed as well as the challenges associated with achieving sustainability. Challenges include, for example, a lack of progress reporting on SDGs within South Africa. Further, the current status of South Africa is discussed in terms of SDGs and the various technologies could improve and/or contribute to the SDGs are highlighted. Existing frameworks and their guidance towards choosing technologies are investigated, whereafter a short list of attributes are identi ed. These frameworks' applicability to the design requirement is determined and reveals that there is no existing framework that connects an industry and technology through the means of SDGs. Guided by the eight phases of Jabareen's Conceptual Framework Analysis, the framework is iteratively developed. The validation process is completed through a series of interviews with Subject Matter Experts (SMEs) and the application of a case study, where after the incorporation of the validation ndings are integrated into the re ned framework. The unique contribution that this study makes is the connection between industry and technologies through the means of SDGs. The framework guides the decision maker in choosing between technologies for implementation that foster similar SDGs to those of the industry. The validation results indicate a positive response; however, further studies on implementation, tracking the framework's performance through its implementation and the critical issues that arise from this are required.
The development of an implementation framework for green retrofitting of existing buildings in South Africa
(Stellenbosch : Stellenbosch University, 2017-03) Geldenhuys, Heinrich Jacques; Brent, Alan C.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: In this study frameworks related to retrofitting were investigated in order to develop a holistic framework for the green retrofitting of existing buildings in South Africa. The developed framework consists of five phases: retrofit feasibility, pre-project planning, construction, post-retrofit activities, and finally operation and maintenance. The framework was validated by means of a case study. The time required by the organisation involved to obtain the necessary funds for constructing the retrofit far exceeds the available time of this study. Therefore only the first two phases of the developed frameworks, retrofit feasibility and pre-project planning, were validated. The framework was developed to be a generic representation for South African retrofit projects, and as with the maintenance phase, many aspects were selected and adapted for the South African context. One of the main barriers for green buildings in South Africa, identified from literature, is the high cost perception South Africans have regarding green buildings. In the case study it was demonstrated how internal resources and expertise of the organisation can be used to reduce the total retrofit cost. Combining a retrofit with maintenance actions can further reduce the additional amount needed to invest in a green retrofit. Fourteen retrofit features are suggested and grouped into seven smaller independent projects according to the types of skills that are required for each installation. This minimises the time, external expertise and resources needed for specific jobs. These sub-projects are generally not fixed to a pre-defined schedule and can be attempted at stages the organisation finds suitable.
Energy metabolism in a hybrid / multi-structured urban informal settlement
(Stellenbosch : Stellenbosch University, 2018-03) Makinde, Abiola Olufolake; Brent, Alan C.; Musango, Josephine Kaviti; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Municipalities and governments at different levels are faced with the challenge of establishing energy policies and strategies for urban informal settlements that are mostly located in marginal areas. This study undertook a literature review to examine the challenges of energy access and provision in urban informal settlements from a resources’ flow perspective. This was achieved by reviewing the concept of urban metabolism with a specific focus on energy flows in urban areas; examining the relevance of the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolisms (MuSIASEM) approach; and, identifying gaps and limitations of assessing energy metabolic patterns of an urban informal settlement. MuSIASEM approach is of relevance because it recognises all factors and characteristics of urban informal settlement in order to provide comprehensive data for their analysis. This approach is one of the appropriate methodologies for examining and understanding energy metabolism in urban informal settlements, because MuSIASEM analyses the society under investigation across various scales, and at different hierarchical levels. The approach then proposes an energy accounting method to measure the quantity of energy required (in demand) by the society in relation to what is available, what is produced and what is consumed. MuSIASEM also defines the energy flow characteristics expressed in terms of the funds generated and flows metabolised in the system. The results of the study show that the energy metabolisms in urban informal households are affected by different variants in the households among them: i. The different building structures (typologies) present in urban informal settlements, with each building typology exhibiting different characteristics across both their household profile as well as energy consumption; ii. The type or composition of household profiles given that urban informal settlements are characterised by different household profiles where change in household type will in turn increase the energy consumption pattern in the household. iii. The energy fuels type or classification used for household energy services and household activities. Whereas, urban informal settlement households are faced with problems of supply inequality and energy poverty. iv. The appliances used in households, where increase in households’ energy consumption is proportion to the consumption pattern based on the different hours of usage for their household appliances. The implication for applying the MuSIASEM approach is to understand urban informal settlements’ energy consumption from a different scale of analysis in order to not only generalise the informal settlements’ challenges to just energy access but also the provision of infrastructure. The aim here is to understand factors that affect households’ energy demand and consumption as well as the reality of materials in the settlements. Such understanding would provide insights into how to address the challenges surrounding urban informal settlements’ development while implementing effective and sustainable policy interventions in such settlements. The study also presents the consumption behaviour and patterns in urban informal settlements arguing on their relevance for decision/policy makers, urban modellers, for utilities planning and implementation towards an inclusive sustainable development and growth. The analysis provides insight into energy consumption complexities, challenges present in urban informal settlement, which can guide in planning, and addressing specific energy related intervention.
Fostering sustainable energy transitions in South Africa: a system dynamics approach to achieving a sustainable electricity sector
(Stellenbosch : Stellenbosch University, 2017-12) Du Plooy, Nicole Tina; Brent, Alan C.; De Kock, Imke; Musango, Josephine Kaviti; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
AFRIKAANSE OPSOMMING: Suid-Afrika ondervind tans talle uitdagings soos lae ekonomiese groei, maatskaplike ongelykhede en swak staatsbestuur, maar ondanks hierdie uitdagings streef die elektrisiteitsektor van die land na ’n oorgang na volhoubare energie. Dít blyk duidelik uit die aantal meganismes wat hierdie oorgang bevorder, waaronder die Nasionale Groeiplan, die Nasionale Ontwikkelingsplan en die Geïntegreerde Hulpbronplan vir Elektrisiteit. Die sukses van so ’n omvangryke oorgang berus op ’n holistiese beskouing van volhoubaarheid oor ’n aantal sektore heen. ’n Volhoubare energieoorgang (VEO) is uiters kompleks en vereis ’n multidissiplinêre benadering om in die samelewing se ontwikkelings- en ekonomiese groeibehoeftes te voorsien, en terselfdertyd klimaatsveranderingsuitdagings en hulpbronbeperkings die hoof te bied. VEO-raamwerke sluit verskeie kwessies in, wat onder meer insluit die verband tussen energieproduksie en -verbruik, die ingebruikneming van volhoubare tegnologie en die sosio-tegniese impak daarvan, die vereiste paradigmaskuif vir beleidvorming, sowel as die ooglopende omgewingsbeperkings. Hierdie studie het ten doel om by te dra tot die kennisbasis vir die bevordering van VEO’s in die elektrisiteitsektor van Suid-Afrika. Daarom konsentreer die studie op die vermoë van die elektrisiteitsektor om ’n VEO te bewerkstellig en terselfdertyd ’n aantal maatskaplike, ekonomiese en omgewingsbeperkings te bestuur. Dít word deur ’n dubbelnarratiefbenadering bereik. Die benadering behels ’n narratiewe fase, wat bestaan het uit ’n sistematiese literatuuroorsig om die verskillende aspekte van oorgange en die verbandhoudende kompleksiteite te bepaal, sowel as ’n modelleringsfase, waartydens ’n toepaslike modelleringsmetodologie deur ’n normvergelykingsproses gekies en ’n model gevolglik ontwikkel is om die VEO vir die Suid-Afrikaanse elektrisiteitsektor op nasionale vlak te modelleer. ’n Uitset van die narratiewe fase was die ontwikkeling van ’n stel kriteria waarvolgens die vordering van die VEO met betrekking tot die tempo en omvang van verandering oor tyd beoordeel kan word. Die gekose metodologie vir die modelleringsfase was stelseldinamika, waarvolgens ’n model ontwikkel is om die Geïntegreerde Hulpbronplan vir Elektrisiteit vir Suid-Afrika te modelleer en alternatiewe scenarios te bepaal wat ’n oorgang na volhoubaarheid kan bewerkstellig. Die model is ontwikkel met die doel om belanghebbendes van verskillende agtergronde by gesprekke te betrek en om toekomsmoontlikhede te skep, versiendheid te ontwikkel en beleidsontwikkelingsprosesse te versterk. Die resultate van die modelscenarios is aan die hand van die ontwikkelde stel kriteria beoordeel, en dui daarop dat die huidige beleid onvoldoende is om teen 2050 ’n VEO te bewerkstellig. Die resultate toon ook dat scenarios met meer hernubare-energietegnologieë doeltreffender is om VEO’s in die hand te werk. Uitdagings wat egter oorweeg moet word, sluit in die aansienlike vereiste finansiële belegging, die wisselvallige aanbod, en die beskikbare elektrisiteit wat vereis word om aan die vraag te voldoen. Hierdie scenarios word uitvoerig bespreek en aanbevelings word ook gedoen. Die studie bied in die geheel ’n alternatiewe benadering om die vermoë te evalueer van Suid-Afrika se elektrisiteitsektor om ’n VEO te bewerkstellig, en dra by tot die VEO-kennisbasis van die land.
Impacts of industrial crops on food security in Swaziland, Tshaneni: a system dynamics approach
(Stellenbosch : Stellenbosch University, 2018-03) Van Zyl Engelbrecht, Francois; Brent, Alan C.; Musango, J. K.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Tshaneni, Swaziland has seen a prolific expansion in the cultivation of industrial crops over the last two decades. The effect of these industrial crops on local and regional food security is unclear. This is because there are multiple drivers of food security in the region. Drivers of food security span the economic, social, and agronomic sector and the interactions within, and between, these sectors mean that the food security system is complex. To explore the effect of industrial crops on food security the systems thinking approach is used to aid in system understanding. The aim of this study is to use systems thinking to analyse the food security system in Tshaneni Swaziland, to build a conceptual model of the system using causal loop diagrams, and to build a fully executional computer-based simulation to model the system quantitatively. A review of the literature revealed system dynamics as the most suitable modelling methodology for this study. The model consists of six sub-models that represent the real system. The sub-models include economic, production, and consumption feedbacks at the household level, where both food crop and industrial crop cultivation is simulated. The model is driven by a combination of external drivers, such as environmental conditions, and internal drivers, such as human decisions. The amount of money and food (in calories) available to the household are used as the food security indicators. The model is run for five different scenarios covering a twenty-year period from 2016 to 2035. These are analysed in order to determine the impact of industrial crops, in this case sugarcane, on food security. Results show that household involvement in sugarcane leads to increased levels of food security, mainly because of an increase in money available and irrigation for food crop production. Education and occupation were additional factors found to play a major role in increasing food security. Scenarios that explored the impact of climate change and potential water scarcity revealed that households in Tshaneni, Swaziland remain vulnerable to drought in terms of food security. However, those households involved in industrial crop cultivation are less vulnerable to climatic conditions than households that farm only food crops. This is because cultivating industrial crops leads to increased access to irrigation, which is also used for small plots of food crops. Based on the findings of this research project, it is advocated that smallholder farmers engage in the cultivation of sugarcane, especially in the context of large state-supported projects that have significant private sector buy-in, such as that in Tshaneni. The study further provides recommendations to stakeholders and policymakers to continue to invest in the sugar cane industry to ensure a food secure future for Swaziland and its people. Benefits of system dynamics are provided and recommendations are made to future researchers attempting to improve this research.
Infrastructure implications of a green economy transition in the Western Cape Province of South Africa : a system dynamics modelling approach
(Stellenbosch : Stellenbosch University, 2015-12) York, T. A.; Brent, Alan C.; Musango, J. K.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: This study investigated the infrastructure implications of a green economy transition in the Western Cape with particular focus on the transport sector. Within South African context, a green economy transition is recognised as one of the key pathways towards achieving an environmentally sustainable, resource efficient, low-carbon economy and just society. In response to the call of achieving a green economy transition, interdisciplinary, integrated approaches to the management and design of infrastructures across all sectors is required. This provided the backdrop in which the research took place and the reasons for this investigation being conducted. With the examination of various literature relating to transition theories and management practices involved in such a problem, an understanding of the complex systems involved in such a transition enabled an appropriate method of analysis to be developed for the research problem. Utilising a system dynamics modelling approach, the research effort aimed to improve understanding, and develop the associated capacities, of how technical, economic, political, social and environmental factors interact, particularly in the context of the uncertainties encountered during this transition. A framework from which the processes and methods involved in the system dynamics technique was identified and described, including the manner in which the model was built and the theoretical grounds on which it stands. From this it was possible to illustrate the important relationships existing between various components of the system. The subsequent implications of the decisions to be made by managerial bodies with regards to the study were disclosed in the form of recommendations to the various stakeholders in order to aid the decision making process. The use of System Dynamics Modelling for the investigation of the infrastructure implications of a green economy transition in the Western Cape provided a holistic manner in which to conceptualise and simulate the complexities of the problem. The ease of creation and its flexibility with regards to simulating dynamic behaviours made it a robust form of modelling. The key findings of the research indicated that through the investment into a better public transport system as well as shifting the movement of freight onto the rail network there would be long term positive effects environmentally, socially and economically. These included reduced truck and private vehicle numbers on the roads resulting in better road conditions, lower traffic densities, lower CO2 emissions and reduced diesel and petrol demand within the province. The combination of the two major intervention strategies of public transport and rail freight yielded a significant reduction in emissions from the transport sector, of up to 17.89% compared to the business as usual scenario. Through the aid of simulation, decision-making based on accurate representations of the future effects of strategies was made possible. It can be concluded that reaching a sustainable green economy in the Western Cape is possible and the implications of such a transition on transport infrastructure are manageable and achievable through strategic development.
An investigation into the required investment to transition the heavy-duty vehicle sector of New Zealand to hydrogen
(Stellenbosch : Stellenbosch University, 2021-03) Kotze, Rick Marius; De Kock, Imke; Brent, Alan C.; Musango, Josephine Kaviti; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Reducing greenhouse gas emissions in the transport sector is known to be an important contribution to climate change mitigation. With looming climate commitments, it is becoming increasingly important for New Zealand to develop a plan for addressing these emissions. Some parts of the transport sector are particularly difficult to decarbonise. This includes the heavy-duty vehicle sector, which is considered one of the “hard-to-abate” sectors of the economy. Heavy-duty vehicles are difficult to decarbonise because they are sensitive to weight, range, and refuelling duration. Current batteries cannot compete with the high energy density of diesel as they are too heavy and take too long to recharge. Transitioning from diesel trucks to hydrogen fuel cell trucks has been identified as a potential way to decarbonise the sector. If the hydrogen is produced with electrolysers powered by renewably generated electricity, then the vehicles would have negligible carbon emissions. Hydrogen produced in this way is known as “green” hydrogen. The current and future costs and efficiencies of the technologies enabling a transition to green hydrogen remain unclear. In light of these uncertainties, the primary aim of this study is to investigate the investments required to decarbonise New Zealand’s heavy-duty vehicle sector with hydrogen; by applying systems thinking. The transition from diesel trucks to hydrogen fuel cell trucks forms part of the energy-and sustainability-transition literature. To better understand the potential transition to hydrogen, a “systems thinking” approach is applied, and simulation modelling is identified as an appropriate tool with which to investigate the transition. Of the three simulation modelling techniques assessed, system dynamics modelling (SDM) is found to be the most appropriate technique for this study. As an SDM methodology designed specifically for modelling hydrogen transitions could not be found, one was created. This was done by combining aspects of the SDM literature with the hydrogen transition modelling literature. The resulting modelling process ensured that aspects of particular importance to hydrogen transitions were not neglected. Using this synthesized modelling process a system dynamics model was constructed. The model was tested to develop a high degree of confidence in the model and to ensure that the model limitations were well understood. The modelling period was set from 2020 to 2050, which is when New Zealand hopes to achieve carbon neutrality. Subsequently, five scenarios were designed and modelled in a manner that explores the wide range of potential outcomes. The results of the scenarios are analysed in order to draw insights from the study and to make recommendations for policymakers. The total investment requirements are assessed by considering the hydrogen production capacity investments, and the investments required to supply marginal electricity to the hydrogen production systems. Production capacity investments are found to range between 1.37 and 2.02 billion New Zealand Dollars, and marginal electricity investments are found to range between 4.33 and 7.65 billion New Zealand Dollars. These investments represent scenarios in which 71% to 90% of the heavy-duty vehicle fleet are decarbonised with fuel cell trucksby the end of the modelling period. The wide range of these findings reflects the large uncertainties in estimates of how hydrogen technologies will develop over the course of the next thirty years. Numerous policy recommendations are drawn from the results of the scenarios. Most notable is the finding that even pessimistic assumptions of progress in hydrogen technology indicate that fuel cell trucks will become competitive with diesel trucks well before 2050.The importance of having a regulatory authority that facilitates and oversees the hydrogen transition is also recognized. Finally, clear opportunities for future work are outlined. These opportunities include data collection, model expansion, and a comparison of the model results to alternative studies that research the investments required to decarbonise the heavy-duty vehicle sector with alternative technologies such as battery-electric trucks, biodiesel, and catenary systems.
An investigation into the urban energy-economy nexus
(Stellenbosch : Stellenbosch University, 2018-12) Dippenaar, Joshua Archibald; Brent, Alan C.; Musango, J. K.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Energy is arguably the most important resource for economic growth since most vital city infrastructures require energy. The majority of the world’s population now live in cities, which is also where the vast majority of the world’s energy is consumed. The pressures and potentials to reconcile economic growth and the sustainable use of resources are thus greatest in cities. This study investigates the city-level relationship between energy consumption and economic growth. Therefore, to answer the research questions posed in the study, the Spearman Correlation Test and the Granger Causality Test were employed to search for correlations and causalities between energy consumption and economic growth. The study performed analyses on three cities, namely: Cape Town (South Africa), Wellington (New Zealand) and Barcelona (Spain). These three cities share similar economic profiles yet have vastly different energy consumption patterns. Decoupling is a central concept of this study; it was defined as a term to describe the efforts to break the link between economic growth and the depletion of resources and the degradation of environments. It was found that when cities showed signs of decoupling, the correlation between energy consumption and economic growth was lost. Through investigating these three cities’ energyeconomy nexus, it was found that Wellington showed the most impressive decoupling. Therefore, Wellington’s policy interventions were studied to find a cause of this decoupling. It was found that the city employed a carbon tax, a strong environmental-awareness campaign, and an increased investment in public transport while reducing investment in road infrastructure. This combination brought about a modal shift where citizens adopted energy-efficiency technologies and public transport. This study therefore recommends this combination as a model for decoupling. Finally, this study has shown the importance of inter-city learning, and argues that cities should be open about policy interventions in order to speed up the transition to a green economy. This study recommends a systems analysis of the urban energy-economy nexus in order to fully understand the dynamics between energy consumption and economic performance.
The normalisation of resource efficiency measures in healthcare facilities: the case of energy and water
(Stellenbosch : Stellenbosch University, 2019-04) Amunjela, Abimelek Shikongo; De Kock, Imke; Brent, Alan C.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Energy and water consumption performance comparisons are used at a healthcare management and policy formulation level when formulating benchmarks and energy improvement targets. Normalising for the differences between hospitals is a key part of hospital consumption performance comparisons. It ensures that the measures used in these comparisons are commensurate, thereby increasing the reliability and robustness of the comparisons. Currently, the measures used in these comparisons are only normalised for the size of a hospital and are not adjusted to account for the inter-hospital differences in the level of medical service provision. This study investigated the feasibility of including normalisation factors that are representative of the level of medical service provision in the normalisation model used to compare the energy and water performance of hospitals. The complexity and level of specialisation of the composition of a hospital’s diagnostic caseload and the output of a hospital were used to quantify the level of medical service provision at a hospital. Measures were also formulated to quantify the size of a hospital. Statistically-based modelling methods were used to conduct an exhaustive analysis of the relationships between combinations of the normalising factors in the analysis and the energy and water consumption of the respective hospitals. Multiple linear regression (MLR) models were developed for all the possible combinations of normalising factors. These models were used to assess and rank the explanatory power provided by each combination of normalising factors in explaining the variations in the energy and water consumption of hospitals. Based on these MLR analyses and the rankings of the explanatory power provided by the respective models, it was concluded that the level of medical service provision of a hospital (as represented by its output, complexity and level of specialisation), does not significantly contribute to increasing the reliability or robustness of the current normalisation model. Furthermore, accounting for the level of medical service provision in the normalisation model would complicate the model without providing any significant additional explanatory power or increasing the objectivity of hospital consumption performance comparisons.
Smallholder food security impacts of industrial crop expansion and land use change in Malawi: a system dynamics simulation
(Stellenbosch : Stellenbosch University, 2018-03) Read, Matthew James; Brent, Alan C.; Musango, Josephine Kaviti; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: Food security is still a pervasive problem, nowhere more so than in sub-Saharan Africa (SSA). Industrial crop (IC) expansion has been at the centre of a debate as to whether ICs are assisting or hindering the quest for a more food secure future. These conflicting views, outlined in a review of pertinent literature, highlight the need for further study into the topic. A review of the literature revealed that food security in the context of SSA is a complex issue and a function of integrated social, economic, and physical systems. To understand this complex system better, it is proposed that a computer-based model is constructed to simulate the dynamics of the system. Models that simulate food security or food security related issues were therefore reviewed and the absence of a simulation that modelled food security from the household level perspective was uncovered. Various modelling attributes and techniques were subsequently reviewed, and system dynamics was chosen as the most appropriate modelling methodology to tackle the research problem under consideration in this study. The software package Vensim was selected as the modelling medium. For the development of the model, Malawi was identified as a suitable country to serve as the case study for this research inquiry. A conceptual model was created explaining the system feedbacks observed in Malawi through causal loop diagrams. The formal simulation was then developed from the conceptual model. It was found that the cultivation of ICs contribute to food security in Malawi. This is largely the result of increased credit options available to smallholder farmers who engage in IC cultivation. Smallholders who cultivate multiple crops are generally more food secure than those who monocrop in cases where limited land is available. This is because mixed-crop farmers are less vulnerable to climate variability. In some cases, mixed cropping leads to staggered income sources and expenses, this reduces the amount of time between harvests and leads to briefer episodes of food shortages overall. Cassava, a plant resilient to extreme weather conditions, is an important food crop in combatting food insecurity. Tobacco, a high-value crop which is well suited to climatic conditions in much of Malawi, remains a lucrative option for smallholder farmers. Contractual agreements between leaf companies, sugar millers, and smallholder farmers could, however, be improved. It is recommended that a regional-level model is developed to capture the effects of higher level system dynamics on smallholder farmers to be used in conjunction with this model. Keywords: food security; industrial crops; computer modelling; Malawi; system dynamics
A strategic and technological framework for sustainable low-cost housing in South Africa
(Stellenbosch : Stellenbosch University, 2019-04) Rynhoud, Greg Beau; De Kock, Imke; Brent, Alan C.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: With a vast majority of South Africans living in poverty, they are consequently unable to fulfil their basic needs. This includes the inability to provide adequate housing for themselves and their family. The only solution for most people is to wait for the government to provide them with low-cost housing. As a result, the government is charged with constructing countless homes. Therefore, the government commissioned low-cost housing frameworks, namely the Reconstruction and Development Plan, which comprises of policies, strategies and technologies. To ensure the construction of these dwellings have a positive effect on the environment, economy and community, it is imperative they be built sustainably. This investigation places South Africa within the context of global sustainability, as a developing country. Furthermore, it examines sustainability in the construction sector and develops an understanding of sustainable buildings. Thereafter, this investigation explores the demand for sustainable low-cost housing in South Africa, and determined there is an abundant need for housing with a high level of sustainability. To determine whether the existing frameworks perform satisfactorily, this investigation used Kayamandi, Stellenbosch as a case study to draw conclusions from. The case study provided a platform to investigate the existing strategic and technological frameworks prescribed for low-cost housing. These frameworks include the Reconstruction and Development Plan (RDP), the Integrated Development Plan (IDP) the strategy of from the Stellenbosch Municipality and the technological guidelines from the Sustainability Institute. To investigate the existing technological framework it was necessary to quantify its performance. This would require building-rating tools and assessment. After reviewing numerous methods, this investigation used a building-rating tool prescribed by the Green Building Council of South Africa (GBCSA). Additionally, this investigation examined the literature on Life Cycle Assessments to determine the most efficient method to reduce the negative impacts buildings have on the environment. With the aid of the building-rating tool, it was possible to investigate the existing strategic and technological frameworks for low-cost housing in Kayamandi. After exploring the existing frameworks of the case study, it was possible to define and examine the shortcomings of the technologies and strategies used to construct low-cost housing. The measurement of the existing technological framework highlighted that it did not meet the standards of the GBCSA and needed improving. Furthermore, exploring the strategic framework revealed there were fundamental changes that need to occur. Subsequently, this aided in the formation of a new strategic and technological framework. Once the proposed new frameworks were developed they were compared to the existing ones. To assess the technological framework, the results of the existing and proposed frameworks were compared graphically. It was determined that the proposed framework out-performed the existing framework, meaning it achieved a higher level of sustainability with a similar cost structure and thus validating the effectiveness of the proposed framework. The proposed strategic framework addresses all the shortcomings of the existing framework with additions to further facilitate synergy between stakeholders, government and the people of Kayamandi. Thus, this investigation presents a proposed framework that aims at achieving and enabling long-term sustainability for constructing low-cost housing. Furthermore, it specifies an outline on the necessary actions needed to provide the impoverished people of South Africans with adequate homes.
A strategic management framework for the commercialisation of multi-technology renewable energy systems: The case of concentrating solar power technologies in South Africa
(Stellenbosch : Stellenbosch University, 2018-03) Prentice, Kennedy Gregory Stuart; Brent, Alan C.; De Kock, Imke; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: In today’s globalised world, mankind faces an increasing number of economic, social, and environmental problems. The complexity and integrated nature of these challenges has led to recognition of the need for sustainable development. One of the underlying elements of sustainable development is the need for clean sources of energy, such as that produced from renewable energy technologies (RETs). In order to increase the rate of adoption of RETs into the global energy supply, there is a need to increase the rate of commercialisation of these types of technologies. It is likely that as the time taken for RETs to reach the market is reduced, a faster rate of adoption will be realised, thus contributing towards the transition to a sustainable energy supply, and sustainable development efforts. In response to this need, a strategic management framework was developed as a tool to support the development of strategies, aimed at increasing the rate of commercialisation of RETs. Given that many subcomponents of RETs may already be considered commercialised, the conceptual term multi-technology renewable energy system (MTRESs) was introduced as an umbrella term for such systems, highlighting the need to focus on those components within the system hierarchy that lie in a pre-commercialised state. As a case study for the framework, concentrating solar power (CSP) technologies in South Africa were selected based on the unique value proposition of CSP, able to operate as a dispatchable, mid-merit, or baseload energy source, the relatively immature state of CSP technologies, and South Africa’s immense solar resources. Following completion of the research study, it is clear that there is no single or universal approach to commercialisation. Comprehensive tools such as the framework developed, which supports strategy development via multiple avenues, are able to provide commercialisation practitioners with a range of options for their toolkit. However, presently there are significant barriers to the use of such tools. In a demonstration of the current political ecology of South Africa’s energy sector, the national government appears not to favour the incorporation of CSP technologies into the country’s energy mix on a large scale. This hinders the potential effectiveness of any strategy developed through use of the framework, given the weak market prospects for CSP technologies in South Africa, and possible loss of technology champions likely to use such a tool, especially within the country’s solar thermal energy associations. While alternative commercialisation prospects may exist in the global production network of CSP technologies, it is difficult to commercialise a technology for a foreign market. As such, the framework presents a proof-of-concept approach of how the rate of commercialisation may (theoretically) be increased, should industry conditions permit. Moreover, it encourages dialogue on the subject, while highlighting the need to investigate how buy-in can be secured from different stakeholders in South Africa’s energy sector, given the country’s complex socio-political dynamics. Lastly, the study contributes towards a recent trend in literature, which aims to move the debate from the analysis of energy transitions towards practical measures aimed at increasing the speed at which such transitions occur, thus accelerating progress towards a sustainable future.
Sustainability assessment of technology systems that address the energy-water nexus: the case of desalination in the Western Cape
(Stellenbosch : Stellenbosch University, 2017-12) Swart, Liesel; Brent, Alan C.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
ENGLISH ABSTRACT: In recent decades, the critical interdependencies that exist between the energy and water sectors, referred to as the energy-water nexus, have been investigated. It has become apparent that a policy change or intervention in one of the sectors can have a significant impact on the other. The impact on the entire energy-water nexus, therefore, needs to be considered when implementing changes in either sector. The Western Cape Province needs to increase its available water supply to ensure that the future water demand can be met. The aim of this research was to investigate the appropriateness of seawater desalination used in conjunction with renewable energy as a possible water supply intervention. The objectives of this research were to: select an appropriate modelling approach; compile, verify and validate the model; simulate different scenarios with and without the technology; and provide policymakers with recommendations regarding the sustainability of implementing a desalination technology system. It was determined that the Western Cape Province’s energy-water nexus is a complex system, because of the number of subsystems that exist within the system. A literature survey of the previous efforts that had been made to model similar systems was conducted. System dynamics modelling was found to be the most appropriate modelling tool, given the objectives of the research and the complexity of the problem. A systems thinking and modelling process was followed to develop a model of the Western Cape Province’s energy-water nexus. The first phase was problem formulation, and the second phase was the development of the conceptual model using causal loop diagrams. The construction, verification and validation of the dynamic computer simulation model was done in the third phase. Once confidence in the dynamic model was established, the fourth phase of the modelling process was completed. For this phase, a number of scenarios were developed and simulated to determine the effect of different desalination technology systems on the Western Cape Province. The impact of multi-effect distillation (MED) and reverse osmosis (RO) were compared. The effects of combining these technologies with different renewable energy sources, including thermal waste heat and solar energy, were also investigated. It was seen that the Western Cape Province’s water supply would be unable to meet the future water demand if no intervention was made. The results indicated that RO with photovoltaics would be the most sustainable and that the system’s life cycle cost up until 2040 is the lowest of all the simulated systems. In phase five, it was recommended to policymakers that, of all the systems that were considered, this system would be the best to implement. Additional water supply interventions, however, need to be investigated, as the recommended desalination system would not be enough to ensure sufficient future water supply. This research provides a better understanding of the complexities involved in the installation of a new technology system, such as desalination, in the Western Cape Province’s energy-water nexus. This research can be used as a platform to further explore the impacts of a desalination system or to investigate the sustainability of other technology systems that will affect the nexus.

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