To remain competitive in an environment with limited natural resources and ever-increasing operational costs, energy efficiency cannot be ignored. From this perspective the need for Energy Service Companies (ESCos) has arisen to address the supply constraint of national utilities and emission reductions faced by governments, to mitigate climate change. This has led to the development of two energy-efficiency finance business applications in South Africa, namely Demand-Side Management (DSM) under Eskom and the Clean Development Mechanism (CDM) under the Kyoto Protocol. The technologies developed by ESCos, primarily for DSM energy efficiency projects, can be directly applied to generate Certified Emission Reduction (CERs) units, or carbon credits under the CDM business model. ESCo executives now need to decide which option will be more profitable; a once-off Rand/MW value from Eskom-DSM or an annual return on investment (ROI) from selling CERs over an extended crediting period. With a volatile CER price and bureaucratic registration procedures, it is very important that managers have all the right information at hand before making such decisions. A unique energy-efficiency investment decision model is developed that incorporates cost benefit analysis, based on the ESCos chosen risk profile. All attributes to the model of both DSM and CDM are defined, discussed and quantified into a decision analysis framework that would minimize risk and maximize profit. These attributes include life cycle analysis, technology transfer, cash flow, future CER prices, and associated project and political risks. The literature and background information that builds up to the development of this decision model serves as a complete handbook with guidelines to the South African energy services industry and investors. This study proposes a new energy-efficiency methodology under the United Nations Framework Convention on Climate Change (UNFCCC) that would increase the amount of CDM energy efficiency projects in South Africa and internationally. The methodology is designed to improve control system efficiency of any large electricity consumer instead of being equipment-specific. This implies that developers can use the same methodology regardless of whether the end-users are clear water pumping systems, compressed air systems, fans etc. This will reduce the cost of registering new methodologies with the UNFCCC and make CDM a more lucrative option to ESCos and other developers. This new energy-efficiency methodology and finance decision model was used in a case study to test its validity and accuracy. Two supporting technologies, REMS-CARBON and OSIMS, were developed in conjunction with HVAC International and tested at the clear water pumping system of Kopanang gold mine. The results from the case study demonstrated that this model is an acceptable tool in ensuring that ESCos gain maximum benefit from energy efficiency finance initiatives. Due to the experience gained with the modalities, procedures and pitfalls of DSM and CDM, further suggestions are made for new protocols to follow the Kyoto Protocol post-2012. South Africa and specifically ESCos could be very well positioned in a global “cap-andtrade” future carbon market. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2009

To remain competitive in an environment with limited natural resources and ever-increasing operational costs, energy efficiency cannot be ignored. From this perspective the need for Energy Service Companies (ESCos) has arisen to address the supply constraint of national utilities and emission reductions faced by governments, to mitigate climate change. This has led to the development of two energy-efficiency finance business applications in South Africa, namely Demand-Side Management (DSM) under Eskom and the Clean Development Mechanism (CDM) under the Kyoto Protocol. The technologies developed by ESCos, primarily for DSM energy efficiency projects, can be directly applied to generate Certified Emission Reduction (CERs) units, or carbon credits under the CDM business model. ESCo executives now need to decide which option will be more profitable; a once-off Rand/MW value from Eskom-DSM or an annual return on investment (ROI) from selling CERs over an extended crediting period. With a volatile CER price and bureaucratic registration procedures, it is very important that managers have all the right information at hand before making such decisions. A unique energy-efficiency investment decision model is developed that incorporates cost benefit analysis, based on the ESCos chosen risk profile. All attributes to the model of both DSM and CDM are defined, discussed and quantified into a decision analysis framework that would minimize risk and maximize profit. These attributes include life cycle analysis, technology transfer, cash flow, future CER prices, and associated project and political risks. The literature and background information that builds up to the development of this decision model serves as a complete handbook with guidelines to the South African energy services industry and investors. This study proposes a new energy-efficiency methodology under the United Nations Framework Convention on Climate Change (UNFCCC) that would increase the amount of CDM energy efficiency projects in South Africa and internationally. The methodology is designed to improve control system efficiency of any large electricity consumer instead of being equipment-specific. This implies that developers can use the same methodology regardless of whether the end-users are clear water pumping systems, compressed air systems, fans etc. This will reduce the cost of registering new methodologies with the UNFCCC and make CDM a more lucrative option to ESCos and other developers. This new energy-efficiency methodology and finance decision model was used in a case study to test its validity and accuracy. Two supporting technologies, REMS-CARBON and OSIMS, were developed in conjunction with HVAC International and tested at the clear water pumping system of Kopanang gold mine. The results from the case study demonstrated that this model is an acceptable tool in ensuring that ESCos gain maximum benefit from energy efficiency finance initiatives. Due to the experience gained with the modalities, procedures and pitfalls of DSM and CDM, further suggestions are made for new protocols to follow the Kyoto Protocol post-2012. South Africa and specifically ESCos could be very well positioned in a global “cap-andtrade” future carbon market. / PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2009

Wireless Sensor Networks (WSN) may consist of hundreds or even thousands of nodes and could be used for a multitude of applications such as warfare intelligence or to monitor the environment. A typical WSN node has a limited and usually irreplaceable power source and the efficient use of the available power is of utmost importance to ensure maximum lifetime of each WSN application. Each of the nodes needs to transmit and communicate sensed data to an aggregation point for use by higher layer systems. Data and message transmission among nodes collectively consume the largest amount of the energy available in a WSN. The network routing protocols ensure that every message reaches the destination and has a direct impact on the amount of transmissions to deliver a messages successfully. To this end the transmission protocol within the WSN should be scalable, adaptable and optimized to consume the least possible amount of energy to suite different network architectures and application domains. This dissertation proposes a Mobile Tolerant Hybrid Energy Efficient Routing Protocol (MT-HEER), where hybrid refers to the inclusion of both flat and hierarchical routing architectures as proposed by Page in the Hybrid Energy Efficient Routing Protocol (HEER). HEER was previously developed at the University of Pretoria and forms the starting point of this research. The inclusion of mobile nodes in the WSN deployment proves to be detrimental to protocol performance in terms of energy efficiency and message delivery. This negative impact is attributable to assuming that all nodes in the network are statically located. In an attempt to adapt to topological changes caused by mobile nodes, too much energy could be consumed by following traditional network failure algorithms. MT-HEER introduces a mechanism to pro-actively track and utilise mobile nodes as part of the routing strategy. The protocol is designed with the following in mind: computational simplicity, reliability of message delivery, energy efficiency and most importantly mobility awareness. Messages are propagated through the network along a single path while performing data aggregation along the same route. MT-HEER relies on at least 40% of the nodes in the network being static to perform dynamic route maintenance in an effort to mitigate the risks of topological changes due to mobile nodes. Simulation results have shown that MT-HEER performs as expected by preserving energy within acceptable limits, while considering the additional energy overhead introduced by dynamic route maintenance. Mobile node tolerance is evident in the protocol's ability to provide a constant successful message delivery ratio at the sink node with the introduction and increase in the number of mobile nodes. MT-HEER succeeds in providing tolerance to mobile nodes within a WSN while operating within acceptable energy conservation limits. AFRIKAANS : Koordlose Sensor Netwerke mag bestaan uit honderde of selfs duisende nodes en kan gebruik word vir 'n legio van toepassings soos oorlogs intellegensie of om die omgewing te monitor. 'n Tipiese node in so 'n netwerk het 'n beperkte en soms onvervangbare energie bron. Die effektiewe gebruik van die beskikbare energie is dus van uiterste belang om te verseker dat die maksimum leeftyd vir 'n koordlose sensor network behaal kan word. Elkeen van die nodes in the network moet die waargeneemde data aanstuur oor die netwerk na 'n versamelings punt vir latere gebruik deur applikasie vlak stelsels. Informasie en boodskap transmissie tussen die nodes is wel een van die aktiwiteite wat die meeste energie verbruik in the netwerk. Die roeterings protokol verseker dat die boodskappe die eindbestemming behaal en het 'n direkte impak op die hoeveelheid transmissies wat kan plaas vind om dit te bewerkstellig. Die roeterings protokol moet dus skaleerbaar, aanpasbaar en verfyn word om die minste moontlike energie te verbruik in verskillende toepassings velde. Hierdie verhandeling stel 'n Bewegings Tolerante Hybriede Netwerk Roeterings Protokol vir Koordlose Sensor Netwerke (“MT-HEER”) voor. In hierdie konteks verwys hybried na die samesmelting van beide plat en hierargiese roeterings beginsels soos voor gestel deur Page in Hybriede Netwerk Roeterings Protokol (“HEER”). HEER was ontwikkel by die Universiteit van Pretoria en vorm die begin punt van hierdie navorsing. Die insluiting van bewegende nodes in 'n Koordlose Sensor Netwerk toon 'n negatiewe tendens in terme van energie effektiwiteit en suksesvolle boodskap aflewerings by die eindbestemming. Die grootste rede vir hierdie negatiewe tendens is die aanname deur gepubliseerde werke dat alle nodes in die netwerk staties is. Te veel energie sal vermors word indien tradisionele fout korregerende meganismes gevolg word om aan te pas by die bewegende nodes. MT-HEER stel 'n meganisme voor om die bewegende nodes te gebruik as deel van die roetering strategie en gevolglik ook hierdie nodes te volg soos hulle beweeg deur die netwerk. Die protokol is ontwikkel met die volgende doelstellings: rekenkundig eenvoudigheid, betroubare boodskap aflewering, energie effektiwiteit en bewustheid van bewegende nodes. Boodskappe word langs 'n enkele pad gestuur deur die netwerk terwyl boodskap samevoeging bewerkstellig word om die eind bestemming te bereik. MT-HEER vereis wel dat ten minste 40% van die netwerk nodes staties bly om die dienamiese roeterings instandhouding te bewerkstellig. Simulasie toetse en resultate het bewys dat MT-HEER optree soos verwag in gevalle waar daar bewegende nodes deel uit maak van die netwerk. Energie bewaring is binne verwagte parameters terwyl die addisionele energie verbruik binne rekening gebring word om te sorg vir bewegende nodes. Die protokol se toleransie teen bewegende nodes word ten toon gestel deur die vermoë van die protokol om konstant 'n hoë suksesvolle bookskap aflewerings verhouding te handhaaf. MT-HEER behaal die uitgesette doel om 'n toleransie teen bewegende nodes beskikbaar te stel, terwyl die protokol steeds funksioneer binne verwagte energie besparings limiete. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted