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Based on field measurement data, the air-conditioning system consumes more than 40% of the building total energy use, followed by 30% of lighting, and 30% of miscellaneous pumping systems.. Among them, 60% power was consumed by chiller plants, while the chilled water pumping and air side equipment each accounts for another 20%. It is no doubt, that the energy efficiency improvement of chillers is one of the most important items in building energy conservation. It is common practice to design an air-conditioning system based on peak cooling load, namely, peak cooling demand on August 17, 3 p.m. Therefore, the chillers were mostly over-sized, while most of the time the chiller plant is operating under partial load conditions (PLF), which consumes more energy resulting in higher kw/RT and lower COP. It is the goal of this project to develop intelligent operation strategies of chiller plants under various seasonal conditions and to validate the effectiveness by full-scale experiment. At first, a typical central air-conditioning system will be selected and operated under various PLF conditions with the supply and return chilled water and flow rates recorded for energy calculations. By applying the simulation procedure developed by the ASHRAE using regression technique, the performance curve of a specific chiller under various PLF can be obtained with the kw/RT value identified. By simulating the multiple chiller cooperating combinations, an optimal operation strategy can be developed with the best economic benefits. Through the execution of this project, such an operation strategy, developed and validated under local weather conditions warrants good potential for engineering applications

South Africa is experiencing a serious electricity supply problem. This problem is expected to persist until at least 2012. During the winter of 2006 load shedding and electricity supply-cuts started occurring in the Western Cape. These spread to the rest of the country during the summer of 2007. By January 2008 daily load shedding was a common occurrence across South Africa. In the 1990s the Department of Minerals and Energy (DME), the National Energy Regulator of South Africa (NERSA) and Eskom started a national demand side management (DSM) programme with the help of energy services companies (ESCOs). The aim is to reduce demand peaks and to promote the efficient use of electricity. These projects can be implemented much faster than building new power stations and are also more cost-effective. In 2008 an accelerated DSM program was launched to address the electricity shortage in South Africa. Unfortunately, South African DSM projects experience the same sustainability problems as their counterparts overseas. These projects have been shown to be unsustainable over the five year projected life-span. There are various reasons for this, including client mismanagement and maintenance problems. An automated and rapid feedback system was identified as the best solution to address this problem. If plant personnel could be informed as soon as a DSM project's performance starts to decline, they would be able to respond much faster to rectify the problem. Reporting on DSM performance is difficult to achieve as these reports and the processing of measured data are time-consuming and presently no system exists to automate the process. A new feedback solution was developed to fully automate the process of data gathering, processing and reporting. The implemented solution reduced the number of man-hours spent by ESCOs' project engineers dramatically. In addition, project performance increased by 13% and showed an increase in over-performance of 12.8%, while financial savings for clients improved by an average of 12%. The feedback solution also provides the client with an accurate maintenance reporting system. This system can be implemented on all DSM projects, maximising Eskom's DSM investment. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.

South Africa is experiencing a serious electricity supply problem. This problem is expected to persist until at least 2012. During the winter of 2006 load shedding and electricity supply-cuts started occurring in the Western Cape. These spread to the rest of the country during the summer of 2007. By January 2008 daily load shedding was a common occurrence across South Africa. In the 1990s the Department of Minerals and Energy (DME), the National Energy Regulator of South Africa (NERSA) and Eskom started a national demand side management (DSM) programme with the help of energy services companies (ESCOs). The aim is to reduce demand peaks and to promote the efficient use of electricity. These projects can be implemented much faster than building new power stations and are also more cost-effective. In 2008 an accelerated DSM program was launched to address the electricity shortage in South Africa. Unfortunately, South African DSM projects experience the same sustainability problems as their counterparts overseas. These projects have been shown to be unsustainable over the five year projected life-span. There are various reasons for this, including client mismanagement and maintenance problems. An automated and rapid feedback system was identified as the best solution to address this problem. If plant personnel could be informed as soon as a DSM project's performance starts to decline, they would be able to respond much faster to rectify the problem. Reporting on DSM performance is difficult to achieve as these reports and the processing of measured data are time-consuming and presently no system exists to automate the process. A new feedback solution was developed to fully automate the process of data gathering, processing and reporting. The implemented solution reduced the number of man-hours spent by ESCOs' project engineers dramatically. In addition, project performance increased by 13% and showed an increase in over-performance of 12.8%, while financial savings for clients improved by an average of 12%. The feedback solution also provides the client with an accurate maintenance reporting system. This system can be implemented on all DSM projects, maximising Eskom's DSM investment. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.

Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.

Eskom, the sole supplier of electricity in South Africa is facing an energy crisis. This is due to the steady increase in demand for electricity in South Africa. Low electricity prices in South Africa have helped the energy intensive industries of South Africa to be more competitive. Unfortunately this has resulted in poor energy efficiency practices and has hampered incentives to save energy. To address this problem, Eskom initiated a Demand Side Management (DSM) programme. DSM is beneficial to both Eskom and the client. However, due to the high cost of implementing such projects, it is feasible to implement it only on sites where the load shift potential is high enough for Eskom to benefit. The mining industry has been targeted for DSM programmes. This is due to the existence of a large mining sector in South Africa and to its energy intensive nature. Most mining operations require large amounts of water which is used to cool the underground environment and so ensure productivity and the safety of the workers. Due to the large amounts of water needed for mining, the electricity usage of these pumping systems is very high. If the use of this electricity can be optimised by implementing DSM principles, this will result in the long term savings of costs for the mines involved. The majority of pumping systems found on mines are single shaft systems. Individually these systems have a very high DSM potential. However, if multiple shaft systems can be used for DSM, the benefits will be far greater. Furthermore, combining several sites with an interconnected water pumping system will increase the potential for DSM and enable sites where individually the potential is too low to be feasible for a DSM project to raise their potential. This will result in more sites where DSM projects can be implemented and more clients who can benefit from the DSM programme. The purpose of this study is to investigate and implement a DSM project on an intricate multi-shaft mine pumping system which will be controlled from a single point. The project required a detailed investigation of the pumping systems on each shaft and how the water system is interlinked between the shafts. This project was carried out on Beatrix Mine Shafts 1, 2 and 3. The pumping systems were analysed and simulated according to the specific constraints and requirements that were specified by the mine. During the investigation and implementation of this project, possible efficiency improvements on certain pump stations were discovered and implemented. The improvements enabled both an increase in water flow to the surface and a decrease in power consumption. Due to this load reduction, the savings achieved were higher than those found in most load shifting projects. Moreover, additional infrastructures were installed to ensure communication between pumping systems. Once the simulation and optimisation of the control system was completed, the pumping system network was automated. The load shift resulted in a ± 3.5 MW shift in the morning peak demand period and a ± 6.0 MW shift in the evening peak demand period. This load shift has resulted in an average cost saving of R 80 000 per month during summer tariff period, and R 300 000 per month during winter tariff period. This saving result was calculated by taking load reduction into account. This project has shown that a DSM project can be implemented successfully, given the necessary historical data and expertise, on a pumping system that is interconnected between multiple shafts. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.

South Africa is fast approaching an era where its electrical energy demand will surpass the generating capacity of it's primary utility. The reason for this is due to the fact that over the past 10 years, the economic growth in South Africa has increased considerably and has become very energy intensive. South African electrical energy consumption is currently estimated to be growing at a rate of around 1 000 MW per year. Due to the electrical energy demand being the greatest during peak-times, Eskom has introduced various "time of use" tariff structures, such as Megaflex and Ruraflex. These two tariff structures differentiate between standard, peak and off-peak periods of the day, as well as different seasons of the year. The tariffs for these different scenarios are adjusted such that the consumers are persuaded into avoiding unnecessary electrical energy consumption during peak periods. It has been identified that electrical energy consumption can be split into two categories. One of the categories considers sectors where there are a large number of electrical energy consumers, each utilising a negligible amount of power. The other category considers sectors where there are few electrical energy consumers, each utilising large amounts of power. This therefore means that the consumers in the latter category have a great potential in implementing more efficient ways of consuming power. In order to try and control the electrical energy demand problem in South Africa, Eskom has implemented a DSM (Demand Side Management) programme in order to help the larger energy consumers in shifting their peak-time loads to off-peak periods. If the client wishes to shift their load to off-peak periods, Eskom will assist by funding all costs to carry out such a project. According to Eskom's monitoring and verification team, Eskom's DSM initiative has proven to be highly successful. Since the inception of Eskom's DSM programme in 2003, up until the end of 2005, an accumulated total load reduction of 296.3 MW has successfully been realised. At present, most water distribution schemes have been developed without making use of Eskom's DSM initiative. As these schemes consume considerable amounts of electrical energy, they are prime candidates for an initiative such as Eskom's DSM initiative. It had previously been identified that the Vaal Gamagara Water Scheme, situated in Delportshoop, was a prime candidate for Eskom's DSM initiative. Presented in this dissertation are the findings of the DSM investigation. Although the project has yet to be implemented, the proposed intervention methodology was manually tested, where a 3 MW load shift in the evening peak and a 3.6 MW load shift in the morning peak was achieved. If the current intervention methodology is maintained, the annual savings will be in the region of R 830,000.00. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2008.

Eskom, the sole supplier of electricity in South Africa is facing an energy crisis. This is due to the steady increase in demand for electricity in South Africa. Low electricity prices in South Africa have helped the energy intensive industries of South Africa to be more competitive. Unfortunately this has resulted in poor energy efficiency practices and has hampered incentives to save energy. To address this problem, Eskom initiated a Demand Side Management (DSM) programme. DSM is beneficial to both Eskom and the client. However, due to the high cost of implementing such projects, it is feasible to implement it only on sites where the load shift potential is high enough for Eskom to benefit. The mining industry has been targeted for DSM programmes. This is due to the existence of a large mining sector in South Africa and to its energy intensive nature. Most mining operations require large amounts of water which is used to cool the underground environment and so ensure productivity and the safety of the workers. Due to the large amounts of water needed for mining, the electricity usage of these pumping systems is very high. If the use of this electricity can be optimised by implementing DSM principles, this will result in the long term savings of costs for the mines involved. The majority of pumping systems found on mines are single shaft systems. Individually these systems have a very high DSM potential. However, if multiple shaft systems can be used for DSM, the benefits will be far greater. Furthermore, combining several sites with an interconnected water pumping system will increase the potential for DSM and enable sites where individually the potential is too low to be feasible for a DSM project to raise their potential. This will result in more sites where DSM projects can be implemented and more clients who can benefit from the DSM programme. The purpose of this study is to investigate and implement a DSM project on an intricate multi-shaft mine pumping system which will be controlled from a single point. The project required a detailed investigation of the pumping systems on each shaft and how the water system is interlinked between the shafts. This project was carried out on Beatrix Mine Shafts 1, 2 and 3. The pumping systems were analysed and simulated according to the specific constraints and requirements that were specified by the mine. During the investigation and implementation of this project, possible efficiency improvements on certain pump stations were discovered and implemented. The improvements enabled both an increase in water flow to the surface and a decrease in power consumption. Due to this load reduction, the savings achieved were higher than those found in most load shifting projects. Moreover, additional infrastructures were installed to ensure communication between pumping systems. Once the simulation and optimisation of the control system was completed, the pumping system network was automated. The load shift resulted in a ± 3.5 MW shift in the morning peak demand period and a ± 6.0 MW shift in the evening peak demand period. This load shift has resulted in an average cost saving of R 80 000 per month during summer tariff period, and R 300 000 per month during winter tariff period. This saving result was calculated by taking load reduction into account. This project has shown that a DSM project can be implemented successfully, given the necessary historical data and expertise, on a pumping system that is interconnected between multiple shafts. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.

South Africa is fast approaching an era where its electrical energy demand will surpass the generating capacity of it's primary utility. The reason for this is due to the fact that over the past 10 years, the economic growth in South Africa has increased considerably and has become very energy intensive. South African electrical energy consumption is currently estimated to be growing at a rate of around 1 000 MW per year. Due to the electrical energy demand being the greatest during peak-times, Eskom has introduced various "time of use" tariff structures, such as Megaflex and Ruraflex. These two tariff structures differentiate between standard, peak and off-peak periods of the day, as well as different seasons of the year. The tariffs for these different scenarios are adjusted such that the consumers are persuaded into avoiding unnecessary electrical energy consumption during peak periods. It has been identified that electrical energy consumption can be split into two categories. One of the categories considers sectors where there are a large number of electrical energy consumers, each utilising a negligible amount of power. The other category considers sectors where there are few electrical energy consumers, each utilising large amounts of power. This therefore means that the consumers in the latter category have a great potential in implementing more efficient ways of consuming power. In order to try and control the electrical energy demand problem in South Africa, Eskom has implemented a DSM (Demand Side Management) programme in order to help the larger energy consumers in shifting their peak-time loads to off-peak periods. If the client wishes to shift their load to off-peak periods, Eskom will assist by funding all costs to carry out such a project. According to Eskom's monitoring and verification team, Eskom's DSM initiative has proven to be highly successful. Since the inception of Eskom's DSM programme in 2003, up until the end of 2005, an accumulated total load reduction of 296.3 MW has successfully been realised. At present, most water distribution schemes have been developed without making use of Eskom's DSM initiative. As these schemes consume considerable amounts of electrical energy, they are prime candidates for an initiative such as Eskom's DSM initiative. It had previously been identified that the Vaal Gamagara Water Scheme, situated in Delportshoop, was a prime candidate for Eskom's DSM initiative. Presented in this dissertation are the findings of the DSM investigation. Although the project has yet to be implemented, the proposed intervention methodology was manually tested, where a 3 MW load shift in the evening peak and a 3.6 MW load shift in the morning peak was achieved. If the current intervention methodology is maintained, the annual savings will be in the region of R 830,000.00. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2008.

In this study a new tool was developed that made new approaches possible for the successful implementation of Demand Side Management (DSM) projects. The new approaches are incorporated into a generic tool that makes it possible for Energy Services Companies (ESCos) to undertake DSM projects that were previously not possible with currently available technology. Through these new approaches, maximum results can be obtained on a sustainable basis on the clear water pumping systems of South African mines. The author was responsible and participated in four different investigations and implementations of DSM projects. These were grouped into three case studies. Each of these studies required different new innovations. The innovations described in this thesis include the adaptation of the Real-time Energy Management System (REMS) that was developed and marketed by HVAC International, to mines with intricate pumping systems, mines without any instrumentation and control infrastructure, as well as to mines that make use of a Three Pipe Water Pumping System. The tool developed and applied in these projects was part of Eskom's DSM programme. In this programme, large electricity clients who wish to shift electrical load out of peak periods, are assisted by having the total costs of such projects funded by Eskom. The fact that the clients will most likely enjoy substantial electricity cost savings, (by not having to pay the high peak prices), is a major attraction of this programme. Nevertheless, the programme is not moving as fast as it should. The National Energy Regulator (NER) has set an annual target of 153 MW load to be shifted since 2003. By the end of 2005, the accumulated target load to be shifted will be 459 MW. However, Eskom has indicated that an accumulated total of only 181 MW load will have been shifted by the end of 2005. This means that the Eskom DSM programme has actually only achieved 39% of its target. The innovations described in this thesis will help ESCos to address this shortfall more effectively / Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2006