Eskom is currently facing an energy crisis due to the limited operational electricity generating capacity in South Africa. The historically low electricity price, the rapid growth in economy and the energy intensive nature of South African industries are the most common reasons for the peak supply problem. Various supply and demand technologies have been identified to address this energy crisis. Due to the lengthy process of building new peaking load power stations, Eskom has initiated the Demand-side Management (DSM) programme as a solution to the short-term supply problem. The National Energy Regulator (NER) has set targets to Eskom DSM to reduce the evening peak demand by 153 MW per annum and 4 255 MW over a 20-year planning horizon. Due to the energy intensive nature of the mining industry, it has been targeted for DSM savings. To date there have been a number of DSM projects implemented on the clear-water pumping systems of various mines, with a large potential for DSM savings identified on future projects still unrealised. The generation benefit of DSM load-shifting projects is twofold; firstly Eskom's evening load capacity increases due to the reduction in demand during these periods and secondly, the mine receives electricity cost savings due to load management practices. Because Eskom DSM is dependent on the client consumer to accept and roll-out the DSM programme, client satisfaction is of paramount importance. Due to the fact that load-shifting efforts require from the mine to change their normal operating schedules, there is uncertainty on the impact and knock-on effects of DSM projects on a mine. Therefore, the purpose of this study is to investigate and thereafter quantify the overall impact of DSM load-shifting on the clear-water pumping system of South African mines. A generic model was developed by performing case studies on existing DSM projects. This model was then applied to future DSM projects to validate the findings made throughout the research study. The case studies performed on existing DSM projects, as well as the results obtained when modelling the overall impact of DSM on future mines, proofs that DSM definitely benefits a mine. The total annual cost saving on the four future DSM projects is predicted to be in the order of R 7.64 million instead of the R 4.27 million when considering only the electricity cost savings to the mine. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.

The purpose of this dissertation is to identify the best alternative method of load shifting on clear water pumping systems in the mining industry. This can be done through a comparison analysis between manual and automated Demand Side Management (DSM) projects. The study holds benefits for Eskom and any client wishing to participate in the program. Eskom, by choosing the best method, will ensure sustainable load shifting while the client benefits financially through lower electricity costs. In order to perform this study, research was conducted on the requirements for additional electricity supply in South Africa. Research showed that there is an urgent requirement for additional electricity supply to ensure continued economical growth. DSM was identified as one of the most favourable methods that could be implemented to address the problem. A reason for this is DSM projects are economically viable and can be implemented in a relatively short time. The initiative would also decrease the need for increasing electrical generation capacity. During the research study important information regarding the computation process for load shifting and cost saving performance was gathered. Research was also conducted on the effect of DSM on labour and maintenance cost reduction, as well as economical engineering methods that can be used for alternative selection. The difference in performance between automated and manual systems was compared. The results showed that a 40% improvement of automated systems over manual systems were attainable and sustainable. This will realise a total saving of approximately 45% in electricity costs for the client. Savings in labour and maintenance costs are shown to be achievable through the automation of pumping systems. These saving results were used in the Engineering Economic alternative selection methods where applicable. Economic calculations confirmed that automated projects are the most viable control method. From the comparison study, it is shown that automated controlled systems are more advantageous than manually controlled systems. It will therefore be in the best interest of the client to automate a manually controlled pumping system, as it will result in additional load shifting and cost saving. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.

The sole electricity supplier in South Africa, Eskom, currently has an electricity supply crisis. The supplier requires additional available electricity urgently, particularly during the evening peak period between 18:00 and 20:00. This electricity shortage is due to a steady increase in the demand for electricity, which exceeded the increase in supply capacity, and the inefficient utilisation of electricity. In order to address this problem, Eskom introduced a Demand Side Management (DSM) programme. The aim of DSM projects is to reduce the load of consumers without negatively affecting consumers. Demand Side Management is beneficial for both Eskom and the client. The client benefits from a lower electricity bill and new equipment, while Eskom benefits from a reduced power demand. Various DSM strategies are implemented in different sectors, such as mining and residential. These projects are managed by Energy Service Companies (ESCo). The ESCo is responsible for the identifying, implementing, and maintaining the DSM project. Any identified DSM project is presented to Eskom, which agrees to fund the project depending on the proposed power saving. The mining industry, which has been selected as a candidate for DSM projects, as it is a major consumer of energy with numerous DSM opportunities, is examined in this dissertation. Because compressors are major consumers of electricity on the mines, significant DSM opportunities exist on compressed air systems. The purpose of this research project is to investigate and implement sustainable DSM projects on the compressed air systems of the mining industry. The focus is on automatically controlling the underground demand for compressed air. Reducing the demand for compressed air will result in lower power consumption by the compressors. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2009.

South Africa experienced a severe shortfall in electricity supply during 2008. Eskom, the national electricity supplier, implemented several strategies to alleviate the situation. The Power Conservation Programme set the mining sector a mandatory target to reduce its annual power consumption by 10%. The quickest way to achieve these savings is by optimising the largest power consumers on the mines. Compressed air is one of these, constituting approximately 40% of total electricity consumption on platinum mines. Several methods to reduce power consumption on compressed air systems were investigated. The investigation revealed that centrifugal air compressors on the mines are typically manually operated at a fixed delivery output. Attempts to reduce electricity consumption by reducing air demand will therefore not necessarily lead to savings. A control system that will enable the compressor to automatically match the supply with system demand is required. An optimised control strategy was then developed and implemented on three compressed air systems. Measurements demonstrated savings between 13% and 49%. With the Eskom tariffs proposed for 2010, this implies a total saving of R 46 million per year for these three case studies. This will achieve, and may even exceed, the mandatory reduction in electricity consumption of the mines. These results demonstrate that one of the quickest ways to reduce energy consumption on South African mines is by implementing optimised compressor controls. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010

South Africa's national power utility, Eskom, initiated a Demand Side Management (DSM) drive to help alleviate the electricity supply shortage experienced in South Africa. The focus of this study is on a load-shifting intervention applied in the mining environment. Load shifting is an appealing way of reducing peak demand. The mining sector is one of the largest consumers of electricity in South Africa. The application of DSM in this sector has the potential of yielding significant electrical load shifting. Firstly, this helps Eskom because they are struggling to keep up their supply. Secondly, the mines also benefit because electrical load is shifted to less expensive off-peak times. Electricity cost as a percentage of the total cost of mining output is bound to increase considerably the next few years. An investigation was conducted into the potential ofperforming load shifting on complex underground rock winders the mining sector. This involved a thorough study on existing load-shifting applications on rock winder systems. Simulations were performed on rock winder systems in their different configurations at deep-level gold mines. The simulation results indicated that there was potential for the application ofload shifting. Tau Tona was selected as a case study. This decision was based on simulations to establish which of the initially identified mines would be the best candidate for load shifting. Tau Tona has a complex underground rock winder system. Multiple rock winders feeding each other are used in a cascaded configuration. A potential load shifting target of 3' MW in the evening peak period was determined by means of simulation. The rock winder system was sequentially automated. An average evening peak demand load shift of 1 MW (or 4,2 MWh) was achieved. This translates to an average annual cost saving of R 240 000. If the load-shifting target of 3 MW could be obtained, the annual cost savings would increase by 30% to R 343 000. A study was also conducted on the feasibility of implementing maximum demand monitoring and control. Rock winders could be used in future to prevent the mines from exceeding their maximum demand. This is because rock winders consume very large amounts of electricity and can be stopped and restarted very quickly. Huge financial obligations can be prevented by making sure that the mines do not exceed their negotiated maximum demand. The necessary - and costly infrastructure to do this could not be procured during this study. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010.

Implementing demand side management (DSM) is expensive and often time consuming. Eskom grants subsidies for DSM projects based on the proposed savings. The subsidy granted is not always adequate to fund all the required control equipment to achieve the desired saving. This study focuses on alternative cost– and time–effective methods to implement DSM on gold mines, specifically on the compressed–air systems where the infrastructure is inadequate, worn out or outdated. The compressors generating compressed air for mining are one of the largest electricity consumer at gold mines. By optimising the energy consumption of these compressed–air systems, the largest potential demand reduction can be achieved. This will lighten the demand load on the already overloaded national power grid. Compressed air at gold mines is mainly used for production purposes, thus the majority of savings on these systems need to be achieved during non–production hours. Fixing air leaks, optimising compressor control, meticulous planning of implementation locations and controlling air usage are all methods that were investigated to achieve alternative cost– and time–effective methods to implement DSM on mine compressed–air systems. The methods were implemented by an Energy Services Company (ESCo) at four different mines. The results achieved from these case studies are documented and discussed in this study. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2011.

Eskom is currently facing an energy crisis due to the limited operational electricity generating capacity in South Africa. The historically low electricity price, the rapid growth in economy and the energy intensive nature of South African industries are the most common reasons for the peak supply problem. Various supply and demand technologies have been identified to address this energy crisis. Due to the lengthy process of building new peaking load power stations, Eskom has initiated the Demand-side Management (DSM) programme as a solution to the short-term supply problem. The National Energy Regulator (NER) has set targets to Eskom DSM to reduce the evening peak demand by 153 MW per annum and 4 255 MW over a 20-year planning horizon. Due to the energy intensive nature of the mining industry, it has been targeted for DSM savings. To date there have been a number of DSM projects implemented on the clear-water pumping systems of various mines, with a large potential for DSM savings identified on future projects still unrealised. The generation benefit of DSM load-shifting projects is twofold; firstly Eskom's evening load capacity increases due to the reduction in demand during these periods and secondly, the mine receives electricity cost savings due to load management practices. Because Eskom DSM is dependent on the client consumer to accept and roll-out the DSM programme, client satisfaction is of paramount importance. Due to the fact that load-shifting efforts require from the mine to change their normal operating schedules, there is uncertainty on the impact and knock-on effects of DSM projects on a mine. Therefore, the purpose of this study is to investigate and thereafter quantify the overall impact of DSM load-shifting on the clear-water pumping system of South African mines. A generic model was developed by performing case studies on existing DSM projects. This model was then applied to future DSM projects to validate the findings made throughout the research study. The case studies performed on existing DSM projects, as well as the results obtained when modelling the overall impact of DSM on future mines, proofs that DSM definitely benefits a mine. The total annual cost saving on the four future DSM projects is predicted to be in the order of R 7.64 million instead of the R 4.27 million when considering only the electricity cost savings to the mine. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.

The purpose of this dissertation is to identify the best alternative method of load shifting on clear water pumping systems in the mining industry. This can be done through a comparison analysis between manual and automated Demand Side Management (DSM) projects. The study holds benefits for Eskom and any client wishing to participate in the program. Eskom, by choosing the best method, will ensure sustainable load shifting while the client benefits financially through lower electricity costs. In order to perform this study, research was conducted on the requirements for additional electricity supply in South Africa. Research showed that there is an urgent requirement for additional electricity supply to ensure continued economical growth. DSM was identified as one of the most favourable methods that could be implemented to address the problem. A reason for this is DSM projects are economically viable and can be implemented in a relatively short time. The initiative would also decrease the need for increasing electrical generation capacity. During the research study important information regarding the computation process for load shifting and cost saving performance was gathered. Research was also conducted on the effect of DSM on labour and maintenance cost reduction, as well as economical engineering methods that can be used for alternative selection. The difference in performance between automated and manual systems was compared. The results showed that a 40% improvement of automated systems over manual systems were attainable and sustainable. This will realise a total saving of approximately 45% in electricity costs for the client. Savings in labour and maintenance costs are shown to be achievable through the automation of pumping systems. These saving results were used in the Engineering Economic alternative selection methods where applicable. Economic calculations confirmed that automated projects are the most viable control method. From the comparison study, it is shown that automated controlled systems are more advantageous than manually controlled systems. It will therefore be in the best interest of the client to automate a manually controlled pumping system, as it will result in additional load shifting and cost saving. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.

The sole electricity supplier in South Africa, Eskom, currently has an electricity supply crisis. The supplier requires additional available electricity urgently, particularly during the evening peak period between 18:00 and 20:00. This electricity shortage is due to a steady increase in the demand for electricity, which exceeded the increase in supply capacity, and the inefficient utilisation of electricity. In order to address this problem, Eskom introduced a Demand Side Management (DSM) programme. The aim of DSM projects is to reduce the load of consumers without negatively affecting consumers. Demand Side Management is beneficial for both Eskom and the client. The client benefits from a lower electricity bill and new equipment, while Eskom benefits from a reduced power demand. Various DSM strategies are implemented in different sectors, such as mining and residential. These projects are managed by Energy Service Companies (ESCo). The ESCo is responsible for the identifying, implementing, and maintaining the DSM project. Any identified DSM project is presented to Eskom, which agrees to fund the project depending on the proposed power saving. The mining industry, which has been selected as a candidate for DSM projects, as it is a major consumer of energy with numerous DSM opportunities, is examined in this dissertation. Because compressors are major consumers of electricity on the mines, significant DSM opportunities exist on compressed air systems. The purpose of this research project is to investigate and implement sustainable DSM projects on the compressed air systems of the mining industry. The focus is on automatically controlling the underground demand for compressed air. Reducing the demand for compressed air will result in lower power consumption by the compressors. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2009.

South Africa experienced a severe shortfall in electricity supply during 2008. Eskom, the national electricity supplier, implemented several strategies to alleviate the situation. The Power Conservation Programme set the mining sector a mandatory target to reduce its annual power consumption by 10%. The quickest way to achieve these savings is by optimising the largest power consumers on the mines. Compressed air is one of these, constituting approximately 40% of total electricity consumption on platinum mines. Several methods to reduce power consumption on compressed air systems were investigated. The investigation revealed that centrifugal air compressors on the mines are typically manually operated at a fixed delivery output. Attempts to reduce electricity consumption by reducing air demand will therefore not necessarily lead to savings. A control system that will enable the compressor to automatically match the supply with system demand is required. An optimised control strategy was then developed and implemented on three compressed air systems. Measurements demonstrated savings between 13% and 49%. With the Eskom tariffs proposed for 2010, this implies a total saving of R 46 million per year for these three case studies. This will achieve, and may even exceed, the mandatory reduction in electricity consumption of the mines. These results demonstrate that one of the quickest ways to reduce energy consumption on South African mines is by implementing optimised compressor controls. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010