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DSM on gold mines, specifically on the compressed–air systems where the infrastructure is inadequate, worn out or outdated.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.

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DSM on gold mines, specifically on the compressed–air systems where the infrastructure is inadequate, worn out or outdated.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.

Carbon tax, increased reactive power charges, tariff increases and the Energy Conservation Scheme (ECS) are some of the worrying electricity cost risks faced by large South African industries. Some of these proposed cost risks are not enforced as yet, but once approved could threaten company financial viability and thousands of jobs. Managing multiple cost risks associated with electricity consumption at several mines can be laborious and complex. This is largely due to circumstantial rules related to each potential electricity cost risk and unique mine characteristic. To limit the electricity cost risks for a mining company, clear strategies and focus areas need to be identified. No literature was found that provides a simplified integrated electricity cost risk and mitigation strategy for the South African gold mining industry. Previous studies only focused on a single mine or mining subsystem. Literature pertaining to potential risks is available, however the exact impact and mitigation on the gold mining industry has yet to be determined. The aim of this study is to accurately predict the impact of electricity cost risks and identify strategies that could alleviate their cost implications. Electricity consumption and installed capacities were used to benchmark mines and categorise them according to investigated risks. The benchmarked results provided an accurate starting point to identify best practices and develop electricity cost saving strategies. This study will highlight the additional benefits that can be obtained by managing electricity usage for a group of mines or mining company. Newly developed models are used to quantify savings on pumping, compressed air and cooling systems. To manage and report on the potential risks and mitigation, an ISO 50001 based energy management system was developed and implemented. The applied and developed models can also be adjusted to review and manage the potential cost risks on other types of mines. Derived risk and mitigation models were further used to quantify the impact on one of the largest gold mining companies in South Africa. These models indicate a potential annual price increase of 12%, while mitigation strategies could reduce the electricity consumption by more than 7%. Mitigation savings resulted from proposed projects as well as behavioural change-induced savings due to improved management. Over a five-year period the projects identified could result in electricity costs savings of between R675-million and R819-million. / PhD (Electrical Engineering), North-West University, Potchefstroom Campus, 2014

Carbon tax, increased reactive power charges, tariff increases and the Energy Conservation Scheme (ECS) are some of the worrying electricity cost risks faced by large South African industries. Some of these proposed cost risks are not enforced as yet, but once approved could threaten company financial viability and thousands of jobs. Managing multiple cost risks associated with electricity consumption at several mines can be laborious and complex. This is largely due to circumstantial rules related to each potential electricity cost risk and unique mine characteristic. To limit the electricity cost risks for a mining company, clear strategies and focus areas need to be identified. No literature was found that provides a simplified integrated electricity cost risk and mitigation strategy for the South African gold mining industry. Previous studies only focused on a single mine or mining subsystem. Literature pertaining to potential risks is available, however the exact impact and mitigation on the gold mining industry has yet to be determined. The aim of this study is to accurately predict the impact of electricity cost risks and identify strategies that could alleviate their cost implications. Electricity consumption and installed capacities were used to benchmark mines and categorise them according to investigated risks. The benchmarked results provided an accurate starting point to identify best practices and develop electricity cost saving strategies. This study will highlight the additional benefits that can be obtained by managing electricity usage for a group of mines or mining company. Newly developed models are used to quantify savings on pumping, compressed air and cooling systems. To manage and report on the potential risks and mitigation, an ISO 50001 based energy management system was developed and implemented. The applied and developed models can also be adjusted to review and manage the potential cost risks on other types of mines. Derived risk and mitigation models were further used to quantify the impact on one of the largest gold mining companies in South Africa. These models indicate a potential annual price increase of 12%, while mitigation strategies could reduce the electricity consumption by more than 7%. Mitigation savings resulted from proposed projects as well as behavioural change-induced savings due to improved management. Over a five-year period the projects identified could result in electricity costs savings of between R675-million and R819-million. / PhD (Electrical Engineering), North-West University, Potchefstroom Campus, 2014