Universiẗat, Diss.--Mannheim., 2006.

The School for Mechanical Engineering at the North-West University is home to one of South Africa's most established Measurement & Verification (M&V) teams. The team is involved with South Africa's electricity utility, Eskom, and their efforts to reduce the energy demand of the nation through Demand Side Management (DSM). One of the DSM initiatives in the residential energy sector is a National Solar Water Heating Program which encourages homeowners to purchase and install an Eskom accredited solar water heating system by means of a financial incentive. Massive financial investments have been incurred and it is only natural for stakeholders to question their return on investment. The need consequently exists to determine the impact of the National Solar Water Heating Program and establish whether it is being sustained. Before developing a methodology to measure and verify the impact of a solar water heating program an in-depth study had to be done on M&V as well as the concepts around solar water heating itself. After considering financial, time and accuracy constraints it was decided that an M&V Solar Water Heating Application along with the M&V methodology be developed. The primary aim of the application was to simulate the electrical hot water demand caused by the electrical-backup elements of the solar water heating systems and thereby avoiding the logistically and financially impossible process of measuring the electrical demand. A high-level simulation application, based on energy balances, was developed with solar water heating system types, geographical locations, weather conditions, hot water demand profiles and installation positions as inputs. The outputs of the application were the uncontrolled, simulated electrical hot water demand and were compared to the actual measured electrical hot water demand of a solar water heating system located in Cape Town. The outputs from two scenarios were compared to the measured data; one calculated with weather data from the global weather database Meteonorm, and the second calculated with the measured weather parameters acquired during the measurement period. The first scenario indicated relative accuracy with a mean bias error (MBE) and coefficient of variation of the root mean squared errors (CV (RMSE)) of 13.5% and 16.00/o respectively. The second scenario revealed improved accuracy with an MBE and CV (RMSE) of -1.1% and 5.5% respectively. The M&V Solar Water Heating Application and methodology has set the process in motion to measure and verify the impact of the National Solar Water Heating Program and will be refined as more data and information become available. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

Various commercial software packages are available for simulating compressed air network operations. However, none of these software packages are able to dynamically prioritise compressor selection on large compressed air networks in the mining industry. In this dissertation, a dynamic compressor selector (DCS) will be developed that will actively and continuously monitor system demand. The software will ensure that the most suitable compressors, based on efficiency and position in the compressed air network, are always in operation. The study will be conducted at a platinum mine. Compressed air flow and pressure requirements will be maintained without compromising mine safety procedures. Significant energy savings will be realised. DCS will receive shaft pressure profiles from each of the shafts’ surface compressed air control valves. These parameters will be used to calculate and predict the compressed air demand. All pipe friction losses and leaks will be taken into account to determine the end-point pressure losses at different flow rates. DCS will then prioritise the compressors of the compressed air network based on the overall system requirement. This software combines the benefits of supply-side and demand-side management. Potential energy savings with DCS were proven and compressor cycling reduced. A DCS user-friendly interface was created to easily set up any mine’s compressed air network. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013

The energy provider in South Africa, Eskom, faces an increasing electricity demand. The need to ensure sufficient supply gave rise to Demand Side Management (DSM) projects scheme. The DSM focus has shifted to the mining sector in South Africa. The large electricity use of the mining sector ensured the need for Energy Services Companies (ESCo’s). The ESCo is contracted to ensure energy savings of DSM projects implemented within the multiple sectors such as mining industry. The mining sector business model has the constant pressure to increase gold production. This pressure to expand has led to rapid expansion plans to increase the gold output for the relevant company. The expansion process and production increase in turn increases the electricity consumption. Compressed air use is a large contributing factor to the monthly electricity use as it is widely used within the mine sector. The implementation of a DSM project on the compressed air ring of an expanding gold mine was the focus of the study. This case study focused on an expanding gold mine within South Africa. The DSM lifecycle was followed to initially determine the DSM saving potential. The possible control strategies were investigated with simulation models and savings calculations. The viable option was to be implemented with a preliminary control philosophy. Results were in turn compared with the initial investigations and control philosophy. The deviations as experienced with implementation were addressed and a potential sustainable control philosophy for an expanding gold mine was constructed. The results indicated, verified Eskom peak clip electricity savings of 2.165 MW of the 2.4 MW target. The energy efficiency component for these performance assessment months was 1.944 MW of the targeted 1.5 MW. The sustainability of the system was proven with production increase on an expanding gold mine. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2013

Using chilled water within South African gold mines is paramount to the purpose of extracting gold ore efficiently. Using water for cooling, drilling and sweeping and the release of underground fissure water causes the accumulation of vast amounts of water in underground dams. Deep mines use cascading pump systems for dewatering, which is an electrical energy intensive dewatering method. Due to the recent equalisation of demand to generation capacity of electrical energy in South Africa, various methods towards demand side reduction have been implemented. With the introduction of a time-of-use (TOU) tariff structure by Eskom, the implementation of projects that shift load from peak TOU times to times of the day when electrical energy is less expensive has increased. To enable load shifting on mine dewatering pumps, preparation before and recovery after peak TOU is needed for effective results. This induces a preparation- and comeback load in the standard TOU. With an annual increase in TOU tariffs and the rate of increase of standard TOU being greater than that of the peak TOU, a reduction in electrical energy consumption before and after peak TOU is needed. To enable this, a step-by-step control technique was developed to promote the shifting of load from standard- to off-peak TOU, while still realising a full load shift from peak TOU. This technique entails dynamic control ranges of underground dam levels as opposed to the conventional constant control range method. Two case studies were used to test the developed technique. Results indicated significant additional financial savings when compared to conventional control methods. Additional savings of R1,096,056.65 and R579,394.27 per annum were respectively achieved for both case studies. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

The world is currently experiencing major issues in the energy sector. The ever-growing human population, limited energy resources and the effect of greenhouse gas emissions have become major global concerns for the energy sector, including the electricity generation sector. This dilemma caused electricity providers to revise their generation methods and created a major need for consumers to utilise electricity more efficiently. Demand side management (DSM) is one initiative developed for consumers to efficiently utilise electricity. Due to their high electricity consumption and technical skills, mines are ideal targets for the implementation of DSM strategies. Therefore, the focus of this study was to investigate South African mines for possible implementation of DSM strategies on their compressed air networks. Compressed air networks at South African mines are relatively old and inadequately maintained. This causes inefficient distribution and use of compressed air. The study will therefore focus on reconfiguring mining compressed air networks for cost savings. Cost savings include financial savings on electricity bills, implementation costs and decreased maintenance. Through several investigations, the possibility of implementing energy savings strategies to reconfigure the compressed air networks of two South African mines was identified. Reconfiguring the networks would respectively entail interconnecting two shafts and relocating a compressor from an abandoned shaft to a fully productive shaft. Theoretical simulations were developed to determine the networks’ responses to the reconfiguration strategies. The simulations assisted in exposing the viability of implementing the reconfiguration strategies on the respective compressed air networks. Positive responses were obtained from the simulations and proposals were made to the respective mines for possible implementation. The proposed initiatives were implemented on the respective mines’ compressed air networks. After implementation of the interconnection strategy, a consecutive three-month performance assessment period commenced to prove the viability of the proposed savings. An average power saving of 1 700 kW was achieved during the performance assessment period. The proposed initiative to relocate the compressor is currently being implemented. A financial saving of approximately R8.9 million per annum was achieved by implementing the interconnection strategy. The large financial saving was due to the utilisation of the mine’s salvaged equipment. Further savings were achieved by the decreased maintenance on the mine’s compressors. Due to the successful implementation of the interconnection strategy, it is safe to state that cost savings can be achieved by reconfiguring mining compressed air networks. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

The School for Mechanical Engineering at the North-West University is home to one of South Africa's most established Measurement & Verification (M&V) teams. The team is involved with South Africa's electricity utility, Eskom, and their efforts to reduce the energy demand of the nation through Demand Side Management (DSM). One of the DSM initiatives in the residential energy sector is a National Solar Water Heating Program which encourages homeowners to purchase and install an Eskom accredited solar water heating system by means of a financial incentive. Massive financial investments have been incurred and it is only natural for stakeholders to question their return on investment. The need consequently exists to determine the impact of the National Solar Water Heating Program and establish whether it is being sustained. Before developing a methodology to measure and verify the impact of a solar water heating program an in-depth study had to be done on M&V as well as the concepts around solar water heating itself. After considering financial, time and accuracy constraints it was decided that an M&V Solar Water Heating Application along with the M&V methodology be developed. The primary aim of the application was to simulate the electrical hot water demand caused by the electrical-backup elements of the solar water heating systems and thereby avoiding the logistically and financially impossible process of measuring the electrical demand. A high-level simulation application, based on energy balances, was developed with solar water heating system types, geographical locations, weather conditions, hot water demand profiles and installation positions as inputs. The outputs of the application were the uncontrolled, simulated electrical hot water demand and were compared to the actual measured electrical hot water demand of a solar water heating system located in Cape Town. The outputs from two scenarios were compared to the measured data; one calculated with weather data from the global weather database Meteonorm, and the second calculated with the measured weather parameters acquired during the measurement period. The first scenario indicated relative accuracy with a mean bias error (MBE) and coefficient of variation of the root mean squared errors (CV (RMSE)) of 13.5% and 16.00/o respectively. The second scenario revealed improved accuracy with an MBE and CV (RMSE) of -1.1% and 5.5% respectively. The M&V Solar Water Heating Application and methodology has set the process in motion to measure and verify the impact of the National Solar Water Heating Program and will be refined as more data and information become available. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2010.

Various commercial software packages are available for simulating compressed air network operations. However, none of these software packages are able to dynamically prioritise compressor selection on large compressed air networks in the mining industry. In this dissertation, a dynamic compressor selector (DCS) will be developed that will actively and continuously monitor system demand. The software will ensure that the most suitable compressors, based on efficiency and position in the compressed air network, are always in operation. The study will be conducted at a platinum mine. Compressed air flow and pressure requirements will be maintained without compromising mine safety procedures. Significant energy savings will be realised. DCS will receive shaft pressure profiles from each of the shafts’ surface compressed air control valves. These parameters will be used to calculate and predict the compressed air demand. All pipe friction losses and leaks will be taken into account to determine the end-point pressure losses at different flow rates. DCS will then prioritise the compressors of the compressed air network based on the overall system requirement. This software combines the benefits of supply-side and demand-side management. Potential energy savings with DCS were proven and compressor cycling reduced. A DCS user-friendly interface was created to easily set up any mine’s compressed air network. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013

The energy provider in South Africa, Eskom, faces an increasing electricity demand. The need to ensure sufficient supply gave rise to Demand Side Management (DSM) projects scheme. The DSM focus has shifted to the mining sector in South Africa. The large electricity use of the mining sector ensured the need for Energy Services Companies (ESCo’s). The ESCo is contracted to ensure energy savings of DSM projects implemented within the multiple sectors such as mining industry. The mining sector business model has the constant pressure to increase gold production. This pressure to expand has led to rapid expansion plans to increase the gold output for the relevant company. The expansion process and production increase in turn increases the electricity consumption. Compressed air use is a large contributing factor to the monthly electricity use as it is widely used within the mine sector. The implementation of a DSM project on the compressed air ring of an expanding gold mine was the focus of the study. This case study focused on an expanding gold mine within South Africa. The DSM lifecycle was followed to initially determine the DSM saving potential. The possible control strategies were investigated with simulation models and savings calculations. The viable option was to be implemented with a preliminary control philosophy. Results were in turn compared with the initial investigations and control philosophy. The deviations as experienced with implementation were addressed and a potential sustainable control philosophy for an expanding gold mine was constructed. The results indicated, verified Eskom peak clip electricity savings of 2.165 MW of the 2.4 MW target. The energy efficiency component for these performance assessment months was 1.944 MW of the targeted 1.5 MW. The sustainability of the system was proven with production increase on an expanding gold mine. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2013

Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2008.