This is the first thorough evaluation of the viability and appropriateness of photovoltaic (PV) water pumping in South Africa. It is a case study of the operation of a PV water pumping system installed in a rural community vegetable garden in KwaZulu. The system comprised a 574 WP array, DC power maximizer, DC motor and a Mono (positive displacement) pump. The pump delivered an average of 15 m3 I day over a static head of 12.5 metres for a Standard Solar Day of 5 kWh/m2/d. Three facets were considered: technical, economic, and social. · For the technical evaluation the operation of the whole system as well as that of each component under various conditions were monitored in the field using a data logger. The economic evaluation compared the Life Cycle Costs of PV water pumping with those of diesel, petrol, and electric pumps. The social evaluation was based on three sets of interviews over a period of five years ranging from before the introduction of the pump to four years afterwards. The following are the most important conclusions. Technical: the system Daily Energy Efficiency was 2.22%. This is low in comparison with values given in Halcrow's authoritative report of 2.35% for their average systems and 3.28% for their best systems. The reason for this was the low efficiency of the Mono Pump: 39% in comparison with 41.5% for Halcrow's average systems and 59% for their best. This was because the head of 12.5 metres at Sondela was not ideal for the Mono Pump which is designed for 45 metres. All the low-cost PV pumping systems available in South Africa, however, use positive displacement pumps and are thus inefficient at low heads. But because PV pumps are more competitive economically at low heads and low flow rates, it is important that an efficient pump for these applications is designed. Submersible centrifugal pumps should be considered. · Economics: the applicability of various assumptions to developing areas has been thoroughly evaluated. This has laid U1e groundwork for a accurate computer program which would accurately compare the Life Cycle Costs of PV, diesel, petrol and electric pumps under a range of conditions. Connecting to the grid has many advantages and should be considered first. However, the costs of the normal tariff are affected strongly by the site and this option is out of the question for more remote sites. PV pumps are at the moment competitive with diesel pumps at only low hydraulic heads (around 40 m4/day). However, if a PV pump which was efficient at low heads were designed and if the path of the sun were physically tracked, then PV pumps could possibly be competitive up to hydraulic heads of 1400 m4/day. Social: the study showed that installing pumps in community vegetable gardens can almost double the productivity of the gardeners' time. The gardeners interviewed indicated that, because of the many advantages of PV pumps, they would prefer them to diesel pumps if their amortized costs were up to twice those of the diesel pump., But few, if any, community gardens would be able to raise the capital required for a PV pump. For this reason, a scheme similar to that just introduced by ESKOM could make a crucial difference to the marketability of PV pumps: ESKOM will buy and maintain the pump recovering the costs from the user at a fixed monthly rate stipulated before installation. This scheme obviates the two major barriers to the sale of PV pumps: I) high initial cost and ii) the risk of damage or loss of expensive equipment due to floods, theft, or vandalism.

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No description available.

Deep gold mines use a vast amount of water for various purposes. After use, the water is pumped back to the surface. This process is energy intensive. The control is traditionally done with manual interventions. The purpose of this study is to investigate the effects of automated control on mine dewatering pumps. Automating mine dewatering pumps may hold a great number of benefits for the client. The benefits include electricity cost savings through load shifting, as well as preventative maintenance and pump protection procedures. By automating pumps, the client will benefit from operating more cost effectively and realising electricity cost savings. The equipment needed for pump automation and the procedures involved in the process are discussed as part of this study. A DSM project was implemented in the form of a pump automation project. All safety and quality procedures were followed and training was provided where needed to ensure that personnel understand their duties and responsibilities. This ensures the sustainability of the project after completion. The performance of the project was tested in manual mode, manual scheduled control, manual scheduled surface control and auto control. Manual intervention achieved the highest electricity cost saving of R8.25 million (11.4 MW load shift saving). To achieve this saving the system was exhausted to a point where columns and infrastructure started failing. Auto intervention achieved an electricity cost saving of R5.57 million (7.7 MW load shift savings). The auto intervention achieved a lower electricity cost savings compared to the manual intervention. However, taking all factors into account, such as the damage to infrastructure after a period of manual control, the auto intervention proved the best balance for controlling mine dewatering pumps to achieve savings on the cost of electricity and system sustainability for optimal control. Automated systems can avoid system overload and protect the infrastructure from exhaustion. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Deep gold mines use a vast amount of water for various purposes. After use, the water is pumped back to the surface. This process is energy intensive. The control is traditionally done with manual interventions. The purpose of this study is to investigate the effects of automated control on mine dewatering pumps. Automating mine dewatering pumps may hold a great number of benefits for the client. The benefits include electricity cost savings through load shifting, as well as preventative maintenance and pump protection procedures. By automating pumps, the client will benefit from operating more cost effectively and realising electricity cost savings. The equipment needed for pump automation and the procedures involved in the process are discussed as part of this study. A DSM project was implemented in the form of a pump automation project. All safety and quality procedures were followed and training was provided where needed to ensure that personnel understand their duties and responsibilities. This ensures the sustainability of the project after completion. The performance of the project was tested in manual mode, manual scheduled control, manual scheduled surface control and auto control. Manual intervention achieved the highest electricity cost saving of R8.25 million (11.4 MW load shift saving). To achieve this saving the system was exhausted to a point where columns and infrastructure started failing. Auto intervention achieved an electricity cost saving of R5.57 million (7.7 MW load shift savings). The auto intervention achieved a lower electricity cost savings compared to the manual intervention. However, taking all factors into account, such as the damage to infrastructure after a period of manual control, the auto intervention proved the best balance for controlling mine dewatering pumps to achieve savings on the cost of electricity and system sustainability for optimal control. Automated systems can avoid system overload and protect the infrastructure from exhaustion. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

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

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

Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2006.

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

The continual increase in electrical energy demand in South Africa has resulted in a precariously low reserve margin in supply from the primary utility, Eskom. This resulted in extensive load shedding throughout the country. Far-reaching measures had to be introduced in order to ensure a reliable supply of electricity. DSM interventions were shown to be very successful short term solutions for the mining industry, reducing the strain on the national grid. This resulted in an increasing number of investigations to broaden the base of DSM projects to other industries. One such intervention was the Usutu-Vaal water distribution scheme, situated near Standerton, South Africa. This scheme includes the Grootdraai, Tutuka, Grootfontein, Rietfontein and Naauwpoort pumping stations. With a combined installed capacity of 36.5MW and the extremely large water storage capacities, these pump stations have been identified as prime candidates for DSM interventions. This dissertation discusses the method followed for a DSM project intervention and the results of the implementation. The national grid was relieved by an average of 12.3 MW during the Eskom weekday peak period, by shifting the pumping load into the off-peak periods. Simulations have shown that an annual financial saving of approximately R4.7million may be expected. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013