Department of Electrical and Mining Engineering

Enhancing water utility bulk meter reading through lot retrofit : a reliable and energy efficient wireless solution : the Rand Water case study in South Africa

Thu, 15 Jan 2026 00:00:00 GMT

Enhancing water utility bulk meter reading through lot retrofit : a reliable and energy efficient wireless solution : the Rand Water case study in South Africa Dlamini, Advisor Mlungisi Water is a scarce resource and appropriate smart bulk water metering and leakage detection are crucial. Current smart bulk water metering methods at Rand Water in South Africa are moving from being essentially manual to being automated. However, the currently used methods remain operationally costly, energy inefficient and not so reliable in terms of their employed communication approaches. This often leads to suboptimal resource allocation. Additionally, most of these bulk water meters are enclosed within concrete chambers and are at mostly at low elevation or even underground. This poses a problem in terms of identifying an efficient wireless solution for remote reading and site security. This study investigates and evaluates the performance of an appropriate Internet of Things (IoT) solution capable of reliably and in an energy efficient manner sending bulk water meter readings to a remote server for processing. The proposed solution can overcome the identified low elevation and penetration issues. It also detects possible water leakages, water chamber overflow, burst detection and any kind of site tampering in the form of alarms to ensure timely response and reduced operational cost. This study employs a simulation-based methodology using MATLAB to develop and evaluate deployment-aware models for both LoRaWAN and NB-IoT protocols, specifically incorporating the effects of reinforced concrete attenuation, low antenna elevation, and join/rejoin dynamics. This approach consists of a wireless communication feasibility study of the existing water utility infrastructure, followed by the implementation of identified low-power wide area network (LPWAN) IoT protocols suited for the application and the performance evaluation and comparison of the identified LPWAN IoT technologies in terms of energy efficiency and communication reliability. The results obtained from the proposed approach demonstrate that NB-IoT achieves superior reliability, maintaining packet delivery ratios above 0.96 even under severe concrete penetration losses up to 30 dB, while LoRaWAN exhibits a sharp degradation in reliability below 0.85 beyond 20 dB attenuation. Conversely, LoRaWAN offers better energy efficiency and extended battery lifetime under moderate conditions, whereas NB-IoT trades higher energy consumption for predictable and robust packet delivery. These findings support a deployment-aware, hybrid technology selection strategy for large-scale underground bulk water metering applications.

Modeling of the solar radiation output in the Democratic Republic of Congo

Wed, 01 Apr 2026 00:00:00 GMT

Modeling of the solar radiation output in the Democratic Republic of Congo Lusamba Yangindu, Dieudonné The Democratic Republic of Congo is not only a geological contrast but also an energy contrast, as it possesses a great hydroelectric potential capable of satisfying its own needs and those of many African countries. However, according to the most optimistic studies, the electrification rate in the Democratic Republic of Congo is less than 19%. Photovoltaic solar energy therefore represents a viable solution to help meet national energy needs. Accurate knowledge of solar irradiance is essential for proper sizing and optimization of photovoltaic systems. This study aims to establish general statistical models to predict solar irradiance (kWh/m²/day) as a function of sunshine duration (h/day) for any province of the Democratic Republic of Congo. Global solar irradiance data were obtained from RETScreen through the Renewable Energy Atlas of the DRC, while sunshine duration data were collected from the European Centre for Medium-Range Weather Forecasts. Five models (linear, quadratic, cubic, logarithmic, and exponential) were developed using the least squares method and validated using normalized statistical errors (NMAE, NMBE, NRMSE), the Nash–Sutcliffe efficiency criterion (NS), and the coefficient of determination (R²). Two scenarios were analyzed: scenario 1: excluding the provinces of Nord and Sud Kivu, and scenario 2: including these provinces. By excluding these provinces, the quadratic and cubic models explained 88% and 93% of the relationship between annual average sunshine duration and solar irradiance, respectively. Including them reduced performance, with R² ≈ 0.70, indicating that additional climatic variables may be required. A national sunshine duration heat map identifying four main exposure zones was also produced, supporting photovoltaic planning across the Democratic Republic of Congo.

Characterisation of innovation and implementation rates across a South African mining organisation

Wed, 11 Feb 2026 00:00:00 GMT

Characterisation of innovation and implementation rates across a South African mining organisation Schoonbee, A. J. D. The aim of this study was to measure shopfloor participation in a corporate innovation program within a South African mining operation. Employees were categorised according to age, gender, years of service, and job grading. The rate of innovation response was measured and analysed in terms of the type of innovation as well as the trajectory. During the first 12 months of the program, from September 2023 to August 2024, a total of 1005 submissions were registered, with 826 (82%) conforming to the criteria set for the program. Sufficient data was obtained through which each of the five (5) research questions could be answered. The 35-45 years age group had the highest level of representation in the program at 26% of the category. A slight bias of female participants over males was noted. The >15 to <= 20 years of service category had the highest level of representation in the program, at 32%. Three Paterson grading categories contributed most to the program: Upper C (Specialists and Supervisors), Lower D (Superintendents), and Upper D (Managers), while B Band employees (unskilled & semi-skilled) reflected lower response rates. Demographic groupings that were relatively under-represented included <25 years age group, the <=5 and >20 years of service categories, as well as the contractor, student and B-band job gradings. Approximately one in ten ideas registered during the period were implemented, showing that ideation exceeded the capacity to implement. ‘Incremental’ innovation was the dominant type, representing 94.9% ahead of ‘disruptive’ innovation at 4.3%. In terms of trajectory, most innovations (i.e., 76%) were aimed at the ‘internal’ work environment, with the ‘production’ environment at 22% as the second highest domain. Return on innovation investment (ROII) was considered in terms of both tangible / commercial and intangible / soft benefits. The program delivered sixteen innovations with tangible financial returns of more than R100,000, while thirteen of these innovations had a return on investment above R1 million, and three had a return of over R10 million measured per calendar year. An analysis of intangible value addition by category showed that ‘operational approach’ was the most frequent intangible benefit at 38.5%, followed by ‘safety and health’ at 28.2%, and ‘maintenance approach’ at 17.0%.

Long-term stability analysis of open pit mine slopes : a case study of Wearne mines in Limpopo

Fri, 23 Feb 2024 00:00:00 GMT

Long-term stability analysis of open pit mine slopes : a case study of Wearne mines in Limpopo Netshithuthuni, Rinae The main objective of the study was to conduct a long-term stability analysis of the slope, which due to blasting and continuous mining activity may deteriorate in its strength and since there is very little slope stability monitoring done, the analysis is warranted. Several methods were applied to achieve the objectives. These methods include Kinematic analysis, Limit equilibrium and Numerical modelling. The kinematic analysis method made use of the discontinuity orientation and the slope orientation to determine the probability of different types of failures occurring. These failures include planar, wedge and toppling. Limit equilibrium method was used to determine the Factor of safety (FoS) of the slope by analysing the driving forces and the resisting forces of the slope. OPTUM G2 which is a numerical method was then used to simulate the failure of the slope in the presence of different length or depths of discontinuities. Lastly the ROCFALL which is also a numerical model was also used to determine the extent at which the rock will travel down the slope in case of failure. The results produced by the kinematic analysis showed that the slopes are most likely to experience toppling failure more than planar and wedge failures. The Limit equilibrium results on the other hand showed that the slopes were stable based on its FoS value. OPTUM G2 proved that the increase in the length of discontinuities reduces the strength of the slope. Lastly, the ROCFALL models showed that the slopes geometries are well on balance and the presence of safety berms will prevent the rock rolling to the lower benches.