http://hdl.handle.net/11189/454 Wed, 14 Oct 2026 23:49:21 GMT 2026-10-14T23:49:21Z http://hdl.handle.net/11189/10923 Title: Cutting-edge progress in offshore wind and tidal stream power technology—State-of-the-Art Authors: kangaji, ladislas; Raji, Atanda; Orumwense, Efe Abstract: The growing global demand for clean and sustainable energy has underscored the critical importance of offshore wind and tidal stream power technologies in addressing energy and environmental challenges. While these technologies hold significant potential to harness marine energy resources, gaps remain in understanding their readiness levels, integration potential, and pathways to overcome existing barriers. This study aims to bridge these gaps by providing a comprehensive review of the latest advancements in offshore wind and tidal stream power systems, focusing on innovations in turbine design, materials, and hybrid systems that combine wind and tidal energy. The methodology involves an extensive review and synthesis of recent research, project reports, and industry developments to evaluate the current technological state, challenges, and opportunities. Key findings include notable progress in turbine efficiency and hybrid system integration, which collectively improve energy conversion efficiency, scalability, and reliability. However, the study identifies persistent barriers such as high costs, environmental impact, and competition with more established renewable energy sources like solar and onshore wind. This paper emphasizes the importance of hybrid systems as a transformative approach to maximizing marine resource utilization and enhancing energy supply stability. The findings have significant implications for guiding future research, fostering innovation, and informing investment strategies in the marine renewable energy sector. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10923 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10922 Title: Development and validation of a real-time testbed for renewable energy integration studies: South African grid code case study Authors: Joubert, Gideon; Raji, Atanda Abstract: Purpose– Despite South Africa’s ailing electrical grid, substantial renewable energy (RE) integration is planned for the country. As grid-integrated RE affects all grids differently, this study aims to develop an adaptable grid code-guided renewable power plant (RPP) control real-time simulation testbed, tailored to South African grid code requirements to study grid-integrated RE’s behaviour concerning South Africa’s unique conditions. Design/methodology/approach– The testbed is designed using MATLAB’s Simulink and live script environments, to create an adaptable model where grid, RPP and RPP guiding grid codes are tailorable. This model is integrated with OPAL-RT’s RT-LAB and brought to real-time simulation using OPAL-RT’s OP4510 simulator. Voltage, frequency and short-circuit event case studies are performed through which the testbed’s abilities and performance are assessed. Findings– Case study results show the following. The testbed accurately represents grid code voltage and frequency requirements. RPP point of connection (POC) conditions are consistently recognized and tracked, according to which the testbed then operates simulated RPPs, validating its design. Short-circuit event simulations show the simulated wind farm supports POC conditions relative to short-circuit intensity by curtailing active power in favour of reactive power, in line with local grid code requirements. Originality/value– To the best of the authors’ knowledge, this is the first design of an adaptable grid code-guided RPP control testbed, tailored to South African grid code requirements in line with which RPP behavioural and grid integration studies can be performed. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10922 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10920 Title: Enhancing performance metrics of an electrical-powered subsea robotic dredging crawler across varied inclination angles Authors: Ojumu, M.O.; Raji, Atanda; Orumwense, Efe Abstract: This research paper introduces a novel passive method for ocean mining using an electricpowered robotic subsea dredging crawler designed to operate in various subsea conditions, including unstructured and rough terrain. The electric-powered robotic subsea dredging crawler is equipped with two driving tracks and features a complex assembly of tank tread chain link, tank tread idler wheels, tank tread sprockets, bronze bushings, motor hub, motor mount, and a 12-volt direct current motor. To evaluate the performance of the electric-powered robotic subsea dredging crawler, it was compared with existing ocean hydraulic exploration crawlers, such as MK3 ROST, in terms of drive performance on an inclined ramp with five angles of inclination (0°, 15°, 20°, 25°, 30°). The experiment aimed to determine the maximum velocity, torque, and efficiency of the crawler at different angles of inclination. The collected data were analysed and plotted using Python, and the effect of the electric-powered robotic subsea dredging crawler’s weight on its driving performance was also considered. The results of this study demonstrate a quadratic relationship between driving performance and inclination angle, which can be used to optimise the electric-powered robotic subsea dredging crawler’s performance for future ocean mining robot drive applications. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10920 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10911 Title: Characterisation and formulation of waste Augmented 3D Printable Concrete for BIM-Based Automation Authors: Immelman, Jandré; Pourbehi, Mohammad S.; Ameh, Alechine Emmanuel; Katambwe, Vinny Ndjate; Petrik, Leslie Abstract: This research aims to develop sustainable waste management practices in the construction industry by substituting components in 3D printing concrete (3DPC) with recycled glass waste material. This substitution not only improved concrete durability but also reduces environmental demand and promotes sustainability in the construction industry. Waste recycled glass was incorporated as cementitious material and fillers to formulate an environmentally friendly 3DPC. The study considered four aspects: waste material characterisation, mix design formulation, formulation modification optimisation for 3D printing, and potential of the obtained paste in a circular economy. Characterisation of materials was performed using X-ray fluorescence (XRF) to determine the elemental composition, X-ray diffraction (XRD) to determine the phase analysis, Fourier Transform Infrared Spectroscopy (FT-IR) to determine the structural bonding, and Particle Size Analysis to determine the particle size distribution. The findings provide a comprehensive understanding of the effects of incorporating waste glass as filler in formulations suited for 3DPC. It contributes to knowledge regarding the optimal percentages and replacement levels of these waste materials to achieve the desired 3D printing properties. Ultimately, this research aims to enhance the sustainability of buildings and infrastructure by addressing material selection, energy efficiency, local sourcing, design optimization, recycling and reuse, durability, labour reduction, and waste reduction. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10911 2025-01-01T00:00:00Z