This paper presents an exploration of the potential of hybrid renewable energy systems (HRESs), combining floating solar photovoltaics (FPV), wind turbines, and vanadium redox flow (VRF) battery energy storage systems (BESSs) to expedite the transition from conventional to renewable energy for the mining sector in South Africa. The feasibility study assesses how to enhance the overall efficiency and minimize greenhouse gas emissions from an economic standpoint by using the Hybrid Optimization of Multiple Energy Resources (HOMER) grid software version 1.11.1 and PVsyst version 7.4. Furthermore, the BESS Covariance Matrix Adaptation Evolution Strategy (CMA-ES) dispatch algorithm is proposed to make the most of the battery storage capacity and capability, aligning it with the dynamic energy demand and supply patterns of an HRES. The proposed HRES includes a highly efficient SFPV with a performance ratio of 0.855 and an annual energy production of 15,835 MWh; a wind turbine (WT) operating for 2977 h annually, achieving a 25% wind penetration rate; and a dynamic VRF-BESS with a 15,439 kWh life throughput and a 3 s dispatch response time. This HRES has a CapEx of R172 million, a 23.5% Internal Rate of Return (IRR), and an investment payback period of 4.9 years. It offers a low Levelized Cost of Energy (LCoE) at 4.27 R/kWh, a competitive Blended Cost of Energy (BCoE) at 1.91 R/kWh, and a positive net present cost (NPC), making it economically advantageous without external subsidies. Moreover, it annually reduces CO₂ emissions by 1,715,468 kg, SO₂ emissions by 7437 kg, and NOx emissions by 3637 kg, contributing to a significant environmental benefit.

Amidst South Africa’s persistent energy crisis, this study explores the viability of microgrid systems as a pivotal solution to enhance energy reliability and sustainability. By scrutinizing factors like resource availability, grid connectivity, demand dynamics, regulatory frameworks, and financial implications, a comprehensive techno-economic analysis reveals the substantial potential of microgrids. These systems not only augment energy access and fortify grid resilience but also facilitate the seamless integration of renewable energy sources, aligning with global sustainability goals. Economic evaluations underscore favorable returns on investment, emphasizing the long-term cost efficiencies and broader societal benefits. The microgrid showcases strong financial performance with an Internal Rate of Return (IRR) of 23.1%, competitive Blended Cost of Energy (BCoE) at $0.073/kWh, Levelized Cost of Energy (LCoE) at $0.186/kWh lower than Eskom grid tariffs, and a rapid payback time of 5.5 years. The proposed microgrid has the potential to save 1,135,949.737 tons of carbon dioxide (CO₂) over its 30-year lifecycle.

The integration of solar photovoltaic (PV) systems and utility grids has gradually gained significant interest in improving the sustainability of clean power supply for society. However, power quality remains a challenge due to partial shading conditions and harmonics. To overcome these drawbacks, a flexible radial movement optimization based on a dynamic safety perimeter maximum power point tracking algorithm is employed to track maximum power out of a PV system and to ensure that the optimum voltage level at the common DC bus is obtained under partial shading conditions using fixed-tilt installation configuration. Furthermore, a novel inverter control loop system with a double second order generalized integrator phase-locked loop (DSOGI-PLL) is also proposed to mitigate harmonics and improve the power quality of the grid interfacing PV system using MATLAB SIMULINK software. The proposed system has several merits, such as better harmonic suppression capability, control adaptivity, rapid tracking speed, low computational burden and phase and grid synchronization.

This paper introduces an innovative Expectation-Conjugate-Gradient (ECG) approach designed for the management of the interfacing inverter in a grid-connected fixed tilt bifacial Photovoltaic (PV) system. The focus of this algorithm is to address current harmonics issues and elevate power quality. Additionally, the proposed control strategy integrates with an Enhanced Dual second-order generalized integrator phase-locked loop (EDSOGI-PLL), enhanced with a Savitzky-Golay Filter (SGF) to achieve grid synchronization, mitigate voltage harmonics, and estimate symmetrical components during unbalanced grid conditions. The state-of-art Double deep Q-network (DDQN) maximum power point tracking algorithm is introduced, integrating centralized start-up condition computation to stabilize voltage levels at the shared DC-link bus terminal. Key benefits include reduced harmonics, enhanced stability, adaptive control, and minimal computational load. Simulation confirms compliance with IEEE 519 Standards, THD < 3%, PF ≈ 1, and reveal a significant reduction in CO2 emissions.