As the world strengthens its commitment in response to climate change while decreasing its dependence on fossil fuels, green hydrogen has the potential to be one of the primary enablers in the global transition. Solar hydrogen production through electrolysis is one of the most promising approaches for harnessing green hydrogen and reducing carbon dioxide emissions. While previous studies have explored renewable energy integration, few have focussed on addressing the efficiency challenges of standalone green hydrogen systems for rural settings, especially those with energy resource constraints. This study focuses on the techno-economic optimisation and performance modelling of a solar-powered hydrogen production system in Limpopo by comparing four photovoltaic-electrolyser configurations. To find the lowest Net Present Cost (NPC) and Levelised Cost of Hydrogen (LCOH), HOMER software was employed to model the system, integrating solar irradiance data, system component characteristics, and economic parameters. Sensitivity analyses were conducted to assess the impact of factors such as electrolyser efficiency, costs, and components costs for load variation. The results obtained with the monocrystalline solar panel and alkaline electrolyser provided the lowest LCOH, of 37.50 ZAR/kg (2.12 USD/kg) with an NPC of ZAR 68 million (USD 3.65 million), which is the second lowest. Furthermore, the study identifies opportunities to make the technology even more affordable, such as improving electrolyser efficiency and reducing the cost of both solar panels and electrolysers. As the costs were decreased, the LCOH of the system showed a decrease of almost 50%. This work establishes the potential for solar-powered hydrogen systems to play an essential role in shifting to renewable energy. The findings contribute valuable insights for participants targeting investing in and developing green hydrogen infrastructure, supporting broader goals of energy security, transition and sustainability.

This study focused on the atomic scale growth dynamics of amorphous Al₂O₃ films microscale structural relaxation. Classical Molecular Dynamics (MD) can not entirely model the challenging ALD dynamics due to the large timescales. The all-atom approach has rules based on deposition actions modelled MD relaxations that form as input to attain a single ALD cycle. MD relaxations are used to create a realistic equilibrium surface. This approach is fitting to this study as the investigation of the sticking coefficient is only at the first monolayer that includes the layering of a hydroxyl surface of alumina. The study provides insight between atomic-level numerical information and experimental measurements of the sticking coefficient related to the atomic layer deposition. The MD modeling was for the deposition of Al₂O₃, using trimethylaluminum (TMA) and water as precursors. The film thickness of 1.7 Å yields an initial sticking coefficient of TMA to be 4.257 × 10⁻³ determined from the slope of the leading front of the thickness profile at a substrate temperature of 573 K. This work adds to the knowledge of the kinetic nature of ALD at the atomic level. It provides quantitative information on the sticking coefficient during ALD.