Life cycle assessment of external impacts and external costs of a potential offshore wind farm off the Southern African coast

Southern Africa's abundant untapped offshore wind resources present a promising opportunity for advancing the region's transition to cleaner and affordable energy while mitigating climate change. Evaluating potential greenhouse gas (GHG) and non-GHG impacts, together with the life cycle costs associated with offshore wind farms, is critical in determining the overall sustainability of the energy system. By carrying out a life cycle assessment (LCA) of a potential 799.20 MW offshore wind farm, this study aims to fill existing gaps in literature. Findings from the study indicate that climate change impacts contribute 34.61 gCO2eq/kWh, while human health impacts are the most significant non-GHG impact at 0.49 g/kWh. The offshore wind farm's total life cycle cost ranges from 4.29 to 5.97 ZAc/kWh (2.21–3.08 €/MWh), with a central cost of 5.30 ZAc/kWh (2.73 €/MWh). Lifecycle costs attributed to GHG costs (1.68 ZAc/kWh; 0.86 €/MWh) and human health costs (3.42 ZAc/kWh; 1.76 €/MWh) contribute to 96.5 % of the total central cost. External costs per unit of electricity generated are lower compared to other electricity generation technologies including onshore wind, due to the large generation capacity of the offshore wind farm.