Technoeconomic assessment of floating offshore wind technology in South Africa.

Umoh, Kubiat

Abstract

Expanding floating offshore wind into emerging and future markets could support emission reduction targets and promote energy security in several national contexts. This implies the need for adequate and systematic assessments to fully comprehend the potential of the major floater typologies (semisubmersible, spar, and tension-leg platform) in these markets. South Africa is a prime case study due to its huge technical potential for floating offshore wind and the ongoing energy crisis in the country. The Government of South Africa also intends to decarbonise its energy sector which is largely powered by coal fired power plants.
This thesis assessed the technoeconomic feasibility of floating offshore wind technology through a multidisciplinary approach that estimated the locational potential of the technology after exclusion of non-feasible sites; selected the optimum sites for deployments using a combined Analytical Hierarchy Process and Geographic Information System methodology; carried out technoeconomic analysis using windPRO, WAsP, and a floating wind cost model developed to understand the economic implications of developing the technology; and conducted sensitivity analysis to establish the most important contextual cost components.
This research found that 2% (246,105.4 km 2) of South Africa’s entire Exclusive Economic Zone (EEZ) is appropriate for hosting floating wind turbines, with a potential to generate a maximum of 142.61 GW of floating wind power. Although the Western Cape (WC) province holds the highest potential (80.52 GW) for floating wind in the country, the Eastern Cape (EC) region, with a locational potential of 20.04 GW, is considered most suitable for early-stage developments due to having the highest availability of grid connection capacity, limited marine traffic, and proximity to appropriate port facilities.
The relative priorities for floating wind site selection, as judged by the experts, includes wind speed (27.69%), distance to port (14.10%), water depth (13.95%), distance from grid (12.95%), distance from shore (9.28%), distance from cables and pipelines (8.95%), shipping density (7.69%), distance from airports (3.34%), and distance from oil and gas deposits (2.05%). By integrating these results in a GIS environment, 25 sites in the Northern Cape (NC), WC, EC, and Kwazulu Natal (KN) regions of the country, which can hold a total of over 71 GW of floating wind capacity, were selected.
Technoeconomic analysis produced LCOE values ranging from £161.1/MWh (3250.88 ZAR/MWh) for tension-leg platform to £190.33/MWh (3841.06 ZAR/MWh) for semisubmersible, and NPV figures varying from -£194.44M for TLP to -£336.9M for semisubmersible. LCOE sensitivity analysis revealed that exchange rate, discount rate, capacity factor, project lifetime, and water depth had the greatest lowering effect on LCOE, respectively, while the NPV sensitivity analysis discovered that a 33.2% increase in cost of electricity could yield positive NPV values ranging from £3.65M to £33.32M. To achieve this potential, industry actors and policymakers must prioritise selected sites in the context of the characteristics that would influence the technoeconomic feasibility of future floating wind projects in South Africa.

Citation

Umoh, K. (2025). Technoeconomic assessment of floating offshore wind technology in South Africa. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/5173184

• Thesis Type: Thesis
• Deposit Date: May 7, 2025
• Publicly Available Date: Oct 24, 2025
• Keywords: Mechanical engineering
• Public URL: https://hull-repository.worktribe.com/output/5173184
• Additional Information: Mechanical Engineering; Faculty of Science and Engineering; University of Hull
• Award Date: Apr 23, 2025