Abstract
The offshore wind-generation energy sector in Australia has been growing steadily in lieu of non-renewable energy sources, towards addressing national calls for greenhouse gas emission reductions. However, the industry in Australia is still somewhat fledgling, hence localised studies on environmental impact are scarce. In this context, the work here analyses greenhouse gas emissions by comparing like-for-like steel versus concrete materials as the main components in the foundation element of an offshore wind turbine throughout its lifecycle, using an adapted Life Cycle Assessment (LCA) method. This paper details a cradle-to-cradle LCA of the two alternative specifications for semi-submerged foundations supporting a 15MW power-rated wind-turbine, one made predominately of concrete and the other made predominately of steel, intended to be installed 100km off-the-coast of Bunbury, Western Australia. The functional unit here is the delivery of 1 kWh of electricity to the onshore grid across an initial 25-year lifetime. The estimated carbon intensity for the concrete foundation was calculated explicitly at 32g CO2-eq/kWh, whilst the steel foundation was pegged at 27g CO2-eq/kWh. Despite the concrete foundation having a greater impact on global warming, it is noted here that every kilogram of steel records higher overarching impacts than every kilogram of concrete. This work presents end-of-life scenarios for residual recycling of materials for combinations of steel and concrete, in light of the 10,000-year return-period for engineering and risk used in standards like ISO 19900.
Keywords
life-cycle-assessment, offshore-wind-turbines-OWTs, floating-foundations, concrete, steel.
DOI
10.5703/1288284318142
Recommended Citation
Castellanos, Isabel C L; Whyte, Andrew; and Urquhart, Stephen M., "Life Cycle Assessment of Semi-Submerged Offshore Wind Turbines’ Foundation Materials: Concrete versus Steel" (2025). International Conference on Durability of Concrete Structures. 6.
https://docs.lib.purdue.edu/icdcs/2025/sce/6
Life Cycle Assessment of Semi-Submerged Offshore Wind Turbines’ Foundation Materials: Concrete versus Steel
The offshore wind-generation energy sector in Australia has been growing steadily in lieu of non-renewable energy sources, towards addressing national calls for greenhouse gas emission reductions. However, the industry in Australia is still somewhat fledgling, hence localised studies on environmental impact are scarce. In this context, the work here analyses greenhouse gas emissions by comparing like-for-like steel versus concrete materials as the main components in the foundation element of an offshore wind turbine throughout its lifecycle, using an adapted Life Cycle Assessment (LCA) method. This paper details a cradle-to-cradle LCA of the two alternative specifications for semi-submerged foundations supporting a 15MW power-rated wind-turbine, one made predominately of concrete and the other made predominately of steel, intended to be installed 100km off-the-coast of Bunbury, Western Australia. The functional unit here is the delivery of 1 kWh of electricity to the onshore grid across an initial 25-year lifetime. The estimated carbon intensity for the concrete foundation was calculated explicitly at 32g CO2-eq/kWh, whilst the steel foundation was pegged at 27g CO2-eq/kWh. Despite the concrete foundation having a greater impact on global warming, it is noted here that every kilogram of steel records higher overarching impacts than every kilogram of concrete. This work presents end-of-life scenarios for residual recycling of materials for combinations of steel and concrete, in light of the 10,000-year return-period for engineering and risk used in standards like ISO 19900.
