Environmental benefits of floating offshore wind farms

Results of polimi study on project off coast of Sicily

Offshore wind farms, on which great expectations are placed for decarbonising electricity production, ensure environmental benefits throughout their life cycle. This emerges from a study published in the international journal Sustainable Production and Consumption in which researchers from Politecnico di Milano analysed the potential environmental impacts of a floating offshore wind farm undergoing authorisation off the coast of Sicily.

The analysis included the phases of procurement of materials, transport of components, assembly and installation with specialised vessels, maintenance during operation, disassembly and end-of-life.

Overall, the results of the analysis provide a rough indication, which is useful for becoming aware of the environmental loads of a renewable electricity generation system and comparing it with other energy sources.

Results show that comparing 1 GWh of energy taken from the national grid with 1 Gwh of energy produced by the wind farm, the overall impacts of wind power are significantly reduced for almost all impact categories analysed: in the ‘climate change’ category, the benefit is a 92% reduction in impacts, and worsening is only observed in the ‘abiotic depletion’ category (+95%). Furthermore, this technology would allow to avoid generating energy from fossil fuels, and therefore, as the results show, related investments would be quickly repaid in terms of greenhouse gas emissions and energy, in 2 and 3 years, respectively.

Scientific literature is still insufficient when it comes to life cycle analysis (LCA) of offshore wind farms with large turbines (over 15 MW) installed on floating structures reflecting recent industry developments and current market trends. However, in order to assess their true environmental sustainability, it is important to analyse renewable electricity generation technologies from a life-cycle perspective.

Authors of this study are, Mario Grosso, professor in Solid Waste Management and Treatment; Lucia Rigamonti, professor in Methodologies for Life Cycle Thinking; and Gaia Brussa, researcher at the Department of Civil and Environmental Engineering.