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Life Cycle Assessment of Offshore Wind Farm Siting: Effects of Locational Factors, Lake Depth and Distance from Shore

CSS Publication Number
CSS16-27
Full Publication Date
December 19, 2016
Abstract

According to previous studies, the life cycle energy intensity of an offshore wind farm (OWF) varies between 0.03 and 0.13 megawatt-hours (MWh) of primary energy for each MWh of electricity generated. The variation in these life cycle energy intensity studies, after normalizing for capacity factor and life span, is significantly affected by OWF location because of geographical properties, namely, wind speed and water depth. To improve OWF siting, this study investigates how an OWF's distance from shore and geographical location impacts its environmental benefit. A process-based life cycle assessment is conducted to compare 20 OWF siting scenarios in Michigan's Great Lakes for their cumulative fossil energy demand, global warming potential, and acidification potential. Each scenario (four lake locations at five offshore distances) has unique foundation, transmission, installation, and operational requirements based on site characteristics. The results demonstrate that the cumulative environmental burden from an OWF is most significantly affected by (1) water depth, (2) distance from shore, and (3) distance to power grid, in descending order of importance, if all other site-relevant variables are held constant. The results also show that when OWFs are sited further offshore, the benefit of increased wind energy generation does not necessarily outweigh the increase in negative environmental impacts. This suggests that siting OWF nearer to shore may result in a better life cycle environmental performance. Finally, we demonstrate how much an OWF's environmental burdens can be reduced if the OWF system is either recycled, transported a shorter distance, or manufactured in a region with a high degree of renewable energy on the grid.

Research Areas
Energy
Energy Systems
Keywords
Industrial Ecology, Life Cycle Analysis (LCA), offshore wind farm, wind energy, wind farm siting, wind turbine foundations
Publication Type
Journal Article
Digital Object Identifier
DOI: 10.1111/jiec.12400
Full Citation
Tsai, Liang, Jarod C. Kelly, Brett S. Simon, Rachel Chalat and Gregory A. Keoleian. (2016) “Life Cycle Assessment of Offshore Wind Farm Siting: Effects of Locational Factors, Lake Depth and Distance from Shore.” Journal of Industrial Ecology 20(6): 1370-1383.