The contribution of wind energy toward total electricity production in the U.S. has increased tenfold in the last decade. Texas leads the nation with total installed wind power capacity over 21 GW, contributing 12.6%. of statewide electricity production. Although the environmental impact of wind farms during operation & maintenance stage is insignificant in comparison to fossil fuel powerplants, there is a potential for high impact during the early stages of the wind energy lifecycle. This study attempts to quantify and mitigate the potential environmental impacts of individual stages (material extraction/processmq, turbine manufacturing, installation, operation & maintenance and disassembly) toward life cycle impacts of wind farms at three locations (onshore, shallow-water and deep-water) in Texas and the gulf coast. SimaPro? 8.3.0 life cycle assessment (LCA) software in combination with impact 2002+ method was used to identify the relative contribution of individual stages toward overall environmental impact across 15 midpoint impact categories and 4 endpoint'damage categories, in accordance with ISO 14040. LCA results reveal that material extraction/processing is the dominant stage with an average environmental impact contribution of 72% for onshore, 58% for shallow-water and 82% for deep-water, across the 15 midpoint impact categories. The high proportion of lignite (29.2%) and hard coat (26.5%) based electricity during the initial stages for processing steel, glass fiber-reinforced plastic (prepreg), epoxy resign and concrete is identified as the dnver for high environmental impact. A sensitivity analysis is conducted to evaluate the effect of varying electricity source mixture on lowering the environmental impact of material extraction/processing and manufacturing stages. Five alternative scenarios were constructed with replacing lignite based electricity with varying proportion of natural gas and renewables (Default. 25% natural gas, 50% natural gas, 25% nuclear, 25% wind and Texas default). Significant improvements could be observed in midpoint impact categories such as aquatic eutrophication (-40%).
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