Valuing the Greenhouse Gas Emissions from Wind Power

Abstract

The growth in both onshore and offshore wind power has been rapid over the past few decades and has led to a need for comparable, consistent and reliable life cycle carbon assessment of wind power in order to provide decision-makers with robust information. The current published estimates for wind power range from 2 to 81 gCO 2 e/kWh. This study reduces this range through a meta-analysis of 82 estimates gathered from 17 independent studies. Through harmonisation of lifetime, capacity factor and recycling, the published range of life cycle carbon emissions estimates is reduced by 56% to between 2.9 & 37.3 gCO 2 e/kWh. Average values for onshore and offshore wind power are estimated as 16 & 18.2 gCO 2 e/kWh respectively after harmonisation and onshore and offshore wind power technologies exhibit similar characteristics in relation to their life cycle carbon emissions. Key differences with previous studies are that this study benefits from inclusion of data from a recently published comprehensive offshore wind farm assessment, and harmonisation is conducted for recycling procedures which results in an increase in the lower band of the range of life cycle carbon emissions estimates. This study concludes that much can be gained from harmonisation of historic life cycle estimates and moving towards a standard approach for carbon assessment of given technologies should be seen as an industry imperative. Wind power estimates lying within the interquartile range of meta-analyses such as presented in this paper and elsewhere should be considered to be reliable. However, the effects of wind generation intermittency on the carbon efficiency of thermal generation plant elsewhere in a supply network is not fully quantified and must be investigated to improve our knowledge of the overall carbon emissions produced by the deployment of wind generation plant.