This is a review article concerning existing energy and CO2 life cycle analyzes of wind turbines. The goal is to use the analyzes to understand the large disparity between results of previous studies. This is done by focusing a large amount on the greenhouse gas intensity. Also, the author examines the influence of different parameters such as the lifetime, load factor, power rating, country of manufacture, vintage year, and the methodology of analysis.
The energy disparity was mainly due to values for the energy content of materials, the analysis scope, the methodology, country of manufacture, recycling of components after service life, and the choice of concrete or steel. However, there is a certain uncertainty in that the differences between the means of energy and CO2 intensities among some renewable energies is smaller than the deviations from each single technology.