| Abstract |
The rational and economical management of natural resources is a challenge to be faced by contemporary so-cieties. An increasing number of new wind farms, including those nearing the end of their lifecycle, have pro-voked a discussion about reducing wind farm end-of-life waste materials through the implementation of new, more efficient recycling methods or life cycle extension procedures. This study presents an analysis of the effi-cient utilization of materials during the lifecycle of a wind farm with respect to three end-of-life management scenarios: the decommissioning of a wind farm after 25 years of use, a 25 year extension of a wind farm lifecycle (assuming a total 50-year long phase of use) consisting in modernizing the facility by means of replacing its rotor, nacelle, and accompanying accessories with new ones of the same type, and a repowering after 25-years of use by means of replacing the entire facility with a new, more efficient and more technologically advanced one. The integrated efficiency index, defined as a ratio of a wind farm's inputs to outputs in its entire lifecycle, was used to assess environmental efficiency. The outputs were taken to be the production of electrical energy, while the inputs were the values of environmental impacts, among others, in the form of a mass of greenhouse gas emission (CO2) equivalents, acidifying substances (SO2), eutrophication substances (PO4) and energy consumption in the wind farm lifecycle determined with the use of ML-IA and CED methods, respectively. The analysis indicated that, in the lifecycle of a wind facility, among all the materials used in a wind farm, steel, cast iron, and polymer materials are characterized by the highest inputs in the form of CO2 and SO2 emissions as well inputs in the form of energy consumption. Analyses of the scenarios considered herein prove that modernization and repowering lead to efficiency reduction in the year these processes are applied. For materials such as steel, concrete, aluminum, copper and cast iron, environmental efficiency is higher for the modernization scenario than for the scenario with decommissioning and repowering, which indicates that it is better to upgrade a wind farm and extend its lifetime (or the lifetime of its subsystems), thus increasing its durability, than to repower it into a wind farm of similar power, which is consistent with the rules of a circular economy. |