Value characterization across the life cycle: A model to support value recovery from used wind turbines

The paradigm of circular manufacturing calls for the value embedded in materials, products, and processes to be recovered and reintroduced into the manufacturing enterprise. This is a subject of ongoing research around the globe. The end-of-use (EOU) management of products based on emerging technologies (e.g., wind turbines) that are capital, energy, and material intensive has received little attention. The value proposition at EOU is not well understood and therefore, not acted upon. Understanding the value proposition is paramount not only to encourage sustainable manufacturing practices but also to create sound economic business models. Renewable energy technologies are growing rapidly and need to compete successfully with traditional energy systems. To date, renewables represent 12% of the total U.S electricity generation capacity. Within the renewables, wind energy has the second fastest growth after hydro and provides 3.5% of the total U.S electricity demand. Their environmental benefits have been limited to green energy generation, and planning in advance of the recovery of value at EOU is required to maximize environmental and economic benefits. The opportunities for value recovery after EOU have been uncharted and with more than 40,000 wind turbines (WTs) installed nationwide, the opportunities for business creation have been underestimated. In this dissertation, a comprehensive study of how to recover value from used WTs has been developed. The wind industry will only be motivated to pursue recovery practices, if the value proposition is noteworthy. Under a system dynamics approach, the first phase involved the identification of logistics challenges associated with the recovery of WTs as well as potential recovery and economic opportunities. The second phase analyzed the environmental benefits derived from the remanufacture of WTs, individual subsystems, and recycled materials. The third phase studied the economic benefits obtained for manufacturers and users of remanufactured WTs; and lastly, the fourth phase evaluated the impact of O&M and technology evolution on the remanufacturing cost of WTs. Findings suggest that three by-products can be obtained when recovering used WTs: remanufactured WTs, remanufactured subsystems, and recycled materials. Remanufacturing the entire WT offers the largest economic benefits. Reducing the variability in quality of the returned used WTs and ensuring the quality of the remanufactured WTs are two of the most important challenges that must be overcome for a successful recovery of value from used WTs and their re-integration to the market