Wind turbine lifetime extension: Analysis and Review

Summary
This pre-study aims to describe and analyze end-of-service-life decision-making within the Swedish wind industry, with a particular focus on lifetime extension. The project addresses this task by two different approaches:

1. By combining interviews with industry experts, decision analysis methods, and insights from international scientific literature, the study seeks to clarify how lifetime extension is addressed in Sweden and to raise industry awareness of existing approaches and emerging perspectives.

2. By aeroelastic simulation of a representative generic wind turbine to produce both design loads and corresponding SCADA data. The simulated SCADA data is then used to compare real SCADA data to evaluate how much life has been used.

Aim and overall goals 
The overall aim of the project is to review and understand the service life extension situation for wind farms in Sweden. This includes (1) to collect information on the industrial situation and (1a) the industrial best practices of handling of service life extension, (2) to provide basic decision theoretical insights and support for service life extension, and (3) to outline integrity management procedures for service life extension. Moreover, it is also an aim to increase awareness of already existing methods and results to Swedish wind industry. 
We shall pursue three main questions: 

1.    What are the main deciding factors in life-time extension decisions in Sweden today? 

2.    How can the life-time extension decision be supported with an economic-technical decision analysis? 

3.    What is a practical method to evaluate the turbine remaining useful life from low-resolution SCADA?