Sustainable electromechanical drives are essential in the transition to a greener future. Electric machines play a central role in this by their efficient energy conversion. Reusing or extending the lifespan of existing drivetrains contributes to sustainability by reducing waste and saving raw materials. Condition monitoring using digital twins plays a key role in this process. These digital replicas of physical drivetrains allow for real-time condition monitoring and early detection of anomalies. This process ensures that the lifespan of the drivetrain can be extended. The digital twin also enables the creation of a digital passport for the machine. This information can be used during the maintenance phase of the drive. Specifically, rewinding the machine based on the information in the passport is very promising. Finally, the experimental validation of the refurbished machine in the form of accurate loss measurements is important.