This talk presents recent advances in the application of space–time, finite-element-based methods (FEM and isogeometric analysis, IGA) to the medium- and high-fidelity simulation of rotating machinery in renewable energy. The focus is on turbulent and multiscale flows, addressed through a stabilized space–time variational multiscale (ST-VMS) formulation. In this context, the variational multiscale approach is presented as an alternative turbulence-resolution strategy that is able to account for the range of scales to be resolved, in both ducted-flow configurations and large-scale machines operating in wind-farm environments. From a methodological standpoint, we will introduce the stabilized formulation and discuss additional variants designed to tackle specific challenges that arise in the two application settings. We will also present a comparison between FEM- and IGA-based results. The talk then considers two application tracks separately. First, we discuss ducted machines and full-rotor simulations, highlighting the role of the space–time stabilized formulation and its variants in handling turbulent, multiscale flow features in confined configurations. Second, we address utility-scale wind energy applications, focusing on the integration of additional modeling for aeroelastic simulations of large wind turbines, including the use of innovative actuator-line techniques.