Real-time simulation has become a cornerstone for validating control, protection, and communication strategies in emerging energy systems, enhancing the design-to-deployment workflow. This talk showcases industrial examples of Real-Time Hardware-in-the-Loop (HiL) testing applied to offshore wind farm integration, future 800 V DC data center power architectures employing solid-state transformers (SSTs), and railway traction systems. Across selected OPAL-RT project examples, we first demonstrate the use of FPGA-based solvers to capture fast electromagnetic transients and multi-rate dynamics in hybrid AC/DC networks. Second, we present the real-time emulation of large-scale offshore wind collector systems, enabling controller validation under grid fault and black-start conditions. Finally, we discuss the testing and validation of railway traction control systems to ensure reliable and robust rolling stock operation.