Danish wind turbine manufacturer Vestas Wind Systems A/S built a novel multi-rotor wind turbine using the DOE Wind Program Sandia National Laboratories’ control software and hardware in the loop system to create, configure, & test the controls system. Sandia created a hardware-in-the-loop system and an open-source rapidly reconfigurable control software environment to test and deploy innovative technology at the Scaled Wind Farm Technology facility (SWiFT). Vestas designed an innovative demonstrator turbine with four nacelles and four rotors (29 m diameter) attached to a single support structure. Offering new opportunities for wind energy production, this cutting-edge concept requires a flexible and unconventional control system.