Real-Time Operation of a Stand-Alone Microgrid With Green Ammonia Storage

A novel stand-alone microgrid concept incorporating green ammonia for energy storage is proposed in this work. Wind and solar energy are captured and used for meeting residential demands or powering water electrolysis. Hydrogen produced from electrolysis is further used to produce ammonia through the Haber-Bosch process. Generator sets are dispatched for power generation from hydrogen or ammonia. A two-level hierarchical control architecture is designed for the microgrid. Local controllers are designed for each module in the framework, taking hourly commands from an upper-level dynamic real-time optimization (D-RTO) layer. Simulation case studies are conducted for Duluth, MN, Phoenix, AZ, and Las Vegas, NV, with 24-h time horizons for different seasons. The results indicate geographical differences in the utilization of renewable sources and the energy storage medium employed, confirming that ammonia is preferred over hydrogen as a long-term energy storage option.