U.S. Department of Energy released the below-linked article that discusses the utility of "droop" or frequency/voltage-based regulation to manage active & reactive power flows (respectively) without the need for communications between power sources. If put it briefly, the author suggests that with droop control they can avoid the need for an EMS for a hybrid microgrid site. https://cleantechnica.com/2022/10/03/microgrids-for-anyone/ //

Let me start by agreeing that the droop control technique is an essential tool in any modern Microgrid control strategy. Not because it's the “be all and end all” of control methods, but rather it’s a very effective fallback strategy. No Microgrid control system supplier worth their weight in salt, wants to deliver a system that cannot manage communications failure events and whilst redundant communications are a solution, droop control is superior in terms of cost-benefit outcomes. //

Whilst the utility of this technique is apparent, the point that I return to is this is by no means a complete solution offering. A holistic Hybrid Energy Management system will provide:

1. Overall power management of both dispatchable energy sources and loads
2. Coupling and decoupling from grid tie-in point including support of:
   • Re-synchronisation
   • Seamless transition during network disturbances
   • Import/Export and Network firming functions.
3. Quality of Service management - ensuring the microgrid provides grid quality power (or better), to energy off-takers at all times.
4. Energy Shifting – utilising renewable energy collected during the day to offset peak consumption during the night; and
5. Microgrid Optimisation both in terms of:
   • Minimising levelized cost of energy (LCoE) in isolated systems; and/or
   • Maximising return on investment potential for grid connected systems.

The net takeaway is this – not only are we far more progressed in terms of control methodology for hybrid microgrids, but the cost of ownership is significantly less than what most, including the article writer believe possible.