The EMS acts as the main controller, coordinating multiple containerized BESS units, achieving 0-to-max power response within 500 ms. It interfaces with the local VPP to maximize participation in ancillary services such as FCR and FFR.

EcoWatt enables real-time communication between the EMS/BESS and the Bulgarian TSO via a TSO RTU supporting the IEC 60870-5-104 protocol, and leverages the EMS to participate in the ancillary services market, providing technical support.

Connected to the 35 kV grid, the system participates in grid frequency regulation ancillary services and, during most time periods, performs electricity price arbitrage. At the same time, by regulating power through energy storage, it reduces the ocean park’s grid electricity demand during performance hours, thereby lowering overall electricity costs.

Under this optimized control strategy, the system leverages electricity price differentials to perform peak-valley arbitrage with 100 MWh of energy storage capacity while actively participating in ancillary service markets, thereby enhancing overall energy efficiency and grid flexibility and generating stable, sustainable revenue.