HVAC IEEE Electrification Magazine / DECEMBER 2021 13 PV-Plus-Storage Plant (ac Coupled) Plant SCADA Power Communication Operations Center SCADA and Database Historian PCS Skid PV Array DS DS Controller DC/ac Inverter Transformer PV Meter BESS BESS Skid BMS Fire Protection System Controller Gas Detection and Ventilation Enclosure PLC DC/ac Inverter Transformer BESS Meter Network Switch PCS Skid Controller Substation POI Meter Network Switch Dispatch Controller Plant Controller Grid Interface Generator Operator Figure 5. The control of an ac-coupled BESS. SCADA: supervisory control and data acquisition; PCS: power conditioning system; POI: point of interconnection. (Source: Urban Grid; used with permission.)