Solar plus Storage can either be couples in an AC architecture or a DC architecture.
In an AC-coupled architecture, installations there are two inverters, one for the PV array and another for the battery energy storage system. With this system configuration, both the battery and solar array can be discharged at maximum power and they can be dispatched independently or together. Examples of this architecture are systems deploying Tesla Powerwalls or Enphase Encharge Storage Systems.
In a DC-coupled architecture, the solar array and energy storage system are connected on the same DC bus and use the same inverter. They are dispatched together as a single facility. DC coupling reduces efficiency losses, which occur when electricity current is converted, such as from DC to AC. This architecture usually needs DC-DC optimizers on the panels. An example is the LGChem RESU10H battery with the SolarEdge StorEdge Hybrid inverter.