One of the limitations of some grid-tied photovoltaic systems is that the owner will only benefit as long as there is sunlight while the grid is functioning. Otherwise, if there is an outage, they may not even use the energy they are generating from the rooftop. During such times when the grid is disconnected, the owner can neither use the rooftop solar nor export the energy to the grid.
Owners of PV systems without backup functionalities can upgrade by adding AC coupling. This enables them to store energy and use it anytime, including during emergencies and grid outages. The AC coupling converts a simple grid-tied system into a Grid/hybrid or grid interactive system. This provides grid-ties savings whenever the grid is up and running, and off-grid independence, as well as security when there is a utility outage.
The main components of AC coupling include an energy storage system, a grid-interactive inverter/charger, a coupling device and the second panel with additional wiring for the critical loads to supply during outages.
Battery storage enables better power management by providing a number of benefits which include: