This Self Consumption storage package contains all components for building a reliable Sunny Island system with ample energy from a LG Chem lithium-ion battery. The system is AC-coupled, so it can be combined with all existing PV inverters. This makes it an ideal system for both existing installations and in combination with other energy sources. If using this storage system for grid Back Up an additional Transfer Switch box will be required, it's not included in the price. This Package is NOT compatible for Off-Grid applications!