Grid-tie systems are designed to feed your locally produced electricity into the central utility grid. In its simplest and most common form, grid-tie systems feed all of their generated power to the grid and do not allow the home owner to utilize any of their generated power. More complex systems allow for both feeding power to the grid and utilizing their generated power locally when the utility grid goes down.
Buy grid-tie systems
Or contact the seller
in section "Installation of PV modules"