Owner grid is a 230 V single-phase AC power network that can be installed between 2 or more ZHERO systems. Through this network, special rules can be followed to transfer surplus solar power production to the other system or to receive it when needed. This exchange of surplus energy is set up as a priority channel with respect to transfer back to the grid to aid energy independence. Currently, this exchange is only permitted in Italy on the condition that a smart grid is created that is completely separate from the national grid, while in various other countries it is already permitted.