In distributed green-energy architectures, where a customer location has energy storage as well as local generation, the present application provides techniques which advantageously prevent the battery from being charged from the grid. This is preferably implemented by using voltage-level signaling to limit power transfer from grid to battery, thereby 1) allowing transfer from PV to battery, and 2) preventing round-trip transfer of net energy from grid to battery to grid. This is particularly advantageous where net energy metering is allowed, or where any analogous form of preferential pricing is given to green energy (or to solar energy specifically).