Charging a home battery with electricity from the public grid is subject to specific requirements in some countries. This is usually due to regulations concerning the remuneration of electricity from renewable energy systems, such as PV systems. This electricity is marketed as so-called green electricity. Because it is labeled as green electricity, the generated power can be sold at a higher price; therefore, it must often be ensured that no mixing of grey and green electricity occurs.
Germany
In Germany, sections §19 (3a) and (3b) of the EEG (Renewable Energy Sources Act) specifically regulate the conditions that must be met for charging a battery from the grid to be legally permissible.
Austria
In Austria, the requirements of the ÖMAG, in particular, mandate that no electricity from the battery is fed back into the public power grid.