In some countries, the charging of a household battery with electricity from the public grid is subject to specific regulations. The background is usually regulations on the remuneration of electricity from renewable energy plants such as PV systems. This electricity is marketed as so-called green electricity. By labeling it as green electricity, the electricity generated can be sold at a higher price, which is why it is often necessary to ensure that there is no mixing of gray and green electricity.
Germany
In Germany, in particular, §19 paragraph 3a and 3b of the EEG regulate the conditions that must be met for charging the battery from the grid to be legally permissible.
Austria
In Austria, in particular, the requirements for the ÖMAG stipulate that no feedback of electricity from the battery into the public supply network may occur.