Does this mean that the solar elements are not connected to the grid, i.e you don't send your excess back to the energy company's grid or does it mean that your

Does this mean that the solar elements are not connected to the grid, i.e you don't send your excess back to the energy company's grid or does it mean that your only power is solar? If is the former how does that work in practice you have different circuits for connected to the solar stuff?