Officially until your panels are all approved and legally connected to the grid you cannot get any feed-in credits.
If you have an old style meter it will not register feed-in to the grid anyway.
With the old meters some of them do not realise that you are feeding into the grid and actually will charge you as a usage.
Unless you have permission to Generate you should leave your panels turned of until its all legal.
I was lucky my old meter did not register anything from the panels, so for the 6 weeks it took them to install a new meter I generated power and fed it back to the grid which meant that I was getting some benefit from my panels as I was not using power from the grid while the panels were in Sun.