A large portion of the energy you generate through your PV array will be exported to the grid because it is unused. You can get paid for this exported energy but at a fraction of what it would cost you to buy back.
Adding battery storage will help you store your excess generated energy (that would normally be exported) for use later when your consumption is higher than your generation. As electricity prices rise this sort of battery storage system will become more and more cost effective.
Add battery storage to your system and be on your way to self-sufficiency.