timi

Most modern inverters will give you some sort of interface that you use to monitor the inverter and how much power is used. I can do that with my Goodwe, and it's by no means uncommon functionality. I know for each day how much power my property consumed and how of much of that power was provided by the PV and how much from the grid.

So depending on what equipment you are using, you may not need a meter. 

Your municipal meter will tell you what you used from the grid. The solar system itself has to provide the rest of the data.