Connection of PV system to the grid or to the private low voltage installation
From Electrical Installation Guide
Direct connection of PV system to the grid
When PV system is installed for "grid feeding", Utility that operates the grid will provide requirements for protection, disconnection, and metering function.
Each utility may have specific requirements according to local habits and grid specificity.
As a general rules the following functions are required :
- Energy meter (both direction)
- Disconnecting device (some countries require visual break)
- Over-current and earth fault protection according to earthing system
- Anti-islanding protection like VDE0126.