PV System Diagram: Documentation and AREI/RGIE Requirements for Solar Installations

A photovoltaic (PV) system on your roof is not just an investment in the future in Belgium — it must also be correctly documented and registered with the distribution grid operator (DSO). In this article, you will learn how the PV system is represented in the single-line diagram, which protection devices are required, and what to consider during registration.

Why Is Documentation Mandatory?

Every PV system must appear in the electrical documentation of your building — meaning:

1. Single-line diagram: The PV system with all components (modules, inverter, protection devices) must be drawn in.
2. Situation plan: The position of the inverter and DC disconnect switch must be marked.
3. Grid operator registration: The system must be registered with the relevant DSO.

Without correct documentation:

• The AREI/RGIE inspection will fail.
• The grid operator can refuse the grid connection.
• Entitlement to feed-in compensation or prosumer tariff is lost.

What Goes in the Single-Line Diagram?

The PV system is shown as a separate branch in the single-line diagram. The signal flow runs from the modules to the feed-in point:

Component Chain

PV Modules (strings)
   │
   ├── DC cable (solar cable, e.g. 6 mm²)
   │
   ├── DC disconnect switch (firefighter switch)
   │
   ├── SPD DC side (surge protection DC)
   │
   └── Inverter
         │
         ├── SPD AC side (surge protection AC)
         │
         ├── MCB for PV circuit (e.g. B20A or C20A depending on inverter)
         │
         ├── RCD 30 mA Type A (or Type B for transformerless inverter)
         │
         └── Feed-in point (connection to main board)

Symbols in the Diagram

Protection Devices for PV Systems

DC Side (Between Modules and Inverter)

Firefighter switch: According to AREI Art. 7.112, the DC disconnect switch must be easily accessible and clearly marked (red sign with lightning symbol). It can also be installed inside the building, provided it is locatable by rescue services.

AC Side (Between Inverter and Board)

Which RCD Type?

Tip: Modern inverters often have an integrated RCMU (Residual Current Monitoring Unit) that detects DC fault currents. In this case, a Type A RCD is sufficient. Check the manufacturer's specifications.

Registration with the Grid Operator

Relevant Grid Operators in Belgium

Registration Process

1. Before installation: Application for grid connection / capacity increase with the DSO (often required for systems > 5 kVA).
2. After installation: Submit the installer's declaration of conformity.
3. AREI inspection: By an approved control body (e.g., BTV, Vincotte, AIB).
4. Meter change: Switch to a bidirectional (digital) meter.
5. Activation: Grid operator authorises feed-in.

Required Documents

• Single-line diagram (including PV system)
• Situation plan
• PV module datasheet
• Inverter datasheet
• Installer's declaration of conformity
• AREI inspection report

Deadlines

• Fluvius (Flanders): Registration within 30 days of commissioning.
• ORES (Wallonia): Registration before commissioning recommended.
• Sibelga (Brussels): Pre-registration for systems > 5 kVA.

Self-Consumption vs. Feed-In

Flanders: Digital Meter

Since 2021, all analogue meters in Flanders are being progressively replaced with digital meters. The digital meter measures consumption and injection separately:

• Self-consumption is directly offset (no grid charges).
• Feed-in is compensated at the current market price (injection tariff).
• Grid consumption is charged at the normal rate.

Tip: Maximise self-consumption through smart control (heat pump, boiler, EV charger during daytime).

Wallonia: Prosumer Tariff

In Wallonia, since 2024, the prosumer tariff applies:

• Compensation between injection and consumption on an annual basis (until end of 2030).
• From 2031, gradual transition to real-time metering.
• Grid charges are calculated based on annual consumption.

Brussels

• Green certificate system: Green certificates per MWh produced.
• Compensation via the meter is possible (depending on meter type).

Battery Integration in the Diagram

If you add battery storage, the diagram is extended:

Additional Components

Inverter (hybrid inverter)
   │
   ├── AC output → Main board (as above)
   │
   └── DC battery connection
         │
         ├── Battery disconnect switch (DC)
         │
         ├── BMS (Battery Management System, internal)
         │
         └── Battery storage (e.g. 10 kWh LFP)

Backup Power Switching (Optional)

For a backup-power-capable system, add:

• Transfer switch (automatic or manual): Isolates the house from the grid and powers it from the battery.
• Must be drawn in the single-line diagram as a changeover switch.
• Backup circuits must be identified.

AREI requirement: For backup power systems, it must be ensured that no back-feed to the grid occurs when the grid is disconnected (anti-islanding protection).

AREI Special Rules for PV (Art. 7.112)

The AREI dedicates a specific section to PV systems — Art. 7.112. The key points:

Building Signage

According to the AREI, a warning sign must be affixed to the building indicating the PV system:

• At the meter box or main board
• At the DC disconnect switch
• At the building entrance (firefighter information)

Text: "Warning: Photovoltaic installation. DC voltage may be present even when the grid is disconnected."

PlanElec: PV in the Single-Line Diagram

With PlanElec, you can document your PV system directly in the single-line diagram:

• Add PV modules as a source
• Place inverter and protection devices
• Automatic AREI validation (SPD present? DC disconnect? RCD type correct?)
• Export as PDF for grid operator and control body

Related Articles

• What Is a Single-Line Diagram?
• Distribution Board Planning: Layout and Sizing
• Cable Cross-Section and Breaker: The Right Combination
• Electrical Inspection in Belgium

Document your PV system to code with PlanElec — inverter, protection devices, and battery storage in the single-line diagram. AREI-compliant, export-ready for the grid operator. Start now →