G98 Regulation & DNO Notification Guide for Plug-in Solar

Engineering Recommendation G98 is the technical standard governed by the Energy Networks Association (ENA) for connecting micro-generators (up to 16A per phase) to the UK low-voltage distribution network.

What G98 Compliance Requires

G98 compliance ensures that small-scale generators do not compromise grid stability or line-worker safety.

• Anti-Islanding: If the local electricity grid drops out, the microinverter instantly disconnects generation. This prevents power from feeding back into external lines where engineers may be carrying out repairs.
• Power Quality: Limits voltage fluctuations, total harmonic distortion (THD), and DC injection into the AC mains.

How to Notify Your Distribution Network Operator (DNO)

Under G98 regulations, plug-in solar installations operate under a “Fit and Inform” process. You do not need prior approval from your DNO before plugging in, but you are legally required to submit a notification on or before the day of commissioning.

1. Identify Your DNO: Locate your regional operator (e.g., UK Power Networks, National Grid Electricity Distribution, SSEN, or Electricity North West) using your MPAN number or postcode.
2. Obtain the G98 Notification Form: Download the standard Form A1-1 from your DNO’s online portal.
3. Attach Microinverter Certification: Include the ENA Type Test summary sheet provided by your equipment manufacturer.
4. Submit the Form: Upload or email the completed documentation to your DNO. You will receive an acknowledgment receipt for your records.