Grid and supply / Connection routes and export limits / G98 notification pathway

G-014·Grid and supply / Connection routes and export limits

G98 notification pathway

Connect-and-notify route for generation up to 16A per phase.

G98 is the usual connection route in Great Britain for a small, fully type-tested generator that operates in parallel with the public low-voltage network. At a single property it is a connect-and-notify process: a qualifying installation can be commissioned before its details are sent to the DNO, then the notification must be submitted within 28 days.

The route is defined by current, not by a familiar label such as “domestic solar”. The aggregate Registered Capacity must be no greater than 16 A per phase. At the nominal voltage used by G98, that corresponds to 3.68 kW on single phase or 11.04 kW across three phases. A system outside those conditions normally needs one of the G99 application routes before it is connected.

What the 16A limit applies to

The relevant figure is the AC rating of the micro-generating plant, not the solar array’s DC peak rating and not the battery’s storage capacity in kWh. A panel array can therefore have a higher kWp figure than the inverter’s AC rating without that difference alone deciding the connection route.

Where a property has more than one micro-generator, G98 uses their aggregate Registered Capacity. Existing generation cannot simply be ignored when another inverter or battery is added. The recommendation also says that diversity of operation is not used in this calculation. Two devices do not count as one merely because their controls are expected to stop them exporting at the same time.

Registered Capacity and export are different quantities. A G100 export limitation scheme controls power at the connection point, but an export cap does not automatically turn a larger generating installation into a 16A G98 installation. Combined solar and storage designs can instead fall within a G99 fast-track process where its conditions are met. The installer should establish the route from the complete design rather than from the proposed export limit alone.

Fully type-tested equipment

G98 applies to Fully Type Tested micro-generators. For equipment already recorded on the ENA Type Test Register, the notification normally uses the manufacturer’s system reference from that register. National Grid’s procedure also allows a type-test verification report to be supplied where the device is fully type tested but is not already registered. Absence from the online register should therefore trigger a documentation check, not an assumption that the equipment is acceptable or unacceptable.

The type test covers the generating unit’s response to network conditions. It does not certify the quality of the whole installation and it does not replace the electrical design, commissioning tests or other certificates required for the work.

The single-premises process

For one G98 installation at one property, the sequence is:

  1. The installer checks the existing connection, all existing generation, the new equipment’s Registered Capacity and its type-test evidence.
  2. The installation is completed and commissioned in accordance with G98 and the applicable electrical requirements.
  3. The installer sends the DNO the G98 Installation Document, the system schematic and the required photograph of the electricity cutout within 28 days of commissioning.
  4. The owner keeps the submitted information and the DNO’s acknowledgement with the rest of the handover documents.

The form is commonly called Form B. The exact portal and supporting information vary by DNO. National Grid Electricity Distribution, for example, asks for the device reference numbers for new and existing generation, the site postcode and installer and customer details. Its online service issues an immediate acknowledgement, but that is a feature of that DNO’s process rather than a timescale to assume everywhere.

Government guidance places a responsibility on the device owner to make sure the DNO has received the notification, even where the installer submits it. A sensible handover check is therefore to ask for the completed form, operation diagram and the DNO receipt. An MCS certificate and a DNO acknowledgement record different things; possession of one is not proof that the other exists.

Multiple premises are handled differently

G98 contains a separate process for an installer connecting micro-generators at more than one property in the same close geographic region within a 28-day period. That route requires the installer to approach the DNO before commissioning so the possible combined network effect can be assessed. It should not be confused with adding several devices behind one property’s meter, which is an aggregate-capacity question for that single installation.

Solar plus battery storage

Electricity storage is included within G98’s definition of micro-generation. The correct route for a battery depends on the electrical arrangement, existing plant and aggregate Registered Capacity, not simply on whether the battery is expected to export.

National Grid’s storage guidance illustrates why this needs care. A single-phase design with G98-compliant solar up to 16A, G98-compliant storage up to 16A and a G100-compliant export limitation scheme may qualify for the G99 fast-track route. It is still a G99 application made before installation, despite export being limited to 16A or less. Other configurations can follow different G99 routes.

Aggregate Registered Capacity determines the connection route; any G100 export limit is a separate value and does not reduce Registered Capacity.

Great Britain and Northern Ireland

G98 in this entry means the Great Britain process for England, Scotland and Wales. Northern Ireland has its own G98/NI document and NIE Networks forms. The numerical 16A threshold also appears in G98/NI, but the GB form and process should not be substituted for the Northern Ireland procedure.

Notification record

Keep the following with the system records:

  • the completed G98 Installation Document
  • the operation or single-line diagram submitted with it
  • the DNO acknowledgement or case reference
  • the system references or type-test reports for the generating equipment
  • the commissioning date and the ratings used to determine the route
  • details of any G100 scheme or separate G99 approval

If an existing system has no DNO record, or the installed equipment differs from the documents, the safe next step is to give the DNO accurate details and ask which form it requires. It is not possible to infer the correct retrospective route from inverter size alone.

Applies to

Solar, Battery

Last reviewed

22 Jul 2026