What is a DNO for solar panels?

A DNO is a Distribution Network Operator. It manages the local electricity network that your solar system connects to, so solar installations need to be notified or approved through the relevant DNO process.

What is the difference between G98 and G99?

In simple terms, G98 is commonly used for smaller type-tested generation installations on a fit-and-notify basis, while G99 is used for larger or more complex generation that may need approval before connection.

Who should handle the DNO process?

In many domestic installations, the installer handles the DNO notification or application. The homeowner should still ask which route applies and what proof they will receive after installation.

What is a DNO acceptance letter?

A DNO acceptance letter confirms that the solar installation was reported to the network operator and approved for export. Some energy suppliers may ask for it when setting up export payments.

DNO G98 and G99 for Solar Panels: UK Homeowner Guide

DNO paperwork is one of those solar details that can sound technical enough for homeowners to ignore. That is risky. You do not need to complete the forms yourself in most cases, but you do need to know that the installer has a plan for them.

The short version: your solar system connects to the local electricity network. The network operator needs to know about that connection, and sometimes needs to approve it before the system can export electricity.

Quick answer A DNO is your Distribution Network Operator. For smaller solar installations, the process is often G98, a fit-and-notify route where the DNO is notified after commissioning. Larger or more complex systems may need G99 approval before connection. Ask your installer which route applies, who submits the paperwork, and what confirmation you will receive.

What the DNO actually does

Your electricity supplier sends bills. Your DNO manages the physical local network. When solar panels export electricity back to the grid, the DNO needs accurate information about the equipment and export capacity.

Energy Saving Trust says the installer should register your solar panel system, and any battery storage, with the local Distribution Network Operator. That makes the DNO process part of the job, not a vague extra.

G98 and G99 in plain English

National Grid describes micro generation under G98 as a simple connection procedure for fully type-tested installations under 16A per phase, usually on a fit-and-notify basis. Its G98 guidance says the DNO should be notified within 28 days of commissioning.

National Grid also explains in its DNO acceptance letter FAQs that G98 and G99 are commonly confused by suppliers. G98 is used for smaller installations, while G99 applies to anything larger in that explanation. The document a supplier often really wants is the DNO acceptance letter confirming the process took place and was accepted.

Term	Plain-English meaning	Question for installer
DNO	The network operator for your local electricity grid	Which DNO covers my property?
G98	Usually a smaller fit-and-notify generation route	Will my system be notified under G98?
G99	Usually a larger or approval-before-connection route	Do we need G99 approval before installation?
Acceptance letter	DNO confirmation that the installation was reported or accepted	When will I receive this document?

Why this matters before deposit

DNO paperwork can affect timing, export assumptions and handover. A quote that assumes immediate export may be too casual if the system actually needs approval before connection. A good installer should be able to explain the route before you commit.

Ask especially carefully if:

the proposed system is larger than a standard small domestic setup;
a battery or export-limiting device is included;
you are increasing an existing solar system;
the quote assumes high export income;
you may need proof for a future SEG tariff application.

The homeowner checklist

Ask which DNO covers your property.
Ask whether the system is expected to be G98 or G99.
Ask whether the installer submits the notification or application.
Ask whether approval is needed before installation.
Ask what document you receive after the DNO process is complete.
Keep the DNO confirmation with your MCS certificate, warranties and handover pack.

A useful question to copy

Please confirm whether my proposed system will be handled under G98 or G99, whether DNO approval is needed before installation, who submits the paperwork, and what DNO confirmation or acceptance letter I will receive after completion.

If an installer cannot answer that clearly, pause before paying.

Related: Pair this with the MCS certificate guide and the solar quote checklist before you compare quotes.

Sources

Disclaimer

This article is general information only. DNO processes and technical requirements can depend on equipment, network area and installation design. Always verify current requirements directly with your installer and relevant network operator.