DNOs: Who is my distribution network operator?

If you are installing solar panels, your system must be registered with your local Distribution Network Operator.

Smaller systems are usually notified after installation under G98. Larger systems require approval before installation under G99. Either way, your DNO must be involved.

When you install with iHeat, we manage this entire process on your behalf. You do not need to contact your DNO directly.

What is a DNO?

A Distribution Network Operator owns and operates the regional electricity distribution network across Great Britain.

There are six licensed DNO groups, each covering a defined geographic area. They are regulated by Ofgem under strict licence conditions covering safety, reliability and service standards.

DNOs are responsible for:

• Maintaining local substations and distribution cables

• Managing grid capacity within their region

• Approving new connections and embedded generation

If your home is connected to the grid, it is connected through infrastructure owned by your DNO.

What does a DNO do for solar installations?

When you install solar panels, your home becomes a small electricity generator.

That generation must comply with national engineering standards before it can export electricity to the grid.

The key standards are:

• Engineering Recommendation G98 – for systems up to 16A per phase, typically up to 3.68kW per phase. These are normally notified to the DNO after installation.

• Engineering Recommendation G99 – for systems above 16A per phase. These require approval from the DNO before installation.

• Engineering Recommendation G100 – used where export limitation equipment is installed to restrict how much electricity can be exported.

These standards govern how small-scale generation connects to the public distribution network.

Your DNO reviews the application to confirm:

• The local network can safely accept exported electricity

• Voltage levels will remain stable

• Protection settings meet regulatory requirements

Export cannot take place without the correct notification or approval.

Do you need to contact your DNO yourself?

If you install solar with iHeat, no.

We:

• Assess whether your system falls under G98 or G99

• Submit the correct documentation

• Manage export limitation requirements under G100 where needed

• Liaise directly with your DNO

• Secure formal approval where required

This ensures your installation is compliant before it goes live.

The approval process is a legal requirement under UK grid connection rules. Managing it properly avoids delays and ensures your system can operate safely and lawfully.

You can learn more about how our systems are designed and installed on the iHeat solar page!

Why your DNO matters for solar capacity

Every regional network has finite capacity.

In areas with high solar uptake, your DNO may:

• Approve an export limit

• Request additional technical information

• Require system adjustments before approval

In some situations, if a customer applies for higher export capacity than the local network can accommodate, the DNO may identify reinforcement works.

These are assessed individually and are not typical for standard domestic systems.

These checks protect the stability and safety of the electricity network.

An experienced installer plans for this.

At iHeat, systems are designed with local grid constraints in mind.

Applications are submitted in line with current engineering standards to minimise delays and ensure compliance.

Who is my DNO?

Your DNO depends on where you live. You can usually find your MPAN number on your electricity bill. The first two digits identify your distribution area.

Below is the current regional breakdown for Great Britain in (updated as of 2026).

If you are unsure, you can use the official Find my network operator tool provided by the Energy Networks Association:
https://www.energynetworks.org/customers/find-my-network-operator

DNO vs electricity supplier

Your electricity supplier sells you energy and sends your bill.

Your DNO owns and operates the infrastructure that physically delivers electricity to your property.

They are separate organisations with different responsibilities.

For solar installations:

• Your DNO authorises grid connection and export

• Your electricity supplier may manage Smart Export Guarantee payments

Understanding this distinction prevents confusion during installation.

DNO final points

Your Distribution Network Operator manages the regional electricity network that your solar system connects to.

Before your system can export electricity, your DNO must be notified or grant approval under UK engineering standards.

When you install with iHeat, we manage that process in full. We submit the correct applications, handle export approvals and ensure compliance before your system goes live.

That means no paperwork for you and no uncertainty about grid approval.