What Is DNO Approval and Why Is It Required for Some Solar Installations?

If you've started researching solar panels, you may have come across the term DNO approval.

For many homeowners, it's one of the most confusing parts of the installation process.

Questions like "What is a DNO?", "Do I need approval?", and "Will it delay my installation?" are incredibly common.

The good news is that, in most cases, your installer handles the entire process for you.

In this guide, we'll explain what DNO approval is, why it's sometimes required, and what it means for your solar installation.

What Does DNO Stand For?

DNO stands for Distribution Network Operator.

A Distribution Network Operator is the company responsible for managing the electricity network in your local area.

While your energy supplier sends your electricity bills, the DNO is responsible for maintaining the cables, substations and local electricity infrastructure that delivers power to homes and businesses.

Every area of the UK has its own Distribution Network Operator.

Why Does a Solar Installation Need DNO Approval?

When your solar panels generate more electricity than your home is using, the excess electricity is exported back into the National Grid.

Before larger systems are connected, the DNO may need to confirm that the local electricity network can safely accept that additional exported power.

This helps ensure:

• The local electricity network remains stable.

• Nearby properties aren't affected.

• The system operates safely.

• Grid equipment isn't overloaded.

It's simply a way of ensuring the electricity network continues operating safely for everyone.

Does Every Solar Installation Require Approval?

Not always.

Whether approval is needed depends on the size and design of the solar system being installed.

Smaller domestic systems often follow a simplified notification process after installation.

Larger systems, or systems capable of exporting more electricity, may require approval before installation begins.

Your installer will determine which process applies to your property.

What Are G98 and G99?

You may also hear installers mention G98 and G99.

These are engineering standards that determine how renewable energy systems connect to the electricity network.

G98

G98 generally applies to smaller systems that fall within certain export limits.

These systems can usually be installed first, with the DNO being notified shortly afterwards.

G99

G99 applies to larger or more complex systems that exceed those limits.

In these cases, approval is normally required before installation can begin.

Although the terminology sounds technical, your installer manages the application on your behalf.

Will DNO Approval Delay My Installation?

Sometimes—but not always.

If approval is required before installation, the DNO needs time to review the application.

The exact timescale varies depending on:

• Your location.

• The size of the system.

• Current application volumes.

• Whether additional network assessments are required.

An experienced installer will factor this into your project timeline and keep you informed throughout the process.

Do I Need to Contact the DNO Myself?

No.

In almost every case, your installer will handle the entire DNO application process for you.

This includes:

• Preparing the required documentation.

• Submitting the application.

• Communicating with the DNO.

• Confirming approval before installation if required.

For homeowners, it's largely a behind-the-scenes process.

Can a DNO Reject a Solar Installation?

It's uncommon, but there are situations where the DNO may request changes before approving a system.

For example, they may recommend:

• A smaller export capacity.

• Export limitation equipment.

• Minor design adjustments.

This doesn't necessarily mean you can't have solar panels—it simply ensures the installation is compatible with the local electricity network.

A good installer will discuss any requirements with you and recommend the most suitable solution.

Does Battery Storage Affect DNO Approval?

It can.

Adding battery storage may alter the amount of electricity your system is capable of exporting to the grid.

Because every battery system is different, your installer will assess the complete system and include any relevant information within the DNO application if required.

This ensures the installation complies with current regulations from the outset.

Why Experience Matters

DNO applications are a routine part of many professional solar installations, but accuracy is important.

Submitting the correct information helps avoid unnecessary delays and ensures your installation progresses as smoothly as possible.

At Sirius Solar, we manage every stage of the process on your behalf—from designing your system to handling any DNO requirements—so you can focus on the benefits of switching to renewable energy.

Ready to Start Your Solar Journey?

Whether your installation requires DNO approval or not, Sirius Solar will guide you through every step of the process.

We'll assess your property, explain everything in plain English and take care of the technical paperwork, ensuring your installation is completed safely, professionally and with minimal hassle.

Contact Sirius Solar today for a free, no-obligation quotation and let our experienced team design the perfect solar system for your home.