If you’re planning to install solar panels or a home battery, there’s a good chance you’ll come across something called a DNO application. It’s one of the more technical steps in the process – but don’t worry. In this guide, we’ll break down exactly what it is, whether you need one, and what to expect.
We’ll also explain what a DNO letter is, how to find out who your DNO is, and how the rules differ depending on where you live in the UK.
What is a DNO (Distribution Network Operator)?
If you're planning to install solar panels at home, you’ll likely come across something called a DNO application. Your Distribution Network Operator (DNO) is the company that owns and operates the electricity cables in your area. Their job is to manage the safe and reliable delivery of electricity to homes and businesses.
If you’re installing a system that connects to the grid – like solar panels or battery storage – your DNO needs to know about it. That’s because your system could export electricity to the grid, and the DNO must check that the local network can handle it.
Here’s what the DNO checks during the application:
- Can the local grid handle it? The DNO looks at whether your local electricity network has the capacity to take on the extra power your solar panels will produce. In some cases, upgrades might be needed.
- Is it safe? The DNO ensures your solar setup meets all the technical and safety standards, helping to prevent any issues like voltage spikes or interference with other homes on the grid.
This isn’t just a box-ticking exercise — it’s an essential step to make sure everything runs smoothly and safely.
What is a DNO application?
A DNO application is a request submitted by your installer to your local electricity network operator. It asks for permission to connect your solar panel or battery system to the grid.
Depending on your system size and setup, the application might be required before installation, or simply submitted as a notification after installation. This is governed by UK standards known as G98, G99, and G100.
G98 vs G99: What’s the difference?
G98 – For smaller systems
If your solar panel system is under 3.68kW per phase, it qualifies under G98. You can install it straight away, and your installer will notify your DNO within 28 days.
G99 – For larger systems or home batteries
If your system is larger than 3.68kW per phase, or includes a battery, you’ll likely need a G99 application. This must be approved before installation.
G100 – If your export needs to be limited
If your DNO determines the local grid can’t handle the full export of your system, they may require you to limit it. In that case, your installer will apply under G100 and install an export limitation device.
What is a DNO letter?
Once your application is approved, your DNO will send you a DNO letter. This document confirms that your system is either approved (for G99/G100), or has been successfully notified (for G98).
It’s an important piece of paperwork that proves your system is legally and safely connected to the electricity network. You may need to show it if you sell your home, apply for smart export payments, or switch energy providers.
How long does a DNO application take?
• G98: Immediate – install first, notify later. No waiting required.
• G99: Can take 4–8 weeks for approval, depending on the complexity.
• G100: May require a longer review, particularly if export-limiting equipment is involved.
Who is my DNO?
Your DNO depends on where you live in the UK. Each region has its own operator. To find yours, you can:
• Check your electricity bill – it’s often listed on there.
• Use the Energy Networks Association postcode tool: Energy Networks Association (ENA) - The voice of the networks
Or, you can match your region using the list below.
DNOs across the UK – Find yours here:
| Region | DNO | Website |
| North West England | Electricity North West | Electricity North West |
| North East, Yorkshire, Northern Lincolnshire | Northern Powergrid | http://northernpowergrid.com |
| Midlands, South West, South Wales | Western Power Distribution (now part of National Grid) | National Grid - Home |
| London, South East, East of England | UK Power Networks | Distribution Network Operator | UK Power Networks |
| Merseyside, Cheshire, North Wales | SP Energy Networks | Welcome to SP Energy Networks |
| Central & Southern Scotland | SP Energy Networks | Welcome to SP Energy Networks |
| South Scotland, North West England | Scottish and Southern Electricity Networks (SSEN) | Scottish and Southern Electricity Networks (SSEN) |
| Central Southern England | Scottish and Southern Electricity Networks (SSEN) | Scottish and Southern Electricity Networks (SSEN) |
Do I need to apply myself?
No – if you’re working with a certified installer (like those partnered with Solar Together), they’ll manage the whole process for you. That includes identifying whether your system is G98 or G99, completing the paperwork, and submitting the application or notification on your behalf.
Final thoughts
Installing solar panels or battery storage might seem like a big project – but with the right support, it’s straightforward. And that includes making sure your DNO application is submitted correctly, so your system is connected safely and legally.
The best part? When you sign up through Solar Together, we connect you with trusted, MCS-certified installers who take care of everything – including your solar panel DNO application.
Want to see if solar is right for your home?
Join your local Solar Together scheme for a personalised offer – no pressure, no hidden costs, and DNO application included.