Table of Contents
- What Is a DNO Application?
- Why Every Solar DNO Application Matters
- G98 or G99: Which DNO Application Do You Need?
- How to Complete a DNO Application Step by Step
- What Is DNO Approval? Letters, Certificates and Timescales
- DNO Application Costs, Delays and Grid Limits
- DNO Application in Perth, Inverness and Across the UK
- Common DNO Application Mistakes to Avoid
- How PTOEdge Supports Your DNO Application
- FAQs About Your DNO Application
- Start Your DNO Application With PTOEdge
DNO Application for Solar Panels: The Complete UK Homeowner Guide
DNO Application tells your local electricity network operator that you plan to connect solar panels to the grid. Therefore, every UK homeowner who installs solar PV should understand this step before the first panel goes on the roof. Moreover, a complete DNO application saves weeks of delay and prevents costly rework.
In this guide, PTOEdge explains what a DNO is, which form your system needs and how to get your DNO letter. Additionally, you will find document checklists, cost notes and local guidance for areas such as Perth and Inverness. As a result, you can plan your solar project with confidence.
Notify or Apply
Small systems notify the DNO after installation. However, larger systems need approval first.
28-Day Rule
Therefore, a G98 notice must reach the DNO within 28 days of commissioning.
Proof of Compliance
Also, your DNO letter proves your system is lawful when you sell or claim export payments.
Six DNO Groups
Moreover, your postcode decides which operator receives your form.
What Is a DNO Application?
A DNO application is a formal request to your Distribution Network Operator. It asks permission to connect a generator, such as solar panels, or it notifies the operator that you have already connected one. In other words, it tells the network that your home now exports power as well as imports it. Because engineers built the grid for one-way flow, every operator needs to know about new generation. Consequently, the DNO checks that your system will not overload local cables or transformers.
Many homeowners search for what is a DNO application after their installer mentions it. Simply put, it is the paperwork that links your solar design to the wider network. For example, it lists your inverter size, export limit and property details. Furthermore, it follows technical rules from the Energy Networks Association, while Ofgem regulates the operators themselves.
What Does DNO Stand For?
DNO stands for Distribution Network Operator. Online, people also type d.n.o or dno energy, yet all of these terms point to the same type of company. According to Wikipedia’s overview of distribution network operators, these companies own and run the local wires that carry electricity from the national grid to homes and businesses. Therefore, a DNO is not your energy supplier. Instead, it manages the network that your supplier uses.
Who Is Your Electric DNO?
Great Britain has 14 licensed distribution areas, and six companies run them. Your electric DNO depends on your postcode, not on who sends your bill. For instance, UK Power Networks covers London, the South East and the East of England. Meanwhile, Northern Powergrid serves the North East and Yorkshire, and Electricity North West serves the North West. In Northern Ireland, NIE Networks takes that role. You can confirm your operator on the Energy Networks Association website, or you can ask your installer to check it for you.
The DNO
The DNO maintains poles, cables and substations. Therefore, it receives and reviews your solar application.
Your energy supplier
Your supplier bills you and may pay for exported power. However, it does not approve your grid connection.
Installer and design partner
Your installer prepares the forms. In addition, UK solar design support from PTOEdge can supply the drawings behind them.
Why Every Solar DNO Application Matters
Skipping the process creates real risk. First, an unreported system can breach connection rules, so your DNO may ask you to disconnect it. Second, a Smart Export Guarantee supplier may want proof of compliance before it pays for exports. Third, a missing record can slow a house sale, because buyers’ solicitors ask for solar paperwork. Therefore, treat every DNO application for solar as a legal and financial step.
Solar energy distribution also depends on accurate records. When many homes on one street export at midday, local voltage can rise. Consequently, DNOs track new connections and sometimes set export limits. A correct DNO application gives them the data they need, so your system keeps running smoothly.
Legal compliance
Because UK rules require notification or approval, a filed application keeps your system lawful.
Export payments
Moreover, many export suppliers ask for your DNO confirmation before they start payments.
Sale readiness
Likewise, buyers expect solar documents. A tidy file, backed by clear solar plan set requirements across the UK, USA and Canada, speeds up conveyancing.
Network safety
In addition, accurate data protects local voltage and your neighbours’ supply.
G98 or G99: Which DNO Application Do You Need?
The answer depends on system size. Most UK homes install between 3 kW and 8 kW, so the route varies from house to house. The table below shows the main difference.
| Route | Typical Size | When to Tell the DNO | Approval Needed |
|---|---|---|---|
| G98 (connect and notify) | Up to 16 A per phase, about 3.68 kW on one phase | Within 28 days after commissioning | No prior approval |
| G99 (apply, then connect) | Above 16 A per phase | Before installation | Written DNO approval |
G98 Notification for Small Home Systems
G98 works as a connect and notify route. You install first, and then you inform the DNO within 28 days of commissioning. Because the system is small, the DNO normally skips a network study. However, the inverter must hold a valid type test certificate, and the total export must stay within the limit.
What Is a G99 Application?
So, what is a G99 application? It is the formal request for generation above the G98 limit. Because larger systems affect the network more, the DNO must assess your site first. Therefore, you submit the DNO application for solar before installation and wait for approval. For example, a typical 4 kW single-phase inverter already exceeds 16 A, so it needs G99. Three-phase homes, in contrast, reach about 11 kW before they cross the line.
Some DNOs also accept an export limiting device that caps output. As a result, they can approve a connection even where the local network is tight. Ask your operator first, because policies differ.
Unsure which form fits your home?
Send your inverter datasheet and roof layout to the PTOEdge team for a tailored DNO application quote. Then the team can help you identify the likely route.
How to Complete a DNO Application Step by Step
A clear process prevents delays. Therefore, follow these five steps, and you will move smoothly from design to confirmation.
1. Identify your DNO
First, check your postcode and note your MPAN. Then confirm which operator covers your address.
2. Choose G98 or G99
Next, compare your inverter and battery output with the 16 A limit. As a result, you know which route applies.
3. Prepare the design pack
Then collect datasheets, a site plan and a single line diagram. Additionally, a consistent solar permit design and drawing workflow avoids mismatched figures.
4. Submit the application
After that, upload the form through your operator’s online portal. Moreover, attach every document in one go to avoid follow-up questions.
5. Keep your confirmation
Finally, save the DNO letter with your MCS paperwork. Furthermore, send a copy to your export supplier.
Documents You Need for a DNO Application for Solar
A complete pack answers the DNO’s questions before it asks them. Consequently, review each item below before you submit.
Property details
Your address, postcode and MPAN identify the connection point, so include all three.
Equipment datasheets
In addition, inverter and battery datasheets confirm output and type test status.
System capacity
Moreover, array size and inverter rating show the total export your home can reach.
Single line diagram
Likewise, this drawing shows how the system connects to your consumer unit and the grid.
Site location plan
Furthermore, a simple plan helps the DNO find your property and your meter position.
Installer details
Finally, installer and certification details prove that a competent person does the work. Therefore, many homeowners also choose a solar design partner in the UK, USA and Canada to keep documents consistent.
How Do I Get a DNO Letter?
Your installer or design partner submits the form, and then the DNO replies by email. That reply is your DNO letter, so you rarely need to request it separately. However, if you installed solar earlier, you can contact your DNO’s connections team. Quote your MPAN and address, and ask them to confirm the record on file. If nothing exists, your installer can submit a late notification. Homeowners who are selling a property often face this situation, so act early.
What Is DNO Approval? Letters, Certificates and Timescales
What is DNO approval? It is the written permission, or acknowledgement, from your DNO that your solar system may connect. With G99, approval arrives before installation. G98, in contrast, ends with a simple acknowledgement. Either way, the letter becomes your proof of compliance.
What Does a DNO Letter Look Like?
A DNO letter is usually an email or a PDF on the operator’s letterhead. It normally shows your property address, MPAN, a reference number, the approved capacity and any conditions, such as an export limit. Furthermore, it may name the installer and the inverter model. Because layouts differ between DNOs, ask your installer to explain each line.
What Is a DNO Certificate?
People often ask what is a DNO certificate. In practice, no single official document carries that name. Instead, the phrase usually means the DNO’s acceptance letter or the G98 commissioning confirmation. Meanwhile, your MCS certificate is a separate document from your certification body. Therefore, keep both together in one folder.
How Long Does DNO Approval Take?
Timescales vary by operator and system size. G98 notices move quickly because the DNO only acknowledges them. G99 responses, however, depend on capacity in your area. Therefore, ask your installer for the DNO’s published response time before you book an installation date. Additionally, build a few weeks of buffer into your plan.
DNO Application Costs, Delays and Grid Limits
Most G98 notifications cost nothing. Small domestic G99 applications can also be free, although larger schemes may bring assessment fees or network reinforcement costs. Therefore, request a written quote from your DNO if your system is large.
Delays usually come from three sources: incomplete forms, missing type test certificates and constrained local networks. Consequently, a complete pack matters more than a fast submission. Moreover, if your area is constrained, the DNO may offer a lower export limit instead of refusing the connection.
Typical costs
G98 is usually free. In contrast, G99 costs depend on system size and any network work.
Common delays
Missing documents cause most hold-ups. Therefore, double-check every datasheet and drawing before you press submit.
Export limits
If you also manage a business roof, read our guide to commercial solar system design in the UK, because larger sites follow stricter G99 routes.
DNO Application in Perth, Inverness and Across the UK
Local searches such as dno application perth and dno application inverness show that homeowners want area-specific guidance. In the north of Scotland, SSEN Distribution runs the network around both cities, so households there usually apply through SSEN. However, always confirm your operator by postcode, because boundaries can surprise you.
Please note that Perth also exists in Western Australia, where different operators and rules apply. This guide covers Perth in Scotland and the wider UK only. Rural Highland feeders also have limited spare capacity, so larger G99 requests there may attract export limits or longer assessments.
UK Power Networks
Homeowners in London, the South East and the East of England therefore apply here.
National Grid Electricity Distribution
This operator also covers the East and West Midlands, the South West and South Wales.
Northern Powergrid
Households in the North East and Yorkshire therefore use this network.
Electricity North West
Likewise, North West England relies on this operator.
SP Energy Networks
It also serves central and southern Scotland, Merseyside, Cheshire and North Wales.
SSEN Distribution
Moreover, it covers northern Scotland, including Perth and Inverness, and central southern England.
NIE Networks
Finally, Northern Ireland has its own network operator.
Whichever region you live in, the process stays similar. However, forms and portals differ, so use your DNO’s own guidance. Additionally, PTOEdge’s UK page explains how its team supports installers across these regions.
Common DNO Application Mistakes to Avoid
Even experienced installers make avoidable errors. Therefore, check this list before you submit your DNO application.
Choosing the wrong route
First, many people assume a small system always qualifies for G98. However, a 4 kW single-phase inverter already needs G99.
Forgetting batteries
Second, a battery inverter adds to your total export capacity. Therefore, include it in every figure.
Missing the 28-day window
Third, a G98 notice must reach the DNO within 28 days of commissioning. Late notices create awkward questions.
Mismatched drawings
Likewise, different numbers on the form and the diagram trigger queries. A clean solar permit design guide for accurate drawings helps you avoid them.
Ignoring existing systems
Moreover, extra generation at the same property adds to your existing capacity. Consequently, the DNO needs the combined figure.
Starting before approval
Finally, installing a G99 system before approval risks forced changes or even disconnection.
How PTOEdge Supports Your DNO Application
PTOEdge UK is a solar design partner that already supports projects in the USA and Canada, and it now serves UK homeowners and installers too. On its UK page, the team explains how it prepares accurate designs, single line diagrams and submission-ready documents. As a result, your installer can reach DNO approval with fewer queries.
Design quality drives approval speed. Therefore, PTOEdge UK focuses on consistent figures across the form, the drawings and the datasheets. Furthermore, a good partner tells you when your DNO sets extra conditions, so you never face surprises on site.
Submission-ready packs
Receive drawings that match your form. Read how PTOEdge supports UK solar projects and DNO documentation from design to submission.
Reliable design partnership
In addition, explore why installers choose a solar design partner for UK, USA and Canada projects.
Commercial and larger roofs
Meanwhile, business owners can review commercial solar design for UK rooftops before they plan a G99 route.
Tailored quotes
Finally, request a DNO application quote from the PTOEdge team and share your inverter and roof details.
Good to know
This guide reflects how UK network operators describe G98 and G99. However, rules and forms change, so confirm current requirements with your DNO before you apply.
FAQs About Your DNO Application
What is a DNO application?
It is a request to, or notice for, your network operator about connecting solar. Therefore, it protects both your home and the local grid.
Do I need a DNO application for solar panels?
Yes, every grid-connected system needs one. However, small systems notify after installation, while larger systems need approval first.
What is a G99 application?
It is the approval request for systems above 16 A per phase. As a result, you must wait for the DNO’s decision before you install.
How do I get a DNO letter?
Your installer submits the form, and then the DNO emails the letter. Alternatively, contact the DNO with your MPAN to request a copy.
What is a DNO certificate?
The term usually means your DNO acceptance letter or G98 confirmation. Meanwhile, your MCS certificate is a separate document.
Start Your DNO Application With PTOEdge
First, tell PTOEdge about your solar system, your inverter and your postcode. Then receive clear guidance on the right route and a design pack that supports your submission. Therefore, a smoother connection starts with one conversation.