G98 & G99 DNO Notifications for Solar in Scotland
Every solar installation in Scotland must comply with G98 or G99 grid connection standards. Without the correct DNO notification, your installation is non-compliant, your SEG export payments are blocked, and your grid connection can be challenged. Scottish Energy Efficiency handles all of this as standard — at no extra cost.
Quick Reference
G98 vs G99 — A Complete Comparison
Both standards govern how solar PV systems connect to the distribution network. The key difference is system size and whether pre-approval is required.
Notification Only
For smaller domestic systems
Most 4kW domestic installations in Scotland fall under G98 — straightforward notification after the system goes live.
Full Application
For larger residential & commercial
G99 systems cannot be installed until the DNO approves the application. Build this 45+ day lead time into your project schedule from day one.
| Feature | G98 | G99 |
|---|---|---|
| System size threshold | Up to 3.68kW/phase | Above 3.68kW/phase |
| Process type | Notification only | Full application |
| When submitted | After installation | Before installation |
| Pre-approval required | No | Yes |
| Processing time | 1–2 working days | 45+ working days |
| Technical review | Minimal | Full network assessment |
| Risk of rejection | Very low | Possible — network capacity dependent |
| Export limit possible | Rarely | Yes — DNO may impose limits |
| Most common for | Standard domestic | Larger homes, commercial |
| SEE handles it? | Yes — included | Yes — included |
What Happens If You Don't Notify the DNO
Missing DNO notification is not a minor administrative oversight — it has serious practical and legal consequences for your solar installation.
SEG Registration Blocked
The Smart Export Guarantee registration process requires a valid MCS certificate, which in turn requires confirmed DNO notification. Without it, all export income is permanently blocked until retrospective notification is completed.
Grid Connection Challenged
Your Distribution Network Operator can require your system to be disconnected from the grid until proper notification is submitted and acknowledged. This can mean your system sits idle generating no benefit.
Safety Risk to Network Workers
Network engineers working on local cables need to know about generation assets on the network. Unregistered generation creates genuine safety risks for engineers who assume no generation is present on a circuit.
Non-Compliant with Building Regs
In Scotland, Building Standards require notification of certain electrical work. An unnotified solar installation may not comply with the requirements of Part 4J of the Scottish Building Standards Technical Handbook.
Mortgage and Remortgage Issues
Lenders and surveyors assessing properties with solar panels increasingly verify compliance documentation. A non-notified system can block or delay remortgage applications and complicate property sales.
Void Manufacturer Warranties
Some manufacturer warranties specify that the system must have been properly notified to the DNO as a condition of the warranty being valid. Non-notification can void the product warranty you paid for.
Always Verify DNO Notification Before Signing
Ask any installer directly: "Do you handle G98/G99 DNO notification and provide documentation confirming it was submitted?" If the answer is unclear or negative, do not proceed.
How the DNO Process Works in Scotland
The process differs depending on whether your system falls under G98 or G99. Scottish Energy Efficiency manages every step on your behalf.
System Design
SEE confirms system size falls within G98 threshold (≤3.68kW per phase). Standard domestic installations typically qualify automatically.
Installation Day
System is installed per MCS standards. All electrical work is completed and the system is tested and commissioned.
G98 Notification Submitted
Within 28 days of energisation, SEE submits the G98 notification to the correct DNO (SSEN or SPEN) on your behalf with all required technical details.
MCS Certificate Issued
Your MCS certificate is issued confirming the installation is compliant and DNO notification has been completed.
SEG Registration
With your MCS certificate confirmed and G98 notification submitted, SEG registration with Octopus Intelligent Flux proceeds.
System Design & Assessment
SEE confirms system size exceeds G98 threshold. Full technical specification prepared for G99 application including single-line diagram and protection settings.
G99 Application Submitted
SEE submits the full G99 application to the correct DNO (SSEN or SPEN) with all required technical documentation. The 45+ working day clock starts here.
DNO Network Assessment
The DNO reviews the application and assesses local network capacity. They may request additional information or impose export limitation conditions.
DNO Approval Received
Once approval is granted, installation can proceed. SEE confirms all conditions imposed by the DNO and incorporates them into the installation design.
Installation & Post-Connection Notification
System installed and commissioned. Post-installation commissioning data submitted to DNO confirming the system has been installed as approved.
SSEN vs SP Energy Networks — Scotland Coverage
Scotland is divided between two Distribution Network Operators. Notifying the wrong one delays your installation and creates compliance issues. Your installer must confirm which DNO serves your specific location.
SSEN
Scottish and Southern Electricity Networks
SSEN is the Distribution Network Operator for the majority of Scotland. Their network covers a vast geographic area from the Borders to the Northern Isles and represents the DNO for the largest proportion of Scottish solar installations.
Areas Covered by SSEN
SP Energy Networks
ScottishPower / SPD (SP Distribution)
SP Energy Networks (the distribution arm of ScottishPower) operates the network in southern Scotland. Also known as SPD (SP Distribution), they manage grid connections for the south of Scotland and have their own separate G98/G99 submission portal and process.
Areas Covered by SPEN
Scottish Energy Efficiency identifies your correct DNO automatically based on your postcode and submits all notifications to the right operator — you never need to determine this yourself.
How Scottish Energy Efficiency Handles DNO
We manage the entire DNO process from start to finish on every installation. You never need to contact the DNO, complete paperwork, or navigate the submission portals.
Identify Correct Standard
We confirm whether your system falls under G98 or G99 based on system size and your connection type — single or three-phase.
Notify the Right DNO
We identify whether SSEN or SP Energy Networks serves your property and submit all documentation to the correct operator.
Full Compliance Documentation
You receive copies of all notifications, acknowledgements, and your MCS certificate confirming DNO compliance on installation day.
No Extra Charge for G99
All G98 and G99 DNO notification and application handling is included in our installation price. No hidden fees. No administration charges. Solar installations start from £6,200 including all DNO compliance.
Every DNO Notification Handled. Every Time.
Request a quote from Scottish Energy Efficiency. All G98/G99 DNO compliance is included in the price — no admin, no additional fees.
Why Request a Quote from Scottish Energy Efficiency?
MCS certified. RECC registered. No pressure. No hidden costs.
"From survey to switch-on in under two weeks. Every step explained clearly and no hidden costs. Exactly what you want from a solar installer."
G98 & G99 DNO FAQs
Get a Fully Compliant Solar Installation
Every Scottish Energy Efficiency installation includes full G98/G99 DNO handling, MCS certification, and SEG registration — all included in the price with no hidden charges.
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