Understanding the Gateway to Grid Connection in the UK Solar Industry
When it comes to installing solar PV systems in the UK, one of the most important steps is submitting a DNO application. If you’re a solar installer or property owner planning a grid-connected solar setup, understanding the Distribution Network Operator (DNO) process is essential to ensure compliance and avoid costly delays.
What Is a DNO?
DNO stands for Distribution Network Operator. These are companies licensed to distribute electricity from the National Grid to homes and businesses in a specific region. They manage and maintain the local network infrastructure—like substations, transformers, and power lines.
In the UK, there are several regional DNOs, such as UK Power Networks, Scottish Power Energy Networks, and Western Power Distribution, to name a few.
Why Do You Need to Apply?
Before connecting a solar PV system to the grid, the DNO must be informed—or in some cases, must give prior approval—to ensure the local network can safely accommodate the energy being exported. This is where DNO applications come in.
Depending on the size and type of your solar installation, different rules apply.
Types of DNO Applications
- G98 Notification (Installations up to 3.68kW per phase)
Also known as “fit and inform”, this applies to most small domestic systems. You install the system, then notify the DNO within 28 days.
✅ Simple notification
✅ No prior approval needed - G99 Application (Installations over 3.68kW per phase)
Required for larger or commercial systems. You must apply before installation and wait for DNO approval.
✅ Full application required
✅ Approval needed before installation
✅ Can take several weeks depending on complexity
What’s Included in a G99 Application?
A typical G99 application includes:
- Site & meter location information
- MPAN (Meter Point Administration Number)
- Letter of Authority from the property owner
- Technical details: panel type, inverter make, system size
- Single Line Diagram (SLD or schematic)
- Export limitation details (if applicable)
What Happens After You Apply?
Once submitted, the DNO assesses the impact of your system on the network. They may:
- Approve the connection with or without conditions
- Impose export limitations
- Require network upgrades (which may come with additional charges)
Once approved, you’ll receive a connection offer or letter of acceptance. After installation, an A3 commissioning form is submitted to close out the process.
Do You Need Help with Your DNO Application?
Handling DNO applications—especially G99s—can be time-consuming and confusing, even for experienced installers. At GridConnect, we offer full application support, from paperwork to schematic diagrams, so you can focus on getting systems installed, not buried in admin.
➡️ Let us take care of your DNO submissions—professionally, accurately, and fast.