What is a Distribution Network Operator (DNO)?
Distribution Network Operators (DNO) are responsible for managing the electricity distribution network in your area, ensuring that power is delivered safely and efficiently. If you’re planning a solar panel installation, it’s essential to understand how DNOs impact the process.
At UPS Solar, we handle all the necessary DNO applications on your behalf, ensuring a hassle-free solar installation experience. Whether you need approvals, technical guidance, or help navigating regulations, we can provide the experience required to make the process as smooth as possible.
How Do DNO’s Work?
DNOs are companies licensed by Ofgem to manage the electricity distribution network in specific regions of Great Britain. Their primary responsibilities include:
• Maintaining and upgrading electricity infrastructure (cables, pylons, substations).
• Connecting new solar panel systems, generators, suppliers, and consumers to the grid.
• Managing power outages and grid faults.
• Approving applications for solar installations and ensuring grid stability.
Who Are the UK’s Distribution Network Operators?
There are 14 regional uk distribution network operators, each responsible for a specific geographical area. These DNOs are managed by six parent companies:
• Electricity North West
• Northern Powergrid
• SP Energy Networks
• Scottish and Southern Electricity Networks (SSEN)
• UK Power Networks
• Western Power Distribution
To find out which DNO manages your electricity supply, check the first two digits of the bottom line on your MPAN (Meter Point Administration Number).
DNO’s Rules for Solar Panel Systems
Maximum Inverter Size for Domestic Properties
• The largest inverter allowed without prior approval is 3.68kW per phase.
• This allows up to just under 6kW of solar panels to be installed.
G98 and G99 Applications: What’s Required?
• G98 Application – Required for small-scale solar installations (up to 3.68kW per phase). This is a simple, standard notification process.
• G99 Application – Required if your system exceeds 3.68kW per phase. Your DNO must approve the installation beforeit can proceed. Processing a G99 application can take up to 45 working days.
Example System Sizing & Approval Requirements
| Solar Panel Configuration | System Size (kWp) | Inverter Size | DNO Application Required |
| 16 x 430w Panels | 6.88kWp | 6kW Inverter | G99 Approval Required |
| 12 x 430w Panels | 5.4kWp | 3.68kW Inverter | G98 Notification Required |
Why Are Inverters Often Undersized?
To optimise efficiency, inverters are often smaller than the total solar panel capacity. This is known as overclocking, and it helps:
• Compensate for low sunlight levels in the UK.
• Increase power output efficiency while reducing system costs.
By selecting the right inverter size, you can maximise solar energy generation without exceeding grid limits.
Distribution Network Operators Export Limits & Grid Stability
One of the key challenges with solar installations is managing how much power can be exported to the grid. DNOs limit the export of excess electricity to prevent overloading the network.
What is an Export Limitation Scheme (ELS)?
An Export Limitation Scheme is used to prevent grid overload by:
1. Measuring how much electricity is being exported.
2. Restricting solar generation or adjusting demand to stay within the agreed export limit.
If your solar system generates more power than your home consumes, a DNO may require export limiting technology to prevent excess electricity from disrupting the grid.
How UPS SOLAR Handles DNO Applications for You
Navigating distribution network operators regulations can be complex, but at UPS solar, we take care of the entire process. Our services include:
✔ Identifying whether your system requires a G98 or G99 application.
✔ Managing all distribution network operators approvals and documentation.
✔ Ensuring your system complies with grid requirements.
✔ Helping you maximise solar efficiency within your DNO’s guidelines.
Whether you’re installing a residential solar system or a larger-scale solar panel installation, we ensure a smooth transition to solar energy.
Have questions? Contact UPS Solar today for expert guidance on solar installation and distribution network operators approvals.
Would you like to receive a no obligation quote for your home or business? We have a dedicated team who can discuss the options available to you over the phone at a time to suit you.
Call us on 0800 644 6887
Or Contact us here and we’ll be happy to explain the process and the benefits of a solar panels installation.
Further information on Independent Distribution Network operators (INDO’s) can be found here
