Key Takeaways
- It ensures your system can export power without affecting the local network.
- Standard systems usually fall under G98 rules and are simply notified after installation.
- These follow G99 rules and can add several weeks to the timeline.
- Most issues are avoided by matching system size and export levels to the network early.
- When done properly, it’s a smooth, invisible part of the process, not something you need to worry about.
DNO approval is the process of informing or getting permission from your local grid operator before connecting solar panels to your home.
It protects the local electricity network and ensures your system exports safely.
Most standard home systems don’t need advance approval, but larger systems do. Your installer usually handles this for you.
What Does the DNO Actually Do?
A DNO is your Distribution Network Operator. They own and manage the local electricity cables that bring power to your street and home.
In Great Britain, there are 14 regional DNOs, each responsible for keeping the network safe and balanced.
Their role with solar panels is simple:
- Make sure the local network can handle exported power
- Prevent voltage issues
- Keep everyone’s supply stable
DNO approval isn’t about selling energy. It’s about network safety.
When do you need DNO Approval for Solar?
It depends on the size of your system.
Small systems (most homes)
Most domestic solar installations fall under G98 rules.
Under G98, systems up to 16 amps per phase, which equals 3.68 kW on a single-phase supply, can be installed first and then notified to the DNO afterward.
This means no waiting before installation for most homes.
Larger systems
If your system is bigger or your setup is unusual, it falls under G99.
G99 systems:
- Need approval before installation
- May require network checks or export limits
- Take longer to process
What are the Basic Steps in the DNO Approval Process?
Here’s the simple version:
- Your system is designed
- The correct form is submitted (G98 or G99)
- The DNO checks the local network
- Approval or notification is confirmed
You don’t usually deal with this directly; a good installer handles it for you.
Forms you might hear about
- G98 notification – for standard systems
- G99 application – for larger or more complex installs
How Long Does DNO Approval For Solar Usually Take?
This is where timelines differ.
For some low-voltage generation connections requiring approval, DNOs have a published timescale of up to 45 working days to issue a connection offer.
Typical Timelines for a DNO approval for Solar
| System type | DNO process | Typical time |
| Standard home solar | G98 notification | Installed first, then notified |
| Larger domestic system | G99 approval | 4–8 weeks |
| Export-limited system | G99 with conditions | Varies by network |
Most delays happen only when approval is required in advance.
What Can Cause Problems with DNO Approval (and How to Avoid Them)?
DNO approval rarely causes issues, but when it does, it’s usually for simple reasons.
Common triggers include:
- Oversized systems for the local network
- High export levels in areas with lots of solar panels already
- Older local infrastructure
- Adding solar, batteries, or EV charging together without planning
How this is handled matters more than the issue itself.
In most cases, the solution is straightforward:
- Limiting export to a safe level
- Adjusting inverter settings
- Phasing upgrades sensibly
None of this affects how much solar you use in your home. It just ensures the grid stays stable while your system works as intended.
When this step is planned early, it rarely adds noticeable time or cost.
Why Does DNO Approval Matter for Your Bills and Control?
Getting this step right:
- Prevents export limits later
- Avoids forced system changes
- Keeps your system running smoothly
- Ensures export payments work correctly
It’s one of those things you don’t notice when it’s done properly, and that’s exactly how it should be.
How Can Synergy PV Renewables Make DNO Approval Simple?
We manage the DNO process from start to finish.
That means:
- Checking which rule applies to your home
- Designing within network limits
- Submitting the correct forms
- Communicating with the DNO on your behalf
- Explaining timelines clearly, without jargon
Our aim is to keep things moving quietly in the background, so you can focus on the outcome: lower bills, more control, and a smoother switch to solar. Consult us for all your solar needs today.
Wrapping Up!
DNO approval is a routine part of installing solar, designed to protect the local electricity network.
For most homes, it’s a simple notification handled after installation. Larger systems take longer and need approval upfront.
When this step is managed properly, the process is smooth and predictable. With the right design and clear communication, DNO approval becomes a quick box ticked, not a hurdle.
FAQs
Do all solar installations need DNO approval?
No. Most standard home systems only need a simple notification after installation.
Will DNO approval delay my installation?
Usually not. Only larger systems need approval before installation.
Can a DNO refuse solar?
Rarely. They may ask for export limits or adjustments if the network is constrained.
Do batteries change DNO approval?
They can. Export capability is what matters, not storage alone.
Do I need to contact the DNO myself?
No. Your installer normally handles everything.
