If you're planning to install solar panels, you'll need approval from your local Distribution Network Operator (DNO) before your system can connect to the electricity grid. The DNO is responsible for ensuring your solar PV system connects safely to their electricity networks — and for most home installations, that means completing the G98 process. This approval is a mandatory step for all new grid connections, whether you're installing solar panels, a battery storage system, or both.

Before your solar PV system can export electricity to the grid, it must be checked for safety and compliance with the requirements set by the Energy Networks Association.

What is a G98 Certificate?

A G98 certificate is official documentation that confirms your solar PV system — up to 16 amps per phase, which is 3.68kW on a typical single-phase home supply — is approved and safely connected to the electricity grid. The G98 process is a simplified, notification-based route designed for smaller systems such as most home solar PV installations and battery storage devices. Rather than requiring pre-approval, it operates on a "fit and inform" basis: your installer completes the installation and notifies the DNO afterwards.

If your solar PV system outputs no more than 16A per phase (3.68kW single-phase, or 11.04kW across a three-phase supply), the G98 process applies. This certificate confirms compliance with grid connection requirements and allows your installation to connect in parallel with the public low voltage network and export electricity to the national grid.

What About Larger Systems? (G99)

If your solar system's inverter capacity is above 16A per phase (more than 3.68kW on a single-phase supply), you'll need to follow the G99 process instead. G99 applies to larger systems, three-phase commercial installations, and any system that the local DNO determines requires a more detailed technical assessment before connection is permitted.

For larger solar systems, there are additional steps, more documentation, and a longer wait. G99 applications can take up to 60 working days, and the DNO may require specific protection settings, export limitation device installation, or a full technical assessment before approving your connection. Your installer will guide you through the G98 and G99 requirements based on your system size and local network capacity.

The Six Main DNOs in the UK

There are six main Distribution Network Operators (DNOs) in the UK, each responsible for a specific region:

• UK Power Networks — covering London, the South East, and East Anglia
• Western Power Distribution (now part of National Grid) — covering the South West, South Wales, and the Midlands
• Electricity North West — covering North West England
• Northern Powergrid — covering the North East and Yorkshire
• SP Energy Networks — covering Scotland and Merseyside
• Scottish and Southern Electricity Networks (SSEN) — covering Northern Scotland and Southern England (including Southern Electricity Networks)

Your installer will know which DNO covers your area and will handle all communications with them on your behalf.

The G98 Approval Process: Step by Step

Step 1: Completing the installation

Your installer completes the solar PV system installation, including any battery storage or electric vehicle charging device. All generation equipment must be type tested and meet the technical standards set by the Energy Networks Association. The installer is responsible for ensuring compliance with all required documentation before submitting to the DNO.

Step 2: Submitting the G98 notification (Form B)

Once the installation is complete, your installer submits a G98 notification — known as Form B — to your local DNO. This must be submitted within 28 days of commissioning the system. The form includes all technical details about your solar PV system: inverter specifications, system capacity, export MPAN (Export Meter Point Administration Number), protection settings, and the address of the installation.

You don't need to worry about the paperwork — your installer submits all documentation directly to the DNO. The G98 is a simpler and faster process compared to G99 applications. Because G98 is "fit and inform", there's no approval to wait for — the DNO typically acknowledges and processes the notification within 10 to 15 working days, and minimal impact on the local network means most are processed without issue.

Step 3: DNO review and national grid registration

The DNO reviews your notification to check your system's compliance and assess its impact on the local electricity cables and networks. Provided the DNO determines your system meets the required standards, your installation is registered on the electricity network. If the DNO has any concerns, they may request additional information or technical details before proceeding.

Step 4: Receiving your G98 certificate

Once registered, you receive your G98 certificate. This confirms your solar PV system is safely connected to the grid, meets all technical standards, and is legally permitted to export electricity. With your certificate in hand, you can also apply to the Smart Export Guarantee (SEG) scheme and begin receiving export tariff payments for the electricity you send back to the grid. Your installer can also provide guidance on the Microgeneration Certification Scheme (MCS) certificate, which is required separately for SEG applications.

Step 5: Note on timeframes

G98 notifications are typically processed within 10 to 15 working days. G99 applications — for larger systems requiring a detailed technical assessment — can take up to 60 working days. Delays can occur during periods of high application volume, and connection time is sometimes outside your installer's control.

Battery Storage, Electric Vehicles, and Upgrades

Adding battery storage or an electric vehicle charging device to your solar system is a great way to maximise your energy savings. Provided your total inverter output remains at or below 16A per phase (3.68kW single-phase), you remain within the G98 process. If you go above that limit, G99 approval is required.

Always check with your installer before upgrading or adding storage, so you stay compliant and your connection remains approved. Any changes to generation equipment, protection settings, or inverter specifications may require a new DNO application or notification.

Why DNO Approval Matters

Failing to obtain DNO approval has serious consequences:

• Your system may not be legally connected to the grid. Without approval, your solar PV installation is not authorised to export electricity.
• You can't export electricity or receive SEG payments. Without a G98 or G99 certificate, energy suppliers will not pay you for exported electricity.
• Your home insurance may be invalidated. Many home insurers require proof of DNO approval for solar installations.
• Selling your home becomes complicated. Buyers' solicitors will ask for G98/G99 documentation as part of the conveyancing process. Missing paperwork can delay or derail a sale.
• The DNO can require you to disconnect the system at your cost. Non-compliant connections can be forcibly removed.
• Safety: DNO approval ensures every device meets strict safety standards, protecting your home and the wider electricity network.
• Quality: Only approved, type tested systems can connect to the grid.

Notifying the DNO of Changes

If you upgrade your system, carry out repairs, or add new devices — such as battery storage or a vehicle charger — you must notify your local DNO. Failing to do so can result in your system losing its approved connection status.

Your Meter Point Administration Number (MPAN) and Export MPAN are key reference numbers for your DNO application and any future correspondence. Always keep these to hand when making changes or switching energy suppliers.

In Summary

Getting a G98 certificate is a mandatory part of installing solar panels at home. For most residential solar PV systems (up to 16A per phase — 3.68kW on a single-phase supply), the process is straightforward: your installer completes the installation, submits Form B to your local distribution network operator within 28 days, and the notification is typically processed within 10 to 15 working days. Larger systems above that limit follow the G99 route, which requires a more detailed technical assessment and can take up to 60 working days.

Your installer handles the whole process — from completing the G98 form to providing all required documentation and keeping you updated. Once approved, your solar system is safely connected to the grid and ready to export electricity.

For further information or support, contact CRG Direct Solar or your local Distribution Network Operator. We're here to help you every step of the way.