The Complete Guide to DNO Applications for Commercial & Renewable Projects (UK)
If you're planning a solar installation, battery storage system, EV charging infrastructure, or a new commercial electrical connection, understanding the DNO application process is essential. Many renewable and commercial electrical projects in the UK require approval before they can be connected to the grid, and delays often occur when the process isn’t fully understood.
This guide explains what a DNO is, when approval is required, and how the application process works.
What is a DNO?
A Distribution Network Operator (DNO) is responsible for operating and maintaining the regional electricity distribution network across the UK. Their role is to manage the infrastructure that delivers electricity from the national transmission network to homes, businesses and industrial facilities.
DNOs ensure that the network remains safe, stable and capable of handling new electrical demand or generation. Before certain systems can be connected — particularly renewable energy systems — the DNO must assess whether the local network has sufficient capacity.
When is a DNO application required?
A DNO application is required whenever a system will generate electricity over 16A (3.68kW) per phase, regardless of intentions to export power to the grid etc.
Common situations where approval is required include:
Solar PV installations
Battery energy storage systems
EV charging infrastructure
Large three-phase electrical upgrades
Commercial or industrial electrical connections
Most renewable energy projects fall under G98 or G99 regulations, depending on the size and export capability of the system. Prior approval is required only for G99 and not like G98 where you can fit and notify.
The DNO application process explained
While the exact process varies slightly between network operators, most DNO applications follow a similar structure.
1. Project design and system sizing
The installer or electrical designer defines the system size, generation capacity and connection requirements.
2. Network capacity assessment
The DNO assesses whether the local electricity network can accommodate the new generation or load without causing instability.
3. Application submission
Detailed technical information about the system is submitted to the DNO. This usually includes equipment specifications, protection settings and export capacity.
4. Technical review by the DNO
The DNO reviews the proposal and determines whether the connection can proceed as planned or if upgrades to the network are required.
5. Connection offer
If the project is viable, the DNO issues a connection offer outlining any required works, costs and conditions.
6. Installation and commissioning
Once approved, the system can be installed and commissioned in accordance with the agreed specifications.
Common delays and how to avoid them
DNO approvals can take time, particularly for larger renewable projects. Some of the most common causes of delays include:
Incomplete or incorrect technical information
Poorly specified system designs
Local network capacity constraints
Missing protection or compliance documentation
Ensuring the application is accurate and technically complete from the outset can significantly reduce approval times.
Capacity checks and network constraints
One of the biggest challenges facing renewable projects today is network capacity. In some areas, the local infrastructure may already be operating close to its limits.
When this happens, the DNO may require:
Export limitations
Network upgrades
Reinforcement works before connection
Understanding these constraints early in the design stage can help prevent costly redesigns later.
Costs and timescales
The cost and timeline of a DNO application varies depending on the size and complexity of the project.
Typical timescales range from a few weeks for smaller systems to several months for larger commercial connections. Costs may include application fees, network upgrades and connection charges depending on the project requirements.
Why specialist support makes a difference
Navigating DNO applications can be complex, particularly for commercial renewable energy projects. Working with specialists who understand the technical requirements, network constraints and approval process can significantly speed up project timelines.
At G59 Projects, we work closely with installers, developers and contractors to support projects involving switchgear solutions, electrical infrastructure and DNO-related requirements, helping ensure installations meet the necessary standards and progress smoothly through the approval process.
Understanding the DNO process early in your project can save time, reduce costs and prevent delays — ensuring your electrical or renewable installation moves forward with confidence.
Need support with a DNO application?
Navigating DNO requirements can be complex, particularly for commercial renewable energy and electrical infrastructure projects. The right design, documentation and equipment specification can make a significant difference to approval times.
🟢 Speak to the team at G59 Projects to discuss your project and how we can support with switchgear solutions and electrical infrastructure.
