DNO approval, explained simply.

Last updated: 3 July 2026 · Written by the ECONEXIS team, MCS-accredited installers.

Every grid-connected solar system in the UK needs to be registered with — and sometimes approved by — your local electricity network operator, the DNO (Distribution Network Operator). It sounds bureaucratic because it is. The good news: a proper MCS-certified installer handles every bit of it, and at ECONEXIS that's exactly what we do.

What the DNO actually is

Not your energy supplier — the DNO owns the cables and substations in your area (UK Power Networks across most of Bedfordshire, Hertfordshire, Buckinghamshire, Essex & Kent). They need to know about generation connected to their network so the local grid stays balanced.

G98 vs G99 — the two routes

• G98 — for small systems (inverter output up to 3.68 kW per phase). It's a notification: the system can be installed and registered within 28 days after commissioning. Simple.
• G99 — for anything bigger (most modern solar-and-battery systems). This is an application before installation: the DNO assesses the local network and approves, sometimes with conditions such as an export limit.

Export limits, in plain English

On busier parts of the network the DNO may approve your system with a cap on how much you can export — commonly around 5 kW. This does not cap what you can generate and use yourself; it only limits the spill to the grid, and your inverter enforces it automatically. With a battery soaking up surplus, a sensible export limit costs most homes very little in practice.

How long it takes

G98 adds no waiting time. G99 typically takes a few weeks for a standard domestic application — we submit early in your journey so approval lands before your install date, not after. The application needs technical documents (inverter type-test certificates, schematics, site plan): we prepare and submit all of it, respond to any DNO queries, and register the commissioned system afterwards.

What you have to do

Nothing. It's part of every ECONEXIS install — along with MCS certification and your handover pack. If you're comparing installers, ask who handles the DNO and whether it's included in the price; with us it always is.See how our install process works →

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