Solar, batteries, heat pumps and chargers: why the network operator must know
By the Offrano editorial team · · 4 min read
When you add solar panels, a home battery, a heat pump or an electric vehicle charge point, one piece of paperwork usually happens out of sight: the Distribution Network Operator, the company that runs the local electricity network, has to be told. Sometimes that is a formality after the work; sometimes the installer must wait for approval before fitting anything. Knowing which applies avoids surprises in the timetable and makes sure the paperwork you will need later exists.
✓ Confirm
Almost done: please confirm your email address.
We have sent an email to {email}. We only release your request to businesses once you have clicked the link in it.
Who the network operator is
Your electricity supplier sends the bills; the Distribution Network Operator, or DNO, owns and runs the cables and substations that bring electricity to your street. Great Britain is divided into regions, each served by one DNO. You can find yours from your postcode on the Energy Networks Association's website.
Government guidance for device owners and installers says that anyone installing solar PV, a heat pump, an EV charge point or battery storage in a home or small business must register it with the DNO. The reason is practical: networks need to know where these devices are, because many of them switching on or off together can overload local equipment.
Source: gov.uk
'Connect and notify' or 'apply to connect'
The installer works out which route applies, using the connection guides and flowcharts published by the Energy Networks Association. For smaller generating equipment such as a typical home solar system, the route is usually 'connect and notify': the installer fits the system and then submits the notification form, known by its engineering reference G98, to the DNO within 28 days of installation.
Larger systems, or combinations such as solar plus a battery that together exceed the small-generation limits, follow 'apply to connect'. The installer submits an application, under reference G99, or G100 where export is limited, before installing anything. The guidance says the DNO will respond within 45 days for low-voltage devices. A fast-track form exists for fully type-tested combined generation and storage systems, which shortens that to 10 days or less. Heat pumps and EV chargers have their own application form with the same two routes.
- which route the installer expects: notify after, or apply before
- who submits the form, and when you will see a copy
- whether an export limit might be imposed, and what that would mean
- whether the programme allows for waiting for DNO approval
Source: gov.uk
It is your responsibility as well
The guidance is explicit that the device owner must make sure the installer has notified the DNO, and, where approval is needed, that it has been granted before the work goes ahead. Installers normally do this as part of the job, but if an installer suggests fitting first and 'sorting the paperwork later' on an apply-to-connect system, that is a warning sign.
Registration also matters later. Suppliers offering a Smart Export Guarantee tariff, future changes of supplier and the sale of your home can all involve questions about what is connected and whether it was notified.
Source: gov.uk
Building Regulations are a separate matter
Telling the DNO is not the same as complying with the Building Regulations. In England and Wales, much of this work is notifiable electrical work. An installer registered with a competent person scheme can self-certify it and should give you a certificate from the scheme operator; an installer who is not registered must submit a building notice to the local authority before starting. In Scotland, local authority building standards services decide whether a building warrant is needed.
Keep both sets of documents: the DNO notification or approval and the building regulations certificate. A buyer's solicitor may ask for either.
What you should receive at the end
- a copy of the DNO notification or the DNO's approval
- the building regulations compliance certificate or building notice completion
- the certification scheme certificate for the installation, such as MCS, where applicable
- commissioning records and product manuals
- for charge points, confirmation that the unit meets the smart charge point regulations
Planning a project with several devices
More households are adding devices in stages: solar this year, a battery next year, a heat pump later. Each addition changes what is connected, and the combined total can move a later project from the simple route to the approval route. Mention anything you already have, and anything you plan, when you ask for a quote.
If you would like a quote, describe your home and the devices you are considering in our request form. It goes to one installer who covers your area and chooses to buy it; we email you that installer's name, address and phone number before it sees your details, and the request is free for you.