What is and IDNO and what are Asset Values?

Written by

When you require an electricity supply for a new development, you need to ask the organisation who owns the cables in your areas whether there is available capacity. This is your Distribution Network Operator (DNO), who will also own or ‘adopt’ any new cables or infrastructure installed to give you a supply.

However, the DNO isn’t the only option: Independent Distribution Network Operators (IDNOs) can own the new network too. Here, you will find all you need to know about each.

What is a Distribution Network Operator (DNO)?

The electricity distribution network carries electricity between the transmission grid (operated by National Grid) and the businesses and householders who are the end users. There are 14 Distribution Network Operators (DNOs) across England, Scotland and Wales, and they are each responsible for a specific
geographical area.

The DNOs are licenced by Ofgem to distribute electricity. They own, operate and maintain the electricity infrastructure (such as primary and distribution substations, pylons and cables) and are responsible for rectifying any faults or power cuts.

If you ask them to install a new supply, they will ‘adopt’ any new cables or substations to their network.

What is an Independent Distribution Network Operator (IDNO)?

Independent Distribution Network Operators (IDNOs) also own, operate and maintain electricity infrastructure. The networks which they adopt are the new, installed assets (for example, connections to new developments) which will connect back onto a DNO’s network.

Unlike the DNOs, they do not have a specific geographical area. They are regulated by Ofgem in the same way as DNOs are, although with slightly amended licence conditions.

What about energy suppliers?

Gas and electricity suppliers are entirely separate entities from the DNOs and IDNOs who own the distribution network. Your energy supplier is who you pay your gas and electricity bill to. When you have a new supply installed, they will arrange the meter installation for you.

How do DNOs and IDNOs generate income?

Both DNOs and IDNOs earn revenue from the Distribution Use Of System (DUoS) charges which are included in your energy bill. They apply to every connection to the distribution network; You pay them to your energy supplier and the DNO or IDNO then invoices the energy supplier.

What is the difference between getting my new connection adopted by the DNO or IDNO?

Regardless of whether your new connection is adopted by the DNO or the IDNO, each is equally responsible for the operation and
maintenance of the installation. If you ask the DNO to install your new connection for you, it can only be adopted by the DNO.

If you ask an Independent Connections Provider (ICP), such as Rock Power Connections, to install your new connection for you, it can be
adopted by either the DNO or an IDNO. The key difference is that the IDNO will offer an upfront sum of money, called an ‘Asset Value’, which is payable upon energisation of your supply. At Rock Power Connections, when we provide a quotation to you, it will include this Asset Value which can make a very competitive offer to the DNO’s proposal.

The amount of the Asset Value is dependent upon the amount of energy to be used and whether it is metered at High Voltage (HV) or Low Voltage (LV).

How can Rock Power Connections help you?

With our experience and engineering knowledge, we successfully manage various ICP projects of varying size and scale across the UK.

By trusting Rock Power Connections with your new or upgraded electrical connection, you can rely on us to deliver your engineering solution on time and on budget.

All our customers work closely with their dedicated Rock Power Connections Project Manager to develop a programme of works that fits with their engineering requirements and is flexible to their needs.

We’d be delighted to offer you a free, no obligation, competitive quote for your electrical connection project. Please email Emma on,

Rock Power Connections is a Mitie Group plc Company. All Rights Reserved.