Licensed electricity distribution businesses, or Distribution Network Operators (DNOs) in Great Britain, are obliged under Condition 21 of their licences to maintain a Distribution Code detailing the technical parameters and considerations relating to connection to, and use of, their electrical networks.

DNOs

Electricity North West
www.enwl.co.uk

Northern Powergrid
www.northernpowergrid.com

Scottish and Southern Electricity Networks
www.ssepd.co.uk

SP Energy Networks
www.spenergynetworks.co.uk

UK Power Networks
www.ukpowernetworks.co.uk

Western Power Distribution
www.westernpower.co.uk

IDNOs

Eclipse Power Networks
www.eclipsepower.co.uk

Energetics Limited
www.energetics-uk.com

ESP Utilities Group
www.espug.com

GTC (comprising both ETCL and IPNL licences)
www.gtc-uk.co.uk

UK Power Distribution Limited
www.ukpowerdistribution.co.uk

Energy Assets Networks Limited
www.energyassets.co.uk

Fulcrum Electricity Assets Limited
www.fulcrum.co.uk

Harlaxton Energy Networks Limited
www.harlaxtonenergynetworks.co.uk

Leep Electricity Networks Limited
www.leeputilities.co.uk

Murphy Power Distribution Limited
www.murphygroup.co.uk

Utility Assets Limited
www.utilityassets.co.uk

Vattenfall Networks Limited
https://networks.vattenfall.co.uk


The GB Distribution Code

All DNOs currently operate the same version of the Code, and the Code is maintained by the Distribution Code Review Panel. All modifications to the Code are approved by Ofgem.

Issue 33: Effective from 23 July 2018

The implementation of the EU Network Codes is creating a substantial amount of modifications to the GB documentation, and has resulted in the creation of two new Engineering Recommendations for the connection of generation to distribution networks, EREC G98 and G99.

These have recently (15 May) been approved by the Authority. In common with the modifications to the Grid Code approved at the same time, an erroneous implementation date of 17 May 2019 was used in the drafting. The correct date should be 27 April 2019. In approving ERECs G98 and G99 the Authority asked that this mistake was corrected.

In parallel with the development of EREC G98 and G99, modifications have recently been approved by the Authority that change the requirements for loss of mains protection fitted to distributed generation. These changes now need to be applied to G98 and G99.

A number of typographical errors have come to light in G98 and G99, all of which are inconsequential, but the opportunity can now be taken to correct them.

Click here to download a copy of Distribution Code Issue 33

Click on the relevant link for a copy of the revised EREC G98/1-1 (2018) or EREC G99/1-1 (2018)

Authority decision can be found here


For previous versions of the GB Distribution Code click here

Distribution Code User Guide

The guide gives a high level overview of the Distribution Code, and is aimed at anyone with an interest in the Distribution Code. It contains information about the regulatory structure in Great Britain and Europe and also provides a simple explanation of the various sections of the Distribution Code.

Click here to download the current version of the GB Distribution Code User Guide

Annex 1 and Annex 2 Documents

Some requirements of the Distribution Code are implemented through other industry documents. They are listed in Annex 1 of the Distribution Code, and are mostly Engineering Recommendations. These documents typically cover certain technical areas in detail, such as connection of generation, switchgear ratings and supply quality planning limits.

There are other industry documents which are not implemented via the Distribution Code, but do have a material impact on distribution network users. These are listed in Annex 2 of the Distribution Code.

Standards and other documents referenced in Annex 1 and Annex 2 of the Distribution Code are available for free and can be downloaded at the following link:

Click here for Annex 1 and Annex 2 documents

Standard Governance Procedure

DNOs or Users may bring proposals for modifications to Annex 1 Standards and Annex 2 Standards for consideration by the DCRP Panel. DNOs and Users bringing forward proposals for modifications to Annex 1 Standards and Annex 2 Standards shall set out in general terms the aims of their proposal and the likely impact, including costs.

Further information on how to submit a modification can be found here.

Useful Links

Association for Decentralised Energy (formerly the Combined Heat & Power Association)
www.theade.co.uk

Association of Meter Operators
www.meteroperators.org.uk

Department for Business, Energy & Industrial Strategy (formerly DECC)
www.gov.uk

Energy UK
www.energy-uk.org.uk

Major Energy Users’ Council
www.meuc.co.uk

Meter Operation Code of Practice Agreement (MOCOPA)
www.mocopa.org.uk

Microgeneration Certification Scheme
www.microgenerationcertification.org

National Grid
www.nationalgrid.com

National Grid
The Grid Code

Ofgem
www.ofgem.gov.uk

Renewable Energy Association
www.r-e-a.net

Renewable UK
www.renewableuk.com

Solar Trade Association
www.solar-trade.org.uk

Sustainable Energy Association (formerly Mircropower Council)
www.sustainableenergyassociation.com