The Grid Code

The Grid Code is a technical document forming the rules to operate, maintain and develop the transmission system. Compliance with the Grid Code is a requirement for using the transmission system. It sets out the procedures overseeing the actions of all transmission system users.

SONI is the code administrator for the Grid Code. As part of that, we maintain and oversee any proposed changes to it. All changes must be reviewed by the Grid Code Review Panel (GCRP). The GCRP is a standing body who meet regularly to discuss the Grid Code.

The GCRP's role is to:

The GCRP is governed by a constitution which you can read in the following document.

See notes from meetings of the Grid Code Review Panel over the last 5 years. Get in contact to request notes from previous years.

The Grid Code is continuously evolving. Modifications ensure it's compatible with the wholesale electricity market, new generation technologies, demand side management and European Network Codes. Find a full list of Grid Code modifications below.

Consultations on Grid Code modifications happen through the SONI consultation portal.

A derogation is a direction from the Utility Regulator. It means the applicant doesn't have to comply with a technical standard or code. Derogations are issued in specific circumstances for a specified length of time.

The European Union is adopting a common set of rules, known as Network Codes. They will enable more efficient operations in all areas of Europe's electricity market.

The Network Codes outline requirements users must comply with including generator, demand and HVDC connections.