General Outage Information

Generation Outages

SONI develops and implements a Generation Outage Plan based on short, medium and long-term outage plans submitted by generators and in accordance with Section OC2 of the Grid Code. This ensures co-ordination of  “planned outages”, when power stations will not be available due to maintenance or other reasons. Additional requests for outages due to, for example, emergent faults are managed as needed and according to transmission constraint groups, operational security standards, etc.

The Generation Outage Plan takes into account security of supply in Ireland and Northern Ireland, as well as the economic operation of the power systems, and the maintenance/resource needs of generators.

For more information on Generation Outage planning or to request a Generator Outage, please go to Generation Outages. This page also contains the latest outage documents and guidelines.

Transmission Outages

The Near Time team within Operations at SONI compiles an annual maintenance programme and manages transmission outages. This involves planned times when transmission infrastructure (lines, cables and substations etc.) will be out of service for maintenance. It also involves times when testing; connection of new plant and decommissioning of old plant is carried out. The latest outage documents and guidelines are available on the Transmission Outages page.

Outturn Availability 

The Single Electricity Market Committee (SEMC) decision SEM-15-071 "Process for the Calculation of Outturn Availability" was published on 29 September 2015.

For information relating to the process for the calculation of outturn availability, please see The EirGrid and SONI Implementation Approach to the SEM Committee Decision Paper SEM-15-071.

The SONI Ex-Post Outturn Availability Connection Asset Annual Maintenance Plan for the 2017 outage season, as reviewed by the Regulatory Authorities, is published here.

The SONI Ex-Post Outturn Availability Connection Asset Annual Maintenance Plan for the 2018 outage season, as reviewed by the Regulatory Authorities, is published here.

The SONI Ex-Post Outturn Availability Connection Asset Annual Maintenance Plan for the 2019 outage season, as reviewed by the Regulatory Authorities, is published here.

The SONI Ex-Post Outturn Availability Connection Asset Annual Maintenance Plan for the 2020 outage season, as reviewed by the Regulatory Authorities, is published here.

The Guide to NIE Networks Transmission Equipment Maintenance is a high level guide to the processes and procedures used by Northern
Ireland Electricity Networks (NIE Networks) in relation to the maintenance of transmission outturn availability connection assets.