SONI Publishes Final Results of First T-4 Capacity Auction for the Single Electricity Market

07 May 2019

There are no changes to the provisional results which were published on 04 April.

The final results have been approved by the Single Electricity Market Committee (SEMC) which is made up of representatives from regulators in Northern Ireland (the Utility Regulator) and Ireland (the Commission for the Regulation of Utilities) and two independent members.  

The auction is a key element of the market and is designed to deliver wholesale electricity at the least possible cost. The T-4 auction also aims to encourage new investment and innovation, but only if it is the most economical solution. The auction procured sufficient capacity to meet security of supply for the period October 2022 to the end of September 2023.

The auction secured 1,865 megawatts (MW) of capacity for Northern Ireland. The auction clearing price was £43,030 per MW per year.

£80 million in capacity payments will be paid to those NI generators who were successful in the auction. 

The auction was designed by the Single Electricity Market Committee (SEMC) to ensure sufficient capacity is secured to meet demand across the island at all times. 

The final results are available at

SONI has also published the following documents on the SEMO website:

T-4 2022-2023 Final Auction Results Quick Guide
T-4 2022-2023 Final Capacity Auction Results Report

Note to editors:

The T-4 capacity auction is part of a series of changes made to the Single Electricity Market to increase cost efficiency and competitiveness. The improvements to the market have integrated the all-island electricity market with European electricity markets. The new arrangements maximise efficiency of electricity trading on interconnectors. It is also designed to encourage new investment and innovation.

The market was designed by the SEMC. This design was implemented by SONI in Belfast and EirGrid in Dublin and the upgraded market has been live since October 1st 2018.

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