After the Day-Ahead Market, SEMOpx run an Intraday Auction Market that allows participants to adjust their physical positions closer to real time.

How it works

The SEMOpx Intraday Auction Market consists of three daily auctions. For the first Intraday Auction (IDA-1) and second Intraday Auction (IDA-2) the SEM is coupled with the GB bidding area via Moyle and EWIC interconnectors. The third Intraday Auction (IDA-3) is a local SEM auction and is not coupled with the GB bidding area.

Auction timelines

The following table outlines the auction start times and auction duration. Unlike the Day-Ahead Market, the Trading Period duration for each Intraday Auction is 30 minutes.

Auction Auction Start Time Trading Periods Auction Duration
IDA-1 17:30 23:00 – 23:00 24 hours
IDA-2 08:00 11:00 – 23:00 12 hours
IDA-3 14:00 17:00 – 23:00 6 hours

Order Book timelines

The following table outlines the Order Book opening and closure times for the three Intraday Auctions.

Auction Order Book OpeningOrder Book Closure
IDA-1 23:00 (D-19) 17:30 (D-1)
IDA-2 23:00 (D-19) 08:00 (D)
IDA-3 23:00 (D-19) 14:00 (D)

Currency

The Intraday Auction Market is a dual currency auction. Exchange Members with Units registered in Northern Ireland are required to submit their bid data in GBP, and Exchange Members with Units registered in Ireland are required to submit their bid data in Euro.

Product information

Simple Orders are available to trade in the Intraday Auction Market. A Simple Order is a buy or sell Order related to one individual Trading Period.


Further information

For more information on the Intraday auctions process, please download our Operating Procedures.