IDM meaning

IDM (intraday market) is the wholesale electricity market in which generators, suppliers and traders buy and sell power within the delivery day, after the day-ahead stage and up to gate closure, to rebalance positions and manage forecast changes and outages. It is a descriptive industry term rather than a single statutory definition; detailed rules and timing are set in market codes and exchange rulebooks (including the GB Balancing and Settlement Code (BSC) and the SEM Trading and Settlement Code). Key features include continuous order-book trading and scheduled intraday auctions, exchange clearing and collateral requirements, and exposure to imbalance charges if positions are not closed before gate closure. Trading and disclosure are subject to REMIT (and the retained UK REMIT regime), and some products may fall within MiFID II/UK MiFIR where they constitute financial instruments. Jurisdictionally, usage is consistent but frameworks differ. In Ireland and Northern Ireland, the I-SEM intraday market operates under EU electricity market rules via SEMOpx, with intraday auctions (IDA1–IDA3) and continuous trading through Single Intraday Coupling (SIDC/XBID) alongside EirGrid/SONI gate closure times. In Great Britain, intraday trading is provided by licensed power exchanges (for example, EPEX SPOT and Nord Pool) under Ofgem oversight and the BSC; cross-border coupling arrangements...