Legacy SEM
The Legacy Single Electricity Market (SEM) was the wholesale electricity market for the Republic of Ireland and Northern Ireland from November 2007 to September 2018. The Integrated Single Electricity Market (I-SEM) project delivered the new SEM arrangement which took over from the Legacy SEM in October 2018. This section allows you to find legacy information about the SEM.
Trading in the Legacy SEM
Discover who could trade in the Legacy Single Electricity Market, and the rules that underpinned the market operation.
Explore Legacy SEM tradingLegacy SEM FAQs
Our FAQ section covers a variety of information to help understand how the Legacy SEM operated.
See the FAQs