Market Overview

The Single Electricity Market (SEM) is the wholesale market on the island of Ireland where electricity generators and suppliers trade the power used by homes and businesses across Ireland. 

Much has changed since the SEM was established in 2007, not least the significant increase of renewable generation, the introduction of new technologies and the increased advantages to be gained from interconnection with other markets. 

To take advantage of new opportunities and to improve the efficiency, competitiveness and operation of the market, new operational arrangements were put in place from 1 October 2018.  This project, known as ISEM, sought to maximise the efficient use of interconnectors and ensure compliance with the EU target model. 

The SEM brings signifiacant benefits for all consumers. It provides trading opportunities for generators, suppliers and investors while delivering an efficient and competitive electricity market. The market is designed to support competition, allow increased renewables on the system, encourage new investment and support security of supply, all while placing a downward pressure on prices.