Interconnection of electricity networks brings significant benefits including the ability to trade electricity between countries and the ability to rely on the generation capability of a neighbouring country for reasons of security of supply.
Given the geography of Ireland the Irish electricity system is relatively isolated compared to systems in mainland Europe and even the UK. However, there is some interconnection to the Northern Ireland system and a project to build an interconnector to the UK is under consideration.
North-South Interconnection
There is one major electricity interconnector between the Republic of Ireland and Northern Ireland electricity grids. The Louth to Tandragee interconnector consists of a 275 kV double circuit (two circuits on the same tower) overhead line.
There are also two small 110 kV standby North-South Interconnectors, Strabane to Letterkenny and Enniskillen to Corraclassy, which allow the System Operator for Northern Ireland (SONI) and EirGrid to provide mutual short-term technical assistance.
Based on a recommendation from the CER and the Northern Ireland Authority for Utility Regulation (NIAUR), Ministers in the North and South of Ireland have decided that a second North – South Interconnector (SNIC) should be built. The construction of the Interconnector is being carried out by the Transmission System Operators in both jurisdictions (SONI and EirGrid) and the project is at preliminary design phase. The new 400 kV line will be located to the west of the existing interconnector and it is anticipated that the project will be complete by the end of 2012.
The South - North Interconnector (SNIC) will significantly increase the electricity transfer capacity between the two systems. This will help to reduce network operating costs, strengthen electricity supply on both power systems, support greater competition on an all-island basis and help in connecting increased levels of wind generation.
EirGrid Invitation to Bid: South North Interconnector Capacity 23 February 2007
On 23 February 2007, the CER published EirGrid's Invitation to Bid for capacity on the South - North Interconnector.
East-West Interconnection
Additional benefits could be gained if the Irish transmission system were interconnected with the UK system which would in turn ensure that the Irish electricity market would be more closely integrated into the wider European energy market.
A government decision has been made to examine the possibility of building an east-west interconnector and the CER has been asked to investigate the matter further. In March 2004 the CER engaged a KPMG-led consortium to advise on the financial, technical, commercial and procurement aspects of new interconnection between Ireland and Wales. In September 2005, KPMG submitted a report to the CER on the issue and the CER has presented the recommendations of the report to the Minister for Communications, Marine and Natural Resources.
Following on from the publication of the Green Paper "Towards a Sustainable Energy Future for Ireland" the Government outlined its decision in relation to the East West Interconnector Project. A letter to the Commission Chairman from the Department of Communications, Marine and Natural Resources outlines this decision, is available below. The Government Decision deals with, among other things, the capacity of the Interconnector, its ownership by EirGrid, a competition for its construction to be designed by the Commission and the next steps in taking this project forward for completion at the earliest possible date before 2012.
The Department's letter is dated 27 July 2006 and anticipated a public announcement by the Minister.
On 2 February 2007, the Commission and Eirgrid published a update on progress towards the development of the East West Interconnector. This information note can be viewed below.