Independent Studies in relation to the North South Interconnector project

Motions were passed in Dáil and Seanad Éireann in 2017 calling for an updated independent study into the North-South Interconnector project. Two independent studies were subsequently commissioned to address the main points of the motions as well as key concerns expressed by parties opposed to the development.

The first is a study to investigate the cost and technical feasibility of undergrounding the North South Interconnector. The report was conducted by an International Expert Commission made up of Bo Normark, Ronnie Belmans and Keith Bell.

The second study examines the levels of compensation provided to land and property owners close to high-voltage transmission lines in a European context. This study was conducted by KHSK Economic Consultants.

In late 2021 the Department of the Environment, Climate and Communications commissioned a review from two distinguished international experts to ensure that the conclusions of the 2018 study remained valid.

This report has now been received and is available below. The report confirms the findings of the 2018 study and supports the choice to build the North South Interconnector above ground. The report concludes that:

• The only feasible options to be considered for the North South Interconnector are an underground DC interconnector with AC to DC converters or an overhead AC interconnector
• An overhead AC interconnector could use specially designed towers to reduce its visual impact, however this could double its cost
• EirGrid has correctly estimated the additional cost of an underground DC interconnector over an overground AC interconnector
• EirGrid was correct to point out the additional complexity of an underground DC connector. However, experience in using this technology is increasing and it should not be ruled out for future projects
• New techniques have recently been developed which allow the quantification of the operational cost impacts of AC and DC solutions. These should be used in the appraisal of future projects