Cross-border connector will be overhead, says NIE

Northern Ireland Electricity is pressing ahead with a planning application for an overhead cross-border electricity interconnector after being told an underground cable would cost seven times as much.

The company today announced the results of an independent investigation into whether the link between Co Tyrone and Cavan should be under or over ground.

The report was one of three investigations commissioned by NIE and Eirgrid in Ireland in response to extensive public consultation, and in particular specific requests from landowners and residents in the Armagh and Tyrone areas for a feasibility study into putting the interconnector underground.

The report from PB Power confirmed, said NIE, there was no underground cable circuit of the kind and length of the project anywhere in the world, and that there were substantial technical challenges associated with underground cables at very high voltage levels.

NIE said: “The report concludes that overhead lines are more reliable and more efficient than underground cables and that the cost of installing an underground circuit in the specific terrain applicable to the proposed route would be more than seven times that of an overhead line construction.”

Other investigations have been carried out for NIE into the possibility of putting the cable underground for part of the route, but that too has been rejected.

NIE is pressing ahead with the second cross-border interconnector at the request of government and the Utility Regulator as part of the development of the all-island electricity market.

David de Casseres, NIE’s transmission project director, said the interconnector was needed to ensure the all-island market was able to work efficiently and at the lowest possible cost for all customers in the future.

He said they also needed to enable the future connection and use of significantly increased amounts of wind powered generation and other renewable resources, as well as ensuring the required level of supply security for future economic development in the North.

“The best way of achieving these three objectives is to build a new high capacity overhead line. Undergrounding technology, besides being far more costly, is simply not robust enough yet.

“Best practice throughout the world, and most recently in countries such as Germany, Denmark and the Netherlands, are at the earliest stages of experimentation with underground high voltage cables,” he said.

Mr de Casseres confirmed NIE would be proceeding with a planning application for an overhead line to be constructed along a carefully selected route chosen to limit the impact of the development on both the environment and upon communities along the route.

Maps detailing the chosen route had recently been sent to all landowners affected by the proposed line and NIE was working on a detailed Environment Impact Statement that would incorporate reference to the PB Power report which would accompany the planning application when it was made later this year.

NIE said it was “keenly aware” of people’s health concerns about power lines, and wanted to reassure the public the proposed interconnector would comply fully with all government guidelines in relation to health and safety, including those relating to exposure to electrical and magnetic fields.