Electricity supplies to Northern Ireland will be squeezed over the next decade without a second cross-Border high-capacity power line, the national grid operator will warn today.

State company Eirgrid and its subsidiary System Operator Northern Ireland, which operate the electricity systems in the North and the Republic, predict in a statement published today that there is likely to be an overall surplus in power supplies across Ireland over the next decade.

However, it also warns that network limitations are restricting the amount of electricity that can be effectively used in Northern Ireland, “leading to tight supply margins”.

The statement says that as a result the gap between electricity supply and demand in the North will be tight in the second part of the 10-year period.

The problem is down to the fact that there is only one major power line connecting the two networks.

Power supplies

According to Eirgrid chief executive Fintan Slye, a second North-South tie-in is needed to ensure that both jurisdictions have enough power supplies to meet demand.

Proposals to build a power line running from Meath through Cavan and Monaghan ran aground in 2010 when a planning hearing detected a mistake in the public notice that formed part of Eirgrid’s planning application.

The high-capacity power line would have provided part of a second North-South connection as it would have continued into Co Tyrone.

Eirgrid still intends building a second cross-Border interconnector.

Its All-Island Generation Capacity Statement 2013-2022, which is published today, says that the recession has subdued overall demand for electricity but one sector where it has been growing is data centres.

Eirgrid says that data centres need “significant amounts of high-quality power” and strong communications links.

“There is currently over 175 megawatts of data-centre demand on the power system and this is expected to double over the rest of this decade,” Eirgrid adds.