Councillors in Meath have reaffirmed their opposition to planned new overhead power lines, despite being told yesterday the alternative could be up to 12 times more expensive.
A special meeting of Meath County Council was also told it is normal international practice to use overhead power lines for the transmission of bulk electrical power.
Independent consultants McLellan and Partners had been asked to give a briefing on the difference in overhead and underground transmission systems.
Councillors are opposed to Eirgrid's plans to use a network of overhead pylons for its planned new 400kv transmission system.
The final route for the system has yet to be chosen, but will stretch for some 56km (35mls) from Woodlands in south Meath to Kingscourt in Cavan.
The councillors want Eirgrid to bury the cables and yesterday the consultants said that like-for-like cost comparisons between both methods are "notoriously difficult" to calculate. But they said using underground cables could be six to 12 times more expensive.
David Linsell, director with McLellan and Partners, said "overhead lines are normal international practice of transmission of bulk electrical power."
While both transmission systems were very reliable, "cables were usually used over short distances such as in the scenic Vale of York and were rarely used for distances above 20 kilometres," he said.
Eirgrid, which controls the national grid, is expected to apply to An Bord Pleanála for permission to construct the network of pylons later this year.
After the presentation yesterday, the councillors called for Eirgrid to make public the cost comparisons of both.
The anti-pylon group Pylon Pressure rejected claims that lengths over 20km were not put underground, saying the Estlink cable which links Estonia with Finland is 105km long and runs undersea and underground.
Cllr Brian Fitzgerald said the power line from Wales to Rush in north Dublin was being brought under the Irish Sea and was then going underground to Batterstown in Co Meath. He asked why the same technology could not be used in Meath.
In a letter to council chairman Nick Killian, Eirgrid chief executive Dermot Byrne has said "the issue of undergrounding will be fully addressed and will be analysed in detail in the Environmental Impact Statement to be submitted with Eirgrid's planning application to An Bord Pleanála later this year".