The Minister for Communications said cost may not be the only factor in deciding whether to underground electricity cables.
A review is underway of plans to erect pylons with high voltage cables from the West to East and East to South of the country.
Pat Rabbitte told the Dáil that one issue to be decided will be whether it is cost effective to put a DC cable underground.
But he said lessons have been learned from other nations.
"When Denmark expressly decided not to underground after a year's study - and they had no difficulties about affording it or anything else - they decided deliberately not to go underground," he said.
"They did it for a combination of reasons … not just cost, but also for technical considerations – how easy it is to find a fault and all that kind of thing."