Energy chiefs in Ireland and France are considering linking the two countries with a 600km cable to secure electricity supplies.
Experts will spend several months this year studying the seabed in order to identify the best potential route for joining the southern Irish coast with the north-west of France.
The aim is to build a connector powerful enough to carry about 700 megawatts of electricity – the equivalent of energy demands from about 450,000 homes. If it goes ahead, it is not expected to be ready before 2025.
Two national transmission operators, EirGrid and French counterpart RTE (Reseau de transport d'electricite), have signed a memo of understanding to make further feasibility studies.
EirGrid chief executive Fintan Slye said: "The benefits of the Ireland-France interconnector could include increased security of supply, downward price pressure on electricity prices through competition, and the potential to export renewable energy."
Pierre Bornard, senior executive vice-president at RTE, said: "The construction of the interconnector would facilitate the integration of renewable energy in the European electricity system, and would benefit from the varying wind resources of Ireland and the continent."