EIRGRID has identified three optimum link-up locations for a new 250km high voltage pylon route across Leinster and Munster.
The energy network company said the €500m project would be best suited to a corridor from Knockraha in Cork to Great Island in Wexford and Dunstown in Kildare.
But as an eight-week public awareness and consultation period began, EirGrid insisted no application for the build would be lodged before the end of 2015.
Under initial proposals the 400kV Grid Link corridor would be overhead, at least 250km long and with pylons every 4km and big enough to bring wind energy to 750,000 homes.
Pat Rabbitte, Minister for Communications, Energy and Natural Resources, said it will provide a secure, long-term electricity supply for homes and businesses in the south and east.
"The grid link project will reinforce the electricity grid and have direct economic benefits for our local communities. I encourage people to engage in the public consultation and provide feedback to EirGrid," he said.
EirGrid said the optimum connection points in Cork, Wexford and Kildare would house transmission substations.
The company said that the three points are capable of bringing the supplies from the new 400kV link on to the existing grid.
They are geographically well-positioned to meet the strategic needs of the network development, EirGrid said.
An area covering Carlow, Cork, Dublin, Kildare, Kilkenny, Laois, Limerick, Tipperary, Waterford, Wexford and Wicklow has been chosen for possible routes.
EirGrid, which has already faced massive opposition to high voltage lines in Co Meath and the Midlands, said the development was needed to plug gaps in the transmission system in the south and south-east.
Dermot Byrne, chief executive of EirGrid, said the link is vital if the goal of 40% electricity from wind, wave and tidal renewables is to be reached by 2020.
"The project will help enable Ireland to shift from a heavy reliance on imported fossil fuels to more sustainable sources of energy," he said.
"It will also help ensure that the most efficient electricity generators in the south and east are utilised in the most effective way."
EirGrid said it favours a 400kV alternating current overhead line.
Harold Kingston, IFA national environment and rural affairs chairman, warned of the need to avoid the development problems and disputes of the past.
"The planned grid development by EirGrid will cause significant disturbance for the many farmers along the route in the counties affected," he said.
"It is essential that lessons are learned from the recent problems in the Midlands.
"Particular attention must be paid to the concerns of farmers at route selection stage and all options in the planning phase must be considered."
EirGrid has faced hardline opposition over some of its developments including in Offaly where 65-year-old landowner Teresa Treacy was jailed for two weeks last year for refusing to allow works to go ahead on an overhead line.
She objected as the work would have seen a substantial number of trees on her land at Clonmore, near Tullamore, felled. Talks are ongoing between the two sides to reach a compromise.
Elsewhere, plans for a cross-border interconnector and high voltage line from Tyrone and south into Co Meath have ended up in the hands of the Joint Committee on Communications, Natural Resources and Agriculture in the Oireachtas which will report to Mr Rabbitte on its preferred options.
Locals are in dispute with EirGrid over the type of lines to be used, claiming that underground will be safer.
There has also been a long-running dispute involving residents in and around Stradbally, Co Laois, over EirGrid's plans for a substation outside the town.