The ESB board has approved the closure of three of its older power stations and one steam generating turbine.
In a statement this afternoon the State-owned company said the stations at Great Island in Wexford, Poolbeg Thermal in Dublin and the oil-fired Tarbert plant in Co Kerry will be closed.
The closures are part of an arrangement with the energy regulator that will see the ESB's generating capacity reduced by 1,300 megawatts to allow other suppliers into the market.
The company has also confirmed that the steam turbine plant at Marina in Cork is to close, although the Gas Turbine plant on that site will remain in operation.
Over 350 staff work at the plants involved and the company said it will shortly begin talks with the union over its future plans. The ESB said there would be no forced redundancies.
The ESB is also to build a plant in Co Cork that will provide 430 megawatts of generating capacity.
