The ESB opens its newest generating station at Aghada in east Cork today.
The gas-fired plant is believed to be one of the most efficient and cleanest plants in Europe and will generate enough electricity to power almost 500,000 homes.
The profile of the ESB's generating capacity has been changing, selling-off old technology and oil-fired stations at Tarbert in Kerry and Great Island in Wexford.
Instead, it has increased its involvement in cleaner, gas-fired stations, such as the plant being opened in Cork this morning.
The new plant took just two-and-a-half years to build and cost €360m.
It was built alongside an existing generating station at Aghada and their combined capacity will make this the biggest power station in the country.
ESB Chief Executive Padraig McManus has said his company will match any offers being put forward by its competitors when the domestic electricity market is fully opened to competition early next year.
