20,000 smart electricity meters will be rolled out to households in the midlands and south by the end of the year.
The upgrade programme by ESB Networks will begin in September in areas around Portlaoise in Laois and Bandon in Cork.
The initial rollout will be followed by 250,000 home installations by the end of 2020, and a further half a million each year between 2021 and 2024.
Eoghan Barrett of ESB Networks says the new meters will help the country reduce carbon emissions and help households save money.
"Smart meters will help every home, farm and business to move to a low-carbon future," said Mr Barrett.
The planned upgrade works will be done with minimum disruption to people.
"We will need an outage to replace the meter, the replacement will take about 45 minutes and we will be in contact with customers to arrange appointments for the meter replacements," said Mr Barrett.
"The meter itself is the same size as the existing meters and it will be replaced in situ so there is no disruption to the household."