The energy regulator is carrying out a probe into smart meter tariffs after it emerged that some of the plans offered are more expensive than traditional ones.
This is despite the fact that smart meter rates are being marketed as a way for customers to save money.
But it has emerged that some of the smart meter time-of-use tariffs work out more expensive a year than conventional energy rates.
Close to one million smart meters have been installed in homes, but just 37,900 customers have activated them and signed up for the time-of-use or smart tariffs which they were designed to facilitate.
Some smart meter unit rates are far higher than standard day/night meter rates.
The Commission for the Regulation of Utilities (CRU), the energy regulator, said it was working with ESB Networks to find out why some of the tariffs are so expensive.
It comes as householders were hit with an eighth price rise in the latest wave of hikes, when Flogas Energy announced its third price rise this year.
Electricity bills are going up by 17pc, and gas bills by 23pc from October 26.
It is the seventh price rise from Flogas Energy since the start of last year.
There is no rise in the standing charge this time. Flogas has some of the highest standing charges at up to €600 a year for electricity.
The latest price rise will add around €340 a year to electricity bills and around €395 to gas bills, Daragh Cassidy of price-comparison site Bonkers.ie said.
In total, two million electricity users are set to be hit with huge energy price rises from next month.
Meanwhile, the CRU confirmed it is probing tariffs for electricity customers who are on smart meters.
The CRU admitted: “In some cases, customers who have a day/night meter and tariff do not compare favourably to the smart meter tariffs that some suppliers are currently offering.”
It said this was down to how the individual suppliers price their products.
“There is ongoing work with ESB Networks and suppliers to understand the reason for some of the higher tariffs or if there are any other barriers that may be influencing the scope of tariffs suppliers are currently offering.”
The CRU urged customers to compare the tariffs available as other suppliers may offer better value.
“As the market continues to evolve and there is a greater amount of data from smart meters, we expect to see an increase in smart tariff offerings to customers that better suit their usage.”
Mr Cassidy said many of the smart tariffs on offer at present in Ireland do not seem to offer great value.
“Depending on the type of meter you currently have (a day/night meter or a standard meter, for example) and when you use your electricity, you could end up paying more for your electricity on a smart tariff if you’re not careful. This is the last thing you’d want when prices are at record levels.”
He said smart tariffs “are great for penalising those who use their energy at peak times between 5pm and 7pm. They’re not so great at offering value outside of these times”.
A smart meter continually records electricity use in the home or premises where it is installed and automatically transmits updated information every 30 minutes to a central database held by ESB Networks.
A smart tariff means higher prices at peak times when there is high demand on the electricity system and cheaper electricity outside peak usage times.
Meanwhile, those who do not have smart meters have been advised by Bonkers.ie to submit a meter reading this week.
This is due to the fact that around two million electricity customers and half a million gas customers are due to be hit with huge price rises next month.
Those who do not submit a meter reading could end up paying for units used before the October price rise at the new higher rate.