Ireland's biggest power plant, Moneypoint in Co Clare, is "quite dirty" in terms of its CO2 emissions, according to an analysis of the more than 50,000 power stations around the world.
However, Moneypoint, which produces an estimated 9.2 million tons of the damaging greenhouse gas each year, is well down the list of offending plants around the world.
And across the State, Ireland's power plants produce a relatively small amount of carbon compared to some of the world's CO2 villains, according to the comprehensive worldwide study.
Ireland's 26 largest power plants emit a combined 16.4 million tons of CO2, or just under four tons per person per year, according to Carbon Monitoring for Action (Carma), an arm of a US-based independent think tank, the Center for Global Development.
Ireland has 184 power plants, says Carma, which includes everything from large industrial generators to nuclear power plants in its analysis.
Moneypoint, near Kilrush, produces 9.2 million tons of carbon, according to Carma's analysis. "That's quite dirty in terms of carbon," said Kevin Ummel, a spokesman for Carma.
"It produces 4000 pounds of carbon per megawatt hour, and anything above 1800 is considered quite a dirty plant," said Mr Ummel, speaking from Washington DC.
The ESB, which operates Moneypoint, says that a €380 million environmental refit at the plant will reduce carbon emissions by up to 80 per cent.
"The use of coal for electricity generation protects the Irish market and consumer from overdependency on any one fuel and the possible risk of price spikes," said the ESB in a statement released in response to the Carma report.
Ireland's next biggest plant, in Poolbeg, produced 1.7 million tons, while Ringsend produces 1.4 million. The world's most polluting plant is Taiching in Taiwan, which releases 41.3 million tons.
About 84 per cent of Ireland's power plants burn fossil fuels, according to the analysis, while around 10 per cent of energy is generated by renewable sources like wind and solar.
The ESB says in 2006 it reduced CO2 emissions by 13 per cent from the previous year, and is continuing to work to lower emission levels by closing less efficient plants.