Ireland must pay €50m to other EU countries after missing a renewable energy target.
The money will have to be paid in the next two months in exchange for help from countries that have exceeded their own targets and have surplus credits to sell.
That is on top of an estimated €100m already squirrelled away to pay for missing a key carbon reduction target.
Denmark and other countries including Lithuania and Estonia have made millions out of slow-coach member states who failed to meet the 2020 targets set 10 years ago by the EU.
The money is used by those countries to invest in their renewable energy projects, enabling them to get even further ahead than stragglers such as Ireland.
The EU has a collective target of meeting 20pc of its energy needs from wind, solar and other renewable sources by the end of this year.
Ireland's individual target was set at 16pc to reflect how much we lagged in renewable energy infrastructure.
That target was to be met by using renewables for 40pc of the country's electricity, 12pc of heating and 10pc of transport.
Ireland has done well on renewable electricity generation and is on track to meet that commitment, but the overall 16pc target is expected to be missed by a gap of 3pc to 3.5pc.
Climate Action Minister Eam- on Ryan said his department was in negotiations with a number of countries about buying credits from them and expected to cut a deal with two before the end of the year.
"It's with real regret that we're not spending €50m to meet the target. Instead, we're going to have to purchase those credits for not meeting it," he said.
"It shows that these European directives, both on renewables and climate emissions, have real teeth. They require us to act."
Ireland has also failed to meet its EU 2020 target for emissions reduction. A 20pc reduction over 2005 levels was required, but substantially less headway was made.
The slowdown in activity because of Covid-19 has made estimating emissions tricky, but Ireland bought just over €100m in carbon credits in recent years in expectation that this would be the cost of failure to meet the target.