Electricity companies in Ireland are set to be hardest hit, if a proposed energy windfall tax comes into force, according to the ESRI.
The European Commission is looking at ways to redistribute the huge profits some energy companies are currently making.
However, the Taoiseach says it's not yet known exactly how much funding Ireland would receive through the EU proposal.
The retail price of electricity and gas, which are linked, has risen sharply since the Russian invasion of Ukraine in February.
Energy Economist with the ESRI, Muireann Lynch, says electricity producers are currently seeing the highest profit levels.
