The answer is blowing in the wind!
In 2001 Irish electricity carbon emission factor stood at 807 gCO2/kWh. In 2011 this factor had dropped to 489 gCO2/kWh, a reduction of 40% in carbon intensity over 10 years!
This reduction is primarily from the introduction of wind generation onto the electricity grid and to general improvements in the efficiency of generation plant and the grid.
Another good reason to support Irish wind energy and associated jobs!