When is Ireland's electricity greenest?
The carbon intensity of Irish electricity swings from under 150 g/kWh on a windy night to well over 400 g/kWh on a still winter evening. Using power in the green windows cuts your carbon, and usually your cost.
Why it changes
When the wind blows, cheap zero-carbon wind covers much of demand and gas plants throttle back, so both carbon and wholesale price fall. On calm, cold evenings the grid burns more gas (and sometimes coal or oil), pushing both up. Demand also peaks around 5 to 7pm as people come home and cook.
The rough pattern
Overnight and the early hours are usually greenest (low demand, and wind often strongest). The 5 to 7pm weekday peak is usually the dirtiest and dearest. But wind changes day to day, which is why the live figure on the front page is the one to watch.
What to shift
The big movable loads are EV charging, the dryer, the dishwasher, the washing machine, and pre-heating a hot-water tank or the house with a heat pump. Put them on timers pointed at the green window.
Make the savings real
Timing helps most on the right plan. Get a free plan review.