How much electricity comes from wind?
There are several useful answers. The right one depends on whether you mean this moment, a whole day or an entire year.
Reviewed 2 November 2026 · Republic of Ireland
Start with the time period
A turbine’s output changes with the wind. An instantaneous reading tells you the rate of electricity production now, measured in megawatts (MW). It cannot tell you how much energy was produced over a day.
To estimate energy, this index adds up the published quarter-hour readings. Each MW reading represents a quarter of an hour: multiply it by 0.25 to estimate megawatt-hours (MWh), then add the intervals. Daily totals are shown only when every paired interval is available.
What the percentage means here
We divide wind generation by system demand for the same place and period. The index uses EirGrid’s Republic of Ireland region, not the all-island series. Imports, exports and other generators are part of the wider electricity system, so the ratio does not trace the electricity reaching an individual household.
The seven- and thirty-day figures divide total wind energy by total demand across the period. They are not an average of daily percentages.
An annual statistic answers a different question
SEAI publishes national energy statistics, including renewable electricity shares. Its normalised wind series smooths weather effects for renewable-energy accounting. Do not compare a single operational reading directly with that annual indicator.
For a dated figure now, return to the index. For annual context, use SEAI’s published series and check the year, geography and definition.