OpenWindCast

Ireland · electricity price and wind power

Ireland day-ahead wind power forecast

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Record updated 27 Oct 2026 Scored against EirGrid

Tomorrow · Wed 28 Oct, 11:00 Dublin

Wind power forecast for Wednesday 28 October 2026

1,976MW

29.1% of 6,785 MW installed

EirGrid, same hour
2,626 MW
Metered
not yet
80% interval
1,410 to 2,163 MW

Most recent scored day, Tue 27 Oct

Metered 3,368 MW. OpenWindCast 3,358 MW, off by 0.2% of capacity; EirGrid 5,214 MW, off by 27.2%. OpenWindCast closer

Scoreboard against EirGrid

Live since 13 Jul 2026 · 90 scored days · 13 Jul to 27 Oct

57% lower error than EirGrid's own day-ahead forecast

OpenWindCast

2.99%

of capacity

EirGrid

7.03%

of capacity

Closer on

74%

of days

Error is the average miss at the 11:00 target, as a share of installed capacity (nMAE). Back-test before go-live, shown apart: 280 days, 62% lower error than EirGrid. Only live days count above.

Forecast against the operator and the metered output

One point per day at 11:00, in MW. The shaded area is what the fleet actually produced; before the Live marker the forecast line is the back-test.

Accuracy by type of day

Live record, split by how windy the day turned out. Average error in % of capacity; further left is better.

OpenWindCast EirGrid
0%5%10%15%20%Low-wind days (49 days)Moderate days (26 days)High-wind days (15 days)0%10%20%Low-windModerateHigh-wind
Type of dayDaysOpenWindCastEirGridCloser on
Low-wind days below 15% of capacity492.24%3.31%69%
Moderate days 15% to 35% of capacity264.07%9.55%77%
High-wind days above 35% of capacity153.60%14.80%87%

The daily record

One row per day at 11:00, in MW. Misses are in % of capacity. Losing days stay in the record.

JSON
Day (11:00) OpenWindCast EirGrid Metered Our miss EirGrid miss Closer
Wed 28 Oct 1,976 2,626 not yet – – pending
Tue 27 Oct 3,358 5,214 3,368 0.2% 27.2% OpenWindCast
Mon 26 Oct 3,922 5,180 3,697 3.3% 21.8% OpenWindCast
Sun 25 Oct 3,568 – 2,413 17.0% – pending
Sat 24 Oct 3,916 5,621 4,000 1.2% 23.9% OpenWindCast
Fri 23 Oct 3,539 3,769 2,591 14.0% 17.4% OpenWindCast
Thu 22 Oct 516 1,141 248 4.0% 13.2% OpenWindCast
Wed 21 Oct 2,918 3,188 3,143 3.3% 0.7% EirGrid
Tue 20 Oct 2,209 2,268 2,753 8.0% 7.2% EirGrid
Mon 19 Oct 540 577 450 1.3% 1.9% OpenWindCast
Sun 18 Oct 121 116 121 0.0% 0.1% OpenWindCast
Sat 17 Oct 215 345 155 0.9% 2.8% OpenWindCast
Fri 16 Oct 1,366 1,295 1,022 5.1% 4.0% EirGrid
Thu 15 Oct 1,010 900 786 3.3% 1.7% EirGrid

EirGrid's forecast is captured on the day it is published and held fixed. Operators refine their forecasts nearer to delivery, so a value published later may differ. The most recent day or two settle once measured generation is published.

Forecasting wind in Ireland

Ireland's wind fleet is concentrated along the Atlantic seaboard, from Kerry up to Donegal. The forecast covers the island's wind output and is scored against the day-ahead forecast EirGrid and SONI publish through the ENTSO-E Transparency Platform.

Irish wind sits along the Atlantic seaboard, from Kerry and Clare north through Mayo, Sligo and Donegal, with further capacity in the Northern Ireland uplands. It is the most exposed fleet in the portfolio. Atlantic depressions reach Ireland with no land upwind to modify them, so the timing of a front is decided far out over the ocean, and a few hours of error in that timing is worth a very large swing in output. Forecast error as a share of capacity is correspondingly higher here than in more sheltered parts of Europe, which reflects the meteorology rather than the operator.

The benchmark

The benchmark is EirGrid and SONI's own all-island day-ahead wind forecast, published through the ENTSO-E Transparency Platform. Installed capacity is maintained separately, from EirGrid and SONI's renewable constraint and curtailment reporting, because the all-island system does not publish it in the usual ENTSO-E series.

What is published for Ireland

One value per day: onshore wind output at 11:00 local time tomorrow, as a load factor and in megawatts. Once EirGrid's own forecast for that day is published it is captured and held fixed, and once the metered output is settled both forecasts are scored against it. Every day is added to the record above and nothing is removed or rewritten later. How this is measured.

Questions about wind in Ireland

Why is Ireland treated as one zone?

Because the Single Electricity Market covers the whole island, and EirGrid and SONI forecast and settle it as one system. Splitting it would not match anything the market trades.

Is offshore wind included?

Irish offshore capacity is very small next to 6.8 GW of onshore and is not separated out.

Official links for Ireland

Grid operators, their published data, the power exchange and the European transparency platform.

Other bidding zones

Compare every operator: how accurate are European TSO wind power forecasts? · How the scoring works