Poland has roughly 10.7 GW of installed onshore wind across more than 1,300 wind farms, and has added around 2.7 GW since 2022, one of the faster build-outs in Europe. OpenWindCast publishes an independent day-ahead forecast of Polish wind output and scores it daily against PSE's own forecast.
Averages across all zones. Every number on this page is recomputed daily from the public record below.
Great Britain has one of the largest onshore wind fleets in Europe, with most capacity in Scotland. The forecast covers GB onshore wind and is scored against NESO's own forecast, published through Elexon.
Every forecast ships with an 80% interval. This shows how often the actual output landed inside it, and how wide it was.
The Polish fleet is concentrated in the north and north-west, across Zachodniopomorskie, Pomorskie, Wielkopolska and Kujawsko-Pomorskie, over flat and open ground near the Baltic. Simple terrain makes the wind field itself more tractable than in mountainous countries. The distinctive feature in Poland is on the market side: when day-ahead prices fall to zero or below, output can be curtailed for commercial rather than meteorological reasons, and metered generation then falls short of what the weather alone would have produced. Because a fleet growing this quickly also makes absolute megawatts a moving target, everything here is measured as a load factor, so the record stays comparable as capacity is added.
The benchmark is PSE's own day-ahead wind forecast for the Polish bidding zone, distributed through the ENTSO-E Transparency Platform, captured on the day of publication and then held fixed.
One value per day: onshore wind output at 11:00 local time tomorrow, expressed as a load factor and published before 12:00 local, ahead of the day-ahead auction rather than after it. Once PSE'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 below and nothing is removed or rewritten later, so the full history is there to be checked rather than summarised. How this is measured.
Because a forecast can look better in megawatts simply because the fleet behind it got bigger. Expressing everything as a share of installed capacity removes fleet growth from the comparison.
Both forecasts are compared against metered output, so a day when generation is curtailed for market reasons affects both. Publishing the full daily record rather than a headline average is what keeps those days visible.
Compare every zone: how accurate are European TSO wind forecasts?
Mean absolute error as a percentage of installed capacity. Lower is better.
The share of days the forecast lands closer to the metered output than the operator's own forecast.
The range the actual output should land in 80% of the time, recalibrated daily.
NESO's published day-ahead 11:00 forecast, a fixed yardstick that is never used as an input.
A forecast of wind generation for the next delivery day, issued before the day-ahead electricity auction closes at 12:00 CET. Market participants use it to decide how much wind energy to bid into the auction.
One value per zone per day: the onshore wind output at 11:00 local time on the next day, expressed as a load factor and converted to megawatts with the installed capacity the grid operator publishes. Every forecast is published in the morning, before 12:00 local time.
Each day, the absolute error of the OpenWindCast forecast and of the grid operator's own day-ahead forecast are compared on the same 11:00 target. The site reports the mean absolute error as a share of installed capacity (nMAE), the win rate, and, where official prices are available, the imbalance cost of bidding each forecast.
Benchmark forecasts, metered generation and installed capacity come from the grid operators: Energinet, Elia, Fingrid, Red Eléctrica, the four German TSOs, PSE, REN, NESO via Elexon, and EirGrid with SONI, mostly through the ENTSO-E Transparency Platform. Weather inputs come from Open-Meteo.
Yes. The dashboard and the daily verification record are public, and each zone's history can be downloaded as CSV from the forecast section. For anything else, email m.sahaf@live.com.