DK2 is the eastern Danish bidding zone, covering Zealand, Lolland, Falster, Møn and Bornholm, with 825 onshore turbines and about 745 MW of capacity. OpenWindCast publishes an independent day-ahead forecast of DK2 onshore wind and scores it daily against Energinet'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.
DK2 is the smallest fleet in the portfolio, and small fleets are structurally harder to forecast as a share of their capacity. With 745 MW spread over a handful of islands there is very little internal averaging, so a single band of showers crossing Zealand an hour early moves the whole zone total, where the same band over a fleet a hundred times the size would barely register. Bornholm adds to that: it lies roughly 150 km east of the rest of the zone, out in the Baltic, and can sit under quite different weather from Zealand on the same day.
The benchmark is Energinet's own day-ahead forecast for DK2 onshore wind, taken from the Energi Data Service. As in DK1, it is frozen on first capture, because Energinet's service can return a revised value for a past hour on a later query and a moving bar is not a bar.
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 Energinet'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 it is roughly one sixth the size and spread across islands. Small, concentrated fleets have little internal error cancellation, so one mistimed shower band moves the whole zone at once.
Yes. Bornholm is part of the DK2 bidding zone, and it sits far enough east to be under genuinely different weather from Zealand.
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.