Greece has around 5.5 GW of onshore wind, more than three times what it had in 2015, running from Thrace in the north east down the mainland ridges to the Peloponnese and across to Crete. OpenWindCast publishes an independent day-ahead forecast of Greek onshore wind output and scores it daily against IPTO's own published forecast.
Averages across all zones. Every number on this page is recomputed daily from the public record below.
Austria's onshore wind fleet stands almost entirely in the flat Pannonian east, across northern Burgenland, Lower Austria and Styria. The forecast covers Austrian onshore wind and is scored against the day-ahead forecast APG publishes through the ENTSO-E Transparency Platform.
Every forecast ships with an 80% interval. This shows how often the actual output landed inside it, and how wide it was.
The Greek fleet stands on ridges and coastlines rather than on plains. The largest single concentration is on the island of Evia and in the hills of Boeotia and Parnassos just across the water from it, with further clusters in Aitoloakarnania, across Laconia and Arcadia in the Peloponnese, in Thrace and Macedonia to the north, and on Crete. Complex terrain is harder to forecast than flat, open country, because wind speed at turbine height can change sharply over a few kilometres. Greece also has a summer regime of its own: the Etesian winds, known locally as the meltemi, blow from the north and north east down the Aegean for long spells, which is a different problem from the Atlantic frontal systems that drive most of northern Europe.
The benchmark is IPTO's own day-ahead wind forecast for the Greek bidding zone, published through the ENTSO-E Transparency Platform, captured on the day it appears and then held fixed, so the comparison is always against what the market could see before the auction closed. Installed capacity and metered generation come from the same platform. Greece is a single bidding zone; the smaller non-interconnected island systems are operated separately and sit outside it.
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 IPTO'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.
Yes. Crete has been connected to the mainland grid since 2021 and sits inside the Greek control area, so its wind farms are part of both the forecast and the benchmark. The smaller non-interconnected island systems, in the Dodecanese and the north east Aegean, are run separately and are outside it.
Not at present. The Greek wind fleet is entirely onshore, so the forecast covers all of it.
Greece has a large solar fleet alongside its wind fleet, and around midday on bright, windy days the system can end up with more generation than it can use. Renewable output is then curtailed, so the metered figure lands below what the weather alone would imply. The scoreboard scores metered output, because that is what a market participant is actually settled on.
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.
APG'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.