Spain day-ahead wind power forecast

Forecasting wind in Spain

Spain operates one of the largest onshore wind fleets in the world, concentrated in Castilla y León, Galicia and Aragón. The forecast covers Spanish onshore wind and is scored against the day-ahead forecast Red Eléctrica publishes through the ENTSO-E Transparency Platform.

The Spanish fleet is concentrated in Castilla y León, Galicia, Aragón and Andalusia, and a great deal of it sits on ridges and elevated ground rather than open plain. Terrain of that kind is the classic difficulty in wind forecasting. A weather model works on a grid several kilometres wide and reports an average wind for each cell, while a turbine on a ridge crest inside that cell experiences something quite different, because the ridge accelerates the flow in a way the grid cannot represent. The effect is a limit shared by everyone forecasting the zone.

The benchmark

The benchmark is Red Eléctrica de España's own day-ahead wind forecast for the Spanish bidding zone, published through the ENTSO-E Transparency Platform and captured on the day it appears. Metered generation and installed capacity come from the same source, so the forecast, the benchmark and the outcome all sit on one consistent basis.

What is published for Spain

One value per day: onshore wind output at 11:00 local time tomorrow, as a load factor and in megawatts. Once REE'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.