Italy · onshore wind

Italy day-ahead wind power forecast

Italy has close to 12.9 GW of onshore wind across more than 7,500 turbines, almost all of it in the south: Puglia, Campania, Basilicata, Calabria, Sicily and Sardinia. OpenWindCast publishes an independent day-ahead forecast of Italian wind output and scores it daily against Terna's own forecast.

Record updated 22 Sept 2026 Scored against Terna

Tomorrow · Wed 23 Sept, 11:00 Rome

3,148MW

24.5% of 12,875 MW installed

Terna, same hour: published later
Metered: not yet
80% interval: 2,337 to 3,541 MW

Most recent scored day, Tue 22 Sept

Metered 2,574 MW. OpenWindCast 3,072 MW, off by 3.9% of capacity; Terna 3,478 MW, off by 7.0%. OpenWindCast closer

Scoreboard against Terna

Live since 18 Jul 2026 · 67 scored days · 18 Jul to 22 Sept

40% lower error than Terna's own day-ahead forecast

OpenWindCast

2.54%

of capacity

Terna

4.26%

of capacity

Closer on

70%

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: 331 days, 32% lower error than Terna. 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 Terna

Type of day	Days	OpenWindCast	Terna	Closer on
Low-wind days below 15% of capacity	56	2.43%	3.77%	66%
Moderate days 15% to 35% of capacity	10	3.29%	6.64%	90%

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	Terna	Metered	Our miss	Terna miss	Closer
Wed 23 Sept	3,148	–	not yet	–	–	pending
Tue 22 Sept	3,072	3,478	2,574	3.9%	7.0%	OpenWindCast
Mon 21 Sept	859	1,335	782	0.6%	4.3%	OpenWindCast
Sun 20 Sept	487	861	509	0.2%	2.7%	OpenWindCast
Sat 19 Sept	379	1,249	393	0.1%	6.7%	OpenWindCast
Fri 18 Sept	1,209	1,584	478	5.7%	8.6%	OpenWindCast
Thu 17 Sept	1,267	1,562	1,154	0.9%	3.2%	OpenWindCast
Wed 16 Sept	382	261	191	1.5%	0.5%	Terna
Tue 15 Sept	3,180	4,363	3,718	4.2%	5.0%	OpenWindCast
Mon 14 Sept	832	851	1,240	3.2%	3.0%	Terna
Sun 13 Sept	3,026	4,478	2,711	2.4%	13.7%	OpenWindCast
Sat 12 Sept	946	1,992	1,291	2.7%	5.4%	OpenWindCast
Fri 11 Sept	3,090	3,178	2,511	4.5%	5.2%	OpenWindCast
Thu 10 Sept	1,685	1,584	1,376	2.4%	1.6%	Terna

Terna'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 Italy

Italy's onshore wind fleet is concentrated in the south, across Puglia, Sicily, Campania, Basilicata, Calabria and Sardinia. The forecast covers Italian onshore wind and is scored against the day-ahead forecast Terna publishes through the ENTSO-E Transparency Platform.

Italian wind is southern, mountainous and clustered into a small number of regions. Much of the capacity sits along the southern Apennines and in the interiors of Sicily and Sardinia, terrain that weather models resolve only coarsely. The coastal sites along the Adriatic, Ionian and Tyrrhenian shores add a land and sea breeze component that varies through the day and is not driven by the large-scale weather pattern alone. Because the fleet is concentrated in a handful of regions rather than spread across the country, there is little of the internal error cancellation that larger, more dispersed fleets benefit from.

The benchmark

The benchmark is Terna's own day-ahead wind forecast for the Italian bidding zone, published through the ENTSO-E Transparency Platform, captured on the day of publication and then held fixed. Metered generation and installed capacity come from the same platform.

What is published for Italy

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

Does this cover Italy's individual market zones?

No. It is the national Italian aggregate that Terna publishes day-ahead. Italy's internal zonal structure is not separated here.

Is solar included?

No. OpenWindCast forecasts wind generation only.

Other bidding zones

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