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Kpler Short Term Forecasts

Wind, solar generation, demand and SPOT price forecasts up to 46 days ahead

Hamza Aourach avatar
Written by Hamza Aourach
Updated over a week ago

Weather inputs

Kpler’s short-term forecasts for wind, solar, demand, and prices rely on two external weather data providers:

  • ECMWF (a.k.a. EC) – European Centre for Medium-Range Weather Forecasts

  • GFS – Global Forecast System from the U.S. National Oceanic and Atmospheric Administration (NOAA)

Both providers run four forecasts per day — 00, 06, 12, and 18 — across two model types :

  • OP (Operational): A single deterministic scenario (AIFS is too)

  • ENS (Ensemble): Multiple scenarios (50 for EC ENS, 100 for EC 46, 30 for GFS ENS)

The table below summarizes the daily forecast update times (Availability D+1) and the forecast length for each run.

Model

00

06

12

18

EC OP
Availability D+1

05:30 UTC
UPD 10:00 CET
UPD 11:15 CET

11:20 UTC

UPD 15:00 CET
UPD 16:00 CET

17:30 UTC

23:15 UTC

Length

14 DAYS

5 DAYS

14 DAYS

5 DAYS

EC ENS
Availability D+1

06:05 UTC

12:05 UTC

18:05 UTC

00:05 UTC

Length

14 DAYS

5 DAYS

14 DAYS

5 DAYS

EC 46
Availability D+1

21:05 UTC

Length

45 DAYS

EC AIFS
Availability D+1

05:30 UTC

11:20 UTC

17:30 UTC

23:15 UTC

Length

14 DAYS

14 DAYS

14 DAYS

14 DAYS

GFS OP
Availability D+1

03:55 UTC

UPD 10:00 CET
UPD 11:15 CET

09:50 UTC

UPD 15:00 CET
UPD 16:00 CET

15:55 UTC

21:55 UTC

Length

15 DAYS

15 DAYS

15 DAYS

15 DAYS

GFS ENS
Availability D+1

04:30 UTC

10:15 UTC

16:15 UTC

22:15 UTC

Length

15 DAYS

15 DAYS

15 DAYS

15 DAYS

Please note that :

  • The default time is UTC, but CET is used for updates.

  • Delivery times are indicative and may vary in case of weather centre delays.

  • The times listed refer to when the first forecasted hour becomes available. It may take up to 1 additional hour to complete the full forecast horizon.

Forecast methodology

Our price forecasting combines machine learning and time series analysis, with a strong foundation in fundamental market drivers such as production, consumption, fuel prices, and interconnector capacity.

To ensure transparency and avoid the “black box effect”, our models operate in two sequential steps:

Step 1 – Fundamental Forecasts

We first convert raw weather data (temperature, wind speed, solar radiation, cloud cover, etc.) into forecasts of demand, wind production, solar production

This stage captures the physical supply-demand fundamentals that will later influence price formation.

Step 2 – Price Forecasts


The outputs in MW from the fundamental models are then fed into our machine learning-based price models to forecast hourly day-ahead electricity prices (€ / MWh). This approach combines fundamental analysis with historical market behavior, effectively capturing the complex interplay of physical system dynamics and structural price signals by combining several key parameters, such as:

  • Annual shape and level of demand

  • Installed renewable capacity

  • Fossil and nuclear power plant availabilities

  • Fuel prices (gas, coal, carbon)

  • Interconnector constraints

From the changes of these different variables, our model is able to predict for each of the future hours a balance between supply and demand on the merit order for the wholesale market and the bid curves for the reserve prices as it has been studied historically.

We use a single coupled machine learning model that predicts all 40+ interconnected bidding-zone prices simultaneously - this structure helps ensure greater coherence across the European day-ahead market. The model is retrained daily, using an expanding historical window from 2015 to the most recent actuals.

It runs on both ECMWF and GFS, and is updated every time a full daily weather run becomes available. In addition to these runs, we publish additional price updates (UPD) to reflect the latest market information. Each update overwrites the previous version. Once finalized, forecast files are not modified further and are made available via FTP and API access.

Coverage

Zone

Live since

Wind

Solar

Load

Price DA

Austria

2019

Belgium

2019

Bosnia and Herzegovina

2025

Bulgaria

2025

Croatia

2024

Czech Republic

2023

DK1

2025

DK2

2025

Estonia

2025

Finland

2025

France

2019

Georgia

2025

Germany

2019

Greece

2025

Hungary

2024

Ireland

2025

Italy

2021

IT-Calabria

2025

IT-Centre-Nort

2025

IT-Centre-South

2025

IT-North

2025

IT-Sardinia

2025

IT-Sicily

2025

IT-South

2025

Latvia

2025

Lithuania

2025

Moldova

2025

Montenegro

2025

Netherlands

2019

NO1

2025

NO2

2025

NO3

2025

NO4

2025

NO5

2025

Poland

2023

Portugal

2025

Romania

2024

SE1

2025

SE2

2025

SE3

2025

SE4

2025

Serbia

2025

Slovakia

2024

Slovenia

2024

Spain

2021

Switzerland

2021

United Kingdom

2020

XK

2025

Access

API

  • Horizon forecasts
    Provides views of forecasts as they appeared from earlier run dates (e.g., D–1, D–2), useful for revision tracking and performance analysis.

  • Ensemble statistics by run date
    For a given run date, provides statistical summaries (min, q25, median, mean, q75, max) calculated across ensemble members from EC ENS and GFS ENS

FTP

For FTP access, connect to:
Host: calc1.cor-e.fr
Port (FTP): 21
Port (SFTP): 2222

Directory paths :

  • Generation: 4_Supply/Forecast/Generation/COR_E/{Country}/yyyy/mm

  • Demand: 3_Demand/Forecast/Load/COR_E/{Country}/yyyy/mm

  • Spot price: 2_Price/Forecast/Day_Ahead/COR_E/{Country}/yyyy/mm

File naming conventions :

  • wind & solar generation: CORE_SUPPLY_FORECAST_Generation_CORE_{Country}_{Wind|Solar}_Hourly_{EC|GFS}_{OP|ENS}_yyyymmdd{00|06|12|18}.csv

  • demand: CORE_DEMAND_FORECAST_Load_CORE_{Country}_Hourly_{EC|GFS}_{OP|ENS|ENS_SCENARIOS}_yyyymmdd{00|06|12|18}.csv

  • Spot price: CORE_PRICE_FORECAST_DayAhead_CORE_{Country}_Hourly_{EC|GFS}_{OP|ENS|ENS_SCENARIOS}_yyyymmdd{00|06|12|18}.csv

For Ensemble forecasts, two files are published for each run:

  • one {ENS} containing the control scenario "0"

  • one {ENS_SCENARIOS} containing the all scenarios (30 for GFS and 50 for EC ENS, 100 for EC ENS EXTENDED (a.k.a EC 46)

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