Load the ENTSO-E day-ahead wind/solar generation forecast.
Reads interim/renewable_forecast.csv (written by spotforecast2_safe.downloader.entsoe.download_renewable_forecast) and returns every renewable generation-forecast column it contains (for Germany typically "Solar", "Wind Onshore" and "Wind Offshore") on a regular hourly UTC grid. Each column independently passes through the fail-safe _apply_on_missing() contract, so missing values are rejected by default rather than silently imputed.
The day-ahead renewable forecast is a near-oracle, leakage-clean prior: it is published on D-1 and is therefore genuinely available at forecast time (CR-3). Use the day-ahead forecast, never the realised generation.
Root data directory. If None, resolved via get_data_home().
None
on_missing
OnMissing
How to handle NaN rows. 'raise' (default) fails fast with the gap timestamps; 'ffill_bfill' forward/back-fills; 'passthrough' returns the raw NaN so an explicit downstream provider can decide.