day-ahead prices

Day-ahead prices are the spot prices set a day before delivery, one value per hour per bidding zone. They are the price signal renewable analysts pair with output: when wind and solar run hard, the same table shows generation climbing and the day-ahead price falling.

The cataloged OPSD Time Series Package (Load, Wind & Solar Hourly) carries them natively. Its short description lists 'load, day-ahead prices, wind and solar generation, installed capacity and capacity-normalized profiles', and its field schema defines {REGION}_price_day_ahead as the 'day-ahead spot price in EUR', alongside columns such as AT_price_day_ahead and IT_SICI_price_day_ahead. The package covers 32 European countries from 2015 through mid-2020 at hourly resolution, with 15-minute and 30-minute variants for selected regions, and ships as CSV in singleindex, multiindex and stacked layouts plus XLSX, SQLite and a 277 MB full zip.

Buying power data without day-ahead prices costs you the revenue line. Generation series tell you what the fleet produced; only the price column tells you what that output was worth hour by hour.

• Capture modelling needs both. Wind and solar capture rates are computed as generation-weighted prices; a dataset with output but no day-ahead price forces you to source a second file and align bidding zones yourself.

• Zone alignment is the hidden work. OPSD aggregates by country, German control area or bidding zone (DE-LU, DK1/DK2, IE-SEM, Italian zones, NO1-NO5, SE1-SE4, GB zones), so a price series keyed differently from your generation series will not join without that mapping.

• Static snapshots date quickly. The cataloged package is version 2020-10-06 and its update_frequency is static, so price series stop at mid-2020.

1. Confirm the price column is in the same table as load and generation. OPSD publishes {REGION}_price_day_ahead next to {REGION}_load_actual_entsoe_transparency and wind/solar generation columns, so price-and-output joins need no cross-file merge.
2. Check the currency and unit. OPSD defines the day-ahead field as 'day-ahead spot price in EUR'; a source quoting per-zone prices in mixed currencies will corrupt cross-country comparisons.
3. Verify the geographic key. The package aggregates by country, German control area (50Hertz, Amprion, TenneT, TransnetBW) or bidding zone; confirm your source uses the same zone definitions before joining.

Adjacent concepts in the same European power-data stack:

• bidding-zone-aggregation — Price and generation series are keyed to bidding zones, the geographic units behind OPSD's {REGION}_price_day_ahead columns
• hourly-time-series-grid — The hourly (plus 15/30-minute) table layout that carries day-ahead prices beside load and renewable output.