hsilvosa/omie-electricity

OMIE: Iberian Wholesale Electricity Market (Spain and Portugal)

Standardized dataset containing over 17.15 million rows of market-clearing data from the Iberian wholesale electricity market, operated by OMIE (Operador del Mercado Ibérico de Energía).

It includes supply and demand bidding curves block-by-block (curva_pbc) for January to June 2024 and the time series of day-ahead marginal prices for Spain and Portugal from 2023 to 2026.

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Dataset Summary

Configuration	Rows	Temporal Coverage	Description	Parquet Size
bidding_curves	17,093,765 rows	1 January to 30 June 2024	Supply (sale) and demand (purchase) bidding steps per hour, matched and unmatched	26 MB
marginal_prices	55,199 rows	1 January 2023 to 20 August 2026	Day-ahead marginal prices (EUR/MWh) for Spain and Portugal, hourly until 30 September 2025 and per 15 minutes from 1 October 2025	330 KB

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Data Structure and Schema

1. bidding_curves (omie_bidding_curves_2024.parquet)

Discrete bid steps submitted by market participants (generators, retailers, and consumers), from the OMIE curva_pbc files:

Field	Type	Description
date	date32	Market delivery date.
year	int16	Year of the delivery date.
hour	int8	Hour of the day (1 to 24).
country	string	Bidding area of the unit: MI (Iberian market), ES or PT.
offer_type	string	C for a purchase (demand) bid, V for a sale (supply) bid.
energy_mwh	float64	Energy volume bid in this discrete step (MWh).
price_eur_mwh	float64	Bid price (EUR/MWh).
status	string	C if the step was matched (casada), O if it was only offered.

2. marginal_prices (omie_marginal_prices_<year>.parquet, 2023 to 2026)

Day-ahead market clearing prices from the OMIE marginalpdbc files. There is one file per year and one row per market period:

Field	Type	Description
date	date32	Delivery date.
year, month, day	int16, int8, int8	Parts of the delivery date.
hour	int8	Market period of the day. It is the hour (1 to 24, 23 or 25 on clock-change days) until 30 September 2025 and the 15-minute period (1 to 96, 92 or 100 on clock-change days) from 1 October 2025.
price_es	float64	Marginal price for the Spanish bidding zone (EUR/MWh).
price_pt	float64	Marginal price for the Portuguese bidding zone (EUR/MWh).

Every calendar day from 1 January 2023 to 20 August 2026 is present. Three days (28 May 2023, 30 October 2025, 27 November 2025) are published by OMIE under a later file version and were added in the release noted below.

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Usage

With Python (pandas / polars / duckdb):

import pandas as pd

# Load the marginal prices of one year
df_prices = pd.read_parquet("data/omie_marginal_prices_2024.parquet")
print(f"Price range: {df_prices['price_es'].min()} to {df_prices['price_es'].max()} EUR/MWh")

# Load bidding curves (17M rows)
df_curves = pd.read_parquet("data/omie_bidding_curves_2024.parquet")
curve_hour_12 = df_curves[(df_curves["date"].astype(str) == "2024-06-15") & (df_curves["hour"] == 12)]
print(f"Bidding steps in hour 12: {len(curve_hour_12)}")

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Applications and Research Use Cases

• Reinforcement Learning (RL) and Battery Storage (BESS) Arbitrage: Simulating and training RL agents for optimal charge/discharge cycles and co-located storage dispatch.
• Short-Term Day-Ahead Price Forecasting: Machine learning models predicting marginal prices and price spikes.
• Merit Order Dynamics and Renewable Impact: Empirical analysis of supply curve shifts due to solar PV and wind generation.
• Zero and Negative Price Modeling: Probability modeling of renewable curtailment and market decoupling between Spain and Portugal.

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Provenance and Attribution

• Source: Operador del Mercado Ibérico de Energía (OMIE).
• Terms of Use: Publicly available data published by OMIE subject to source citation and attribution.

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Release notes

• 2026-10-11, price correction. In earlier revisions price_es and price_pt had lost their decimal separator, so values were multiplied by 100, 10 or 1 depending on how many decimals the source text had (for example 86.1 EUR/MWh was stored as 861 and 82.78 as 8278). All 54,983 rows were rebuilt from the OMIE marginalpdbc files and now hold the published EUR/MWh values. Dates, row order, schema and row count are unchanged. If you downloaded an earlier revision, replace it. The README now also describes the files and columns that are actually published.
• 2026-10-11, three days added. 28 May 2023 (24 rows), 30 October 2025 (96 rows) and 27 November 2025 (96 rows) were missing because OMIE publishes them under a different file version. marginal_prices now has 55,199 rows (previously 54,983). Existing rows are unchanged.