Data collection

This section outlines why we in ACER collect energy data (our legal mandate), what energy data we collect, how we do it (data reporting) and how we ensure high data quality (through rigorous checking procedures) and confidentiality.

Two key features distinguish ACER from other energy data sources: 

1. our legal standing as an EU Agency; and 
2. our mandate in monitoring and assessing trading activities and in building trust in the integrity of EU energy markets.

REMIT is the EU-wide framework that protects wholesale energy markets from abuse, ensuring open and fair competition. Under the REMIT Regulation, ACER is mandated to collect data to monitor and assess trading activities on wholesale energy markets across the EU.

This EU-wide oversight of every trade in energy wholesale markets is unique to ACER. Working closely with national regulatory authorities (NRAs), we detect potential market abuse (such as insider trading and market manipulation). This supports market integrity, transparency and fair price formation.

Beyond its REMIT mandate, ACER also collects other data on wholesale and retail energy markets (e.g. under the electricity Capacity Allocation and Congestion Management (CACM) Regulation) to support its broader monitoring.

ACER and national regulatory authorities (NRAs) work closely together to protect energy markets from abuse. Increased transparency and monitoring build confidence that energy markets work well for EU businesses and citizens and that prices are determined in a fair way.

The rules for reporting energy market data to ACER are set out in the REMIT Implementing Regulation. Following the 2024 revision of REMIT, the Implementing Regulation has been updated in 2026 to include:

• new quarterly ‘exposure’ reporting, which requires market participants to report their trading positions (i.e. showing how exposed they are to future energy price movements over the next 18 months);
• new reporting elements for algorithmic trading and Direct Electronic Access (DEA);
• a clarified definition of obligations for ‘organised market places’ (OMPs) and other reporting parties; 
• extended reporting obligations for Liquified Natural Gas (LNG) and hydrogen transactions; and
• the introduction of ‘periodic data reporting’ (e.g. for balancing processes).

Based on these rules, ACER sets the procedures, standards and electronic formats (including reporting manuals such as the Transaction Reporting User Manual) that market participants must follow when submitting data. This centralised and structured system supports consistent data collection and effective market monitoring.

A full list of relevant documents is available on the REMIT Documents page.

To fulfil its mandate, ACER collects several types of data, including: 

• Transaction data: Records of trades and orders to trade relating to wholesale energy products, either traded on 'organised market places' (OMPs) or bilaterally. The wholesale energy product definition encompasses supply, transportation capacity allocation and storage of electricity, natural gas and hydrogen. This includes information on product type, quantity, price, delivery date, counterparty and beneficiary.
• LNG market data: Information about LNG transactions, used for both market monitoring activities and related ACER’s functions (including publication of its daily LNG price assessment and benchmark).
• Inside information: Market-sensitive information that must be publicly disclosed under REMIT, so that all market participants receive it transparently and at the same time. This concerns events that may affect wholesale energy prices (such as planned outages, unavailability, reduced capacity, maintenance delays or other events affecting production, storage or transmission). 
• Fundamental data: Information about energy assets, such as capacity and use of facilities for the production and storage of electricity, gas, LNG and hydrogen, including storage levels, consumption, transmission and generation outputs, as well as planned or unplanned outages.

ACER may request additional information or clarifications from market participants and reporting parties if the data submitted is incomplete or unclear. Reporting parties are responsible for submitting complete, accurate and timely data in line with the legal requirements and reporting arrangements.