Glossary

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1. Market Regulation

This section contains short editorial summaries prepared from official sources only. The source texts are the official ENTSO-E, ACER, European Commission and EUR-Lex documents listed below. The summaries are intended for website glossary use and should not be treated as legal advice or as a substitute for the source acts and official implementation documents.

MARI

The Manually Activated Reserves Initiative is the pan-European mFRR balancing energy platform. For OnGrid, it matters because mFRR-ready operations, bid handling and activation-related workflows increasingly need to align with the common European balancing framework.

PICASSO

PICASSO is the pan-European aFRR balancing energy platform. It is relevant wherever real-time control, reserve activation and balancing-market integration must align with the European aFRR model.

Network Code on Demand Response

The upcoming EU-wide Network Code on Demand Response is intended to set harmonised rules for demand response, storage and distributed generation. It is strategically important because it expands the regulatory framework for flexibility participation across European electricity markets.

Network Code on Cybersecurity

This network code sets sector-specific cybersecurity rules for cross-border electricity flows. It raises expectations for cyber risk management, minimum requirements, monitoring, reporting andcrisis management across the European power system.

NCCS

NCCS is the common shorthand for the Network Code on Cybersecurity. In website linking logic, it should resolve to the same glossary concept unless a separate shorth and entry is preferred for navigation purposes.

NIS2

Directive (EU) 2022/2555 establishes the EU’s updated horizontal cybersecurity framework for essential and important entities, including energy. For electricity-market participants, it is agovernance, risk-management and incident-reporting baseline rather than a market-design rule.

CER Directive

Directive (EU) 2022/2557 strengthens the resilience obligations of critical entities, including in the energy sector. It broadens the focus from cybersecurity alone to operational resilience, business continuity and protection of critical infrastructure.

CACM Regulation

Commission Regulation (EU) 2015/1222 establishes the EU framework for capacity allocation and congestion management. It is foundational for day-ahead and intraday market coupling, bidding-zone-border capacity allocation and the broader SDAC/SIDC market design.

Source: Directive (EU) 2019/944

FCA Regulation

Commission Regulation (EU) 2016/1719 establishes the EU framework for forward capacity allocation. It governs cross-zonal transmission-capacity allocation in forward markets and matters for long-term hedging and cross-border trading.

SOGL

Commission Regulation (EU) 2017/1485 establishes the guideline on electricity transmission system operation. It provides the operational backbone for scheduling, load-frequency control, coordination and system-operation processes across the interconnected grid.

Electricity Balancing Guideline (EBGL)

Commission Regulation (EU) 2017/2195 establishes the EU balancing rulebook. It underpins balancing-market harmonisation and the implementation of pan-European platforms such as MARI and PICASSO.

Regulation (EU) 2019/943

The Internal Market for Electricity Regulation is the core market-design regulation for the EU electricity market. It frames wholesale market functioning, dispatch principles, flexibility, balancing and cross-border integration.

Source: Regulation(EU) 2019/881

Directive (EU) 2019/944

The Internal Market for Electricity Directive sets the governance framework for market access, consumer rights, suppliers, DSOs and retail-market structures. It complements Regulation (EU) 2019/943 on the institutional and market-participant side.

REMIT

Regulation (EU) No 1227/2011 on wholesale energy market integrity and transparency prohibits insider trading and market manipulation in wholesale energy markets. It is central to market surveillance, transparency and conduct compliance.

2. Market Roles

This section is a condensed, website-oriented extraction of electricity-market player roles from the attached role-model source document. Role names and baseline role meanings are derived from “The Harmonised Electricity Market Role Model”, Version 2025-01, maintained jointly by ENTSO-E and EU DSO Entity, with website-oriented shortening for readability.

Primary source used in this section:

• ENTSO-E and EU DSO Entity, “The Harmonised Electricity Market Role Model”, Version 2025-01 (especially Section 5.1 Roles) — attached PDF in this project package.

• File title: Harmonised_Electricity_Market_Role_Model_v2025-01_ICTC approved.pdf

Only role entries relevant to electricity-market participants and market-operation actors are included here. Domains, resources, accounts and CIM objects from the source document are intentionally excluded.

Balance Responsible Party

Party financially accountable for imbalances within the applicable settlement framework.

Balancing Service Provider

Party providing balancing services, including balancing energy and/or balancing capacity; a specific type of flexibility service provider.

Capacity Trader

Party contracted to participate in the capacity market and acquire transmission capacity through a transmission capacity allocator.

Consumer

Party that consumes electricity.

Consumption Responsible Party

Balance-responsible role for consumption, covering the imbalance between physical withdrawal and final nominated volume.

Coordinated Capacity Calculator

Entity responsible for coordinated transmission-capacity calculation at regional level or above.

Coordination Centre Operator

Party responsible for coordinating its coordination-centre zone with respect to scheduling, load-frequency control, time deviation and unintentional-deviation compensation.

Energy Service Company

Party offering energy-related services to the party connected to the grid without being directly active in the energy value chain or physical infrastructure itself.

Energy Supplier

Party that delivers electricity to, or takes electricity from, a party connected to the grid at an accounting point.

Energy Trader

Party that sells or buys electricity.

Flexibility Service Provider

Party offering flexibility services based on acquired or aggregated resources across energy, power or capacity marketplaces.

Grid Access Provider

Party responsible for providing access to the grid through an accounting point, including creation and termination of accounting points.

Imbalance Settlement Responsible

Party responsible for determining the difference between nominated and delivered energy quantities within a scheduling area.

Interconnection Trade Responsible

Balance-responsible role, or a role dependent on one, recognised for nomination of already allocated interconnection capacity.

LFC Operator

Role responsible for load-frequency control within its LFC area or block, typically performed by a TSO.

Market Information Aggregator

Party providing compiled market information based on data supplied by different market actors.

Market Operator

Party providing compiled market information based on data supplied by different market actors.

Market Information Aggregator

Party operating a market service that matches offers to sell electricity with bids to buy it, including day-ahead and intraday exchanges.

Nominated Electricity Market Operator

Designated entity responsible for tasks related to single day-ahead or single intraday coupling; a specific type of market operator.

Nomination Validator

Role ensuring that nominated capacity remains within allowed limits and confirming valid nominations to the involved parties.

Party Connected to the Grid

Party that contracts for the right to inject electricity into, or withdraw electricity from, the grid at an accounting point.

ProducerMarket Information Producer

Balance-responsible role for production, covering the imbalance between physical injection and final nominated volume.

Reconciliation Accountable

Party financially accountable for reconciled energy volumes for a profiled accounting point.

Reconciliation Responsible

Party financially accountable for reconciled energy volumes for a profiled accounting point.

Reserve Allocator

Role that informs the market of reserve requirements, receives bids and assigns the bids that meet prequalification criteria.

Resource Aggregator

Party aggregating resources for use by other market participants, subject to applicable market rules.

Resource Capacity Mechanism Operator

Party operating a resource-capacity mechanism in a Member State, either as a TSO or as an independent entity.

Resource Provider

Role that manages a resource and, where required, provides production or consumption schedules for it.

Scheduling Agent

Entity tasked with providing schedules, often acting on behalf of a balance responsible party.

Scheduling Area Responsible

Party responsible for coordination of nominated volumes within a scheduling area, typically a TSO.

System Operator

Party responsible for operating, maintaining and, where necessary, developing the system in a given area and its interconnections.

Trade Responsible Party

Party that can be held legally and financially accountable for imbalances between nominated and consumed energy for associated accounting points.

Transmission Capacity Allocator

Role that allocates available transmission capacity for a bidding-zone border on behalf of system operators and bills capacity traders for allocated capacity.