In order to guarantee security of supply and the competitiveness of the sector, to defend energy consumers, and promote European solidarity, the European Union promotes the liberalization of energy markets and the exchange of energy between Member States.

With that in mind, European legislators have attributed to national energy regulators the task of guaranteeing:

  • Non-discriminatory access to gas and electricity networks
  • Effective competition between market players
  • Optimised interconnection of the energy grids

As Portuguese energy policy also follows legislation established by the European Union (EU), regulatory cooperation at European level is fundamental in order for ERSE to achieve its mission.

ERSE produces an annual report on the electricity and gas markets in Portugal that is presented to the European Commission, in which it presents the main developments of the markets, including issues of competition (both in wholesale and in retail markets), security of supply and consumer protection. The report also includes the regulatory measures adopted and an overview of ERSE’s annual activity and provides updated information on the Portuguese energy market.


Annual Report on the Electricity and Natural Gas Markets

Legal framework

The EU’s energy policy promotes the development of sustainable, secure and cost-effective energy. Based on the desire to create an internal energy market and an Energy Union for all Europe, the EU’s policy aims to:

  • Ensure the efficient functioning of energy markets
  • Guarantee the security of energy supply in the European Union
  • Promote energy efficiency and energy savings, as well as the development of renewable energy sources
  • Promote the interconnectivity of the energy grids in order to ensure solidarity between members of the European Union

In order to achieve these goals, the EU adopted over the years a vast set of legislation on the design and functioning of European energy markets. The most recent legislative package is called “Clean Energy Package for all Europeans”, and was concluded in June 2019. This package updates and reinforces the legislation that had been introduced by the “Third Energy Package”.

In December 2019, the EU announced an ambitious agenda called the “European Green Deal” which aims to transform the EU into a fair and prosperous society, with a modern, resource-efficient and competitive economy where there are no net emissions of greenhouse gases in 2050 and where economic growth is decoupled from resource use. In this context, the EU is developing a range of policies across all sectors of the economy to deliver the energy transition towards a carbon-neutral society. Energy systems and markets are part of this process.

Legal documents

Institutional framework and multi-sectorial texts:


Natural Gas:

Renewables and Energy Efficiency:

Consumer rights:

Institutional relations

ERSE guarantees its European regulatory coordination through two institutional structures:

  • The Agency for the Cooperation of Energy Regulators (ACER)
  • The Council of European Energy Regulators (CEER)

European public consultation

In order to promote knowledge and the opportunity to participate in the development of the European energy sector, ERSE shares below the links to key EU level bodies which hold public consultations on energy issues.


ACER – The Agency for the Cooperation of Energy Regulators is a specialised agency of the European Union, established in 2009, which assists the work of the 27 national regulatory agencies, and incentivises mutual coordination and cooperation.

ACER’s structure is defined by the EU Regulation establishing it. ACER consists of an Administrative Board, a Board of Regulators, a Director and a Board of Appeals, as well as regulatory Working Groups.


  • Mediates conflicts between national regulatory agencies
  • Publishes rules which guarantee a good regulatory practice at European level
  • Publishes opinions, recommendations, or binding decisions on issues within its sphere of competence
  • Monitors the performance and development of European energy markets
  • Monitors the transparency and integrity of wholesale energy market under REMIT

ERSE actively engages in several ACER activities, namely:

  • Participates in Board of Regulators meetings
  • Has experts accompany and participates in working groups and elaborate joint papers
  • Coordinates said working groups, when nominated to do so


For more information, please visit the website


Working groups

Working groups are expressly foreseen in the ACER Regulation. They support the development of technical codes which ACER has the power to issue, promote debate and produce technical reports or other types of documentation, which allow ACER to fulfil its objectives. The Agency’s working groups are divided by theme:

  • Monitoring, Integrity and Transparency (AMITWG)
  • Electricity (AEWG)
  • Gas (AGWG)
  • Retail Markets (ARWG)

ERSE is the Chair of ACER Gas Working Group since March 2019 and co-chairs the Retail WG established in January 2021.

For more information, please visit the website.


In order to see and participate in ACER’s public consultations, please visit the section European public consultations



CEER – Council of European Energy Regulators is a Belgian non-profit organization, established in 2000, which gathers regulatory agencies of 39 European countries, and whose aims are to:

  • Develop the energy market to benefit the energy consumer
  • Serve as a forum for the exchange of knowledge and experiences between regulators 
  • Promote solutions to the common problems which all countries face, and whose answer requires concerted action.
  • Promote and defend the point of view that energy regulators hold with the players in the energy sector.

CEER's organizational structure consists in a General Assembly, a Board of Directors, a Secretariat and Working Groups. CEER achieves its objectives through Working Groups dedicated to individual topics.

ERSE actively cooperates in CEER’s activities, such as:

  • Participating in the General Assembly and the Board 
  • Providing experts to accompany and participate in working groups and develop joint papers
  • Coordinating those working groups, when nominated to do so

ERSE was the first President of CEER (2000-2005), and was Chair of the Gas Working Group between 2016 and 2017, and again, since March 2019. As from January 2021, ERSE co-chairs the Consumer and Retail Markets Working Group (CRM WG), having previously served as its Vice Chair between 2017-2020.

For more information, please visit the website CEER


Working groups

CEER working groups are composed of collaborators of several national regulatory agencies and are split among the several themes:

  • Distribution Systems (DS WG)
  • Consumers and Retail Markets (CRM WG)
  • Gas Working Group (GWG)
  • Electricity Working Group (EWG)
  • Market Integrity and Transparency Working Group (MIT WG)
  • International Relations Group (IRG WG)

Within each working group there are several technical teams, composed by experts working on specific issues. Two of these teams are co-lead by experts from ERSE: Wholesale Energy Markets Workstream (WEM WS) and Gas Decarbonisation Legislation Workstream (GDL WS).


Iberian energy market

The Iberian Energy Market is the name given to agreements in the field of energy between Portugal and Spain, with the intention of creating a free, competitive market, open to entry of new participants, which promotes greater economic efficiency and better quality of service for the consumer.

The Iberian Energy Market is made out of two areas: MIBEL (Iberian Electricity Market) and MIBGAS (Iberian Natural Gas Market).


Iberian electricity market (MIBEL)

The Iberian Electricity Market was created by the Santiago de Compostela Agreement, of 1 October 2004, which was later revised in Braga, on 18 January 2008.

MIBEL established a Council of Regulators, which includes:

  • The Spanish regulators:
    • Comisión Nacional del Mercado de Valores (CNMV
    • Comisión Nacional de los Mercados e la Competencia (CNMC), formerly Comisión Nacional de Energía (CNE)
  • The Portuguese regulators:
    • Comissão do Mercado de Valores Mobiliários (CMVM)
    • Entidade Reguladora dos Serviços Energéticos (ERSE) 
  • The Council of Regulators:
    • Accompanies the development of the Iberian Market
    • Issues opinions on serious infractions which have been committed
    • Coordinates actions with the other regulators
    • Accompanies the  energy supply contracts that are celebrated by suppliers of last resort
    • Presents, to the Portuguese and Spanish governments, proposals on how to alter the existing rules of regulation
    • Determines which companies are to be considered dominant

To learn more about MIBEL, please visit the MIBEL entry on our website.

Iberian gas market (MIBGAS)

In the context of the convergence of the Portuguese and Spanish energy markets which began with MIBEL, a new agreement was reached in 2007 to develop an Iberian Gas Market. ERSE and its Spanish counterpart, CNMC, developed a document concerning “the organisation and principles of the functioning of MIBGAS

In that document, both regulators took responsibility to:

  • Participate in a MIBGAS Coordination Committee
  • Analyse the functioning of the market
  • Prepare studies on the conditions to obtain a supplier’s licence and propose measures to harmonise those conditions
  • Develop joint proposals to regulate the transit tariffs between Portugal and Spain

To learn more about MIBGAS, please visit the MIBGAS entry on our website.

Trans-European Energy Networks

Regulation (EU) 2022/869 of the European Parliament and of the Council of 30 May 2022, establishes guidelines for the timely development and interoperability of the priority corridors and areas of trans-European energy infrastructure that contribute to ensuring climate change mitigation and to ensuring market and system integration. In particular, this Regulation:

  • Provides for the identification of projects of common interest (PCI);
  • Facilitates the timely implementation of PCI on the Union list by streamlining, coordinating more closely and accelerating permit granting processes, and by enhancing transparency and public participation;
  • Provides rules for the cross-border allocation of costs and risk-related incentives for PCI;
  • Determines the conditions for eligibility of PCI for Union financial assistance.

As laid out in paragraph 4 of Article 14 of this Regulation, each national regulatory authority shall submit to the ACER its methodology and the criteria used to evaluate investments in energy infrastructure projects and the higher risks incurred by those projects, updated in view of latest legislative, policy, technological and market developments.

On this subject, ERSE has developed the document “Methodology and criteria for evaluating investments in electricity and gas infrastructure projects”.

This document briefly presents the legal framework for approving investments in electricity and gas transmission infrastructures in Portugal, as well as the regulatory framework that currently apply to electricity and gas transmission, outlining the risks that TSO face and the mitigation measures that the regulatory methodologies provide.

While preparing this document, ERSE took into account "Recommendation no. 3/2014" and the "Report on Investment Evaluation, Risk Assessment and Regulatory Incentives for Energy Network Projects", both from ACER.