The Code for Infrastructure Operation (ROI), approved by ERSE, regulates the functioning of the National Gas System (SNG), focussing on interoperability and on the coordinated operation of the networks and infrastructures of the public gas network (RPG), according to article 112 of Decree-Law no. 62/2020, of 28 August. This law foresees the possibility of producing renewable or low carbon gases and injecting them into the natural gas networks. The ROI also includes the coordination of outages and the operation in contingency situations.

The ROI (and respective regulations) implements the European network code on Gas Balancing of Transmission Networks - Commission Regulation (EU) no 312/2014 of 26 March 2014.

The European network code was adopted in ROI on 2016, although this was partially derogated by the absence of a trading platform for standardized gas products in Portugal. On March 16, 2021, a new trading platform for the Portuguese balancing point started regular operation, under MIBGAS S.A. The trading rules were approved by ERSE by Directive no 14/2020, of 30 September. The trading platform allowed the full implementation of the balancing network code, as it is set in ROI.

The ROI sets the rules for daily management of the infrastructures that compose the Gas Transmission Network, Storage infrastructures and LNG terminals (RNTIAT), mainly:

• Programming of the Operation of RNTIAT, which includes general operation criteria, set according to the pressures, gas stocks and nominal flows in each infrastructure, and the elaboration of the Operation Program (discriminating injection and extraction profiles in each interface between RNTIAT infrastructures, distribution networks, interconnections and customer facilities connected to the transmission network).
• Procedures for trade notification, nomination and renomination in RNTIAT relevant points, for calculating deemed consumption at city gate points and for data sharing on supplies and consumption.
• Daily operation of RNTIAT, containing rules for the participation of each player in RNTIAT operation, for the definition and use of operation gas, for performing balancing actions by the TSO and for definition of safety and control variables. Also identifies the situations of regular and contingency operation and requires contingency action plans.
• Daily imbalance calculation and reconciliation for market agents, within the balancing of the transmission network, as well as setting the balancing neutrality costs.
• Infrastructure outages’ coordination, including the RNTIAT Annual Maintenance Plan and the Outage Plan.

Complimentary norms to the ROI include procedures relating the system functioning (MPGTG) and logistics of distribution networks supplied via Satellite LNG stations (MGLA).

The current ROI was approved by Code no 341/2021, of 14 April. Access previous versions of the code at ERSE’s normative documents.

Consolidated version of ROI

Complimentary norms to ROI include:

• Procedures’ Manual for Global Technical Management of the Nation Gas System (MPGTG, in its consolidated version), approved by Directive no 9/2021, of 12 May, changed by Directive no. 13/2022, of 8 June, and changed by Directive no. 8/2024, of 16 January: sets detailed procedures for the integrated functioning of the National Gas System (SNG) and the operation of its infrastructures.
• Procedures’ Manual for the logistics of distribution networks supplied via Satellite LNG stations (MGLA, in its consolidated version), approved by Directive no 9/2024, of 1 February: sets the criteria and procedures for the logistics of LNG transportation to satellite stations of distribution networks.