Transmission System

The National Natural Gas System (NNGS) is the Natural Gas System (of high pressure) which, according to paragraph 1 of article 67 of Law 4001/2011 (Government Gazette A ‘179/2011), includes:

  1. the main gas transmission pipeline,its branches, and the programmed extensions of NNGS. The metering, regulating, compression and decompression stations, the natural gas operations control, the remote control and communication system, the operation and maintenance centers, the dispatching centers and in general the facilities that are elements of the operation and support of the natural gas transmission system, as well as the existing entry points located at Sidirokastro, Kipi and Agia Triada metering stations.
  2. The LNG facility on the island of Revithousa
  3. The projects for the expansion and reinforcement of the NNGS, the facilities, the interconnections, the infrastructure or the storage and reimportation of natural gas in the NNGS that are executed according to the approved Network Development Plan according to the provisions of National Gas System Administration Code. The projects included in the Network Development Plan are projects of public interest and major national importance.

Today, there are 3 natural gas entry points in Greece:

  • From Bulgaria, the entry point of Sidirokastro (Bulgartransgaz)
  • From Turkey, the entry point of Kipi (Botas)
  • From the LNG terminal of Revithousa, in the area of Megara, where it is unloaded from LNG carriers, gasified and injected into the NNGS at the entry point of Agia Triada

In addition, in December 2020 the flow of natural gas from the TAP pipeline (TAP AG), at the entry point of Nea Mesimvria is expected to begin.

Operator of the National Natural Gas System

The Operator of the National Natural Gas System is DESFA S.A., which was established in 2007 based on Law 3428/2005 for the liberalisation of the natural gas market (Government Gazette A ‘313 / 27.12.2005), with which the provisions of Directive 2003/55/ΕC were transposed into the national legislation.

Today the shareholders of DESFA are the Greek State (34%) and the SENFLUGA ENERGY HOLDINGS SA (66%), which is a consortium of the following companies: “Snam S.p.A.” (Transmission System Operator of Italy), “Enagás Internacional S.L.U.” (Transmission System Operator of Spain), “Fluxys S.A.” (Belgium Transmission System Operator) and “DAMCO S.A.” as a passive shareholder.

DESFA has been certified under the Ownership Unbundling model of the Directive 2009/73/EC with RAE’s Decision 1220/2018, which was later revised by Decision 460/2019. DESFA S.A. must operate, maintain, manage, operate and develop the NNGS and its interconnections, in order for the system to be cost-effective, technically sound and complete, to serve the needs of the natural gas users in a reliable, adequate and cost-effective manner, and to ensure the functioning of a single natural gas market in the European Union and the protection of the environment.

Regulatory framework

The transmission of the natural gas is a monopolistic activity. RAE, within the framework of its responsibilities, monitors and controls the exercise of DESFA’s activities and issues the regulatory framework that governs the transmission activity. The main regulatory documents are:

  • The National Natural Gas System Operation Code, according to which the operation, maintenance, and development of the NNGS is carried out. This Code regulates the operator’s relations with the System Users. The right to make use of the system (potential NNGS Users) can be exercised by the Users registered in the NNGS Registry. The following categories are registered in the NNGS Registry by RAE, upon submission of a relevant application to the regulator:
    • The natural gas Suppliers
    • The Eligible Customers, for the quantities of natural gas that are supplied, and
    • Any person who provides sufficient guarantees of financial solvency and technical adequacy.

RAE assesses the applications for registration in the NNGS Registry in accordance with the provisions of the NNGS Users’ Registry Regulation (Government Gazette B’451 / 16.04.2010) and decides on the outcome of the applications. After the registration process is completed, the NNGS Users have the right to conclude a Shipping Agreement for Natural Gas or/and a LNG Facility Utilization Agreement with DESFA, in accordance with the respective Standard Contracts approved by RAE.

  • The Tariff Regulation for the Basic Activities of the National Natural Gas System sets the methodology for determining the tariffs for each basic activity provided by the Operator. The determination of the transmission tariffs is an exclusive competence of the Regulatory Authority for Energy based on the provisions of par. 1 of article 41 of the Directive 2009/73/EC, so that there is no discrimination between the NNGS Users. The entry-exit system of the Regulation (EU) 715/2009 and the provisions of the Regulation (EU) 2017/460 on the establishment of a network code on harmonised transmission tariff structures for gas are applied.
  • The NNGS Tariffs for 2021 have been approved by RAE’s Decision 1038/2020.
  • The NNGS Tariffs for 2022 have been approved by RAE’s Decision 512/2021.
  • The NNGS Tariffs for 2023 have been approved by RAE’s Decision 498/2022.


Network Development

Each year, according to the provisions of the National Natural Gas System Operation Code, DESFA SA prepares a plan of the NNGS Development for the next ten (10) years. The draft NNGS Development Program defines the projects for the development, reinforcement and interconnection of the NNGS, which are required to be performed in the next ten (10) years, the schedule and the method of construction of these projects, as well as and their estimated cost. The Ten-Year Development Plan is approved by RAE.

Ten-year NNGS Development Plan 2020-2029