Enagás obtains authorization to inject biomethane in Bilbao

Federal authorization for key infrastructure in Biscay

The Directorate General for Energy Policy and Mines of the Ministry for the Ecological Transition and the Demographic Challenge has granted Enagás Transporte del Norte, SL (ETN) the administrative authorization, approval of the execution project, and declaration of public utility for the facilities corresponding to the biomethane injection project into the primary transmission gas pipeline Arrigorriaga-Santurtzi, in the municipality of Bilbao (Biscay). The resolution, signed on 28 July 2026 by the Director General Manuel García Hernández, was published on Tuesday 18 August 2026 in the BOE No. 202, Section III, with the official reference BOE-A-2026-17907 (pp. 115603-115608).

The resolution enters into force on the day following its publication in the Official State Gazette. An appeal for reconsideration may be lodged against it with the Secretary of State for Energy within one month.

Origin of the project and agreement with Metabarri

ETN requested the authorization on 28 May 2025, as a result of an agreement signed with the biomethane production company Metabarri, SA. The objective of the project is the construction of a new position (45.01.DX.02) with a Metering Station (MS) G-65 at the split of the primary transmission gas pipeline Arrigorriaga-Santurtzi, allowing the injection of locally produced biomethane into the natural gas transmission network.

The application and the technical project were submitted to public consultation in accordance with Law 39/2015 and Royal Decree 1434/2002. The corresponding notices appeared in the BOE No. 234 (29 September 2025), in the Official Gazette of Biscay No. 184 (26 September 2025), and in the newspapers Deia and El Correo (30 September 2025). Once the regulatory period had elapsed, no objections were received from private individuals.

Technical characteristics and scope of the facilities

The project includes the following main technical specifications:

2-inch diameter connection with a design pressure of 72 bar from the direct line coming from the biomethane producer, with a shut-off valve with electric actuation and inlet to the Metering Station EM G-65.
Metering station in 1+1 configuration (one operating line and one standby), both with identical characteristics, at a maximum operating pressure of 72 barg.
Outlet connection with bypass valve to the Arrigorriaga-Santurtzi gas pipeline of 30 inches in diameter, at the new position 45.01.DX.02, for biomethane injection.
Hot tap on the gas pipeline loop at kilometer point 9,964 by means of a NPS 30" x 2" weldolet.
Gas quality analyzers and measurement equipment for water and hydrocarbon dew point.
Electrical, control and communications panels, odorization equipment, and auxiliary facilities for electricity, instrumentation, control, gas detection and fire protection.

The maximum biomethane flow rate to be conveyed through the bypass line will be 475 Nm³/h.

Legal framework, budget and ETN obligations

The authorization is granted under Title IV of Royal Decree 1434/2002 of 27 December, subject to the conditions established in the resolution. The main obligations imposed on ETN are:

Compliance with current regulations on hydrocarbons, industry and the environment, including Law 34/1998 on the hydrocarbons sector, Royal Decree 1434/2002 and Law 21/1992 on Industry.
Execution of the works in accordance with the technical project signed by a Senior Industrial Engineer (charter number 0025430 of the Official College of Industrial Technical Engineers of Madrid), approved with number 2505146/01 and dated 23 May 2025.
Maximum period of 18 months for the expansion of the facilities and submission of the request for the issuance of the commissioning certificate, counted from the notification of the resolution. Failure to comply will result in the extinction of the authorization, unless a justified extension is granted.
Provision of a guarantee of €14,157.24 (equivalent to 2% of the budget) with the General Deposit Fund in favor of the Directorate General for Energy Policy and Mines.
Prior notification to the Provincial Office of Industry and Energy of the Government Sub-delegation in Bizkaia of the start dates of works, tests and trials, to allow inspections during execution.

The total project budget amounts to €707,861.84. The favorable report from the National Commission on Markets and Competition (CNMC) was issued by its Regulatory Supervision Chamber at its session of 1 July 2026.

Relevance for the promotion of biomethane in Spain

This authorization represents a concrete step toward the integration of biomethane into the Spanish gas transmission network, by enabling an injection point in a strategic infrastructure in the Basque Country. The project connects local biomethane production —promoted by Metabarri, SA— with the primary transmission pipeline Arrigorriaga-Santurtzi, allowing renewable energy of local origin to be distributed through the existing gas network. For readers, the news highlights the progress of the energy transition in the gas sector, an area in which the administration is creating the necessary regulatory channels for market players to inject renewable gases into conventional infrastructures.

Source: Official State Gazette (BOE) No. 202, Tuesday, August 18, 2026, Section III, pp. 115603-115608 (official reference: BOE-A-2026-17907).