After years of engineering and 14 months of public consultation across 13 regions, Madrid is processing the first four pipeline segments in emergency mode. Here is what is being built, and why it matters for Europe's hydrogen supply chain

 

Spain's Ministry for Ecological Transition has begun formal authorisation of the first four segments of the country's national renewable hydrogen backbone, developed by Enagás. The pipelines — 234 km in total across Andalusia, Aragon, and the Basque Country — will be processed on an emergency track that halves ordinary administrative timelines. Each segment still requires a full environmental impact assessment and public hearing before construction can begin. Once permits are secured, construction is estimated to take between eight and twelve months per segment.

 

Enagás filed for administrative authorisation, environmental impact declarations, and public utility status for all four segments on 30 June 2026 — the formal trigger for the ministerial processing now under way.

 

What is being built and where

 

Huelva–Aznalcázar (Andalusia): 59 km, €95.7m [$105m]

 

This segment serves the Onuba project — Moeve's 300 MW renewable hydrogen plant in Palos de la Frontera, Huelva, whose construction began this month after Prime Minister Pedro Sánchez attended the inauguration. Onuba is the first phase of the Andalusian Green Hydrogen Valley and has received €303.75m [$334m] in PRTR support. The segment forms part of the future Huelva–Almendralejo axis.

 

Caspe–Tivissa (Aragon): 75 km, €98.6m [$108m]

 

Tivissa–Tarragona Industrial Estate (Aragon/Catalonia): 62 km, €126.5m [$139m]

 

Both segments serve the Catalina project — a 500 MW electrolysis scheme promoted by Copenhagen Infrastructure Partners and Enagás Renovable in Aragon, with €245m [$270m] in PRTR aid. Catalina is designed to produce hydrogen and green ammonia and connect to industrial demand centres on Spain's east coast, making the Tarragona link a direct feed into one of Europe's largest chemical and petrochemical clusters.

 

Muskiz–Arrigorriaga (Basque Country): 38 km, €68m [$75m]

 

This segment serves Petronor's 100 MW renewable hydrogen project, which holds €160m [$176m] in public support and recently took a final investment decision on a new 100 MW electrolyser in Bilbao. The pipeline forms part of the future Reocín–Arrigorriaga corridor.

 

The selection logic

 

The four segments were chosen specifically because the projects they serve have already cleared final investment decisions — or are close to doing so. In the first half of 2026 alone, 400 MW of Spanish electrolyser capacity reached FID: Petronor's 100 MW in Bilbao, and Onuba's 300 MW in Huelva. That commercial commitment makes these the clearest early demand anchors in the country — and the ones where the absence of transport infrastructure would most directly delay project execution.

 

Emergency track — but not a shortcut on environment

 

The emergency procedure compresses ordinary administrative timelines by half. But Enagás and the government have been explicit that environmental impact assessment stages remain unshortened — including public hearing periods. Spain's experience with gas infrastructure permitting suggests environmental review will still take twelve to eighteen months for most segments, meaning first construction is unlikely before late 2027 at the earliest for the most advanced pipeline.

 

The bigger picture: 2,600 km, 15 sections, five axes

 

The four segments being processed today are the opening move in a much larger programme. Enagás' full Spanish Hydrogen Backbone covers approximately 2,600 km of buried hydrogen pipelines — new builds and converted gas infrastructure — distributed across 15 sections and five major axes: Vía de la Plata, Cornisa Cantábrica, Levante, Transversal Castilla-La Mancha, and Valle del Ebro. More than 80% of the route follows existing gas infrastructure corridors, and roughly 21% of the network will be built by converting existing gas pipelines.

 

Total investment in the backbone is estimated at €2.645bn [$2.91bn]. Enagás has received €40.2m [$44m] in EU Connecting Europe Facility funding for studies and engineering, plus €35.5m [$39m] for H2Med — the international interconnections linking Spain to France (BarMar subsea pipeline, Barcelona–Marseille) and to Portugal (CelZa corridor, Celorico da Beira–Zamora). Both the backbone and H2Med retain EU Projects of Common Interest status.

 

Authorisation applications for the remaining sections — including Mérida–Salamanca, León–Llanera, Arrigorriaga–Haro, Haro–Zaragoza, Tivissa–Salzadella, Salzadella–Paterna, and Almendralejo–Puertollano — are expected to be filed between Q4 2026 and Q1 2027.

 

The Spanish government has by now committed more than €3bn [$3.3bn] of PRTR funding to 124 hydrogen-related projects. Enagás' most recent market consultation logged participation from 128 companies and around 300 hydrogen projects, signalling strong industrial demand for the transport infrastructure these pipelines will provide.

 

For Spain to realise its ambition as Southern Europe's dominant green hydrogen exporter — and for H2Med to carry Spanish molecules to France and Germany — the backbone needs to be built. Processing four segments in emergency mode, backed by FID-committed production projects, is how that building starts.

 

source：FuelCellsWorks