Transport of equipment for energy infrastructure: green hydrogen, LNG terminals and gas corridors

Spain is one of the centres of gravity of Europe's energy transition: four flagship green hydrogen projects under simultaneous construction, the H2MED corridor with its BarMar submarine section, and a consolidated position as an LNG hub with six regasification plants. Behind every project, a quiet but enormous flow of German electrolysers, 120-tonne rectifier transformers and compressors manufactured in Italy.

Spain has become one of the centres of gravity of Europe's energy transition. Four flagship green hydrogen projects are under simultaneous construction — the Andalusian Green Hydrogen Valley of Moeve (formerly Cepsa) in Huelva, the HyVal cluster of BP and Iberdrola in Castellón, the Enagás Renovable and Naturgy plant in La Robla, the Catalan projects grouped under Hydrogenizing BCN. To these add the H2MED corridor with its submarine BarMar section linking Barcelona and Marseille, and a consolidated position as a European LNG hub: six regasification plants that in 2026 process more volume than any other EU country. Behind each of these projects there is a quiet but enormous flow: electrolysers arriving from Germany, 120-tonne rectifier transformers, compressors manufactured in Italy and regasification modules crossing half a continent. This article is addressed to the project logistics planner who has a German electrolyser waiting in Hamburg and needs to decide how it enters the country and by which route.

The Spanish energy wave 2026-2030

The map of renewable hydrogen projects advancing in Spain in 2026 is no longer a roadmap: it is a chain of simultaneous works. The flagship project — Onuba, the first phase of the Andalusian Green Hydrogen Valley led by Moeve (formerly Cepsa) in Palos de la Frontera (Huelva) — received final investment decision in early March 2026. Initial capacity 300 MW extendable to 400 MW, investment €1 billion for the Onuba phase alone, with a total horizon of 2 GW and €3 billion for the entire valley (Palos + San Roque). The electrolysers are supplied by Thyssenkrupp Nucera and Siemens Energy, both German OEMs; the industrial partners are Masdar and Enalter (the joint venture of Enagás Renovable and Alter Enersun).

In Castellón, the HyVal cluster, a 50% partnership between BP and Iberdrola through the company Castellón Green Hydrogen S.L., plans to commission a first phase of 25 MW in the second half of 2026 — five PEM containers of 5 MW each, supplied by Plug Power. The cluster's full plan envisages €2 billion to 2030 and the decarbonisation of the ceramic and chemical industries of the Comunitat Valenciana.

In León, Enagás Renovable and Naturgy are building a 280 MW renewable hydrogen plant in La Robla — on the site of a former coal-fired power station already dismantled —, with €485 million investment and commissioning forecast for 2026. The project has €42 million from the EU Innovation Fund and counts Fertiberia and Cementos Tudela Veguín as anchor consumers, alongside Alsa for sustainable mobility.

Alongside these three majors, the H2MED corridor — Europe's first hydrogen corridor, with its submarine BarMar section linking Barcelona and Marseille, and a total investment of €2.5 billion — set up its operating company in July 2025 between Enagás (via Enagás Infraestructuras de Hidrógeno), NaTran and Teréga. Geophysical surveys of the submarine route concluded in November 2025 with confirmed technical feasibility. Commissioning planned for 2032. In the Barcelona metropolitan area, the Hydrogenizing BCN initiative — twenty institutional partners under the Port of Barcelona umbrella — articulates hydrogen hubs in Zona Franca, Martorell and Mataró, with initial capacity of 20 MW extendable to 120 MW.

In parallel, the Strait of Hormuz crisis — closed since 28 February 2026 following military strikes on Iran — has reconfigured gas supply to Europe: Qatar out of play (Ras Laffan damaged, recovery estimated at 3 to 5 years), TTF prices multiplied, and US LNG, which had already overtaken Algeria as Spain's top supplier in January 2026 with 44.4% of total imported volume. Enagás regasification plants operate at high capacity — 40,320 GWh monthly available — and attract LNG-carrier fleets that, in many cases, also discharge equipment associated with the expansion of the terminals themselves.

What is transported to a hydrogen, LNG or gas plant

The most visible equipment in a green hydrogen plant is the electrolyser, but the electrolyser is only the core. A 100 MW plant comprises several equipment families, each with its own logistics:

• Electrolyser stack modules: in PEM technology, container-format modules of 5 MW weighing between 25 and 30 t per unit and fitting into 20-foot and 40-foot ISO containers. In large-scale alkaline technology — the typical case of Thyssenkrupp Nucera for projects like Onuba —, the stacks arrive as bulky assemblies of 40 to 80 t each, in configurations that fall squarely into special transport.
• Rectifier transformers: convert grid AC into the high-intensity DC needed for electrolysis. For a 100 MW plant, the typical rectifier transformer is 50 to 110 MVA, with weights between 80 and 150 t. They are classic indivisible cargoes: the electrical heart of the plant.
• Hydrogen compressors: raise the pressure of the produced hydrogen to storage or grid injection levels (between 30 and 200 bar depending on destination). Common manufacturers: ABC Compresores (Zumaia, world specialist in reciprocating compressors), Burckhardt Compression (Switzerland), Atlas Copco (Sweden/Belgium). Weights between 15 and 60 t per unit, frequently as skid modules (pre-assembled modular frame).
• Pressurised storage tanks: for high-pressure gaseous hydrogen, mainly imported from Italy and Germany.
• Balance-of-plant auxiliary equipment: water treatment, gas-liquid separators, drying systems, cooling, instrumentation. Usually arriving as prefabricated modules.

For a regasification plant — the case of the Enagás Barcelona expansion or the terminals at Cartagena, Sagunto, Mugardos and Huelva — the flows change in nature but not in scale:

• LNG vaporisers: large heat exchangers, frequently of the open rack vaporiser (ORV) type using sea water, with weights between 50 and 150 t.
• High-pressure cryogenic pumps: critical equipment, moderate weight but high operational sensitivity.
• Ammonia cracker modules: for NH₃→H₂ conversion at terminals receiving green ammonia as a hydrogen transport vector, the case of the corridor Moeve and Yara are developing between San Roque and Rotterdam.
• Steel structure for skids and pipe racks: support structures for process piping.

And for the corridors — H2MED and the future Spanish hydrogen backbone — the dominant equipment is specialised high-pressure piping for hydrogen and intermediate compressor stations. The backbone enters public planning in 2026.

These equipment families share one pattern: gear designed for a specific plant, custom-manufactured and transported to a site where any piece's delay can paralyse the whole construction.

Why almost all this flow activates special transport

Mass and geometry set the tone. A 110 MVA rectifier transformer for an electrolysis plant weighs 120 tonnes. A large-scale alkaline stack is around 12 metres of usable length and exceeds 60 t. A large-flow reciprocating compressor for hydrogen exceeds 4 metres width once mounted on its frame. The dimensions of the combination comfortably cross the thresholds of Anexo IX del RGV, and the operation falls squarely into the special-transport regime.

Indivisibility adds to the physical parameters: an alkaline electrolyser or a rectifier transformer is not broken down en route. They arrive as a single unit because their value lies in factory calibration; opening them to reduce dimensions would void the manufacturer's warranty.

The operational consequence is direct: the Complementary Circulation Authorisation (ACC), in specific or exceptional category according to the parameters of the combination, is mandatory on each stretch of the itinerary. And when the itinerary crosses the Catalan regional border, the regime moves from DGT control to that of the Servei Català de Trànsit.

The required equipment is also specific. An extendable low bed covers compressors and medium-sized vaporisers; large rectifier transformers and alkaline stacks require hydraulic modular, frequently with asymmetric axle-mass redistribution. For singular pieces — loads above 300 tonnes — the assembly on multiple modular lines comes into play and, in final accesses to the plant, the self-propelled SPMT.

And escort. A piece with width above 3 metres triggers a private pilot vehicle; above 5 metres, mandatory officers. For Catalan itineraries, competence falls to the Mossos d'Esquadra, through the SCT; in the rest of Iberian territory, to the Agrupación de Tráfico de la Guardia Civil, via the DGT.

The result: an operation starting from a plant in Schwanau (Germany), Zumaia (Basque Country) or Brescia (Italy), crossing several jurisdictions, requiring permits coordinated between different administrations and delivering a unique piece of equipment to a site still under civil works. Each link is special transport.

Equipment, escort and authority: how delivery is prepared

Three parameters dictate the configuration of transport and the administrative chain supporting it:

Mass and axle distribution. A 110 t rectifier transformer sits typically on 12 to 14 axle lines of hydraulic modular, which guarantees axle pressure within the legal pavement limit. Axle pressure is not just a road question: the final accesses to a hydrogen or regasification plant — site roads, crossings over buried installations — have their own limits, in some cases stricter than those of the main network.

Combination dimensions. For pieces longer than 25 metres — the case of a large alkaline stack with its transport support — the combination in transport position can approach 35 metres with the tractor. When the overhang exceeds 3 metres, the DGT authorises self-escort by default on every stretch of the itinerary; the piece travels with mandatory officer escort and, depending on parameters, with a feasibility study signed by a chartered engineer.

Inter-regional itinerary. Almost every Spanish hydrogen plant receives imported equipment from Europe: Onuba from Hamburg or Bremerhaven via the Atlantic corridor, HyVal from the port of Castellón or via the Mediterranean corridor, La Robla from northern ports via the Ebro corridor, the Catalan hubs entering via Barcelona, Tarragona or the future BarMar landing point. ACCs are filed in jurisdictional blocks — SCT for Catalonia, DGT for the rest of the national route — and must be synchronised so that the piece does not stop at a regional border with no current permit in the next jurisdiction.

For equipment entering through the Port of Barcelona — electrolysers arriving on Mafi trailers from northern Europe or regasification modules for the expansion of the Enagás Barcelona terminal itself — the port-specific regime is added: Special Circulation Authorisation processed through the port's Centro de Servicios al Transporte, port police escort for internal movements, and coordination with quay planning and gate.

On the Mediterranean corridor and the Ebro corridor — two of the arteries that structure PASTOR's logistics operation — the pattern is repetitive: departure from a Catalan industrial estate or a coastal port, entry to the state network via AP-7 or AP-2, inter-regional crossings coordinated with several provincial traffic offices. What the shipper sees as a delivery is internally a sequence of five or six administrative procedures linked end to end.

The real bottleneck: access to the plant under construction

Moving an electrolyser is not moving a piece of equipment. It is delivering the heart of the plant.

The last kilometre to the site is where the special-transport energy operation is decided. A green hydrogen plant is usually built on reconverted industrial land — former coal-fired power station, expanded industrial estate plot, terrain adjacent to an existing refinery. Accesses to these plots are rarely sized for a 120 t piece with 30 m in transport position.

Critical points of the final access, identified before moving the equipment:

• Bearing capacity of the site road. A hydraulic modular platform on a straight stretch can transmit acceptable axle pressure, but, when turning on a site roundabout, it concentrates mass on a reduced quadrant. The calculations are made on the actual pavement profile, not against a generic standard.
• Available turning radius. Plants under construction have provisional accesses; roundabouts, intersections and curves are not yet in their final geometry. A combination with 12 axles and 30 m length needs a minimum free radius of 18 to 22 m.
• Clearance at gantries, existing piping and overhead lines. For pieces exceeding 4.50 m in height — the case of some compressors and the large vaporisers —, a low-voltage line crossing the site road can invalidate access. The solution is usually a scheduled cut with the electricity company, a procedure that adds 48 to 72 hours to the schedule.
• Time window. Plant works have their own rhythms: unloading with a crane contracted for a specific hour, installation team immobilised in wait. The transport delay translates directly into lost hours of expensive equipment standing idle.

The planning that avoids these bottlenecks is done before loading the piece at origin, not en route.

Common mistakes when planning energy-equipment transport

Underestimating the rectifier. The electrolyser hogs attention — it is what the shipper sells externally — but the rectifier transformer is usually the heaviest piece in the plant. Underestimating it during logistics planning means falling short on equipment and permits when the piece reaches the port of origin.

Treating the ammonia cracker as standard equipment. Hydrogen plants with a green-ammonia line — the case of San Roque, of the future Moeve-Yara corridor terminal, of several installations in planning — incorporate ammonia crackers as large-format modules. They are relatively new equipment in the market and do not always come with a reliable dimensional drawing until an advanced stage of the project. Parameters must be confirmed with the manufacturer before committing to a delivery date.

Assuming a hydrogen compressor is transported like a natural-gas one. Hydrogen operates at higher pressures and compressors are of more robust, often heavier construction. A typical hydrogen compressor for a 100 MW plant can weigh twice its natural-gas equivalent at equal flow rate.

Applying for the ACC without having confirmed equipment and configuration. The real parameter of the combination in transport position depends on the piece and the low bed or modular used. An authorisation obtained with estimated parameters is invalidated when the piece arrives with different dimensions, and the procedure has to be repeated, with its up to 3 months lead time for exceptional authorisations.

Forgetting the Mediterranean corridor as an outbound corridor. In Spain, logistics attention concentrates on the inbound corridor for imported equipment. But plants like Onuba or HyVal also generate outbound flows: green ammonia to Rotterdam, hydrogen via the future BarMar to Marseille. The associated equipment logistics — transport tanks, export modules, equipment for ammonia terminals — is part of the same project and should be coordinated from the start.

Underestimating coordination with the port authority where applicable. When the equipment enters via the Port of Barcelona, Bilbao, Algeciras or Huelva, the documentary chain does not end with the ACC: there is specific port authorisation, quay coordination, port police escort and, frequently, time restrictions for the movement of oversized equipment within the port area. Treating the port as just another destination is an operational error.

Not including partial dismantling in the logistics plan. Some equipment — large compressors, cracker modules — arrives in a transport configuration that requires partial dismantling at the plant before final installation. The dismantling operation needs space, crane and specialised personnel. If not planned together with transport, the piece sits in the plant yard waiting.

How we approach this at PASTOR

Sixty years of family tradition in special transport from Catalonia leave something measurable: frequent presence on projects across the Mediterranean corridor and the Ebro corridor, specific accreditation at the Port of Barcelona where applicable, own fleet with conventional and extendable low beds, hydraulic modular configurable to platforms moving singular cargoes of several hundred tonnes, and operational access to SPMT for final on-plant manoeuvres. PASTOR operates with a qualified gestor de transporte under ROTT arts. 111 and 112 and RD 70/2019, current MDP authorisation, fleet ITV up to date and a documentation file closed before each operation.

For each piece of equipment — a 60 t alkaline electrolyser from Germany, a 110 t rectifier transformer from Italy, a hydrogen compressor from Zumaia — the PASTOR operations engineering team prepares: analysis of the physical parameters (mass, height, length, width, overhang, mass distribution), proposal of combination configuration, sketches in transport position, turning-radius simulation against the critical points of the proposed itinerary, validation against the clearances of urban and site accesses, categorisation of the ACC applicable on each stretch under DGT or SCT regime, and coordination with the port authority when the equipment enters via the Port of Barcelona.

When the equipment starts moving, the permits cover the real parameters of the combination, the competent authorities know what is arriving, when and by which route, the destination plant has a confirmed unloading window, and the shipper knows the piece is arriving on the day we said. The shipper holds a single point of contact: ours.