The Ministry of Transport and Sustainable Mobility has launched a Preliminary Market Consultation to study the use of green hydrogen on non-electrified railway lines and compare this option with other fossil fuel-free technologies. This open initiative requests proposals and technical evidence from industry to define how to replace diesel traction with cleaner solutions on several corridors of the General Interest Railway Network.
The aim is to assess whether it is more advantageous to electrify entire sections of track or to opt for alternative systems—such as hydrogen fuel cell or battery-powered trains—in areas where overhead lines are not viable in the short term. This action falls within the commitments of the Recovery and Resilience Facility (RRF) and the new Indicative Strategy , the development of which is expected to be finalized in 2026.
What the consultation studies and why it focuses on green hydrogen
The Directorate General for the Railway Sector is collecting information from operators, manufacturers, and suppliers on alternative technologies to diesel, their infrastructure requirements, operating costs, and limitations. The procedure, published on the Public Sector Procurement Platform , remains open until September 30 at 23:59 p.m. and, if necessary, may be extended without implying any contractual obligation for the participants.
For green hydrogen , fuel cell trains are being analyzed that transform hydrogen into electricity to power electric motors, emitting only water vapor. This option can be combined with overhead lines on electrified sections, allowing flexible operation on mixed-use lines and offering an alternative when full electrification is costly or complex. More information on the use of green hydrogen in public transport can be found at this link.
The Ministry is also considering other solutions: rechargeable battery -powered trains operating under overhead lines, hybrid systems (electric with battery and/or hydrogen) with strategic electrification at key points, and even the use of biofuels or e-fuels in retrofitted diesel fleets. However, the main focus of this consultation is to promote technologies that significantly reduce dependence on diesel and cut emissions in real-world service.
This process also seeks to guarantee transparency, equal treatment and non-discrimination among agents in the sector, integrating industrial knowledge into the design of effective and realistic solutions for a more attractive railway for passengers and goods.
Non-electrified lines under evaluation
The consultation focuses on six conventional corridors where the implementation of green hydrogen traction and other alternatives to diesel is being studied, as well as the possibility of total or partial electrification depending on its technical and economic viability:
- Ávila–Salamanca
- Torralba–Soria
- Huesca–Canfranc
- Cáceres–Valencia de Alcántara
- Zafra–Huelva
- Mérida–Los Rosales
Currently, of the 11.672 kilometers of the conventional rail network managed by Adif, 6.719 km (57,5%) are electrified, leaving 4.953 km (42,5%) without overhead lines. On the high-speed network, the total length is approximately 3.976 km , of which 94,2% (around 3.748 km) are electrified, highlighting the work still needed to modernize the conventional lines. Green hydrogen engine technology could be particularly relevant in these cases.
Participation is open to individuals or organizations , public or private, interested in contributing their expertise to define investments and timelines. With the contributions received by September 30, the DGSF will inform the analyses that will form the basis of the Indicative Strategy currently under development, aimed at accelerating the decarbonization of rail transport through operational and scalable solutions.
Green hydrogen traction is seen as one of the most promising options for decarbonizing non-electrified lines, complementing the overhead contact line where it is most cost-effective and facilitating an orderly transition from diesel to a more sustainable and competitive rail service that meets European climate objectives.
