Train maker Alstom, using an existing hybrid diesel-electric model called a Régiolis as a base, will build the trains in French factories, if the SNCF and the regions can agree on how to finance them.
At least three regions, Occitanie, Nouvelle Aquitaine and Grand Est, have said they are in favour of using hydrogen trains.
Régiolis trains are designed with four carriages having their own power units, rather than being pulled by a locomotive, and have a top operating speed of 160 kph.
They can take 232 seated passengers. The diesel engines are in the roof, allowing for a low floor, which does not require a step up from platforms.
A fuel cell and batteries will provide enough power to run the trains on portions of track that do not have an electric power source and where diesel engines are now used.
“We are ready to go and as soon as we get an order that is large enough to start industrialisation, we will be able to build,” an Alstom spokesman told The Connexion.
SNCF president Guillaume Pepy, said he hoped the talks with the regions would allow about 15 train sets to be ordered, and that they would be ready in around two years.
A hydrogen-powered train is already running in Germany, where a diesel train was converted, and reports say the train was 30% more expensive to buy than a modern diesel replacement.
Alstom did not want to say how much each train would cost.
“What is important is the cost of buying and running a train over a number of years because that is where the choice of fuel and the amount of maintenance that has to take place is taken into account,” the spokesman said.
“We are confident that these first hydrogen-powered trains will have the same running costs as their diesel competitors in 10 years and are much cheaper than the alternative of electrifying the tracks where they will be used.”
Lower maintenance costs will come about as a result of the fuel-cell system having a lot less moving parts than a diesel motor.
Hydrogen is also cheaper to buy than diesel and less affected by the price of oil, although 95% of commercial hydrogen is made from fossil fuels.
Trains will have tanks able to take 200kg of compressed hydrogen gas, which will give them a range of between 400 and 600 kilometres using hydrogen alone.
A mobile hydrogen filling station is likely to be used, as is the case in Germany, until stations are equipped with their own hydrogen storage tanks.
While running on hydrogen, the only exhaust products will be steam and water, and the noise will be less than when the train runs on electricity from overhead wires.
Alstom has also signed a partnership agreement with a rail operator in the UK, to see if it is possible to convert existing diesel-electric trains to hydrogen-electric trains.
So far the study has not got beyond a theoretical stage.