Le Mans organiser the Automobile Club de l'Ouest set up a working group in 2017 to establish a zero emissions class at the famous endurance race, and had targeted a launch in 2024 after revealing plans for Red Bull Advanced Technologies and Oreca to design a concept chassis.
GreenGT, which has partnered with the ACO to develop a hydrogen-powered LMP3 racer, that has managed times comparable with GT3 machines in the Michelin Le Mans Cup contributed to understanding the technology's specific requirements and hydrogen fuel tanks would be supplied by Plastic Omnium.
But delays caused by the COVID-19 pandemic and a desire to ensure that hydrogen cars are truly competitive before being introduced to the world-famous endurance race meant it was already set to be delayed by a year before the latest decision to postpone to 2026.
The ACO's hydrogen consultant Bernard Niclot told Motorsport.com: "I don't think we will have the racing category in 2025, it's too short now.
"It's much more probable for 2026. Eventually, for 2025 we could have some Garage 56 car but it's not yet finalised.
"You have two reasons for this delay. The first reason obviously the COVID situation that has delayed everything, especially for hydrogen cars.
"We have seen with the GreenGT [MissionH24] programme that some components were very long to get in normal times, but with COVID it was even more difficult, so it's difficult for manufacturers or whoever to manage or put a development programme in these conditions.
"Second, we really believe that a hydrogen car can be competitive in Le Mans against gasoline cars, but it is very challenging.
"We consider it is feasible, the Red Bull Advanced Technology study clearly demonstrated that the target of performance is achievable, but on the other side it's not easy.
"For the moment we have paperwork with a nice study but then you have to demonstrate on the track and we all know from engineering to the track there are some differences.
"It's clear it's not easy for anybody to build such a car and to be sure to be competitive. And the OEMs that want to go in this category, somehow they take some risk.
"It can be very rewarding for them because they can be the first but they have to develop it carefully and to be sure of what they do and this takes time, so it's another reason why the programme has shifted."
However, Niclot doesn't think the development is a concerning one as it will mean hydrogen cars aren't competing for attention with the influx of manufacturers entering the Hypercar division.
Next year Alpine, BMW and Lamborghini will join 2023 newcomers Ferrari, Porsche and Cadillac.
"At the end this is good news to focus momentum on endurance racing and the H2 programme can only profit from this," he said.
"In the meantime, I believe the co-existence with Hypercars will be easier in '26, '27 than it will have been in '24 which is more or less the year where Hypercars will be really under the lights.
"It would have been difficult in the meantime to have introduced this hydrogen category so at the end this delay is not a big deal."
Regulations for the class are set to be written this year pending further discussions with manufacturers, with the next working group meeting set to be held later this month.
"We know what we want to do," added Niclot. "We have a clear view of what is feasible, what is possible and how we should steer the regulations, but they are not written in black and white.
"We need to do it and it's a job we do this year with the manufacturers in order to have something that fits the needs of the category and answers to the requirements of what the manufacturers would like to have and to show."
