It has now been seven years since the ACO confirmed it wants to introduce hydrogen to its top class and compete for the overall win at the 24 Hours of Le Mans. Since then, the technology has advanced so quickly that the final choice of what to use has still to be made, and the timeline is being pushed further away because of it.
As Racecar reported last year, the original plan was to introduce fuel cell hydrogen cars, but refuelling them led to a fear of dramatic temperature changes from empty to full as pressure increases when the tanks are filled.
Research into hydrogen ICE technology has advanced since then and using hydrogen as a combustion fuel is now a real possibility. There, the temperature of stored hydrogen is low, and engine builders have to cope with a pressure change from 700bar to 40bar at the combustion chamber. Despite this, work on ICE engines running on hydrogen is progressing faster than the fuel cell concept.
However, fuel cell technology is fighting back, with new materials and processes coming online rapidly.
Consequently, what the rule makers are currently trying to do is understand where hydrogen technology is
