There is a problem with hydrogen that is being slightly forgotten here.
The only tailpipe emission from burning hydrogen fuel is water, which will exit the tailpipe at high temperature and be dispersed into the atmosphere , right?
In a warm climate , no problem, but there is an issue in cold climates where the air is already saturated with water vapour, now the water will rapidly condense and form "clouds"
In the 80s I witnessed a Mercedes winter testing programme in Finland, and one 300E C Class was fuelled with hydrogen. When it drove along a road at any sort of speed the cloud of water vapour didn't just exit the tailpipe , it enveloped the whole car , the road, and a fair part of the surrounding countryside as well. The following vehicles had to stop and wait for the clouds to disperse before visibility was restored. The testing with that vehicle was stopped.
This was a while ago of course, and technology will have advanced since then, but I would be very wary of buying a hydrogen fuelled vehicle if you reside in the cooler parts of the world until the manufacturer can show that they have a solution to this.
