I work for a truck and bus OEM, and I’ve watched a lot of proposals and pushes for alternative fuels be worked on as projects in the 9 years I’ve worked there.
I work in chassis so I am not in the front lines as far as these projects so my observations are from talking to other engineers involved in the projects and seeing company communications.
When I first started working there, CNG was a big push but that faded, other than we did end up putting CNG busses on the market.
We are selling some EV busses now too, and development work has been done to carry that technology over to the medium duty truck line which is on the same chassis.
The latest push seems to be with fuel cells. We were in a partnership with a European OEM, and now are owned by them, and that seems to be where Europe is going.
A lot of it boils down to vocation as far as practicality of different energy sources to propel trucks and busses. School buses can work ok as EV, as they can charge overnight than go out and do their routes for a few hours, then return and charge for hours before going back out for afternoon routes.
Some delivery trucks in urban areas might do OK electric.
CNG never took hold except for several vocations it seems. Some refuse truck fleets love CNG as they can make their own fuel from landfills. I’ve seen cement mixer fleets that use CNG.
I have doubts EV is going to ever be practical for over the road. Stopping for an hour or two to charge a semi isn’t going to work. I’ve seen proposals where low battery packs would be quickly swapped for fresh charged ones at trucks stops but that seems impractical to set up the infrastructure to do that.
Other vocations EV is doubtful to ever be practical, fire trucks, construction, utility companies where trucks operate remote and running equipment off the power train for their work are several examples.
It’s going to take a long while to figure it all out but I think in the end there will be different fuel power for different truck vocations just like is happening with school buses now.
Cars and light trucks will probably end up being similar, EV can grow in % of the fleet, but can it ever be 100%? I have my doubts!