My understanding is that hydrogen may be most useful for heavy good vehicles rather than cars. EVs could be great for short range urban delivery vans etc but long haul infrastructure may be built around hydrogen if the supply chain is viable.

Might, but if the Tesla Semi becomes a reality, the potential market for hydrogen in trucks becomes much smaller too.

The dynamics of moving heavy loads long distances has never favored electric power. Diesel currently powers tractor semis because it produces more energy than gasoline and creates much more low speed continuous load torque.

EVs are well suited to light loads and short distances, rapid acceleration and altitude change but are not well suited to long range hauling of heavy loads due to the enormous energy required.

EVs are great if you are pulling heavy loads across hills, as you get your energy back going downhill (at least large parts of it). The torque also rather is an advantage of EVs. Diesel engines are popular because they are more efficient than gasoline engines and if you have continuous high loads, that adds up. Guess what is much more efficient than Diesel engines? Electric engines! And they are way more efficient than going the route via hydrogen.

The only open question is: can you put enough batteries into a battery electric semi? If you can't, then of course the question about efficiency is moot. But if you can, everything speaks for battery electric vehicles. That is where the Tesla Semi comes into play. It promises ranges that are just enough for most applications, for those applications it has basically "won" right from the start. What remains to be seen is how large exactly the sector is which isn't served by the Semi. But in any case, with every improvement of the battery technology, that sector shrinks a bit further.

An electric semi's battery weight alone makes them not viable imo. I think it's a good idea to ignore the endless Tesla sales hype and brand reinforcement and focus on the basic logic and physics. Musk is as fake as his hair imo and spends most of his time being very misleading while aggressively selling theoretical future projects.

I grew up in the UK with electric milk floats, a practical use of EV's for short, quiet urban delivery. There's a reason electric heavy trucks, which were marketed in the 20's and 30's lost out to diesel. https://en.wikipedia.org/wiki/Walker_Electric_Truck

Why would you think a semi's battery weight would make it not viable? If you calculate what the batteries would weight and subtract the weight of the engine, transmission and of course fuel in a full tank, you get to about 2 tons more for the battery powered semi, if not less. That is a small reduction of the maximum load capacity.

https://tfltruck.com/2020/01/electric-truck-towing-battery-w... See this link

Also for an 18 wheeler just the amount of tires on the road requires tremendous torque to create a rolling load and sustain it. Freightliner are working hard to make E trucks viable but the acid test is fleet buyers and maintenance, it's a ruthlessly efficiency first market. https://freightliner.com/electric-trucks/