Test drive: Kenworth’s hydrogen fuel cell T680 (see here
An interesting test application: it has enough battery for about 30 miles of range on stored energy, and while it can carry enough hydrogen for an additional 120 miles, it is only expected to travel about 50 miles per day. In other words, the fuel cell can be non-functional most of the time, or can run at very low power all of the time.
Another interesting set of numbers: with only one ton of batteries, the complete truck weighs three tons more than the diesel version. That's an incredibly heavy combination of motor, fuel cell, set of hydrogen tanks (containing very little hydrogen), and set of supporting equipment.
Despite having a substantial extension on the daycab, it still has equipment mounted behind the cab. It looks like the fuel cell is under the hood (in the engine space), the motor is in the front part of the original transmission space, and the hydrogen tanks are behind the cab. This leaves the ton of battery presumably in side pods where the diesel tanks would normally be. This illustrates the challenge of packaging any hybrid, and is a reminder of why purpose-built electric trucks tend to have motors mounted at the axle (leaving space for everything else in the usual engine and transmission locations).
That fuel cell sure is big... as big as the 14-litre diesel engine which it replaces.