| Trucks have greater total mass, but a much higher net:gross weight ratio. Curb weight of Tesla Model 3 is 1.6 tonnes. This is about 300 kg (23%) heavier than a typical ICE automobile: Mazda 6: 1.3 tonnes, Honda Accord: 1.4 tonnes, Toyota Corolla, 1.3 tonnes. Payload is 1.5 adult humans[1] at 0.08 tonnes each, total 0.12 tonnes. Payload:gross ratio is 7%. Note that the additional mass of the Tesla is > 2x the payload mass. Total battery mass is 530 kg, so Telsa have lightweighted their vehicle by 230 kg and still added another 300 kg mass. Total energy storage weighs 4.4 times the human payload. An "18-wheeler" tractor-trailer weighs about 35,000 lb empty (16 tonnes), and has a maximum loaded gross weight of 80,000 lb (36 tonnes).[2] The average loaded gross weight is closer to 20 tonnes, for a payload:gross ratio of 55%. Personal automobiles have a vastly greater overhead of vehicle mass to payload, and can accommodate a comparatively larger batter storage pack. This added mass is partially offset by reduced motor, drivetrain, and structural elements. Cargo vehicle mass is largely dictated by load requirements. I'd be surprised if lightweighting of electrified cargo vehicles, especially of trailers, could achieve much. Tractor-trailer fuel capacity is typically 120--300 gallons, or 4.8 -- 12.1 MWh. Because electric motive conversion is more efficient than internal combustion, that can be reduced to about 1.6 -- 4.0 MWh. The Tesla Model S battery stores 85 kWh in 530 kg, or 6.4 tonne/MWh. Multiplying out, we get 10.24 to 25.6 tonne battery to provide equivalent motive power, when factoring in the greater efficiency of electric traction. Note too that fuel is burned off during travel, battery mass is not. (Air-metal batteries gain mass as charge is expended.) Engine weight for a big rig is about a tonne.[3] I'm not finding a transmission weight, though I'll assume it's roughly comparable, and that electrification shaves 50% off this. So we lose 1 tonne electrifying the drivetrain.[4] That's ... fairly minimal. So, our electrified truck starts with a 16 tonne dry mass, drops 1 tonne for drivetrain, and adds 10--25 tonnes of battery storage, for a total vehicle weight of 25--35 tonnes. Our maximum gross weight is 36 tonnes. We have from 1 to 11 tonnes cargo capacity, compared against 4 tonnes average and 20 tonnes maximum for a fuel-powered truck. Increasing total vehicle mass tremendously increases roadbed deterioration, as well as traffic safety considerations. It is probably not an option. Other alternatives are lighter loads, more trucks (and drivers, or driver automation), more frequent recharging or in-transit power supply, or battery swaps. A separate "battery trailer" might permit reasonably swapping batteries. Otherwise, a battery integrated into navigation or trailer chassies doesn't seem reasonably swappable. I've suggested a similar option for passenger vehicles where daily vs. touring ranges could be supported through an additional "touring battery". Alternatively, trucks could operate either entirely or significantly in a wire-fed configuration, where the vehicle is powered and/or charged from a grid-fed electrical infrastructure. For various reasons, this is probably best done at at lower speeds or when stopped --- the slower the vehicle during the charging phase, the more efficient charge-capacity per unit length of charging infrastructure. Given multiple independent ownership and maintenance of equipment, traffic-induced variances, and the need for physical contact with charging infrastructure (probably), odds are high that this will be a high-maintenance, and failure-prone option. Other alternatives include far more efficient multimodal transport transistions, with rail used for long-haul segments and dedicated tracked trucks or trollies for local distribution. I've done some casual search of literature on rail technology developments, and in the freight realm have found virtually none. High-speed passenger rail, yes. Greater freight / cargo efficiencies, not so much. The US freight rail system is tremendously efficient. It's still plauged with delays, congestion, theft (as noted in recent news), and other issues. It is an excellent option for large, massive, and time-insensitive loads. It's less suited to high-value or time-sensitive shipments, particularly of fresh (or even frozen) food. It's cumbersome to navigate for small-scale shippers. And it's an increasingly monopolistic / oligopolistic industry with almost all significant routes in a handful of rail lines. There are five Class I freight railroads in the US: BNSF Railway, Canadian National Railway, Canadian Pacific Railway, CSX Transportation, Kansas City Southern Railway, Norfolk Southern Railway, and the Union Pacific Railroad.[5] ________________________________ Notes: 1. Average vehicle occupancy: 1.5 persons (2018). https://css.umich.edu/factsheets/personal-transportation-fac... 2. https://www.tcsfuel.com/blog/truck-weight-classification/ 3. https://www.cummins.com/engines/heavy-duty-truck 4. To be clear: this is an assumption. We can recalculate based on more accurate data, but this gives a point for moving forward. 5. https://en.wikipedia.org/wiki/List_of_Class_I_railroads |