Electric trucks are the future of freight.
Why? Cost, not decarbonization, but decarbonization is a nice side-benefit.
The rest is details.
OK, you want the details? Fine. But remember, I’m a chemical engineer and this isn’t my principal area of study. But even to someone like me, it seems pretty obvious- there’s a clear driving force away from diesel and toward electric for medium and even heavy trucks.
People are notoriously confused between wants and needs. They confuse what they’re used to with what will always be. And so, when confronted with the fact that we must stop burning fossils as fuels, they ask automatically, “what else can we burn, aside from fossils?”. Eric Idle’s character from Monty Python and the Holy Grail replies, “More fossils!” – but of course Cleese’s idiot, was turned into a newt but “got better”, replies “Hydrogen!”. And there was much rejoicing…
My Monty Python and the Holy Grail meme. Use with attribution or I shall taunt you a 2nd time!
We’ve been told that batteries are too heavy, and that freight companies value labour and equipment productivity too much to make electric trucks possible. They must be able to drive for 12 hours straight without refuelling, must refuel in 10 minutes, and can’t be a kilogram heavier than they are now.
Of course this is rubbish. And if that were a firm requirement, hydrogen with its absurdly poor energy density per unit volume would be no solution either. And anyone who thinks you can fill a giant high pressure tank with 700 bar or -253 C liquid hydrogen in 10 minutes needs to give their head a good shaking too.
The North American Council for Freight Efficiency estimates that about 75% of freight loads are limited by factors other than maximum gross vehicle weight, such as vehicle volume or trailer floor space. Of the remaining 25% which are weight sensitive, a fairly significant portion are tankers of fossil fuels that we simply won’t be shipping in a decarbonized future.
NACFE also estimates that the net weight increase of a fully battery electric truck relative to the diesel it replaces is on the order of 3 to 4 tons, i.e. 6-8,000 pounds. That’s perhaps 10% of the maximum gross vehicle weight at most.
Furthermore, in most jurisdictions, drivers must take regulated rest breaks. While on some routes, teams of drivers permit rest breaks to be taken without delaying delivery, that’s not the case with every load or even with most loads. Pairing rest breaks with battery recharging, battery swaps or tractor swaps is an obvious alternative.
A class 8 truck will need a battery on the order of 1000 kWh to match with the maximum distance between rest breaks permitted in many locations. Such a battery can be recharged between 20 and 80% state of charge (SOC) in less than an hour, just as it can be done with a car’s battery. Megawatt charging standards are already under development. But most trucks return to a depot and do routes of less than 200 miles per day. Those will likely be depot charged, at night when electricity rates are already low.
Even better, in some locations we only need a battery suitable for the first and last portion of the journey. The rest can be provided via overhead wires. I was skeptical about overhead wires on roadways but David Cebon convinced me otherwise. They offer a clear decarbonization advantage- where the alternative of moving these loads onto electric trains isn’t on the table.
But what will drive this transition away from diesel? Cost. Electricity costs less per mile driven than even fossil diesel, even without carbon taxes. The vastly greater efficiency of the electric drivetrain, as a result of better energy conversion efficiency and regenerative braking, make this possible. That savings easily pays back the investment in batteries. And in an industry so sensitive to energy cost that it charges its customers a “fuel surcharge”, the notion that vehicle or driver productivity matter more than energy cost is tough to swallow.
Electric trucks will also be easier to drive- by far- than diesels. They will have considerably lower maintenance costs as well.
Unlike purchasers of cars and light trucks, who can easily be distracted by cup holders and the entertainment system, freight owners understand total cost of ownership. They aren’t going to switch to hydrogen. Hydrogen will use at least three times as much source energy to do the same job as a battery electric vehicle. Add the considerable cost and complexity of hydrogen logistics and hydrogen refuelling infrastructure, and you’ll soon be looking at perhaps five times the cost of energy for hydrogen versus battery electric. Hydrogen is simply not a realistic option for road transport at any scale, including for heavy trucks. And no, the reasons for that will not change as a result of either innovation or wishful thinking. Hydrogen as a vehicle fuel is structurally inefficient and ineffective.
Electrification will start on routes and with vehicles that are easy for electric vehicles to handle. Shuttling operations, last mile delivery (think of all those courier delivery trucks) etc. are already within reach of trucks with very modest battery sizes. Until battery scale drives cost down even further, these will pay their owners back most quickly because large batteries are simply not required.
Finally, we all know of some applications which aren’t going to be done by electric vehicles. Freight loads running on ice roads to resupply First Nations communities in northern Canada? Forget it! But they a) amount to 3/4 of eff all in terms of total GHG emissions in the world and b) will not use hydrogen, either. We can either biofuel these applications, as we must with long distance ships and aircraft too, or we can simply let them continue to burn fossil fuels- and focus on the 95+% of road transport that is an “easy to decarbonize sector”. The last 5% of emissions shouldn’t stop us from pursuing the easy 95%.
The transition is already happening, and not just in typical class 8 tractor-trailers. There’s a demonstration project with 3-trailer “road trains” in Australia, as well as super-heavy mining vehicles- some of which recharge simply on the potential energy of the ore they carry from a mine at high elevation, down to a processing facility at lower elevation.
Don’t take my word for it. Listen to people like James Carter who have studied this in detail.
