Electric Trucks are Coming, but Where?

You may have heard that Tesla is developing an all-electric semi-truck that can haul standard shipping container trailers 300 miles or more.  Daimler Trucks and Volvo Trucks, the two largest truck manufacturers in the world, are also actively working on their own versions of all-electric heavy duty trucks with stated target release dates in the next 18 months.  But what exactly will these trucks be good for and where will they be used?

The Weight Challenge

The biggest challenge electric trucks face is weight.  Batteries are heavy, and the heavier a truck is the less efficient it is at hauling cargo.  If you want to scale up the range, you have to add more batteries, which means more weight, which means more problems.  An electric truck’s battery pack could easily account for a quarter of the total weight of the truck (minus the trailer) while providing relatively low range.  To provide a quick comparison, it’s not unusual for a diesel heavy duty semi-truck to have a range of over 1,000 miles and realistically be limited more by the driver than by the fuel tank.  Electric trucks under development, on the other hand, are mostly being designed for trips from 80 - 300 miles, necessitating multiple stops to recharge along many popular long-haul routes in the US.

So What Are They Good For?

So if electric trucks aren’t being developed for long-haul routes, where will they be used?  Short haul routes are more popular than many people realize and are a perfect use case for several reasons.  Here are a few examples:

• Port to Distribution Center.  A huge portion of truck trips occur over a distance of just a few dozen miles between sea ports, airports, or rail yards and distribution centers.  These tend to be back-and-forth trips throughout the day to pick up and drop off trailers at both sides of the trip.
• Last-mile to In-City Loading Docks.  A trend in logistics has been to establish large shipping and receiving centers outside of urban areas that receive long-haul cargo and then send trucks from these centers to their final destinations like grocery stores and big box retail stores.
• City-to-City Logistics in Close Corridors.  A surprising number of city-to-city goods transport happens over distances less than 300 miles.  Think Irvine to San Diego, Portland to Seattle, or New York to Philadelphia. Many of these shorter-haul trips make more sense via truck than via rail when deadlines are tight and loads might not fill a full rail car.

In all of these examples, a significant portion of the driving is in stop-and-go conditions where total driving time is easily completed in a single shift.  This is exactly where electric trucks make sense for a few reasons.

• Torque Availability.  Unlike traditional powertrains, all-electric powertrains provide instantaneous torque even from a standstill, and are able to get heavy loads moving quickly even in urban environments with stop signs and traffic lights.  This is why diesel locomotives actually use their diesel to power electric generators that drive the wheel motors, and it makes sense for heavy duty trucks as well.
• Ease of Driving.  If you’ve ever driven an electric vehicle, you know that it doesn’t have a geared transmission in the traditional sense - you push the accelerator and it goes from 0 to 60 without ever pausing to shift gears.  An electric truck driving in urban environments would benefit tremendously from this simplified driving model in comparison to today’s trucks which often require drivers to shift through 10 or more gears to get up to speed.
• Efficiency.  A huge component of operating costs for trucking companies is fuel, especially with the average semi-truck getting somewhere around 7 miles per gallon of diesel.  Thanks to natural efficiency improvements in urban settings from things like regenerative braking and the relatively low cost of electricity in comparison to fuel in most locations, electric trucks could cut “fuel” cost by up to 50%.

The bottom line is that electric trucks make a lot of sense in specific roles.  You probably won’t see them driving the highways between Texas and California any time soon, but don’t be surprised if a shiny electric semi silently pulls up to you at a traffic light two years from now.