Tesla’s Class 8 electric truck, first showing due tomorrow, is important, but hardly the second coming of Christ

The long-awaited Tesla big rig is due to be shown tomorrow, after being delayed a few times supposedly because of focus on ramping up Tesla Model 3 production.  Of source the Model 3 is the make-or-break product of the moment and therefore Elon Musk and others at Tesla Motors must focus on that.  But, given the hype I am seeing about this vehicle announcement it’s like the second coming of Christ or something.  Are people not aware that other companies have built fully electric Class 8 electric trucks?  What can Tesla Motors do that will break new ground?  (I have an idea to share below, actually)

Generally speaking replacing a gasoline powered family car with an electric powered family car won’t make that much of an impact on the environment or the climate.  Regular cars see a couple hours of use per day, maybe, and therefore the opportunity for environment/climate improvement is small.  If Tesla Motors is true to their goal of preventing global catastrophe, the company should look for vehicle development with greater bang-for-the-buck.  Vehicles that are inherently dirty, and are used for many hours per day, such as Class 8 big rig trucks.

There’s also an economic incentive that makes electric big trucks attractive.  It’s the fuel cost savings potential.  The more ones fuel cost is, the more miles per day are driven, the greater the potential savings by using electricity as the vehicle fuel rather than diesel.  The key is understanding the cost to travel a given distance on diesel versus electricity.  I have published calculations on another website, the bottom line is that electricity-as-a-fuel is a fraction of the cost of gasoline or diesel (unless gasoline/diesel costs fall tremendously).  Therefore, if one drives enough miles the fuel cost savings can pay for any price premium or even for the entire vehicle.

The typical family car owner doesn’t drive enough miles for the fuel cost savings to make much of an impact.  But, a vehicle used all day long every day, like a taxi-cab, or a big truck, or a city bus, those vehicles can save big bucks on fuel cost savings.

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While we wish Tesla Motors would focus on the task at hand (Tesla Model 3) so the company has a better chance of success, branching out to big vehicles is something which would serve the corporate goals.  Here’s hoping Tesla’s management knows what they’re doing and are not stretching themselves too thinly.

Here’s a list of electric big trucks from 2015.  I captured this list from a presentation shown to the California Air Resources Board at that time-frame.  California has been funding electric big truck development for several years because of a nasty problem surrounding the Port of Los Angeles.

That port is one of the primary destinations for the big container ships that are a side effect of globalization.  That most everything is manufactured in China means any China-sourced product sold in the USA must arrive here via container ship, and is most likely going to be shipped to a West Coast port such as the Port of Los Angeles.  The rail heads serving that port are several miles away, and as a consequence there are thousands of trucks hauling containers back and forth between the Port and the rail heads all day long every day.  As a result, that corridor has a lot of diesel exhaust emissions, and it’s very well known that diesel exhaust contains carcinogenic materials, and causes negative cardiovascular impacts, as well as being a major contributor to climate change and other environmental ills.  California is working to eliminate those problems by promoting development of several kinds of zero emissions big trucks.

Note from this list that the battery packs, in 2015, were “large” but actually not so large considering the sort of vehicle.  But, those trucks have a limited daily driving needs given the short distance between the Port and the rail heads.  Another thing to note is the charging rate, such as Balqon’s 1 hour recharge time using DC fast charging into a 380 kWh pack, meaning the charge rate had to be around 400 kiloWatts.  Unfortunately Balqon since went out of business.

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One wonders what’s required for an electric class 8 big truck to be used for long haul trucking?  BTW, “class 8” means the big rigs, 18 wheelers, whatever you want to call them.

Balqon big truck in Los Angeles

One of the most interesting stories I know about currently is the rapid advances for electric city buses.  Several companies are selling such vehicles, and indications are that the field is getting ready for a “break out”.   Here’s a rundown of some news:

That’s just the tip of the iceberg, there’s a lot more news of this sort going on.  I recall recently seeing a news piece about Siemens’ project to mount on big trucks the sort of power receiver units used on light rail trains.  That would power a big truck from overhead wires just as street-cars and light-rail cars are powered today.  That project has been underway for several years, I first wrote about it in the 2012-2013 time-frame, and is an interesting idea even if it would require installing overhead wires on the highway.

What might Tesla Motors to implement electric long-haul trucking?

Implementing long-haul electric trucking might be done using one of these three methods:

  • Big battery pack: As our friends at Proterra have proved, put a big battery pack on the vehicle and you can drive a long distance.  The downside of this is battery pack cost (which is falling rapidly) and weight (which is falling less quickly).
  • Fuel cells: Remember that a fuel cell vehicle is an electric vehicle, where the electricity comes from running stored hydrogen through a fuel cell.  Theoretically hydrogen storage has higher energy density than battery electricity storage, and can refuel more quickly.  That might make fuel cells attractive for big trucks.  There is a (cough cough) issue with (cough cough) the fact that hydrogen is overwhelmingly derived from (cough cough) natural gas, meaning fuel cell vehicles are actually fossil fuel powered.
  • Battery exchange: Consider a network of battery swapping stations at truck stops.  This is simpler than building such stations for the general public since truck stops are highly centralized facilities.

The last, battery swapping, is where I think Tesla Motors can make a significant contribution for electric big rig trucking.  The company has already shown a battery swapping system they developed for the Model S.  One instance was installed in California between San Francisco and Los Angeles, and then it was quietly de-installed a year or so later.  The system Tesla developed is roboticized, and can exchange battery packs in three cars in the time required to fill the gasoline tank on a gasser car.

Suppose instead that Tesla would utilize the Supercharger system to recharge a big truck.  How big is the battery pack likely to be?  Let’s say that the 600 kiloWatt-hours that Proterra used to drive 1000 miles would give a class 8 big truck a useful driving range.  At 150 kiloWatts you’re talking about a 4-6 hour recharge time.  Of course the recharge time would be 7-8 hours for a 1 megaWatt-hour pack, and so on.

In other words, there’d be an incentive to increase the charge rate to perhaps 400 kiloWatts per vehicle.  How many trucks would be getting charged simultaneously?  That many trucks times the charging rate is the energy required at the site.  The energy requirements start building up rapidly, and the cost for provisioning electricity service could become prohibitive.

With battery swapping the charge rate can be more modest.  The truck was fully recharged in a couple minutes and is probably back on the road already, therefore the battery can recharge at a more leisurely rate.  Plus, that battery pack can be providing smart grid services while it’s recharging, and Tesla has the where-with-all to install a solar array as well as stationary energy storage systems.

Where battery swapping wasn’t feasible for family cars, it might be very feasible for big trucks.  That’s my prediction anyway, that fulfilling the hypery Elon Musk is spreading about the Tesla EV truck might require a battery swapping system.  Or else a super-high-power Supercharger, but I think that’s less likely.










About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.


  1. David, As ever, interesting article. But one possible disagreement: charge time could be less than an hour, regardless of pack capacity. I speculate this because Tesla seems to like to do things in a modular way (ex: its fast chargers are stacks of regular chargers). What if Tesla has a truck with a 1000KWH pack, but that pack is really comprised of 10 100KWH packs? We already know that Tesla’s fast charge stations can handle multiple cars charging at once. Tesla could have a truck-specific 1250KW charger, that is really 10 125KW chargers charging 10 100KWH packs. Look, I don’t know if you have to drag over ten different cables (I doubt it), but the splitting / unsplitting of that power through one or two cables is certainly doable. And yes, alternatively, that whole 1000KWH pack could be autonomously removable and chargeable and replaceable. (BTW: I am using 1000KWH for no important reason: it could be any multiple of 100KWH — and using round numbers, I’m guessing that a 100KWH pack (using the good new cells) weighs about 1000 lbs., so having a 10,000 lb. lump of battery to pull around all the time is a lousy way to improve vehicle efficiency.)

    • Yes… that solves for the issue of pumping 1 megaWatt charging rate through a single cable. It doesn’t solve the issue of the total energy required for a full facility to handle several Tesla Semi’s at once. At 1 megaWatt per truck how many trucks can Tesla affordably handle the charging?

      I would think there’d be no free charging tier for Tesla Semi’s. As long as Tesla’s price for energy is less than the cost of Diesel it’s economically attractive. But the big question is about electricity supply to the entire facility.

  2. Do you know anything about whether Tesla — like it’s cousin SolarCity — intends to have a leg in both new sectors, that of electricity generation as well as electricity use? My view of things is that Rockefeller was right: total vertical integration in energy is the way to go. Here, Musk can do Rockefeller one better, by not only controlling all aspects of electrical generation (well, save for the transmission piece, but a piece of paper should be able to address that), and then even the use of that energy in transportation (as if Rockefeller was also Ford).

  3. Tesla and SolarCity are one company now. So yes, Tesla has a leg in both sectors – electricity generation, electricity storage, and electricity consumption. Before the merger SolarCity was at Solar conferences talking about distributed energy resource management, and building a virtual power plant out of its customers solar arrays.

    The long term plan for the Supercharger locations is incorporating solar and energy storage INTO the site. That long term plan was announced shortly after the Superchargers were announced. In some cases it is becoming true. Having energy storage at the site is simple – you can see that at the Gilroy supercharger location, and I presume all the others as well. Having energy storage is the first step to mitigating the energy requirements because Tesla can use the local energy storage to reduce demand peaks. Adding solar should further reduce demand peaks …

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