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The transportation sector accounts for 28% of greenhouse gas emissions, and heavy-duty trucks account for 23% of that. Even though transitioning passenger cars to electric is well underway at this point, we’re right at the beginning of transitioning trucks and semis. But there’s a major wrinkle. While EVs are far more energy efficient than gasoline vehicles, towing a lot of weight takes a major hit on efficiency. Let’s explore the future of electric trucks and just how well batteries stand up to diesel.

Heavy-duty trucks are one of the backbones for shipping goods around the world, but they’re usually powered by noisy diesel engines, which means they’re also creating a lot of pollution. In the U.S., transportation is the largest contributor for greenhouse gas emissions, and from a worldwide perspective, diesel truck engines account for 5% of global fossil fuel derived CO2 emissions. But there’s a wave of electric trucks and semis coming to the market to address this.

When you look at how gasoline compares to battery electric vehicles for energy use, it’s pretty clear that EVs come out on top. The fantastic YouTube channel, Engineering Explained has a great video breaking down energy and range comparisons between battery and gasoline, as well as towing impacts, so be sure to check it out if you’re interested in the math behind this. But in a nutshell, a 200 kWh Cybertruck would have a range of about 500 miles vs. a Ford F150’s full tank providing the equivalent of 775-1,200 kWh of energy for 437-684 miles of range. That’s quite a gap going from 200 kWh to 775 kWh for roughly the same range. Battery wins there.

But that’s where the big challenge comes in. That’s under ideal conditions for just the vehicle itself. When you start towing tens of thousands of pounds of cargo, the range on EVs takes a much bigger hit than the gasoline competition. When towing, the range of a gasoline truck is a little over double the capability of a battery electric truck. They may be more inefficient, but that shear energy density in a tank of diesel makes up for it. For electric trucks and semis to really be competitive they need to double the energy density of their battery packs … or do they?

In 2017, Elon Musk stood on stage and announced the Tesla Semi, which most people are expecting to be a major market disrupter. This all-electric semi-truck should get somewhere between 300 to 500 miles on a single charge, while consuming less than 2 kWh per mile. 1 2 That’s impressive … and to do that it’s going to be taking advantage of Tesla’s new 4680 battery cells.

But even with the 4680 cells, it’s still going to require an absolutely massive battery. We’re talking about 5 to 10 times the battery capacity of a typical Tesla car. While the Tesla Model 3 has battery pack capacities ranging from 50 kWh to 82 kWh, Semi’s might range all the way up to 800-900 kWh. On that exact topic Elon said:

“You want something in the order of probably a 500 kWh pack. What we have in the Model S and X is a 100 kWh pack and probably something like a 500 kWh pack in the Tesla Semi.” 3 4

Again, that’s only in reference to the 300-mile version, and it’s another catch for battery electric trucks: not enough batteries. The massive battery pack and number of cells needed is one of the reasons for the Semi’s production delay. When asked about Semi’s launch timeline on Twitter, Elon said:

“We are too cell-constrained right now, but probably ok next year.”

Earlier reports said the company was planing to start building five Semis a week in a new pilot line near the Nevada Gigafactory later this year. And add to that the announcement from Pepsi that they’re expecting to be using 15 Tesla Semi electric trucks by the end of 2021. 5 6 Based on Elon’s tweet it sounds like we’re not going to be seeing any significant Semi production this year, but there’s still a chance we could see limited runs … but 2022 is the more realistic timeframe now.

The production delays will get resolved eventually, so let’s take a look at how well an electric truck, like the Semi, stacks up in other areas like cost. The expected price for the 300-mile range Tesla Semi is $150,000 and $180,000 for the 500-mile range version. And the reason many companies are excited to buy it even at that price, like Pepsi, is because of the expected $200,000 savings in operational costs … but I’ll get into that in a minute. 1

Besides Tesla, the top truck seller, Volvo Trucks America, is also developing a zero-emission truck. The Class 8 Volvo VNR Electric has a 264-kWh lithium-ion battery pack that can provide a driving range from 120 to 150 miles, and be charged up to 80% within 70 minutes. 7

VNR Electric 4x2 Straight
VNR Electric 4×2 Straight

They’re expected to start producing the VRN Electric this year. While it’s rated up to 33,200 lbs. and doesn’t have the same range as the Tesla Semi, it doesn’t need to. It’s a great fit for local pickup and delivery applications, coping with demanding routes with many stops utilizing a single charge. It has a different use case, but for those bigger loads, they do have more options coming, like 66,000 lbs and 82,000 lbs variants. For now we still have no prices. 8

VNR Electric 4x2 Tractor
VNR Electric 6x2 Tractor

Another company is Freightliner, a brand of the Daimler Group, which also owns several companies, including Mercedes-Benz. The Freightliner eCascadia semi truck is a 100% battery electric that can haul up to 82,000 lbs, with a range of 250 miles on a single charge. Its 475 kWh battery … another big boy … can be recharged to 80% in 90 minutes, and Freightliner announced that the eCascadia is entering in production in 2022. 9

eCascadia
The company is also developing the eM2 model, a medium-duty truck for lighter loads (26,000 to 33,000 lbs.) with a 315 kWh battery can go 250 miles. Unlike the eCascadia, this model already has an estimated price of $400,000, four times more expensive than the diesel-powered Daimler M2 it’s based on. 10 11 Yikes.

That much higher cost is a good transition into how they compare to traditional diesel versions. The best way to look at this is the exact way the companies buying them will: from the economics perspective. Let’s take the Tesla Semi as an example.

For our conventional diesel-powered semi truck comparison, we’ll use the 2021 Peterbilt 579 Sleeper. This truck features a 500 hp engine and costs $146,500, while the 300-mile and the 500-mile versions of the Tesla Semi cost $150,000 and $180,000, respectively. 12

Although the electric truck has a higher cost than a traditional diesel, it’s in the operation cost that we can see the real benefits. But, to start doing the math, we need to understand the baseline:

  1. According to the Federal Highway Administration, long-distance trucks can cover upwards of 100,000 miles per year. 13
  2. Semi-trucks get around 6.5 miles/gallon (mpg) on average. 14
  3. The current average price of diesel in the U.S. is $2.86/gallon. 15
  4. According to Commerce Express, a semi-truck can last 750,000 miles, but some can reach 1,000,000. 16

Considering a 6.5 MPG efficiency and an 100,000 miles per year coverage, we’ve got 15,385 gallons of diesel used a year. Since the current price of diesel is $2.86 per gallon in the U.S., that annual fuel cost is $44,000 ($0.44/mile). For some international comparison, in the U.K. where diesel is significantly more expensive than in North America, a liter of diesel there costs about $1.79, meaning $6.79 per gallon (I’m sticking with gallons and miles for the sake of an apples to apples comparison. Metric is the true measurement system … yes … but it doesn’t matter for this comparison.). This adds up to $104,462 a year for a traditional diesel truck in the U.K., giving us $1.04/mile! 17 A little over twice the U.S.

When Tesla unveiled the Semi, they stated that the annual energy cost will be half that of diesel, at $19,231 — but that statement was based on a price of $2.50/gallon for diesel, a bit less than the current $2.86. So that $19,231, with today’s diesel price, means a $24,769 savings in the U.S., which is a 56% reduction in cost annually.

Still, considering the current average cost of electricity (9.64 cents per kWh) and the annual energy usage of the Tesla Semi (100,000 miles or 199,489 kWh) we end up with a 1.99 kWh per mile. The cost per mile in the U.S. would be about 19 cents, while in the U.K., where the cost of electricity is 14.4p per kWh (¢19.7), the cost per mile would be around 39 cents. So a Tesla Semi in the U.K. would cost about $39,355.25, saving $65,106.29 on diesel. 18 19 That’s kind of nuts.

At the Tesla Semi unveiling, they presented a total operating cost of $1.26/mile against $1.51/mile for a diesel, but there’s more to operational costs than just energy savings. Usually when we talk about the benefits of EV over gas, yearly maintenance savings comes up as another area, but it’s not clear cut for a semi. If you factor in operation costs from Freightwaves Sonar to our calculations: 20

  • Driver’s salary and benefits: $0.78 per mile
  • Trailer Financing: $0.27 per mile
  • Repairs and Maintenance: $0.17 per mile
  • Truck Insurance: $0.10 per mile
  • Permits, Licenses, and Tolls: $0.03 per mile

Half of the recommended maintenance tasks for class 8 trucks aren’t related to the diesel engine, for instance tires are a major cost, so for the most part we have to consider that the electric trucks will have close to the same maintenance costs of a diesel truck. 21 Adding up all these expenses to the cost per mile for fuel and energy, we’d get a total operating cost of $1.79/mile for the diesel and $1.54/mile for the Tesla Semi in the U.S. And in the U.K., cost per mile would be $2.39 for diesel and $1.74 for the Tesla Semi. So even when factoring that maintenance might remain the same, electric still comes out on top.

Yet, one of the biggest questions that remains for electric semi-trucks is: will there be enough range day-to-day? According to the Hours of Service regulations of the Federal Motor Carrier Safety Administration (the good old FMCSA), truckers are only allowed to drive a maximum of 11 hours per day. Considering that a trucker will drive about 55 to 60 miles per hour on average, at the end of the 11-hour driving shift, this could add up to 605 to 650 miles per day. Of all the models we’ve covered, only the 500-mile Tesla Semi can come close to that. 22

But, electric isn’t the only option to get off fossil fuels. This is where I might get a little controversial for some of you: hydrogen. Some companies like Hyundai and Mercedes-Benz are developing hydrogen-powered trucks utilizing fuel cells. Fuel cells introduce hydrogen and oxygen to a catalyst generally composed of platinum, which starts an electro-chemical reaction that produces electricity, heat and water. The electricity is then used to drive the truck’s powertrain. 23 At the end of the day fuel cell trucks are still electric trucks and use batteries to manage energy generation and storage.

The big advantage of fuel cell trucks is that they can achieve a longer range without sacrificing payload since they have much smaller batteries, and hydrogen tanks can pack in more energy density. Not to mention the faster refueling times. Charging batteries usually takes hours, while filling up 120 pounds of hydrogen can be done in minutes. But there are some big challenges with hydrogen. Right now it’s more inefficient to use electricity to make hydrogen, which in turn is converted back into electric power for generating torque, rather than just filling up batteries with electricity from the start. In addition, hydrogen is primarily sourced from natural gas right now using something called steam reforming, so while it’s a zero-emission fuel when powering a vehicle, it creates carbon emission during hydrogen production … although less than using diesel. 24 25 But that’s starting to change with green hydrogen, which I have a video on if you’re interested.

Some examples of fuel cell semis come from Daimler, with the Mercedes-Benz GenH2 Truck that can travel up to 621 miles on a single tank, which is much closer to the range a trucker drives every day. They expect to start customer trials in 2023 and enter production sometime in the “second half of the decade.” 26 It’s pretty vague right now.


A more current example is Hyundai, which is testing heavy-duty fuel cell electric trucks (FCETs) in Switzerland right now and plans to start selling them in the U.S. in 2022. 27 Most of these companies seem to be ramping in 2022.

And before anyone starts chiming into the comments that fuel cell is stupid and takes additional infrastructure that doesn’t exist, neither path is has a significant leg up here. Electric trucks are going to require all new infrastructure too. Tesla’s Superchargers aren’t capable of delivering the massive power these battery packs will need for fast charging.

That’s why Tesla’s designed a new charger specifically for this purpose called the Megacharger, which will be much more powerful than the current Superchargers. In fact, Tesla and a few other companies are racing to produce a greater than 1 MW high-power charging standard for electric trucks within CharIN, which is the industry association behind the CCS standard. 28 29 30 Bottom line: there’s all new infrastructure needed to support battery electric trucks.

Both electric and fuel cell options offer viable solutions as diesel alternatives. Both require new infrastructure to support operation with either fuel cell stations or Megacharger installations near truck depots. So neither has an advantage there over the other, but unlike passenger vehicles, it’s easier to target those station locations because trucks typically have set routes.

With Hyundai already testing fuel cell trucks in Switzerland, and Pepsi testing Tesla Semis later this year, it’s clear that the age of electric trucks is coming … soon. 31 32 And the operational cost advantage of electric over diesel is going to drive adoption in a big way.


  1. Tesla Semi ↩︎
  2. 2019 Tesla Semi ↩︎
  3. Tesla Semi Will Have A 500-kWh Battery Pack ↩︎
  4. Tesla Model 3 ↩︎
  5. Tesla Semi may be delayed until 2022 due to battery shortage ↩︎
  6. Reports: Tesla Plans To Start Building 5 Semi Trucks A Week ↩︎
  7. Volvo Trucks leads electrification of North American trucking industry with commercialization of Volvo VNR Electric model ↩︎
  8. The Volvo VNR Electric ↩︎
  9. eCascadia ↩︎
  10. Daimler Trucks Delivers Its First Electric Freightliner to Penske ↩︎
  11. eM2 ↩︎
  12. 2021 Peterbilt 579 Sleeper ↩︎
  13. Semi Trucks: By the Numbers ↩︎
  14. Getting the Best MPG For Your Semi Truck ↩︎
  15. Gasoline and Diesel Fuel Update ↩︎
  16. 5 Quick Facts About Semi-Trucks ↩︎
  17. United Kingdom Diesel prices, 05-Apr-2021 ↩︎
  18. Average Price of Electricity to Ultimate Customers by End-Use Sector ↩︎
  19. Compare energy prices per kWh ↩︎
  20. INFOGRAPHIC: The Cost of Operating a Truck ↩︎
  21. We estimate Tesla Semi drivers will break-even 7 months ahead of Musk’s 2 years promise ↩︎
  22. How Far Do Truckers Drive In A Day? (Miles and Hours) ↩︎
  23. Hydrogen-powered Class 8 rigs: How fuel cell trucks produce electric power and how they’re fueled ↩︎
  24. Will Future Trucks Be Powered by Batteries or Fuel Cells? ↩︎
  25. Batteries Or Hydrogen For Big (Clean) Trucks? Volvo Group Bets On Both ↩︎
  26. Why the next truck you see may be a quiet, zero-emission hydrogen fuel cell rig ↩︎
  27. XCIENT Fuel Cell ↩︎
  28. Tesla Semi: 500-Mile Range, Cheaper Than Diesel, Quick to Charge ↩︎
  29. Tesla is working with mysterious third-parties to deploy Megacharger network for electric semi trucks ↩︎
  30. Tesla is pushing for its own >1 MW high-power charging standard for electric trucks ↩︎
  31. Hyundai plans to introduce HD hydrogen truck to U.S. by 2022 ↩︎
  32. 15 Tesla Semi electric trucks are expected to be delivered to PepsiCo this year ↩︎
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Matt Ferrell
Matt Ferrell lives in the Boston area and is a UI/UX designer by trade, but has always been obsessed by technology and how it works. In 2018 he started his YouTube channel, Undecided with Matt Ferrell, where he explores sustainable and smart technologies like EVs, solar panels, and smart homes.

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