Lack Of Tesla Semi Details Means It’s Time To Speculate

2 weeks ago by Sebastian Blanco 60

Tesla Semi Rendering

Tesla Semi Rendered By Peisert Design/Facebook

When Tesla CEO Elon Musk Tweeted about the upcoming Tesla Semi yesterday, he said the truck would be “seriously next level.” We, of course, want to know what that means. We can’t yet hack into Musk’s brain to figure that out, but we can try to make some educated guesses, and collect everything we know so far into one post. Here goes.



What we know for sure

Previous official messages from Tesla indicate that the semi will be a “heavy-duty truck” and Musk has said that the semi will necessarily need to have a pack over 100 kilowatt hours (kWh). We also know that Jerome Guillen is in charge of the Tesla semi program. Guillen previously was a Model S Program Director and worked at Daimler on the team that developed the Freightliner Cascadia. The closest we’ve come to an explanation about what the semi will do is this line from the not-so-secret Master plan part 2: “We believe the Tesla Semi will deliver a substantial reduction in the cost of cargo transport, while increasing safety and making it really fun to operate.”

What we can guess

This is where things get tricky. Speculations abound. And the best image we have is just a rendering (as seen above). But we can think about how an electric semi would be used to guess what might be in the works.

Tesla has a nationwide network of Supercharges installed, but they’re not at truck stops and they’re not fast enough to recharge a giant semi battery in 30 minutes. Still, this might not be a problem. With one driver, the charging time wouldn’t need to be all that fast, since drivers are required by law to take a 10-hour break after driving for 11 hours. While there are team drivers who have one person cozy up in the sleeper berth while the other drives, let’s speculate that Tesla will design its semi without a berth. This will reduce the weight of the cab and force the truck to stop every 11 hours. Now, if the things gets true, level 5 Autopilot, that’s a whole different story.

At a maximum speed of 70 miles, a semi like this would need a range of 770 miles. Since most trucks are limited to 65 miles per hour or less on the highways, 770 miles is probably too many. How big a pack would you need to have a range of many hundreds of miles? We’ll go with what some smart people are saying on Reddit, for example that, “680kWh should get us about 570 miles at 65,000 lbs, maybe 500 miles at 80,000 due to the increase in rolling resistance.” This is based on a log of assumptions, like how much weight will be removed when you don’t need the engine, fuel tanks, etc. and how much giant battery packs will weigh. Redditor tkulogo says that he, “suspect[s] 2170 packs will have about 250Wh/kg so a 3 ton battery should be around 680kWh.” In other words, for about the same weight as today’s diesel trucks, you might be able to get 500 or so miles from an all-electric truck. Is that enough?

Well, Teslarati has an interesting article up about the potential ROI of a Tesla Semi, and if it makes more sense for it to be a short-haul (under 250 miles) or long-haul (over 250 miles) machine. It’s the writer’s opinion that only the short-haul Tesla Semi makes sense:

“A battery-electric Tesla Semi would be nearly impossible for long-haul given the size and thus weight of the batteries required. So something involving very fast charging, battery swapping, or similar would be required. That adds costs to the equation that we cannot easily quantify without knowing what those logistics are.”

Lastly, while the Model S battery swaps have gone the way of the dodo, there’s no reason why it couldn’t be revived for long-haul semis.

And with that, let’s end the speculation and look outside of Tesla to see what we can learn.

Proterra electric bus operating costs chart.

Proterra electric bus operating costs chart.

The competition. Or, what else is out there?

There are two obvious next-gen, big vehicle companies to look at for hints are a new start-up and an established player that’s particapting in separate ball game (think baseball vs. softball, or football vs. rugby).

The established player is Proterra, which doesn’t make any semi trucks, but already has hundreds of all-electric passenger buses in operation today. So, we can look at what Proterra is offering to get a general feel for what might be possible with the Tesla Semi. The best place to start is Proterra’s 35-Foot Catalyst, which can be configured with a huge 440-kWh battery that charges in under 3.5 hours and has a nominal range of 251 miles. It weighs 29,000 pounds. It’s not logical to just apply those numbers over to Tesla, but for people who are used to seeing electric car numbers (75-kWh battery packs, for example), it’s good to remember that there are bigger – way bigger – EVs in operation now.

The start-up is Nikola Motors, which has explained its plan to dominate the highways of America with its long-distance, hydrogen-powered electric trucks. Sure, these semis will need H2 refueling stations (Nikola has a plan to build hundreds of them by the highways where they will be needed most), but the truck will also carry a 320-kWh lithium battery. The cab of the Nikola is one of the most impressive parts of the truck, and we expect Tesla to come up with something just as amazing (and probably without the giant door that seems designed to let all of the rain in).

Oh, and there’s also Toyota, which has started talking about a hydrogen semi project but hasn’t given out any real details. Whatever Tesla has cooking, it won’t have the zero-emission semi space to itself, it seems.

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65 responses to "Lack Of Tesla Semi Details Means It’s Time To Speculate"

  1. Alaa says:

    It will have solar panels.

    1. John says:

      I’ve thought about that too.

      But the typical 8 x 40 box trailer only has 320sq ft of solar panels. The panes on my roof are 18 sq ft each, putting out about 300 watts each. Assuming the ENTIRE roof of the trailer was covered in panels, end to end getting similar efficiency (unlikely, since they’ll be flat) That would only be about a 5Kw system. It would definitely run the lights, climate control, etc. But wouldn’t do much to increase range or recharge a massive battery pack. It would, however, be cool as hell. And that might be a good enough reason for Tesla to do it =)

      1. VazzedUp says:

        And the other issue being that often the trailer is not owned by the same company that the cab is owned by.

        1. Paul Stoller says:

          That’s true. The utility companies should look at starting a subsidiary that builds and leases “solar trailers” They would be cargo trailers with solar panels integrated into the roof of the trailer and batteries integrated into the floors. The trailers would gather power during the day and then could supply power at night when the trailers are docked. They own the power generation equipment but can make back some of the capital costs by leasing the trailers out to trucking companies.

          1. Mikael says:

            Or unicorn fart collectors…it would be about as useful.

      2. needa says:

        Can squeeze a little bit more than that. Long haul trailers are generally 48′ and 53′.

      3. FrackaWoner says:

        How about a rifer trailer with a separate battery and charging system to run the cooling system?

        1. Pushmi-Pullyu says:

          The advantage of a tractor-trailer rig is that any tractor can (in theory) pull any trailer. If you limit the tractors to using only specially built trailers, then the trucker would lose most of his business. Even trucking fleets using their own trailers would be reluctant to invest in this sort of thing, because if a trailer broke down on the road there would be no easy or fast way to get a temporary replacement.

      4. Taylor S Marks says:

        5 kW gives you an average of 60 kWh per day, right? If the battery is ~600 kWh, that means you get a 10% boost in range between recharges thanks to the solar panels. That sounds like it’s definitely worthwhile to me.

        The only reason you wouldn’t do it would be if they increase the weight by more than 10%, which I doubt they would. And having them tilt to face the sun at all times would further increase efficiency.

        Actually… as I’m thinking more about this… would you adjust schedules to maximize the time you’re driving right under the sun? IE, you time when you leave heading East to West to maximize the how much noon sun you get? As I recall, XKCD’s What-If has done a question like this before… I think they found you could increase how long you’re exposed to the sun by a few minutes at highway speeds near the equator…

        1. ModernMarvelFan says:

          “5 kW gives you an average of 60 kWh per day, right?”

          No. it doesn’t.

          Typical Solar generation is averaged on per day for a best case of 7 to 8 hours… It will be on for about 12 hours, but no way to generate at peak hours for 12 hours.

          So, more like 40kWh at best (near equator, completely clean panels and absolutely clear day).

          1. HeisenberghtNUTS says:

            First let me state that I really like to see that we all have finally come the looooong way to see the “solar panels on the roof” idea pop up as the first response! (great job Alaa!)

            Furthermore it’s great that the idea is not simply ridiculized by those responding but finally we can discuss the numbers! (imagine that 3 to 5 years ago… )

            Let’s be conservative and say it can add about 30 kWh on a good day. I think everyone should be OK with that. Still we have to remember that there can be days without sun, so the bonus range will be nothing the operator would rely on. Nonetheless 30KWh would be more than 5% for a short haul semi.

            If we can reduce battery weight by 5% we would be happy, wouldn’t we?

            If we could reduce load stress on the battery we would be happy, wouldn’t we?

            If we could easily add a cheap and clean range extender for unexpected cases just as a insurance measure we would happily do it, right?

            There may be drawbacks but at the low cost solar cells now are at and at the low weight they add if incorporated properly and given the fact that solar city is now part of Tesla and with all the good connections to panasonic it really should not be the question if solar cells will be on top of the semi, but how many they can fit at which price.

            (many, low)

            Topic closed.

            Now we can happily move on to ultracapacitors and regen.

            1. Alaa says:


              The Swiss have been doing that for some years now.


              It is in German but maybe you can translate it. Some time back in time I read that the solar give 25%. I can’t find it now, but it makes sense. I would not depend on it but
              every little bit helps.

              Here in Egypt in theory at least trucks are not allowed to drive at night. Or maybe this was a law and no longer a law. It was to limit the number of hours a driver can drive. At any rate 10% or more increase in range is a good thing. As the efficiency of cells get better who knows. Maybe one day these trucks will run forever on the sun. The Pharos worshiped the sun, now I understand them. We have 3400 sunny hours per year in Cairo and 4500 in Aswan.

              As for the ultra capacitors, I used to think that they are of value but now not so much so. You see if we look at the voltage of the Tesla 100 D you will find that because the voltage is high then the amps taken or given is very little per cell. The capacitor has no added value here. In fact it adds complications. It self discharges and then we have to find a way to use that energy from the caps only. I don’t think it is worth it.

              1. HeisenberghtNUTS says:

                “It is in German but maybe you can translate it.”

                No need to translate, I read german, English, Spanish and even French if I need to…

                “The Pharos worshiped the sun, now I understand them”

                That’s a nice point to think about. Ancient civilisations have quite a lot of things to learn from. Unfortunately a lot of knowledge got lost, some of it intentionally, some of it by accident.

                In fact I think that storing information via hieroglyph was partially smart because it is easy to get the basics, but really hard to understand the more complex systems.
                With all the emoticon stuff going on, I wonder if our grandkids will end up with no
                Understanding of letters. It really seems to be some kind of circle.

                If we (humanity) can this time find a way of distributing knowledge and power in a smart and fair way, we could be heading into a really bright future.

                Personally I can not imagine any reason for war once ALL people on earth live in good condition. Now is the best time to reach that goal. Solar is getting cheap enough, to be owned by people in really poor countries.

                Once electricity is affordable, water can follow and last but not least knowledge. Never before in history it was so easy to get and share information. Never before it was so easy to communicate worldwide. We should not take it for granted, we better use that power to create a safe place for our children.

                Sometimes we get distracted by all the negative news on TV or google news, while at the same time really miraculous things are happening all around the world all day every day.

                I enjoy this website, cause it is positive news 98% and it is nice discussion in an ever growing, more and more international community.

                All of you guys go out and spread the word : power (solar) to the people!

      5. Robert Vallentyne says:

        Don’t forget the truck sides. Each side is larger than the top by quite a bit. My guess by is 50%. That would mean a 20kWh system is possible, although it would not all by working at once. Still my 5kWh system produces almost a megawatt of power per year, and I suspect 20 kWh hours on a truck trailer might produce 2 megawatts per year.

  2. Bill Howland says:

    The cost analysis from Proterra is obviously going to favor them…..

    It will of course depend on When and WHERE the charging facility is and what Utility it has to suffer under.

    1. georgeS says:

      I agree Bill H.

      I’m thinking that Musk will just put in a nationwide charging network for their Semi’s.

      The question is how big a battery pack is the right one….and how far apart do you space the chargers.

      Nobody has built a semi w/ regen. I’ve always thought all trucks should have that.

      I bet Tesla has a pretty good handle on the numbers. It will be very interesting to see what size packs these big trucks have!!

  3. jamcl3 says:

    The initial target market is probably port operations, likely in California. There have been massive electrification efforts in ports, everything from “cold-ironing” the ocean vessels (turning off diesel generators in port and requiring the ships to connect to shore power) to electrifying the cranes that load and unload the ships. This is just another step. The port of LA/Long Beach has terrible air quality problems and most trucks serving those ports do not go very far.

    1. georgeS says:

      I’m thinking they will set up a route between the giga facory and Freemont.

      Maybe 1 or 2 truck Super chargers on the route.

      Stations all equipt with batteries to keep demand charges down.

      1. ModernMarvelFan says:

        Why not just hyper loop that route instead?

        Way faster and don’t have to worry about weather conditions over Sierra Nevada.

        1. The first Tesla Semi’s would likely be hear first, for one.

        2. Someone out there says:

          Because hyperloop doesn’t exist yet and maybe never will

    2. Pushmi-Pullyu says:

      “The initial target market is probably port operations…”

      A BEV “yard mule” tractor is one niche already being served by BEV semi tractors, and it’s the only place you’ll find them being used for a practical purpose. That is a niche for BEV semi tractors which run at low speeds for short distances. You can tell that at a glance, because they are built with no streamlining whatsoever.

      But BEV “yard mule” semi tractors are a niche that is already served by multiple manufacturers, so I doubt Tesla is going to try to enter that market.

      No, I think Tesla has a more ambitious goal: An actual highway-capable BEV semi tractor. As Teslarati noted, it will likely be aimed at short haul routes of <250 miles. It might be possible to sell one at a cost-competitive price within a few years, after battery costs come down some more. I doubt even Tesla could sell one at a competitive price with today's battery prices, which is why I am predicting that Tesla will show only a concept vehicle, not a production-intent one.

      1. przemo_li says:

        Nobody in that market look solely at the price.

        Total cost of ownership.

        Diesel fuel is expensive. Maintainance is expensive.

        Semi can be costlier to operate even if it’s sticker price is competitive.

        1. Pushmi-Pullyu says:

          Replacing a 1000-2000 kWh battery pack every few years will be quite expensive, too. Why do you think that FedEx and UPS haven’t yet converted their trucking fleets to BEVs? Because the batteries are expensive to buy and expensive to replace.

          A typical passenger car is used only 5-10% of the time, so a properly built battery pack (which does not include Leaf packs) can be expected to last the life of the vehicle. Contrariwise, a commercial truck is expected to work many hours every day, and that will likely wear out those very expensive battery packs within just a few years.

          TCO (Total Cost of Ownership) does not favor the commercial heavy BEV truck… yet. Give it a few more years and further reduction in battery price, and that equation hopefully will change.

  4. Leeper says:

    How about the entire trailer is a giant single row battery pack. Solar paint (CIGS) on the top and sides to generate a small amount of energy cheaply.

  5. Dan says:

    Dedicated Short haul where distances are fixed and routes are known basically a City truck is the only application that seems to make sense for battery-electric Freight moving at this point with current battery technology

  6. darth says:

    Majority of truck routes are short haul. These will be short haul trucks. Think distribution center to local stores. Lots of stops, starts, urban driving. Battery swapping, ginormous batteries or solar panels on trailers make no sense.

    Also that rendering is terrible. It will be low drag. Wonder if they will also supply trailer tails for drag reduction on the rear end?

    1. Pushmi-Pullyu says:

      “Majority of truck routes are short haul.”

      But not semi trucks; those are mainly used for long haul trucking. Local deliveries are made mainly using smaller trucks.

      However, there is one important exception: Most deliveries to supermarkets are made by semi trucks, which means there would be at least a small market for short haul semi tractors, if one could be built at a competitive price. With today’s battery prices, that’s a big “if”!

  7. RaVOLT Australia says:

    Tesla have a gas turbine patent do they not? Also, the PV suggestion is assistive and effective, particularly if you consider Spectrolabs terrestrial cells at 40% efficiency and the the new theoretic limit of PVs was raised from 44 to 85% a few years back due to broad spectrum capture.

    1. Pushmi-Pullyu says:

      “Tesla have a gas turbine patent do they not?”

      No. That was an April Fools’ joke.

      The Nikola startup was promoting the idea of a gas turbine powered PHEV semi tractor, but sadly they switched to the wholly impractical technology of “fool cells”. 🙁

  8. David Foulger says:

    The Capstone Turbine Microturbine will be an integral part of the long-haul electric 18-wheeler. The battery pack can be smaller as batteries can be recharged while under way. Cheap natural gas will be the fuel although diesel can be used. Nikola One originally was designed with the Microturbine concept and that makes sense because fueling stations exist for natural gas and diesel. Also, Walmart’s WAVE 18-wheeler is equipped with the Capstone Turbine Microturbine.

  9. Pushmi-Pullyu says:

    From the article:

    “…based on a log [sic] of assumptions, like how much weight will be removed when you don’t need the engine, fuel tanks, etc. and how much giant battery packs will weigh. Redditor tkulogo says that he, “suspect[s] 2170 packs will have about 250Wh/kg so a 3 ton battery should be around 680kWh.” In other words, for about the same weight as today’s diesel trucks, you might be able to get 500 or so miles from an all-electric truck.”

    I call B.S. There is no way a battery pack which will power a loaded semi tractor-trailer rig at highway speed for 500 miles without using a battery pack which is significantly heavier than the diesel powertrain it would replace.

    I’d like to see a list of the premises which produced that conclusion; I suspect it contains “a log lot of” overly optimistic assumptions and/or unrealistic figures.

    My own “napkin math” analysis is reproduced below (with an update), with premises and assumptions clearly spelled out, for those who haven’t read it and those who want to see how I’ve tweaked it.

    * * * * *


    (revised April 14, 2017)


    A modern diesel semi pulling a load gets 6.5 MPG; therefore uses 0.1538 gallons of diesel per mile

    1 gallon of diesel contains 40.7 kWh of energy

    1 gallon of diesel varies in weight between 6.85lbs. and 7.5lbs per U.S. gallon, depending on temperature. (I’m going to use the figure of 7.1 lbs/gallon)

    diesel semi typical engine weight 2880 lbs

    Eaton Fuller 18-speed transmission weight 738 lbs

    Tesla Roadster upgrade battery pack: 70 kWh in ~10 cubic feet

    standard sized semi trailer dimensions: 110″ high x 96″ wide, or 9.167′ x 8′

    DOT weight limit for a six-axle semi tractor-trailer: 80,000 lbs

    Typical price of a relatively high-end new semi tractor: $150,000

    Typical trucker may drive as much as 600-700 miles in a day, and can legally drive up to 11 hours per day.

    * * * * *


    What we need is a BEV battery pack for our semi tractor which will allow it to pull a load for ~750 miles. This should allow the trucker to complete a daily run on one charge. We assume at the end of the run either the battery pack is swapped out for one that’s charged up, or the pack is charged during the hours the trucker is sleeping. Either way, we avoid the need for fast charging and very high current.

    Our hypothetical BEV semi will have an energy efficiency 2.6 times that of a diesel semi. (An EV car is about 3.5 x as energy efficient as an average gasmobile, but diesel engines are about 30-35% more efficient than gas engines.)

    Therefore, our BEV semi pulling a load needs (0.1538 x 40.7 / 2.6 =) 2.4 kWh of energy to run 1 mile.

    Estimated weight of a 2016 Tesla battery pack using 18650 cells: 11.5 lbs / kWh

    Estimated price for a Tesla battery pack (not just the cells): $180 / kWh

    * * * * *

    We need to look at three limiting factors for the BEV semi tractor’s large battery pack: Space, weight, and cost.


    The space behind a long-haul trucker’s cab, the space now devoted to storage and sleeping space, is about 4.1 feet long, at least on the diagram I looked at; I’m assuming the height and width are the same as a typical semi trailer. (At least, the dimensions should be close enough for this ballpark estimate.)

    Let’s use that space for the battery pack. I don’t see losing this space as a problem. Since we no longer need a long nose for the diesel engine, which isn’t there, we can shove the cabin forward, and leave room for the battery pack behind. The tractor now looks more like a “cab-over” tractor with an extended space behind the cabin, rather than a long-nose tractor.

    So I estimate that space at 4.145 x 9.167′ x 8′ = 303.977 cu.ft.

    An upgraded Tesla Roadster’s battery pack has 70 kWh and measures ~10 cubic feet.

    Assuming a similar configuration, that gives us (303.977 / 10 * 70 =) 2127.8 kWh.

    At 2.4 kWh per mile, that’s 886.6 miles.

    This is comfortably beyond our needs of ~750 miles.

    Space isn’t an issue.

    * * * * *


    Weight *is* an issue, altho perhaps not a deal-killer.

    At 2.4 kWh per mile, enabling a range of 750 miles requires our BEV semi tractor to carry a (750 x 2.4 =) 1800 kWh battery pack. At an estimated 11.5 pounds per kWh, that’s 20,700 lbs. We save just a bit by losing the diesel drivetrain; maybe 3000 lbs or so. We also save half the weight of the fuel*, which for a trip of 750 miles (using ~115.35 gallons) would be approximately 409.5 lbs. (We could also subtract the weight of the transmission, but then the EV motor, inverter etc. do weigh something, so let’s assume that cancels out the 738 lb transmission weight.) This brings us down to an estimated ~17,300 lbs. That’s 21.6% of our maximum weight limit of 80,000 lbs. And note that various State laws may reduce the maximum weight even further, depending on what States our long-range truck travels through.

    Now, that’s not to say this makes the idea impractical. It may well be worth sacrificing some shipping capacity as a tradeoff for lower cost per mile of moving the freight. But it does limit the market for our BEV semi a bit, or perhaps more than a bit, depending on what the customer’s needs are.

    *We can only deduct half the weight of the diesel fuel, because that weight will disappear over the course of the day’s trip. Now that’s assuming the driver starts with as much fuel as he needs for the entire day’s trip, which may or may not be correct. So far as I can find by Googling, there isn’t any standard size for semi tractor fuel tanks; one source says they range from 100-400 gallon capacity, and I see a reference to 2 x 150 gallons as a typical size. So then, it appears reasonable to assume ~115 gallons is carried at the start, with no stops for refueling for the entire shift.

    * * * * *


    Cost for the battery pack is the real issue here. And that cost is almost certainly why, for example, UPS, FedEx, Wal*Mart, and other companies with large trucking fleets have not already started switching to heavy BEV trucks.

    That 1800 kWh battery pack, at $180 / kWh at the pack level, will cost an estimated $324,000. And that’s Tesla’s estimated cost, not price, so you can likely add another 15-25% to that. Note a reasonably high-end diesel semi tractor costs $150,000, so adding that battery pack is more than tripling the cost. With a 20% markup, it’s $388,000, which is 259% of the diesel semi tractor’s $150,000 price. Sure, Tesla will save some money by using an EV powertrain instead of the much more complex, and more expensive, diesel powertrain. But as a percentage of the price of that battery pack, I doubt losing the diesel engine, exhaust, etc. etc. will make much of an impact on price.

    There is also the matter of battery life. A Tesla battery pack may be expected to last the life of the car, but the typical car is only driven about 5-10% of the hours in a day. Contrariwise, a long range truck is expected to be on the road as much as possible. A truck just sitting around still has to be insured, and the owner still has to pay all those fees for a heavy commercial vehicle. A truck just sitting around is losing money for its owner.

    So we need to ask: Just how many times will that very expensive battery pack have to be replaced, over the lifetime of the truck? A semi truck is expected to last an average of 20 years, significantly longer than the average life of a passenger car. Will the truck save enough on fuel costs to justify the amortized cost of buying replacement packs?

    That’s a subject beyond the scope of this analysis.

    * * * * *


    Several people responding to this “napkin math” analysis have pointed out that if we assume the driver only drives for half a shift, then uses either battery swap or fast recharge while eating lunch, then this will allow us to use a battery only half the size, weight, and cost. This of course allows us rather more optimistic assumptions. We’re not sure how realistic it is to think that a trucker would always stop to eat lunch at a battery swap station or a BEV truck stop, but let’s do the math anyway.

    First, we will assume a 60% battery pack size, not 50%, because there needs to be a least a bit of flexibility in what time the driver eats lunch and how far he drives before stopping in mid-shift.

    60% battery pack size weighs 12,420 lbs. Losing the weight of the diesel engine and the diesel fuel saves approx. (3000 + 204.75) ≈ 3200 lbs, totaling 9220 lbs, which reduces the 80,000 lb. carrying capacity of our hypothetical BEV semi tractor-trailer rig by 11.53%, which makes this a much more optimistic scenario!

    1. HeisenberghtNUTS says:

      Let me summarize:

      Tesla should do whatever they can to reduce battery size needed.

      Recharge possibilities
      Drivetrain efficiency
      (and if they really need to swap stations, aaaargh!)

  10. Pushmi-Pullyu says:

    “Teslarati has an interesting article up about the potential ROI of a Tesla Semi, and if it makes more sense for it to be a short-haul (under 250 miles) or long-haul (over 250 miles) machine. It’s the writer’s opinion that only the short-haul Tesla Semi makes sense…”

    I think that’s the most likely scenario. I am pretty sure what Tesla will show only a concept vehicle, not anything intended for production. But even at that, I can’t see them building a BEV semi tractor with the range needed for an entire day’s travel for long-haul trucking; 700-750 miles. Nor even 500 miles; the cost/benefit analysis doesn’t support that either.

  11. Wouter says:

    Why not a tractor-sharing concept?

    If you keep your trailor but swap the tractor every time it needs recharging you can keep the cost of the tractor low.

    Ok for Tesla it means a big investment in the tractors, the space to park them and the new infrastrucure to charge.

    1. Pushmi-Pullyu says:

      One hypothetical engineering solution for long-haul BEV trucking is battery swap stations along fixed routes, where the trucks would stop at lunch time and at the end of a driver’s shift to swap out the battery pack.

      That would require that every semi tractor has to have two very expensive battery packs, making an already strong economic disadvantage (i.e., BEV heavy trucks cost more than comparable diesel heavy trucks) even worse. Your suggestion would replace swapping battery packs with swapping the entire tractor, which would be even more expensive.

      Trucking fleets (and independent truckers) have to pay a lot in annual road use fees and taxes on their semi tractors. They don’t like a tractor sitting around unused for much of the day, because they still have to pay all those fees and taxes.

      A semi tractor that you can’t use for half (or even a third) of every 24 hour period isn’t going to attract a lot of buyers.

      1. Wouter says:

        Maybe my idea is not legally interesting.

        I assumed that the ownership of a truck (the tractor) could be part of a lease/car-share system. By that I mean the owner would own the right to use a working tractor not necessarily always the same tractor. I bit like the battery swap for model S. You do not need to know which battery you have, you just know it works and it’s fully charged.

        Maybe my idea works better in a Western European context where companies own most trucks and the drivers get a tractor appointed for a specific job.

  12. Alan says:

    Here in the UK they have been testing induction charging on a motorway (Freeway), I wonder if this could be possible to help extend range in Semi’s ?

    1. HeisenberghtNUTS says:

      In Germany they also have something going on in that regard:

      I really hate the aesthetic of that solution but as long as it works out I’ll be OK with it.

      Maybe on the way from gigafactory to Fremont Tesla might be able to find one or two stretches of highway where no one cares about aesthetic and just put up those ugly stuff.

      If by that measure they can reduce battery size by about 25% it could be more cost effective than bigger batteries or supercharger stops.

      Maybe they want to put it on uphill downhill stretches, that way regen from downhill trucks could add power to uphill trucks

      (to make that work obviously we will need a fleet of Tesla semis big enough to make sure that everytime one travels downhill another truck goes uphill, so I guess this option will still have to wait… Nonetheless the uphill downhill solution would also be helpful to move battery stress to grid stress…)

      I really have problems with the battery swap concept (which imo is that kind of bridge technology we have to use until better solutions are available), and therefore prefer on the fly concepts.

      Be it solar, wire or wireless. Or maybe even both 😉 of the three.

    2. Doggydogworld says:

      Korea has a bus loop with inductive charging. But I like Honda’s system, which puts wires in a standard guardrail. One mile of wires every 25 miles keeps infrastructure costs low.

      Cheap, lightweight autonomous trucks with 200 kWh batteries could go coast-to-coast non-stop with 100 miles of range for local delivery. Cost savings vs. current trucks would be massive.

      Cars can use the same system, of course. 3000 miles in a Leaf? No problem!

  13. JH says:

    I did some calculations on this for the european market (yes. I am an Engineer). And arrived to a optimum battery pack of about 750kwh. European truck can be as heavy as 60 tonnes, and I added a bit of safety for bad weather conditions (cold and so forth). The targeted range where 350 kilometers. The battery size is curiously enough dependent on two more important factor the safe C for charging, and the charging time you seek. In the scenario I was after I sought a charging time of about 30 minutes, and it was calculated on the bio induced pauses along the way (food, toilet and so forth).

    It should be noted that I needed a power density of about 0.3kwh/kg in order to not adversely affect payload. Anything above that will increasingly favour the BEV. We should be more or less there now with the very latest generation of batterytech. It should also be noted that battery swap _could_ be sensible for _some_ routes in this scenario (many trucks runs along the same routes night and day, and for those a 5 minutes stop for battery swap could be easily done (without all the usual drawbacks of battery swapping which otherwise would occur). Battery swaps on large vehicles should also be considerably simpler than on passenger cars.

  14. sveno says:

    Here is what I posted to Arstechicas similar article about the Tesla Semi:

    “What I believe Elon could mean by “next level”:

    1. All-wheel drive. A motor between each axle, each with a different ratio fixed reduction gearing (Like on S and X). Superior ultra-smooth traction control (easy on EVs) – driver could even select a desired desired rate of acceleration depending on cargo.
    2. Fully autonomous. Driver optional.
    3. Autonomous powered trailers. Trailers have their own batteries, solar panels (alot of space for that), own traction motors so they can drive alone in the yard to park, load, charge.
    4. Remote control – in very tight or dangerous places the driver can come out and remote control the vehicle.
    5. Train mode – Semis drive in a very long row with only an extremely narrow gap between them as one logical unit to minimize drag. They swap places when the front-runner is running low on power. Only one supervisor/driver for the train.
    6. The “yard computer” will control all the vehicles and trailers for optimal productivity/space use etc – much like what Amazon is doing in their warehouses.
    7. It will be the most powerful road-going semi-truck in the world. Not because its necessary but because Elon 🙂 . Unlike ICEs, a bigger motor doesn’t mean significantly less efficiency as evidenced in Teslas other models. The cost difference will also be small to insignificant. If Elon has it his way it will be described as crazy-powerful. I mean megawatts of power.”

    Not saying that I believe they are ALL true however.

    1. Some Guy says:

      There is another one,
      8: It will be the only electric semi that one can use to haul several fancy ICE sportscars to the dragstrip. Then unload the ICEers just for show, but enter (and win) the competition with the semi (unless there are other Tesla’s there to compete).

  15. Someone out there says:

    The most sensible thing right now is to have a 50-ish mile battery plus overhead lines on the highway.

    1. Simon Mac says:

      Otherwise known as trains.

      I had a delivery from over 2000 miles away delivered purely* by electrified transport.

      Looking at the track and trace it went like this:

      – <100 miles to the hub in Italy by one of the city haul truck
      – Long haul by electrified train to the nearest hub to me in the UK
      – Onward delivery by another city haul truck.

      Rather than put up overhead lines on roads, put them up over the rail lines.

      At least in Europe this is another form of competitor to whatever Tesla's semi may be.

      (*some artistic interpretation required, while I know the delivering truck was EV, because I saw it, I don't know if the initial collection one was).

      1. Someone out there says:

        Trains are good but they require a rail and that isn’t cheap. Trucks are more flexible.

        1. sveno says:


          Both have their roles. Both are great.

          Even with the “Train mode” I mentioned above I meant it in a use case where trains are not an option – due to time, short distance or other criteria (I dont work in the sector).

  16. Eco says:

    Aluminum contains 8 kWh per lb.

    Phinergy has demonstrated a primary aluminum-air battery that extends the range of a Leaf by 1,000 miles (1,600 km) on 50 kg (110 lb) of aluminum.

    Phinergy also signed up with Alcan to recycle the aluminum hydroxide byproduct back into aluminum plates.

    It seems to be a perfect solution for long haul trucks with about 400 kWh Li-ion batteries and aluminum-air range extenders.

    1. sveno says:

      Wikipedia says its energy efficiency is in the 15-20% range. If thats true then its a horrible idea!

      1. Pushmi-Pullyu says:

        Hmmm, is it really that bad? I had read that a serious problem with rechargeable metal-air fuel cells (often mis-labeled “batteries”) is the poor efficiency, as compared to secondary (rechargeable) batteries. But even if it’s somewhat better, the 33-35% I think I’ve read elsewhere, that would still be a serious hit to the economic advantage of BEVs vs. diesel powered vehicles.

        On the other hand, if they can get them up to 33-35% energy efficient, that might well make them economically competitive with diesel power. Even at triple the cost, electricity is still considerably cheaper than diesel (on a per-mile basis) in many regions.

        1. sveno says:

          Wiki says their goal is to reach 20%! So the only thing going for it is that it could be sustainable and clean (hopefully one day) but what a waste of energy. Unless you live in Siberia and can could use that 80% that is turned into heat 🙂

  17. koz says:

    Reveal will not mean ready for production. Expect production in 2019 earliest, more likely 2020.

    -Fully autonomous
    -Bullet train lead shape
    -3 or more motors, all with different gear ratio and all with brake regen
    -Smoother underbody
    -All BEV, with @300kwh capacity, comprised of 3 distinct “packs” with separate charger and power electronics for each
    -3 outlets corresponding to each charger for 3x supercharging rate
    -Long haul trucking included

    Full autonomy allows for radical changes in design and makes a BEV more practical. Yes, more frequent stops but no rest needed. Current regulations limit human drive time, both in 24hr period an in one shot.

  18. tftf says:

    Daimler has a short-range truck (200 km, test specs not mentioned):

    I don’t see how a long-range semi-truck makes any sense using Li-Ion batteries.

    There would be need battery swaps or this makes no sense given weight.

    As a Tesla short (I added to my position above $300) I welcome them wasting resources on this project.

    Any other Tesla car project would make more sense:

    Model Y (M3 SUV variant), next-gen Roadster, small delivery van, literally ANYTHING.

    PS: Pricing these batteries is another huge issue, I didn’t even touch on that.

    1. koz says:

      Tesla’s mission is to supplant fossil fuel burning as quickly as possible. They know much better the limits of their technology than you or I do.

      1 long-haul semi = @50 average cars in annual fuel consumption

    2. Pushmi-Pullyu says:

      tftf said:

      “As a Tesla short (I added to my position above $300) I welcome them wasting resources on this project.”

      Give the Devil his due; at least Tftf is being honest about his motive and his desire in this particular comment.

  19. Tripp says:

    With the Hybrid Nikolal already set for debute/operations late 2018/19 at 1200 plus miles; all with onboard trucking/booking, Teslas market will need to be the short hauls.

    1. Pushmi-Pullyu says:

      If the Nikola startup sticks with the hydrogen powered “fool cell” technology that it has said it is switching to, then their vehicle won’t offer any significant competition to any mass produced Tesla vehicle. Or even negligible competition, for that matter.

      But then, I’m predicting that Tesla’s BEV semi tractor will only be a concept vehicle, not anything intended for production.

  20. SJC says:

    Focus on building cars and batteries.

  21. Serial anti tesla troll thomas says:

    Why is my post deleted about the Mercedes eTruck?

    1. Jay Cole says:

      Hey SATTT,

      I don’t see any comment in the holding queue (or deleted) in this thread on the Mercedes eTruck. I do see you posted on the project in a related thread (jump to your comment here):

      Elon Musk: Tesla Semi Truck To Debut This September, Pick-Up Truck To Follow

      Perhaps you got the two mixed up? Or maybe they were duplicates? Not sure, but I don’t see any logs in the system over the past 48 hours for a post of yours being deleted. But nothing is perfect, something may still have happened, feel free to repost.

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