That tesla truck is ugly!

You might be miscalculating the power used by these things. And it'd be better as a diesel genset, because who wants to try and get a big rig in car pumps.

 

A fully loaded, aerodynamically efficient semi uses about 160 HP at 65 mph on flat ground, no wind (based on Cummins data).

Take that number, subtract about 10% for recharging during down time (pit stops, reduced speeds, traffic, etc), and 70 continuous HP would cover roughly 50% of the HP requirement. So if you reduce the battery range to 300, and half of the operating power is provided by the generator, you are at 600 miles. Stop for dinner, load, unload, etc, while the genset charges, and you have another couple of hundred miles. Stop to sleep, and you have another 600 miles the next day, combined. I think it would work.

I agree that fueling gasoline would be a PIA, but for the sake of simplicity, reliability, cost and weight, a gas engine is tempting.

 

There's also efficiency losses in electrical generation, and conversion you'd have to factor in. Alternator efficiency is 55%.

 

oops, doiuble

 

Sure, there's engineering considerations. But whether it's 60, 70 or 80 HP is not really relevant. My Toyota Tacoma four cylinder generates over 150 HP. Whatever HP is optimal is well within the capabilities of a small automotive gas engine.

 

whatever creates the most profit is what will be around in the future, nobody cares about the future of humanity, at the moment the money is in big oil, good luck competing with that. unless warren buffet plans on turning all the pilots into charging stations big oil isnt goin anywhere, big money always wins.

 

Its a standard american truck ....
What do you expect????

 

Hi everyone. I just registered on this forum specifically because of this thread. There's a rather interesting intersection of worlds going on here because truck people usually aren't EV people and EV people usually aren't truck people, so each side has insights with things that the other does, and I figured it'd be good to learn from each other. For example, I could address a lot of the issues raised on this forum concerning batteries, range, EV drivetrains, etc - but for example I've never heard of, say, a PTO until I saw someone mention it here.

To cover some of the major things discussed concerning electric drivetrains and EV batteries here.

Range: Some people were referring to Tesla Semi as a 400 mile range vehicle. It's a 500 mile range vehicle. Nearly 2kWh/mi, nearly a MWh battery pack. The 500 miles is at 60 miles per hour with 80000 lbs gross weight. EVs are more speed-sensitive than ICEs (internal combustion engine vehicles). At 70mph, expect somewhere around 380 miles range with a full load. On the other hand, it works on both directions; ranges dramatically increase at low speed driving (even when start/stop driving is included). At a steady 25mph the fully loaded range will probably be at least 1000 miles, based on experience with smaller EVs. Start-stop driving will reduce this, but range will still significantly exceed highway range. Also, EVs do not idle. The climate control power is almost meaningless compared to the drivetrain power needed for a semi, and can essentially be written off. A megawatt hour can run a climate control system essentially forever We're talking nearly a month to drain a full pack.

Without a full load, range will also be dramatically increased over the base 500 miles. Cold weather, will, however reduce range. The exact details depend on the circumstances. For a Model S, you have a base 15-20% range loss in the winter. On top of that varying factors can lower it further: ice, wet roads, snow, headwinds, etc; driving in a blizzard against the wind, for example, you might lose 40% in a Model S. That said, things should be more favourable for the Tesla Semi, due to its pack's high volume to surface area ratio, high ratio of rolling to aero drag, and the proportionally insignificant power needed for cabin heating. A word of note: while steady-state power consumption is only about 15% higher in the winter, if you're driving a vehicle whose battery pack starts out cold, pack heating can dramatically increase initial power consumption. However, once the pack reaches its desired operating temperature, this consumption drops off dramatically; generally waste heat from the drivetrain on a good EV (such as what Tesla does, not what Nissan does) is far more than is needed to keep the pack warm.

A pack can be kept warm at all times when plugged in. If the vehicle is unplugged, it will let its pack get cold (but not cold enough to damage it - generally not below -20°C or so), in order to save power. One nice thing about EVs vs. ICEs is that there's never any trouble starting a cold vehicle. It just goes. However, acceleration will be reduced, and regenerative braking will not work until the pack rises to above freezing. Teslas have two settings for this: range mode enabled or disabled. With range mode disabled (default), it will use the pack heater to get it up to temperature as quickly as possible (but consuming power in the process). With range mode disabled, it lets waste heat heat the pack - saves energy, but takes longer to get power and regeneration back. Again, if the vehicle is left plugged in, this does not come into play.

One nice thing about EVs in the cold (or hot weather) is that they run their climate control systems without idling. You can remote preheat / precool the cabin with the app even if the vehicle is in an enclosed space, without worries of carbon monoxide building up.

Another issue that can affect range is mountains - but in an interesting manner. If you start at a high altitude and end up at a low one, it extends your range, while if you start at a low one and end at a high one, it decreases your range. It's normal to see a difference of 7-10 miles (greater or reduced) per 1000 feet climb/descent on existing Tesla vehicles. It should be somewhat more on Semi, since weight is a more meaningful fraction than aero drag. Note however that this only applies to where you start and end, as if you climb and then descend, you regain range. If you have to regen on the way down, you do have some recapture penalty (about 70% of the climbing energy recaptured), but if you don't have to regen, there's almost no penalty. Efficiency of electric motors doesn't change very much relative to how much power you're demanding of them (there are differences, but they're small).

Charging: as was mentioned, Tesla is expanding its current global Supercharger network to the new Megachargers. So that's 30 minutes to 80% (400 miles). This is very similar to the experience with supercharging, just at much higher powers. So to get into Supercharging. The lower the battery pack's state of charge, the faster it can take power. So "30 minutes to 80%" doesn't tell the full story. You could also say "20 minutes to nearly 50%".... but also "75 minutes to 100%". It's your choice how much you want to add based on how far it is until you plan your next stop. It's optimal to pull into your stop at as low of a state of charge as you feel comfortable with, because that gives you the maximum charging speed. Most people time their charging stops with meal breaks, so that they don't actually have to wait.

Connecting a charger is pretty straightforward. Tesla hasn't disclosed the sort of charge connector to be used; clearly it's not going to be the same as with the Model X, Model S, or Model 3, as it's much higher power. In order to keep the weight down for such high powers, they'll probably do some combination of higher voltages and/or liquid cooling. Tesla is also increasingly moving towards battery buffers on the chargers, which they'll almost certainly have to do with the Megachargers. The grid trickle-charges the battery buffers, which then surge charge the vehicle when it connects, so you don't need some absurdly powerful grid feed that alternates between "doing nothing" and "being heavily loaded". As a side benefit, it means that - during low traffic periods - you can still charge even during a blackout. Tesla also is very good about something that no other EV manufacturers are: there's always multiple chargers at each stop and they're very well monitored and maintained (most EV manufacturers only have one or two chargers per stop and don't maintain them well).

Battery pack: there's a lot of misinformation about battery packs, so it's important to into it here. First off, degradation. You can see typical Tesla pack degradation rates here - click "charts" on the bottom. Typical degradation is about 4% in the first year, then it slows down to under 1% in each subsequent year. Semi should be "roughly similar" - the vehicles will spend more time driving, which means more degradation, but it also takes a lot more driving time to go through a full discharge cycle on Semi, which means less degradation. Either way, degradation should not be a problem.

There's also a lot of myths about battery pack construction and environmental effects, so first, what are battery packs made of?
* Pack casing: typically aluminum
* Cooling: Water plus glycol coolant (basically: antifreeze). Sealed system. Tubing is plastic.
* Cell casing: aluminum
* Wiring: aluminum and copper
* Anodes: graphite (carbon) and some silicon (sand)
* Electrolytes: miscellaneous organic liquids, depending on the particular task (hydrocarbon-sourced)
* Separator membranes: plastics
* Cathodes: metal oxides. The mix Tesla uses in vehicles is known as LCA; the metals are 80% nickel, 15% cobalt, and 5% aluminum.
Lithium moves between the anode, electrolyte, and cathode (a relatively small amount compared to the battery mass)

The elements of interest deserve discussion on their own. I'll mention their prices so that you can get a sense of their rarity (compared to, say aluminum at $1.50/kg and gold at $41000/kg)

 

* Nickel is a commonly mined metal, about $12/kg. Despite the fact that most of the mass of the cathode is nickel, EVs are only expected to increase global demand by 10-40% by 2025; it's widely mined already for things like stainless steel. That's an important thing to remember, that *everything* we make today - even steels - involves mining. Nickel is often allergenic as a metal (although this is an oxide). Dusts and soluble nickel compounds can be toxic, but neither are involved in the batteries; like most metal oxides, they're not soluble (nor would anyone ever use a soluble battery!).

* Cobalt is a metal commonly found wherever nickel and copper are found, but in smaller quantities. It typically sells for around $50/kg. Most mines today do not recover cobalt; half of the world's supply comes from the Congo, where ores have the highest cobalt percentage. However, increased demand is not for the most part expected to come from Congo; it's expected to come from additional recovery circuits elsewhere (such as in the Sudbury area). Some concerns have been expressed about mining in the Congo; while over 80% of Congo mining is modern mines from international firms, the remaining is so-called "artisinal" mining, which means improvised mines with hand work; some of these are villages mining their own land, while others involve labour exploitation by third parties. In the past year there's been a big crackdown by cobalt buyers to keep artisinal mining out of their product streams; however, one can expect artisinal miners to try to disguise the source of their cobalt, and/or sell to less scrupulous buyers (such as in China). Cobalt properties are similar to nickel - toxic as dusts or when dissolved at significant quantities, but the oxides are highly resistant to dissolution. Much of the world's soils are cobalt deficient anyways (cobalt is an essential nutrient in small quantities for B12 production).

* Lithium is a light metal, commonly found as soluble salts ($10-15/kg). While a significant minority of lithium is recovered from spodumene mining, the majority comes from salars (salt flats with brine underneath). It's some of the most low-environmental-impact mining on Earth; brine is pumped up into evaporation ponds, precipitating out unwanted salts and concentrating the lithium, which is then sent for refining. Many of the salars flood annually, wiping out the drying ponds (you basically have to rebuild the mine each year, nature reclaims it). Essentially nothing but bacteria and sometimes salt flies live on the salars. As for lithium itself: while it is soluble, it's not very toxic, and more to the point, there's a lot of evidence that we consume too little lithium. It's naturally found in our drinking water, but the amount varies from location to location. Areas that have more lithium are associated with lower rates of depression, violent behavior, and a variety of neurodegenerative diseases; it appears to have a protective effect on the nervous system.

The rates of recycling on EV battery packs are expected to be extremely high. While battery packs used to be primarily limited by production costs, as the world moves more and more into mass production, they're increasingly raw material cost limited. The cathodes in particular are amazingly similar to natural high-grade nickel cobalt ore, so nobody is going to be throwing away big boxes of high-grade ore.

Motors: There's not too much to say about them. Earlier Tesla vehicles used induction motors, which have no permanent magnets. They're cheap and easy to make very powerful, compact motors, but they're not as efficient, and at prolongued high power usage can overheat in the rotor. Tesla's new motors (including those used in Semi) are permanent magnet motor. These use rare earth magnets, and are much more efficient, including having minimal rotor heating. "Rare earth" is a misnomer; rare earths actually aren't very rare. China cornered the market a few years ago via dumping (they have some excellent deposits), but they went too far - causing a price spike, which caused other mines to start to reopen elsewhere (including one in California). Recently Japan made a huge discovery on a small Japanese island, although it's yet to be mined.

If made poorly, a motor has no guarantee of a long lifespan. In particular, the early Tesla Model S motors all failed prematurely - not so much due to the motor itself as due to a bad bearing, which had been made with too tight of tolerances and was shaving metal into the coolant. However, properly made, an EV motor lasts essentially forever. Semi has 4 of them, and can drive even with three of them dead, and outpower a traditional diesel semi with 2 dead. Of course, you still have to replace any dead motors, but they won't leave you stranded. Tesla's focus on batteries has been "extreme mass production to bring prices down", and they're doing the same thing with the motors; these motors are the same motors that are being used int the Model 3 sedan and Model Y crossover. They should be quite cheap to replace. They're machine-made, not handmade.

Weight: Tesla hasn't publicly disclosed a detailed spec sheet. However, the battery pack should weigh about 4 tons, based on the energy density of other Tesla battery packs. The motors will add a couple hundred pounds each. There's no transmission, pollution control systems, or anything else; it's pretty simple. Climate control systems have nothing to do with the motors (excepting that Tesla can - but doesn't have to - route waste heat from them into the cabin; heat can be moved from anywhere in the vehicle, to anywhere else).

Environmental effects of power generation: We'll ignore Tesla's solar awnings over their chargers, as they provide only a small fraction of the power used at the charging station. We'll focus also only on the US grid. The US grid used to be overwhelmingly dominated by coal. This is no longer the case.



This doesn't tell the whole story. Almost no new power being added to the grid, as a percentage of the total, is coal; it's almost exclusively solar, wind and natural gas. Since EVs add incremental power to the grid, they're adding solar, wind and natural gas demand, and are effectively solar, wind and natural gas-powered vehicles.

Even when power comes from entirely coal, EVs can prove highly competitive with ICEs in terms of emissions, as power plants tend to be more efficient, transmission losses are low (6-7%), and EV batteries and motors are very efficient. Versus natural gas, however, it's no contest. Modern combined cycle natural gas plants can be upwards of 60% efficient, while a diesel semi with a peak efficiency of 45% might average 35-40% efficiency - burning a fuel that's much more polluting than natural gas, with poorer scrubbing than the power plant has, and emitting its exhaust at ground level by the roadside, while the power plant emits it at altitude in less densely populated areas. Marginal petroleum production meanwhile is getting dirtier, as "easy" sources (shallow, light, sweet crude in conventional reservoirs) gets used up, and more crude comes from sources like bitumen, deepwater, tight oil, etc.

As for the grid's ability to provide the power, a number of studies have been done on this, and the general conclusion was - for passenger vehicles at least - there already is enough capacity everywhere in the US except the Pacific Northwest. Electric freight vehicles will change the calculus, but it's beside the point, as nobody is going to swap out every vehicle for electric overnight. A transition will take decades, and thus be effectively a blip relative to the rate that power infrastructure is normally built (while decreasing the amount of oil infrastructure that has to be built during that timeperiod to maintain production).

 

Alternatives: I saw some mention of Nikola motors earlier. It should be mentioned that discussing Nikola Motors' plans is akin to discussing the Tooth Fairy's plans. This is an extremely capital intensive industry, and Nikola Motors has a meaningless amount of it. And they change what their plans are every six months or so. I would just ignore them except every now and then they get people to think that they're actually legit, so....

Sometimes hydrogen is discussed as an alternative, but it's a real nonstarter, for a number of reasons. A FCV averages about 1/3rd as efficient well-to-wheels as electricity, which is really a disaster. If you want to get that hydrogen from electricity, for example, that means *bare minimum* three times the cost (actually much more, as hardware to produce, compress and distribute hydrogen has to be paid for), three times the number of power plants, etc. Hydrogen can also be produced by natural gas reforming, but that's less efficient than just using the gas directly. Hydrogen tends to be far more expensive than electricity (which is an incredibly cheap form of propulsion) per mile traveled. Fuel cell stacks have worse longevity than batteries. FCVs still require large battery buffers (just not as large as BEVs). They have more moving parts. And then there's issues related to hydrogen itself.

Despite how proponents like to present it, hydrogen *is* explosive. Unlike gasoline and natural gas, which require very specific fuel-air mixtures to burn, hydrogen burns at almost any ratio in air (4-75%), and can explode at 18-59% mixing ratios. Some people point out that it rises rather than pooling at low points, but this causes problems in reverse; it pools under overhangs. NASA regulations require that any facilitiy that handles more than 20kg of hydrogen at once has to have a roof designed to be blown off in an explosion. Hydrogen that does escape destroys ozone. Hydrogen, due to its small molecular size, leaks through almost anything, and has the additional annoying property of embrittling metals that it comes into contact with. It also leaks *into* pipes over it, following them to their destinations and pooling there. Liquid hydrogen by contrast is even worse; if air contacts liquid hydrogen, it freezes out into a slush, which can detonate in a manner similar to high explosives. And speaking of igniting hydrogen, it ignites with less than a tenth the energy of gasoline vapours. Most electronic devices are not rated to suppress sparks that weak.

We're not even talking about the high pressures that you have to store hydrogen at here (higher than a scuba tank).

Speaking of safety...

Battery safety: Some types of li-ions are completely non-flammable. The NCAs that Tesla use do not fall into this category. They can and will burn if heavily damaged. Tesla compensates for this with a variety of means of fire suppression to prevent failures from cascading between cells, including:

* Physical isolation (barriers between cells)
* Active cooling (cycling coolant through)
* Passive quench (it takes a lot of energy to heat the coolant even if it's not moving)
* Ventillation

... and a number of other means. The same technology is used in Tesla Powerpacks; you can see what happens when you try to make one burn here (the short of it: it's really hard!). There have been cases of Teslas burning entirely to the ground without managing to set their battery packs on fire - example:



That said, in a bad enough wreck, if you mangle everything enough, all bets are off. Teslas have caught fire in accidents, and will continue to. However, the rate is approximately 1 fire per 100 million miles driven. The average rate of ICE fires in the US is 1 fire per 20 million miles, so Teslas have approximately 1/5th the rate of fires per mile traveled.

Subsidy: Not really related to the vehicles but a couple people mentioned this. It's not relevant to Semi; there will be no more federal subsidy program at that point in time. The current subsidy programme was not designed by Tesla, but GM; indeed, the maximum battery subsidy caps out exactly at the size of the pack of the Chevy Volt. Tesla does not get any money from the programme itself, although the discount certainly has encouraged EV buyers. That said, it's mattered a lot more to buyers of lower-end EVs and PHEVs (such as the Volt, Bolt, Leaf, etc) than to higher end vehicles like the Model S and Model X, since it's a fixed dollar value, not a percentage of the vehicle price. Tesla also got a federal loan at one point, but unlike some of the Big Three, paid it back in full. Years early. With interest.

I think I've covered the major issues raised... did I miss any?

Anyway, I'm really interested in knowing any "trucking specific" issues, as I have no background at all with trucking. I'd like to learn from you guys