11,000pounds for a battery implies 170Wh/kg. High end lithium ion cells can do about 300Wh/kg, and even with some overhead for the battery, we’re talking 250Wh/kg.. So… That’s beatable, & we can’t back out the weight directly from the energy of the pack as we know Tesla has been working on improving chemistry and specific energy and pack efficiency.
The vehicles that they delivered did not use all the available aerodynamics tricks that their prototypes did, and uses duals instead of super singles, so it also makes sense it’s only achieving 1.7kWh/mile right now.
Note that a ton of people claimed a 500 mile electric semi with a full load wasn’t feasible. This proves that it is. (The jersey barriers they pulled weighed about a standard 44,000pounds.) The Toyota hydrogen semi has only about a 300 mile range and with fuel an order of magnitude more expensive.
So if I read [1] right, some kind of average price for electricity used in the transport sector in the US as of September 2022 was 12.48 cents/kWh. That would mean that the 500-mile trip costs 500 * 1.5 * 12.48 / 100 = $93.6 in energy.
If that includes hauling tens of thousands of pounds of cargo, that sounds rather a lot like it would make transport powered by electricity commercially sane, right? Nice.
EDIT: I hadn't read the article much; it seems the current power value given is actually 1.7 kWh/mile, so that increased the price to 500 * 1.7 * 12.48 / 100 = $106.08. Not a huge increase, obviously.
> If that includes hauling tens of thousands of pounds of cargo...
That is the question. I am very curious if that includes cargo and if so how much weight. I suspect it doesn't include cargo. If it doesn't include cargo, diesel trucks will be far cheaper
If you're looking at historic fuel prices ($3/gal diesel [1]) and what modern trucks are getting (7-10mpg [2]) with loads. You're talking ~$150-$215 for a diesel truck. Plus you have fuel everywhere (less infrastructure costs), quicker refuels, easier repairs, etc.
The cold and time will also siphon off the efficiency of the battery powered trucks. Colder climates will see a 5-10% drop in efficiency in winter, and that'll grow over time. Making it less cost effective in northern climates.
The only way this truck makes any sense would be short-haul (single day round-trip deliveries) and government subsidies IMO. Plenty of market, but not quite where it needs to be.
You're talking about battery cells, but you need to look at the battery _pack_ energy density. The model 3 battery pack, which uses the same cells as semi, is about 170Wh/kg. The numbers in TFA are very reasonable estimates.
I already addressed that by including mass overhead for the overall battery. And sure, it’s always possible to assume more conservative numbers for a whole battery and assume Tesla DIDN’T do any engineering work to reduce overall battery mass, but that’s not something you should put in a headline.
(Tesla has typically done better than their peers in overall battery specific energy as well as energy per mile.)
Prettttty sure that's the case in the U. S. Are they taxed enough? There's a strong argument to say that they're not. But here's just one URL indicating that there is a tax on heavy vehicles: https://www.irs.gov/newsroom/truckers-must-pay-heavy-highway...
Seems like it would probably be a bigger win to put a 100kwh pack in and create a modular generator package. A lot of the polluting big rigs do is particulate matter when accelerating. Using batteries as the buffer between power generation and power consumption would do a lot of good.
Being able to run different kinds of small 20-80hp generators at their max efficiency RPM would be great. And if it were a reasonably sized module different folks could compete to make different highly efficient generator packages running on gas, diesel, CNG or LNG, ammonia, DME, hydrogen, ethanol, or whatever.
I think you are describing a hybrid. The power company at my previous location had hybrid rigs for working on high voltage [1]. There are also hybrid fire engines. [2]
Thats a series hybrid idea. they are already doing that, however, car industry has been exceptionally poor in making a efficiency optimized generator mostly because their R&D depts have been tweaking engines that operate over a big rpm range to send power directly to wheels. the design gets much simpler if you are making a high efficiency generator. recently companies like Aquarius have done some work on that.
That said, the main utility for hybrids is in stop&go situations where gas engine has to operate over a large RPM range and energy is essentially lost in stopping. In case of big rigs I actually agree that you need full electrification (or maybe ammonia/H2 engine IFF conversion efficiency to carrier is high). We 'just' need to get the battery energy density up 30-40%. Quite doable IMO.
There are a few startups that are doing carbon capture for trucks the closest to a market solution is probably https://remoracarbon.com/ they also have an interesting business model where they offload the CO2 and sell it off and have a profit sharing with the truck/fleet operator.
It doesn’t solve all emissions problems like NOx and other particulates but it’s a good step and likely we will be seeing both electrified trucks for short hauls and carbon capture for long hauls and for more efficient reuse of existing vehicles.
No? A hybrid powertrain is really expensive by itself, requires a more expensive-per-kWh battery pack, and has little efficiency advantage over an optimally geared Diesel engine in cruise, as it’s already running optimally.
And you’re only making a marginal improvement in CO2 emissions. All the synth fuels are much more expensive than electricity.
Right but even the 'diesel in cruise' is still less common than you'd think. There are hills up and down, there's passing, there are bridges, headwinds and tailwinds, etc. Required power is different if you're fully loaded vs partially vs empty vs no trailer. Even on interstates there are towns every 50-100mi that have their own traffic and thus non-cruise speeds.
If the exception to cruise is only 0.1% then I agree it's dumb to consider. If it's 10% or more and the emissions during non cruise are significantly worse, it could end up accounting for 30-40% of total emissions instead of just 10%
So, a hybrid truck? You can just buy those from Volvo or Scania right now. The problem is it does nothing to gratify the ego of America's foremost megalomaniac.
Hot swap and multiple sizes (weights) of battery would be very killer features.
Fleet vehicles like this are exactly where it makes the most sense to have a stop and swap strategy for refueling, especially when so much energy needs to be transferred at once. Though that is lessened by the size of the battery since they could argue it gets recharged during a mandatory rest period.
Is it really a problem ? I mean, apart from the quantity of lithium needed to create this « enormous » battery, is weight a real limitation factor ?
We currently have no info on the full truck weight but I am sure Tesla found ways to optimise weight everywhere else. Mechanical components for a 1000000 miles rated vehicle are heavy and without a gearbox and a crankshaft, I assume the rest of the truck is lighter than its gas counterparts. I am no expert so maybe we are dealing with other orders of magnitude.
Anyway, would this impact the maximum cargo weight ?
> ... but I am sure Tesla found ways to optimise weight everywhere else.
This is kind of a "the entire industry is dumb" assumption.
I mean, sometimes industries are dumb, and there are certainly people driving oversized vehicles on the road right now, but if you can find places to optimize vehicle weight outside of the engine/transmission/fuel you're replacing with batteries/motors, that applies to regular old semi-trucks; if you can make a semi-truck weigh 5000 lbs less without compromising on its design parameters, you can make every other semi-truck on the road more fuel efficient and save like 6% of your fuel costs, while also allowing you to haul bigger loads than competitors' trucks.
Everyone making semi-trucks is interested in that, not just Tesla.
Everybody else is using a chassis designed for ICE, so something that handle a vibrating 5000 lb engine, a vibrating 1000lb transmission and can hang 2000lb in fuel. They then need to add reinforcement to hang a 10,000 lb battery.
I'm fairly confident some of the rest of the industry could get a comparable weight if they started from scratch and they optimized for EV only. But that's two assumptions that don't currently hold.
Though I only gave it a quick search and it seems annoying difficult to find straightforward spec sheets for semi tractors like you can for any piece of CAT equipment, [0]"As we highlighted above, there are several ways to measure a semi-truck’s weight, and the maximum legal weight for a fully-loaded semi in the United States is 80,000 pounds. The lowest unladen weight is roughly 25,000 pounds, but will typically be closer to 35,000."
So, 10,000+ pounds for the power pack alone is a sizable chunk of the maximum allowable weight, and could potentially eat into the allowance for cargo, more so for restricted routes like older inner city bridges with tight weight limits and the like.
Tesla does get a small buffer for the battery size, due to EV trucks being allowed 82k instead of 80k lbs max.[0] Doesn't save the entire extra budget though.
> NGVs and PEVs may exceed the federal maximum gross vehicle weight limit for comparable conventional fuel vehicles by up to 2,000 pounds (lbs.). The NGV or PEV must not exceed a maximum gross vehicle weight of 82,000 lbs. (Reference Public Law 116-6 and 23 U.S. Code 127(s))
The Youtube channel Engineering Explained went over the Tesla Semi, and the weight of the EV cab should be pretty similar to an ICE cab. Also EV trucks are allowed another 2k pounds.
"Also EV trucks are allowed another 2k pounds" - Ah that explains the 82,000lbs mentioned in the Tesla demo. Max weight for conventional trucks is 80K.
There were about 10-12 concrete barriers as load in the demo each weighing 39,000lbs. So the weight being carried is around 40ishK lbs. So rough approximation - half the weight of the truck is load and half is the truck itself.
Speaking as a former shipping and receiving guy, well, yes. It suggests some 11,000 pounds less capacity on a standard semi, which are highly regulated as far as maximum weight/mass goes.
A semi weighs between 10,000 and 25,000 lb. A semi's ICE engine weighs around 3,000lb.
I don't work in the industry. I just observe three things:
1) the weight variance of a semi encompasses the amount imputed to the battery
2) 3,000lb of weight can be saved by not having a diesel engine plus another 2,000lb not having fuel. (Both of which will be in the total gross weight of the semi) some of which will of course be replaced by electric motors.
3) it's a speculative weight. It might also not weigh that much. Might is doing a lot of heavy lifting.
A fourth point: trucks routinely travel partly empty because of weight distribution issues. Not every TEU is full.
Logistics is fascinating. TCO is the closest most computer scientists get to "how can owning a Mac be cheaper than owning a Windows PC" but logistics does this almost every sum. Weight and carry capacity may not be the sole deciding factor here when a semi is worth $500k and has a 2nd hand value and is a finance decision with tail costs and operation costs.
You can make some of that back by the removal of the engine and fuel (though you still need something akin to a motor and perhaps a transmission). Likely parts of the truck will have to be converted to aluminum - perhaps the trailer itself.
A full semi can have 300 gallons of diesel which itself is about 2000 pounds, so we're down to a 9,000 pound difference.
And some percentage are short haul, which are often not even near to fully loaded. Could be as high as 40-50%.
Except the vehicle has made weight reductions elsewhere, including engine, transmission, emissions control, fuel tank, etc. A typical useful payload is around 44,000pounds still keeping under the 80,000pound limit, and the Tesla Semi was able to do that (electric trucks are allowed ~2000pounds extra).
I wonder if this will lead to increased or decreased quality of life for truck drivers. The UK and EU are still aligned on truck driving rules for the time being. In the UK, trucks are limited to 60mph on the motorways which means there's a theoretical max limit of 540 miles a day on a standard day or 600 miles on an extended day. It's also mandated that you have to take at least 45 minutes rest every 4h 30 minutes which I imagine should be sufficient time to charge the vehicle to get the extra 40 - 100 mile range so I don't think EU drivers would really be impacted at all. It may have more of an effect in other countries which have higher speed limits however.
I believe the laws in America are much looser so the effects there may be far greater. I believe US truck drivers can drive for up to 12 hours, so if these were widespread you would imagine US truck drivers may be getting more and longer breaks than if they were driving ICE.
Could a different technology, one perhaps with a higher weight per Wh but a higher Wh capacity per volume, make more sense in a semi-trailer-truck? Since on some routes they cruise for up to 11 hours, the weight could be less significant that a car doing city driving.
Yes, but the range wouldn’t necessarily be better. IIRC, the Toyota hydrogen semi has a range of about 300 miles. And very little fueling infrastructure (with extremely expensive fuel). EDIT: yup: https://www.hotcars.com/heres-what-you-need-to-know-about-to...
Also, it’d require dumping a lot of heat. I talked to a contractor who once helped make the Nikola One heat exchanger, and he said it took as much power as a Nissan Leaf powertrain just to cool the dang thing.
Readit News
Anyway, the claim by Musk that they can achieve 1.5kWh/mile is reasonable, and fits in with my calculations here: https://selenianboondocks.com/2017/11/tesla-semi-part-1/
The vehicles that they delivered did not use all the available aerodynamics tricks that their prototypes did, and uses duals instead of super singles, so it also makes sense it’s only achieving 1.7kWh/mile right now.
Note that a ton of people claimed a 500 mile electric semi with a full load wasn’t feasible. This proves that it is. (The jersey barriers they pulled weighed about a standard 44,000pounds.) The Toyota hydrogen semi has only about a 300 mile range and with fuel an order of magnitude more expensive.
So if I read [1] right, some kind of average price for electricity used in the transport sector in the US as of September 2022 was 12.48 cents/kWh. That would mean that the 500-mile trip costs 500 * 1.5 * 12.48 / 100 = $93.6 in energy.
If that includes hauling tens of thousands of pounds of cargo, that sounds rather a lot like it would make transport powered by electricity commercially sane, right? Nice.
EDIT: I hadn't read the article much; it seems the current power value given is actually 1.7 kWh/mile, so that increased the price to 500 * 1.7 * 12.48 / 100 = $106.08. Not a huge increase, obviously.
That is the question. I am very curious if that includes cargo and if so how much weight. I suspect it doesn't include cargo. If it doesn't include cargo, diesel trucks will be far cheaper
If you're looking at historic fuel prices ($3/gal diesel [1]) and what modern trucks are getting (7-10mpg [2]) with loads. You're talking ~$150-$215 for a diesel truck. Plus you have fuel everywhere (less infrastructure costs), quicker refuels, easier repairs, etc.
The cold and time will also siphon off the efficiency of the battery powered trucks. Colder climates will see a 5-10% drop in efficiency in winter, and that'll grow over time. Making it less cost effective in northern climates.
The only way this truck makes any sense would be short-haul (single day round-trip deliveries) and government subsidies IMO. Plenty of market, but not quite where it needs to be.
[1] https://agtransport.usda.gov/Fuel/Historical-Diesel-Fuel-Pri...
[2] https://lonestarclassictruckclub.org/average-fuel-mileage-fo...
(Tesla has typically done better than their peers in overall battery specific energy as well as energy per mile.)
Being able to run different kinds of small 20-80hp generators at their max efficiency RPM would be great. And if it were a reasonably sized module different folks could compete to make different highly efficient generator packages running on gas, diesel, CNG or LNG, ammonia, DME, hydrogen, ethanol, or whatever.
[1] - https://www.pge.com/mybusiness/environment/pge/fleets/
[2] - https://chargedevs.com/newswire/los-angeles-fire-department-...
That said, the main utility for hybrids is in stop&go situations where gas engine has to operate over a large RPM range and energy is essentially lost in stopping. In case of big rigs I actually agree that you need full electrification (or maybe ammonia/H2 engine IFF conversion efficiency to carrier is high). We 'just' need to get the battery energy density up 30-40%. Quite doable IMO.
It doesn’t solve all emissions problems like NOx and other particulates but it’s a good step and likely we will be seeing both electrified trucks for short hauls and carbon capture for long hauls and for more efficient reuse of existing vehicles.
And you’re only making a marginal improvement in CO2 emissions. All the synth fuels are much more expensive than electricity.
If the exception to cruise is only 0.1% then I agree it's dumb to consider. If it's 10% or more and the emissions during non cruise are significantly worse, it could end up accounting for 30-40% of total emissions instead of just 10%
Deleted Comment
Fleet vehicles like this are exactly where it makes the most sense to have a stop and swap strategy for refueling, especially when so much energy needs to be transferred at once. Though that is lessened by the size of the battery since they could argue it gets recharged during a mandatory rest period.
That also means the batteries must be carried like cargo. That'd add a lot of extra weight.
This is kind of a "the entire industry is dumb" assumption.
I mean, sometimes industries are dumb, and there are certainly people driving oversized vehicles on the road right now, but if you can find places to optimize vehicle weight outside of the engine/transmission/fuel you're replacing with batteries/motors, that applies to regular old semi-trucks; if you can make a semi-truck weigh 5000 lbs less without compromising on its design parameters, you can make every other semi-truck on the road more fuel efficient and save like 6% of your fuel costs, while also allowing you to haul bigger loads than competitors' trucks.
Everyone making semi-trucks is interested in that, not just Tesla.
I'm fairly confident some of the rest of the industry could get a comparable weight if they started from scratch and they optimized for EV only. But that's two assumptions that don't currently hold.
So, 10,000+ pounds for the power pack alone is a sizable chunk of the maximum allowable weight, and could potentially eat into the allowance for cargo, more so for restricted routes like older inner city bridges with tight weight limits and the like.
[0]https://www.jdpower.com/cars/shopping-guides/how-much-does-a...
[0]: https://afdc.energy.gov/laws/11682
> NGVs and PEVs may exceed the federal maximum gross vehicle weight limit for comparable conventional fuel vehicles by up to 2,000 pounds (lbs.). The NGV or PEV must not exceed a maximum gross vehicle weight of 82,000 lbs. (Reference Public Law 116-6 and 23 U.S. Code 127(s))
https://youtu.be/Uv44W7xa4IU
There were about 10-12 concrete barriers as load in the demo each weighing 39,000lbs. So the weight being carried is around 40ishK lbs. So rough approximation - half the weight of the truck is load and half is the truck itself.
I don't work in the industry. I just observe three things:
1) the weight variance of a semi encompasses the amount imputed to the battery
2) 3,000lb of weight can be saved by not having a diesel engine plus another 2,000lb not having fuel. (Both of which will be in the total gross weight of the semi) some of which will of course be replaced by electric motors.
3) it's a speculative weight. It might also not weigh that much. Might is doing a lot of heavy lifting.
A fourth point: trucks routinely travel partly empty because of weight distribution issues. Not every TEU is full.
Logistics is fascinating. TCO is the closest most computer scientists get to "how can owning a Mac be cheaper than owning a Windows PC" but logistics does this almost every sum. Weight and carry capacity may not be the sole deciding factor here when a semi is worth $500k and has a 2nd hand value and is a finance decision with tail costs and operation costs.
A full semi can have 300 gallons of diesel which itself is about 2000 pounds, so we're down to a 9,000 pound difference.
And some percentage are short haul, which are often not even near to fully loaded. Could be as high as 40-50%.
I believe the laws in America are much looser so the effects there may be far greater. I believe US truck drivers can drive for up to 12 hours, so if these were widespread you would imagine US truck drivers may be getting more and longer breaks than if they were driving ICE.
Summary of EU Driver Laws for anyone interested: https://www.gov.uk/drivers-hours/eu-rules
I think 45 minutes is enough to get closer to 300 miles of additional charge than 100.
Deleted Comment
Also, it’d require dumping a lot of heat. I talked to a contractor who once helped make the Nikola One heat exchanger, and he said it took as much power as a Nissan Leaf powertrain just to cool the dang thing.