There was a time when "source material" wasn't both infinite in volume and nearly devoid of value. There was a time when corporations released rational information, instead of videos of chatter, so that a graph didn't need to be extracted from a video. And I linked to the source of the graph on which I was commenting, which is a reputable publication; as usual, my contribution here is far more rigorously backed up and clearly presented than most of this forum's content, so I don't see the need for the shot.
I did later skim through the official Tesla video and confirmed that it is the source of the graph, as expected.
Yes, devoid of value
Luckily for you Tesla posted an edited down 35 minute version on their Youtube channel.
I don't really know anything about semis but here are a couple things that popped out to me from watching the Tesla event myself and then reading this thread:
-The Tesla semi uses a 1000+ volt architecture while the other EV semis use lower. Daimler comes close at "800-900." More voltage is an efficiency advantage, especially on a vehicle like this that will pull massive amps on a regular basis.
-Tesla designed a semi from the ground up whereas the legacy brands adapted their existing engineering that is really still 60s technology for the most part. They still have "fuel tanks" on the sides under the steel cab with fiberglass wind deflector for instance. There are benefits to doing it both ways. A cheap EV truck to move smaller trailers around a yard or make local deliveries might not need to be super advanced but obviously due to the technical challenges a long-haul EV semi does need to be super advanced.
-It's a 4WD truck standard with advanced traction control. Your comments about it being bad in winter conditions is pretty telling. In the event, they did spend some time talking about winter conditions and how the semi has advanced traction and stability control to prevent jackknifing and other things. They said "it drives like a Tesla" because Teslas are famed for their winter performance and traction control. The open differential matters less with traction control using the normal disc brakes and single motor modulating, the rear axle should be able to torque vector and use disc brakes, both axles can be driven independently. Also the boost motors are able to connect and start providing torque before the cruise motor reaches full power when the driver puts their foot down as stated in the event. The 4WD should be able to seamlessly activate whenever needed or the driver can just turn it on for snow. Now heater performance and range in winter, that's another thing entirely.
-The brakes barely ever get warm due to regen, as to be expected but that is a massive benefit to truckers not having to let their brakes cool or check them. They have to pull over and get out of the truck and inspect etc. I've seen semis with their brakes literally on fire coming down I-70. A few years ago a run away semi killed several people after he lost control coming down from 9000ft into rush hour traffic. Not having to shift through the gears and change axle ratios etc is a massive improvement for driver fatigue as well. Much less brake pad dust in the environment longer service intervals.
-Yes, any EV truck will suffer a max payload penalty. But most trucks are not running at their max capacity or anywhere close. I don't think you can fit enough potato chips in a semi to hit 80k. Maybe if it's full of Pepsi. The Semi has an estimated 11,000 lbs of battery which definitely takes a chunk out of payload but in a lot of cases that doesn't matter.
-Advances in technology like going to super single rear tires instead of dualies and aluminum trailers can tip the scale back towards an EV. For instance the Kenworth EV semi uses dualies and the Tesla semi uses big singles. The big single tires can save 1000 lbs by themselves. It's the sum of the parts coming together that make the end result significantly better than each small change can do on it's own.
-Average diesel semi engine/trans is 5000lbs
EV Semi +11,000lbs battery
-1000lbs aluminum wheels/tires
-2000 aluminum trailer
-1000lbs aluminum cab
= 7,000lbs net
EV truck 2,000lbs gross weight bonus = 5,000lbs net. Payload capacity unaffected. Obviously these are napkin level calculations for the purpose of discussion.
-Battery tech at launch is usually updated quickly by Tesla. I'm not a fanboy by any means but their track record shows. They upgrade batteries in first gen Model S and Roadsters for a really great price.
-In the delivery event livestream they showed their semi supercharger infrastructure. They spent several minutes showing acres of backup battery storage to deliver to Pepsi and Frito-Lay for their locations. It looked like Elon had batteries coming out of his ears he has so many.
-Elon said that Tesla will guarantee lifetime 7 cent/kwh Semi Supercharging and they will go 1,000,000 miles. The youtube channel below calculated that would be $180,000 for electricity vs. $700,000+ of diesel at current prices for 1,000,000 miles. It's unclear if the battery itself will go 1mn miles or just the chassis and drivetrain. I doubt the battery can come close but I bet it lasts about the same amount of time as an engine needs before it's time for an overhaul.
Like I said I'm no Tesla fanboy and do not like their marketing vaporware and anti-right to repair stuff like Rich Rebuilds is famous for but Tesla's track record is pretty good otherwise. I think EV makes more sense in a lot of cases for larger vehicles than small ones simply because a larger vehicle can carry more batteries. I also hate sitting behind two semis trying to pass eachother for 5 minutes on the interstate and I hate the smell of diesel.
The "up-and-down equals level" effect is not so clearly true. Cycling energy through the powertrain and battery is far from perfectly efficient, so the net effect is not a wash - the result here is good, but that can't be assumed. The efficiency of any powertrain varies with load, so the average efficiency of high power on the climb and low power on the descent can't be assumed to be the same as constant power for the same time - in this case switching between three motors on the way up and one motor on the way down is probably very helpful.
There are a couple of advantages because of air resistance on a large vehicle like a semi it's better to drive at a slower speed and regen more vs. on a smaller EV to allow the car to accelerate with gravity and regen less. If there was no aero drag or safety issue it would be most efficient to just let the vehicle coast all the way down hills as fast as possible and then slow as you go up the next hill or use the speed to carry you are far as possible til you need to add power. Speed limits, traffic, and aero drag tip the scales towards driving 55 and regening. The 1000 volts also likely helps a lot in the losses of cycling the battery. Either way I know from my time commuting in an EV that the hills and ups and downs didn't matter anywhere near as much as the starting and ending elevations.