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Well, a class 8 trucks has a gross weight of over 33,000 pounds. Let's pretend that Musk gets that 1MWh by slapping some Powerwall 2 units on a truck frame. Th
by lscharen 9y ago
Well, a class 8 trucks has a gross weight of over 33,000 pounds. Let's pretend that Musk gets that 1MWh by slapping some Powerwall 2 units on a truck frame.
The Powerwall 2 has a capacity of 200 kWh, costs $5,500 and weighs ~3,500 pounds. So we're looking at 17,500 pounds and $27,500 for that 1 MWh of batteries.
That's about half the minimum gross weight of the truck at a fairly reasonable price compared to the vehicle cost as a whole.
I'm sure there would some significant weight savings using a electric drive versus the large diesel engine + drivetrain. How much savings? I have no idea, but it should significantly cut into the battery weight penalty.
Edit: Looks like a typical heavy duty engine (Cummings ISX15) is only about 3,000 pounds, dry weight. The Model S electric motors are only 70 pounds, so let's say at least one Powerwall is "free" weight-wise.
Also, the ISX15 looks to be >$20,000 for rebuilt engine, so the battery costs look approximately comparable to a traditional engine price.
- deleted 9y ago[deleted]
- SigmundA 9y agoPowerwall 2 is only 14kwh at 270lbs for $5500, or about $400 per kwh. You must mean the power pack 2 which cost 80k. Musk wants $100/kwh cost from the Gigafactory, but market is currently above $300. Semi tractors only weigh 15-20k lbs your talking a battery that weighs as much as the tractor. 300 gallons of diesel is 2000 lbs and the engine and transmission is about 3000 lbs. it would be at least 10k heavier which reduce carrying capacity since gross is capped at 88,000 lbs total not to mention space.
- gameshot911 9y agoNow throw in the autonomous factor. Subtract driver labor costs and throw in near 24/7 operation (vs. human drivers which are required to stop for rest breaks).
- SigmundA 9y agoSemi doesn't have be electric to be autonomous, Frieghtliner is already showing diesel autonomous prototypes.
- gameshot911 9y agoTrue, and to those add the cost of externalities like mining on natural ecosystems and pollution on climate warming and our health.
- deegles 9y agoAre recharge breaks less time than human breaks?
- greglindahl 9y agoI suspect battery swaps are on the agenda.
- lscharen 9y agoYou are correct re the Powerwall and Powerpack confusion. I had gotten the information off of the Wikipedia article and accidentally combined information from the two tables. That definitely changes the cost/weight/power equations.