Hey, if you think you can lay (and then remove) dozens of miles of 2000kVA line for less half a million dollars, go for it. Contracts must be piling up on your desk.
It really isn't. These aren't household extension cords we're talking about. They're on the order 1-2 thousand kVA, sometimes more. These are not cheap to lay.
Batteries running on a 2-hour swap cycle, however, are 2-4 megawatt hours in capacity. Just going with an unimpressive $200/kWh, that's only about half a million dollars worth of batteries, give or take.
People pay to use transportation infrastructure to save them money (or if they don't have a vehicle) all the time. The former group includes things like toll roads, toll bridges, ferries, etc. The latter group includes... well, all public transportation.
Loop is designed for both (vehicle capsules and passenger capsules). Are you saying that you wouldn't use a system that could cut, say, an hour commute down to a 15 minute commute? And even if you didn't, the fact that others would would directly benefit you on the surface.
1) The curves are at the start and end (accel / decel). The trip will be purely accel and then decel.
2) This is just a 3km test tunnel. I seriously doubt the top speeds will be anywhere near those of Loop.
3) It's not even clear that Loop is going to use rails at all. As of the last discussions, it was still under investigation as to which option would be best.
4) Boring Company's goal isn't to make some sort of uber-sepecial-fancy tunnels. Their goal is to make tunnels cheaply and quickly.
5) The test tunnel's TBM (Godot) is only the first phase of that. They still have two more generations of TBMs to go through (Linestorm, and ultimately Prufrock). Godot is still pretty standard, although they modified the means to remove tailings, switching from diesel to battery-powered locomotives. Linestorm will make tunnels with passing zones so inbound and outbound trains can pass each other, and the TBM will run on battery packs delivered by the inbound locomotives. These two changes will save them from having to lay A) the powerful ventilation systems normally used to clear locomotive exhaust, and B) the expensive power cables. I'm not sure if Linestorm is going to take the first steps toward automatic continuous casing or whether that's going to wait for Prufrock (same with the hot-swappable chilled cutting discs). Continuous casing and hot-swappable discs would on their own double tunneling speeds. But ultimately their goal is to additionally push cutting head speeds up to several times higher than they are today, since they're nowhere near physical limits.
The model 3 battery pack - which also includes not just modules, but the charger, DC-DC converter, cooling, etc etc - can deliver 370kW and weighs 478kg, or 774 W/kg. It also has 77,8kWh usable, so 163Wh/kg Note that the modules (which also include an integrated BMS) are just over 3/4ths of the mass, so there's some real potential for weight reduction when you go to larger scales and use lighter materials (as aircraft do vs. cars). Let's say that in an aircraft pack you get 1kW/kg and 200Wh/kg (the modules are 223Wh/kg, and the cells even higher).
(Note: Even this may be somewhat pessimistic with respect to power. The Model 3 pack is rated for 1200A at 402V when fully charged (aka at takeoff) - that's 482kW rather than 370kW. But we'll stick with the amount you can actually use in current Model 3s)
Now let's look at a case where you try to push range and power to their limits - half the aircraft's mass as batteries. So the net power and energy densities of the plane are 0,5kW/kg and 100Wh/kg, respectively.
Now let's say that we're trying to reach a cruising height FL330 (10km) and a velocity of 600mph / 965 kph (268m/s). The energy required for the altitude is 9,81*h*m, so per unit mass, 9,81*10000 = 98100J/kg (27,5Wh/kg). Kinetic energy is 1/2 mv^2, so per unit mass, 0.5*268^2 = 35912J/kg (10Wh/kg). So 3/8ths of your energy is just required by fundamental physics - ignoring all losses - to get up to your flight level and velocity. If you get 80% net propulsive efficiency (between the drive units and propellers), now you're at half your energy just to reach cruising altitude and velocity. Now factor in the drag losses during your climb, particularly at low altitudes... and remember that we're talking about an aircraft where half its mass is batteries...
Clearly, electric aircraft are highly energy limited. You get more of your range during the glide down than you do cruising at altitude.
Now let's look at power. To accelerate up to... oh, let's say 70m/s... that's 1/2* m *70^2, or 2540J/kg (2540 W/s / kg). Our batteries can provide power at a rate of 500W/kg. Thus it could reach 70m/s in just over 5 seconds, or an average acceleration of 14m/s^2 (1,42 lateral g forces). Even factoring in the above assumed 80% drive unit / prop efficiency, you're still at an average of 1,1 lateral gs. Commercial aircraft are normally only 0,2-0,3 lateral gs. So clearly we are not power limited; indeed, with such extreme power possiblities, electric aircraft would be prime candidates for VTOL.
Summary: focusing on power is focusing on the wrong problem.
A side note: energy density improvements in batteries have a much more significant impact to range than one might think. With an electric car, if you double the energy, you double the range. But with an electric aircraft, you far more than double the range. Not simply due to the fact that the first half-or-more of your energy is needed just to get up to cruising altitudes and velocities, either. Electric aircraft have a much higher altitude theoretical operating envelope than combustion-based aircraft, due to the lack of need to maintain sufficient pressure inside an engine to sustain combustion, and avoiding the problems that occur with trying to maintain combustion at ever-increasing airspeeds. Higher altitudes come with lower air densities; optimal speeds increase and energy consumption per unit distance drops significantly.
There's another factor at play that combines that those high accelerations that we calculated previously with the energy density issue: if you can have full - or even just partial - VTOL, then you don't have to have the wetted area for takeoff and flight at lower velocities. Aka, you can make a more stub-winged aircraft. This makes your aircraft lighter (lower lift required, aka less drag via the L/D ratio) and more efficient at higher altitudes. In short, there's a significant virtuous cycle at work. You use the high power provided b
ICE has effectively unlimited range due to comprehensive fuel network and rapidity of refuel operation.
And as your, quote, "silly scenario" made clear, that's irrelevant in a person's daily life. In one's daily life, EVs save a great amount of time by not requiring you to regularly detour to a gas station and pay out the nose for the privilege of standing outside in whatever weather to pump carcinogens into a tank.
Tesla Model 3 LR (75 kWh) has a demonstrated real world range of ~200 miles.
Tesla superchargers is at best 1.0 hour charge time for every 3.5 hours driving.
Wrong. Regardless of whatever your dead link says, Model 3 charges at nearly 120kW on a V2 supercharger (should be up to 180kW on V3) up to 50%, followed by a linear taper. A bit under 2 kWh (a bit over 8 miles) per minute. Hence, for the aforementioned "73 miles added during the drive", assuming that they're late in the drive rather than early, is 13 minutes on a V2, less on a V3.
Some people might say you have no bloody clue what's in a NMC battery
You want me to comment on that? I already did. In the article. It's a really silly game that people play, latching on to whatever fake, non-peer-reviewed "study" from a company working for gasoline car manufacturers says what they want, when the corpus of actual peer-reviewed studies says precisely the opposite.
I get it now. You talk like a commuter who wants a cheap reliable daily driver.
Wrong.
First off, the model 3 is $70k to get the top end model 3 not 59k.
Wrong. You can order one today (deliveries in a few weeks) for $64k and that includes the $5k Premium Upgrades Package, so be sure to add any premium upgrades to your competing gasoline car. PUP will be made optional early next year.
Yes taxes count on top of that.
I don't know about your environment, but where I am, there's no taxes on EVs, while a BMW M3 would have about 40% taxes. So that's probably not the argument you wanted to make. I deliberately omitted incentives, but hey, if you want to introduce them!
Second, your city driving only plan is ridiculous
It's not a "plan", it's the EPA numbers. Model 3 city range (usable pack size divided by measured city energy consumption) is longer than M3 city range (tank size divided by city mpg). Given typical fill levels - 90% daily for EVs, and an average of 60% for the M3 (with a great deal of variation) - the Model 3 goes further (well further) in combined cycle as well.
I am going to make up an equally silly scenario where we drive from San Francisco to LA and back every other day
You're right. That is a silly scenario. Which serves to illuminate how pointless these range discussions are in people's everyday lives. In your everyday life, the gasoline car has to regularly detour to gas stations, and the EV doesn't. Which makes the comparison obviously "winner: EV".
But in case your - I quote, "silly scenario" - matters to you: it's 383 miles between LA and SF. If you were driving there in the morning and back in the evening, you'd need a nominal 73 miles range added during the drive (plus whatever "buffer" you want - say, 30 miles). That's a 13 minute stop on each of your 5 1/2 hour drives. That's 13 minutes with the current V2 superchargers - should be under 10 minutes on V3.
Thirdly, my ICE car (msrp 65k, pre-tax, a bit less than your model 3), can be repaired anywhere over night. Parts are available RIGHT NOW.
Apparently you're unaware that anyone can order Tesla parts now. No wait times. By the way, I have two vehicles, one of which is a pickup truck which has been in the shop for much of a month - first waiting on a replacement bearing, and then when they tore it down, they discovered that they needed a second bearing replaced as well, and now I'm waiting on that. But I guess wait times only ever count when the vehicle under discussion is a Tesla?
Fourth, the build quality on the model 3 is random
Consumer Reports rates it as "average" - which for a car in its first model year, is quite good.
Fifth, the batteries in model 3 are toxic as fuck
You have no bloody clue what's in a NMC battery.
The cathodes are metal oxides. Inert. Non-soluble. The anodes are graphite. Lithium is intercalated, not bound, into both. The electrolytes decompose rapidly on exposure to water, with the most meaningful decomposition products being lithium ions (same as can leach from the electrodes) and fluoride ions. Excepting in abnormally high quantities, both lithium and fluorine in groundwater are good for peoples' health - to the point that we fluorinate our drinking water and lithium spring waters have long been used as health baths and drinks (7-up was initially a lithiated soda). Places where the groundwater is naturally richer in lithium have lower rates of violent crime and suicide than places where the groundwater is poor in lithium. This shouldn't come as a surprise, as high doses of lithium are used to treat mood
* "Battery" is a generic term, and can refer at any scale.
* "Cells" or "Battery cells" refers specifically to the subunits
* "Packs" or "Battery packs" refers to the bulk object which contains multiple cells.
Pack production is at least as complicated as cell production (including the production of 2-meter-long PCBs, fine wire bonds for every of thousands of cells, etc - plus the packs also contain the charger, the DC-DC converter, cooling, insulation, etc etc). But both are obviously critical. It's a good division of responsibility between Tesla and Panasonic that lets them spread out the capital costs.
No. It's because there's only so fast you can expand. I'm not sure what world you live in where nearly doubling cell capacity in six months isn't an impressive scaleup rate, but in my world, that's pretty dang impressive.
The ICE car Im looking at buying next is about as fast as the maxed out model 3, costs less,
What sub-$59k (not counting tax credits or fuel savings**) ICE car are you referring to that nearly does 0-60 in 3,3 seconds?
** - About $1k per year for the average US driver, $2k for the average European driver, and about $3k where I live. So e.g. in 5 years of ownership that's $5k/$10k/$15k.
has a longer range
Almost certainly depends on the conditions. The Tesla Model 3 Performance goes further in city driving than the BMW M3 even if you credit the BMW to a full tank every day. If you assume that the Model 3 is charged to 90% every day and the BMW averages a 60%-full tank at any random point in time, the Model 3 goes further in combined-cycle driving as well. The M3's range is obviously far more variable, which is of course not a good thing.
refuels faster
Yes, detouring regularly on your way to or from work to drive to a gas station so you can pay out the nose for the privilege of standing outside in whatever weather you're in to pump carcinogens into a tank is so much faster than plugging in when you get home and disconnecting when you leave.
But hey, if you like wasting your life... Maybe we can find you a cell phone that you don't plug in at night, but rather have to detour out of your way to "cell stations" once a week to fill up - would you be interested in that?
is not produced by a sociopath.
Which of the 45 thousand employees at Tesla responsible for the design and construction of the vehicles are you referring to?
a bazillion gas stations
About 150k. On a relentless, steady decline that EVs are only going to accelerate. Meanwhile, the number of car-accessible electric sockets in the US alone surely numbers in the billions.
And remember, unlike EVs, cars must visit not-at-home gas stations at regular intervals.
Yeah, they've been seriously cell deprived. It's not enough that between 18650s and 2170s the Tesla-Panasonic alliance is now making 60% of the world's total EV battery capacity - Tesla has also been having to buy cells from other manufacturers to keep their Powerwall and Powerpack production going. Tesla's been consuming cells like a beast, mainly for Model 3, and it's impacting their other product lines.
Panasonic has been lagging, but they're trying to catch up. At the end of Q3, GF1 was producing 2170s at an annualized rate of around 20GWh/year (current global production for EVs is around 40GWh/year). Panasonic is installing three of its new, faster line design (joining the 10 lines of their older design); this is expected to bring them up to 35GWh/year by March.
Gotta love those sorts of scaling factors. We live in interesting times.
BTW, Panasonic has stated that they're not going to be building out lines in Shanghai next year, although might in the long-term. Their capital is currently focused on GF1. Model 3 production at GF3 will be started using a mix of cells, both imported from GF1 and from local Chinese manufacturers. From the 10-Q, it looks like they're planning to take the route I laid out on TMC a couple weeks ago:
* Fremont's lines are all designed for 10k/wk production rates, but some - namely, paint and GA (general assembly), look likely to bottleneck out at 7k/wk. Upping these rates would require meaningful investment and/or downtime to boost to 10k - but Tesla doesn't really need 10k/year in the US. The body, stamping and plastics lines all look ready for 10k.
* Tesla has already started site work at Shanghai. Their first step will be to have it leveled and prepped, with utility and transport connections in place. A factory is worthless if things and people can't move smoothly in and out.
* GA lines are the fastest and easiest to build; Tesla made one in a month out of scrap in Q2 this year. I expect them to have the first GA line up in late Q2 of next year.
* Paint lines are more complicated to get running smoothly and consistently. I expect them to open their first paint line in Q3/Q4 of next year.
* At this stage, they'll import BIWs (Body In Whites), made using the extra 3k capacity in the body, stamping and plastics lines at Fremont, and finished packs and drive units from GF1. So Fremont will be at 7k and GF3 at 3k. BIWs will need either dry packaging or temporary anti-corrosion coatings for shipping, so Tesla will have to prep for this.
* Stamping, plastics, body, pack, and cell production will come on line in early '20, along with new GA and paint lines to ramp local production (specifically, to add Model Y production into the mix). This also frees up 3k capacity at Fremont and GF1.
* In the meantime, GF4 prep work, the first GA line, and the first paint shop will have been completed in Germany (early '20, 2-3 quarters behind Shanghai). So the extra BIWs, drive units and packs get shipped to GF4, and the Shanghai process repeats.
Tesla's messaging has been consistent: these are products that they need to offer a lifetime warranty on, with a 30 year warranty on electricity generation; they need to make damned sure they're going to last in the real world (and use the meantime to refine the installation mechanism to be as cheap as possible). So while Tesla has done a limited rollout to a small number of houses, they don't want to enter bulk production until they're ready.
That said... IMHO, there's no question that the half year delay in the Model 3 ramp consumed a lot of cash that they would otherwise have put into GF2. I'm sure we'd be a lot further into the ramp - warranty periods or no - had this not happened. GF2 is behind schedule on hiring. They're now planning for a big rampup in production in Q1. A good indicator would be to watch their hiring late in Q4.
Only if management actually believes said study. At any large organization, there will exist some people people who believe that any given schedule is too optimistic, and will say so. To argue that because some people in an organization expressed concern about a schedule, but management overruled them, that this is criminally actionable, would be to argue that almost any delayed project where anyone protested is actionable. What matters is whether the decision makers believed their own schedules. Aka, the case would be to argue that Musk has no record of excessive optimism about schedules.
Yeah, good luck with that. We're talking about a guy who literally just the other day just fired his Starlink managers because he felt their schedules were too pessimistic.
A great example of the above was the attack series launched by UAW-tied organization "Reveal". First they alleged a high injury rate (with a bunch of BS about beeping forklifts and yellow caution tape being banned) - but Tesla rebutted it by pointing out that they're using old data, that they're around the industry average now, and that the plant used to be the highest injury-rate plant in the US before they bought it. So Reveal switched gears to arguing that they were "hiding" injuries off the books. They even got CAL-OSHA to investigate, and the latter's investigation concluded just recently: the biggest problem they found was an extension cord to a fan that could pose a trip hazard, and one injury whose date was wrong. Vs. its competitors which actually have been found to be hiding injuries off the books, and fined.
Each time the Reveal reports came out, the news was picked up widely. The actual facts? Crickets. Scandal sells. "Wait, there wasn't actually a scandal" doesn't.
In case you're curious, the full context of that quote:
Kara: "You pick fights with the press over Twitter, and then you have all your fans, of which there are many. Are you aware of what they do once you start them off?"
Elon: "Well, I have to say, my regard for the press has dropped quite dramatically."
Kara: "Explain that, please."
Elon: "The amount of untruthful stuff that is written is unbelievable. Take that Wall Street Journal front-page article about, like, “The FBI is closing in.” That is utterly false. That’s absurd. To print such a falsehood on the front page of a major newspaper is outrageous. Like, why are they even journalists? They’re terrible. Terrible people."
Kara: "I get that, but do you understand the mood in this country around the press and the dangers of attacking, especially when the president is doing that? In quite an aggressive, “enemy of the state” and everything else. It’s disturbing when someone like you as a leader does that, too, or goes along with it."
Elon: "The answer is for the press to be honest and truthful, and research their articles and correct things properly when they are false. Which they don’t do."
Kara: "Okay. But I’m asking if you understand where it goes to."
Elon: "Yes, of course I do."
Kara: "What do you think of that? Are you worried about unleashing a dangerous cycle that a lot of the press are worried about? Justifiably."
Elon: "I suggest the press take it to heart and do better."
Kara: "What about what Donald Trump does, about “enemy of the people”? Do you look at it that way?"
Elon: "No."
Kara: "Just that you don’t like falsehoods."
Elon: "Yeah. There are good journalists and there are bad ones, and unfortunately the feedback loop for good versus bad is inverted, so the more salacious that an article is, the more salacious the headline is, the more clicks it’s gonna get. Then somebody is not a journalist, they are an ad salesman."
Kara: "What about things that are just critical of you that you don’t like? Do you think you’re particularly sensitive?"
Elon: "No. Of course not. Count how many negative articles there are and how many I respond to. One percent, maybe. But the common rebuttal of journalists is, “Oh. My article’s fine. He’s just thin-skinned.” No, your article is false and you don’t want to admit it."
The criticism of the WSJ article was that it recycled old information and presented it as new. The fact that there had been a DOJ investigation was not news; Tesla confirmed a Bloomberg story on it in September. The request for documents from Tesla happened over a month ago. WSJ made this big front-page "DOJ is closing in!" article based on the fact that... the FBI sought documents and testimony from some former employees. It caused the stock price to plunge, but by the end of the day it had almost fully recovered (and surged past that the next day) as investors realized that they were just recycling a story. Then after the 10-Q repeated the news that broke in, I'll repeat, September (that the DOJ had requested, and been given, documents related to the production ramp), a number of outlets ran prominently with the exact "Tesla confirms DOJ investigation!" article, as if this was actual, new news. They're milking the heck out of this.
FYI: the DOJ case was launched simultaneously with a civil case on the exact same issue. Tesla already won the civil case. Obviously. Seriously: if missing projections while publicly describing what's going on as "production hell" is actionable, then virtually every company in the United States would be bankrupt.
1) The sun will not go supernova 2) The sun actually does lose significant mass in its red giant phase:) 3) There's a wide variety of stellar processes that affect orbits of objects around them (although the larger the body, the less effect these processes have)
Surprisingly enough, it doesn't really matter what you siphon off. In a star the mass of our sun, there's relatively little inflow of new fuel into the core. Smaller stars are fully convective, in that everything can cycle through the core. So just by simply "lightening" the star by any means, down to a red dwarf (note: not a brown dwarf!), you let all of that new fuel get in. Also, the higher mass of the sun increases the reaction rate in the core, so reducing the mass slows that down significantly. And red dwarfs are strictly hydrogen-burning; there's never a helium flash, no triple alpha process.
Red dwarfs never turn into giants. Instead, they're predicted to evolve into blue dwarfs. Although since it takes orders of magnitude longer than the age of the universe for this to happen, there are no blue dwarfs in the universe yet to observe!
Even before the sun's red giant phase it will have doubled in luminosity. Assuming no feedback effects, that would increase Earth's equilibrium temperature by 19% on an absolute temperature scale. So if you assume that feedback mechanisms remain the same, you're talking at least 50 degrees celsius temperature increase.
Of course, that's far too simplistic of an approach to take; feedback levels will change, and the details of that are a complex modeling task. Runaway greenhouse effects are quite possible (such as: loss of crustal water = reduce crustal viscosity = reduced / eliminated large-scale plate tectonics = Venus-like geology).
Of course, the biggest question is whether any sort of sentient life would exist in the system at that point in time. If so, it would likely be so far advanced (billions of years of technological development) that building an orbital solar reflector would be a laughably trivial task, and even relocating the planet might be within their reach. The ultimate achievement would be if they were to develop technology to siphon off matter from the sun over billions of years, ultimately reducing its mass to under 0,3Msol. Then it would not only burn slower, but also be fully convective - greatly extending its lifespan. Very low mass main sequence stars can potentially burn for trillions of years.
Fun fact: Sgr A* got its "star" postfix based on a nerdy joke: in atomic physics, excited states are denoted with asterisks, and Robert Brown found the signal coming from it "exciting";)
Slashdot Mirror
Hey, if you think you can lay (and then remove) dozens of miles of 2000kVA line for less half a million dollars, go for it. Contracts must be piling up on your desk.
It really isn't. These aren't household extension cords we're talking about. They're on the order 1-2 thousand kVA, sometimes more. These are not cheap to lay.
Batteries running on a 2-hour swap cycle, however, are 2-4 megawatt hours in capacity. Just going with an unimpressive $200/kWh, that's only about half a million dollars worth of batteries, give or take.
People pay to use transportation infrastructure to save them money (or if they don't have a vehicle) all the time. The former group includes things like toll roads, toll bridges, ferries, etc. The latter group includes... well, all public transportation.
Loop is designed for both (vehicle capsules and passenger capsules). Are you saying that you wouldn't use a system that could cut, say, an hour commute down to a 15 minute commute? And even if you didn't, the fact that others would would directly benefit you on the surface.
1) The curves are at the start and end (accel / decel). The trip will be purely accel and then decel.
2) This is just a 3km test tunnel. I seriously doubt the top speeds will be anywhere near those of Loop.
3) It's not even clear that Loop is going to use rails at all. As of the last discussions, it was still under investigation as to which option would be best.
4) Boring Company's goal isn't to make some sort of uber-sepecial-fancy tunnels. Their goal is to make tunnels cheaply and quickly.
5) The test tunnel's TBM (Godot) is only the first phase of that. They still have two more generations of TBMs to go through (Linestorm, and ultimately Prufrock). Godot is still pretty standard, although they modified the means to remove tailings, switching from diesel to battery-powered locomotives. Linestorm will make tunnels with passing zones so inbound and outbound trains can pass each other, and the TBM will run on battery packs delivered by the inbound locomotives. These two changes will save them from having to lay A) the powerful ventilation systems normally used to clear locomotive exhaust, and
B) the expensive power cables. I'm not sure if Linestorm is going to take the first steps toward automatic continuous casing or whether that's going to wait for Prufrock (same with the hot-swappable chilled cutting discs). Continuous casing and hot-swappable discs would on their own double tunneling speeds. But ultimately their goal is to additionally push cutting head speeds up to several times higher than they are today, since they're nowhere near physical limits.
You walk before you run.
It's a test tunnel. Most companies wouldn't open a test tunnel to anyone.
You don't just jump into a major commercial project as your first endeavour.
GM’s National EV Proposal Hides Call To Roll Back Vehicle Efficiency
Spelling wasn't the actual problem with your post.
Power really is not the limit; energy is.
The model 3 battery pack - which also includes not just modules, but the charger, DC-DC converter, cooling, etc etc - can deliver 370kW and weighs 478kg, or 774 W/kg. It also has 77,8kWh usable, so 163Wh/kg Note that the modules (which also include an integrated BMS) are just over 3/4ths of the mass, so there's some real potential for weight reduction when you go to larger scales and use lighter materials (as aircraft do vs. cars). Let's say that in an aircraft pack you get 1kW/kg and 200Wh/kg (the modules are 223Wh/kg, and the cells even higher).
(Note: Even this may be somewhat pessimistic with respect to power. The Model 3 pack is rated for 1200A at 402V when fully charged (aka at takeoff) - that's 482kW rather than 370kW. But we'll stick with the amount you can actually use in current Model 3s)
Now let's look at a case where you try to push range and power to their limits - half the aircraft's mass as batteries. So the net power and energy densities of the plane are 0,5kW/kg and 100Wh/kg, respectively.
Now let's say that we're trying to reach a cruising height FL330 (10km) and a velocity of 600mph / 965 kph (268m/s). The energy required for the altitude is 9,81*h*m, so per unit mass, 9,81*10000 = 98100J/kg (27,5Wh/kg). Kinetic energy is 1/2 mv^2, so per unit mass, 0.5*268^2 = 35912J/kg (10Wh/kg). So 3/8ths of your energy is just required by fundamental physics - ignoring all losses - to get up to your flight level and velocity. If you get 80% net propulsive efficiency (between the drive units and propellers), now you're at half your energy just to reach cruising altitude and velocity. Now factor in the drag losses during your climb, particularly at low altitudes... and remember that we're talking about an aircraft where half its mass is batteries...
Clearly, electric aircraft are highly energy limited. You get more of your range during the glide down than you do cruising at altitude.
Now let's look at power. To accelerate up to... oh, let's say 70m/s... that's 1/2* m *70^2, or 2540J/kg (2540 W/s / kg). Our batteries can provide power at a rate of 500W/kg. Thus it could reach 70m/s in just over 5 seconds, or an average acceleration of 14m/s^2 (1,42 lateral g forces). Even factoring in the above assumed 80% drive unit / prop efficiency, you're still at an average of 1,1 lateral gs. Commercial aircraft are normally only 0,2-0,3 lateral gs. So clearly we are not power limited; indeed, with such extreme power possiblities, electric aircraft would be prime candidates for VTOL.
Summary: focusing on power is focusing on the wrong problem.
A side note: energy density improvements in batteries have a much more significant impact to range than one might think. With an electric car, if you double the energy, you double the range. But with an electric aircraft, you far more than double the range. Not simply due to the fact that the first half-or-more of your energy is needed just to get up to cruising altitudes and velocities, either. Electric aircraft have a much higher altitude theoretical operating envelope than combustion-based aircraft, due to the lack of need to maintain sufficient pressure inside an engine to sustain combustion, and avoiding the problems that occur with trying to maintain combustion at ever-increasing airspeeds. Higher altitudes come with lower air densities; optimal speeds increase and energy consumption per unit distance drops significantly.
There's another factor at play that combines that those high accelerations that we calculated previously with the energy density issue: if you can have full - or even just partial - VTOL, then you don't have to have the wetted area for takeoff and flight at lower velocities. Aka, you can make a more stub-winged aircraft. This makes your aircraft lighter (lower lift required, aka less drag via the L/D ratio) and more efficient at higher altitudes. In short, there's a significant virtuous cycle at work. You use the high power provided b
And as your, quote, "silly scenario" made clear, that's irrelevant in a person's daily life. In one's daily life, EVs save a great amount of time by not requiring you to regularly detour to a gas station and pay out the nose for the privilege of standing outside in whatever weather to pump carcinogens into a tank.
Hahahahahhahaahahaaha!!!!!
But seriously.
Wrong. Regardless of whatever your dead link says, Model 3 charges at nearly 120kW on a V2 supercharger (should be up to 180kW on V3) up to 50%, followed by a linear taper. A bit under 2 kWh (a bit over 8 miles) per minute. Hence, for the aforementioned "73 miles added during the drive", assuming that they're late in the drive rather than early, is 13 minutes on a V2, less on a V3.
You want me to comment on that? I already did. In the article. It's a really silly game that people play, latching on to whatever fake, non-peer-reviewed "study" from a company working for gasoline car manufacturers says what they want, when the corpus of actual peer-reviewed studies says precisely the opposite.
Wrong.
Wrong. You can order one today (deliveries in a few weeks) for $64k and that includes the $5k Premium Upgrades Package, so be sure to add any premium upgrades to your competing gasoline car. PUP will be made optional early next year.
I don't know about your environment, but where I am, there's no taxes on EVs, while a BMW M3 would have about 40% taxes. So that's probably not the argument you wanted to make. I deliberately omitted incentives, but hey, if you want to introduce them!
It's not a "plan", it's the EPA numbers. Model 3 city range (usable pack size divided by measured city energy consumption) is longer than M3 city range (tank size divided by city mpg). Given typical fill levels - 90% daily for EVs, and an average of 60% for the M3 (with a great deal of variation) - the Model 3 goes further (well further) in combined cycle as well.
You're right. That is a silly scenario. Which serves to illuminate how pointless these range discussions are in people's everyday lives. In your everyday life, the gasoline car has to regularly detour to gas stations, and the EV doesn't. Which makes the comparison obviously "winner: EV".
But in case your - I quote, "silly scenario" - matters to you: it's 383 miles between LA and SF. If you were driving there in the morning and back in the evening, you'd need a nominal 73 miles range added during the drive (plus whatever "buffer" you want - say, 30 miles). That's a 13 minute stop on each of your 5 1/2 hour drives. That's 13 minutes with the current V2 superchargers - should be under 10 minutes on V3.
Apparently you're unaware that anyone can order Tesla parts now. No wait times. By the way, I have two vehicles, one of which is a pickup truck which has been in the shop for much of a month - first waiting on a replacement bearing, and then when they tore it down, they discovered that they needed a second bearing replaced as well, and now I'm waiting on that. But I guess wait times only ever count when the vehicle under discussion is a Tesla?
Consumer Reports rates it as "average" - which for a car in its first model year, is quite good.
You have no bloody clue what's in a NMC battery.
The cathodes are metal oxides. Inert. Non-soluble. The anodes are graphite. Lithium is intercalated, not bound, into both. The electrolytes decompose rapidly on exposure to water, with the most meaningful decomposition products being lithium ions (same as can leach from the electrodes) and fluoride ions. Excepting in abnormally high quantities, both lithium and fluorine in groundwater are good for peoples' health - to the point that we fluorinate our drinking water and lithium spring waters have long been used as health baths and drinks (7-up was initially a lithiated soda). Places where the groundwater is naturally richer in lithium have lower rates of violent crime and suicide than places where the groundwater is poor in lithium. This shouldn't come as a surprise, as high doses of lithium are used to treat mood
* "Battery" is a generic term, and can refer at any scale.
* "Cells" or "Battery cells" refers specifically to the subunits
* "Packs" or "Battery packs" refers to the bulk object which contains multiple cells.
Pack production is at least as complicated as cell production (including the production of 2-meter-long PCBs, fine wire bonds for every of thousands of cells, etc - plus the packs also contain the charger, the DC-DC converter, cooling, insulation, etc etc). But both are obviously critical. It's a good division of responsibility between Tesla and Panasonic that lets them spread out the capital costs.
I find it funny that you think that joke still works after Tesla just had a free cash flow of nearly a billion dollars in Q3 ;)
No. It's because there's only so fast you can expand. I'm not sure what world you live in where nearly doubling cell capacity in six months isn't an impressive scaleup rate, but in my world, that's pretty dang impressive.
What sub-$59k (not counting tax credits or fuel savings**) ICE car are you referring to that nearly does 0-60 in 3,3 seconds?
** - About $1k per year for the average US driver, $2k for the average European driver, and about $3k where I live. So e.g. in 5 years of ownership that's $5k/$10k/$15k.
Almost certainly depends on the conditions. The Tesla Model 3 Performance goes further in city driving than the BMW M3 even if you credit the BMW to a full tank every day. If you assume that the Model 3 is charged to 90% every day and the BMW averages a 60%-full tank at any random point in time, the Model 3 goes further in combined-cycle driving as well. The M3's range is obviously far more variable, which is of course not a good thing.
Yes, detouring regularly on your way to or from work to drive to a gas station so you can pay out the nose for the privilege of standing outside in whatever weather you're in to pump carcinogens into a tank is so much faster than plugging in when you get home and disconnecting when you leave.
But hey, if you like wasting your life... Maybe we can find you a cell phone that you don't plug in at night, but rather have to detour out of your way to "cell stations" once a week to fill up - would you be interested in that?
Which of the 45 thousand employees at Tesla responsible for the design and construction of the vehicles are you referring to?
About 150k. On a relentless, steady decline that EVs are only going to accelerate. Meanwhile, the number of car-accessible electric sockets in the US alone surely numbers in the billions.
And remember, unlike EVs, cars must visit not-at-home gas stations at regular intervals.
Ed: "the extra 3k capacity in the body, stamping and plastics lines at Fremont" -> "the extra 3k capacity in the body and stamping lines at Fremont".
Yeah, they've been seriously cell deprived. It's not enough that between 18650s and 2170s the Tesla-Panasonic alliance is now making 60% of the world's total EV battery capacity - Tesla has also been having to buy cells from other manufacturers to keep their Powerwall and Powerpack production going. Tesla's been consuming cells like a beast, mainly for Model 3, and it's impacting their other product lines.
Panasonic has been lagging, but they're trying to catch up. At the end of Q3, GF1 was producing 2170s at an annualized rate of around 20GWh/year (current global production for EVs is around 40GWh/year). Panasonic is installing three of its new, faster line design (joining the 10 lines of their older design); this is expected to bring them up to 35GWh/year by March.
Gotta love those sorts of scaling factors. We live in interesting times.
BTW, Panasonic has stated that they're not going to be building out lines in Shanghai next year, although might in the long-term. Their capital is currently focused on GF1. Model 3 production at GF3 will be started using a mix of cells, both imported from GF1 and from local Chinese manufacturers. From the 10-Q, it looks like they're planning to take the route I laid out on TMC a couple weeks ago:
* Fremont's lines are all designed for 10k/wk production rates, but some - namely, paint and GA (general assembly), look likely to bottleneck out at 7k/wk. Upping these rates would require meaningful investment and/or downtime to boost to 10k - but Tesla doesn't really need 10k/year in the US. The body, stamping and plastics lines all look ready for 10k.
* Tesla has already started site work at Shanghai. Their first step will be to have it leveled and prepped, with utility and transport connections in place. A factory is worthless if things and people can't move smoothly in and out.
* GA lines are the fastest and easiest to build; Tesla made one in a month out of scrap in Q2 this year. I expect them to have the first GA line up in late Q2 of next year.
* Paint lines are more complicated to get running smoothly and consistently. I expect them to open their first paint line in Q3/Q4 of next year.
* At this stage, they'll import BIWs (Body In Whites), made using the extra 3k capacity in the body, stamping and plastics lines at Fremont, and finished packs and drive units from GF1. So Fremont will be at 7k and GF3 at 3k. BIWs will need either dry packaging or temporary anti-corrosion coatings for shipping, so Tesla will have to prep for this.
* Stamping, plastics, body, pack, and cell production will come on line in early '20, along with new GA and paint lines to ramp local production (specifically, to add Model Y production into the mix). This also frees up 3k capacity at Fremont and GF1.
* In the meantime, GF4 prep work, the first GA line, and the first paint shop will have been completed in Germany (early '20, 2-3 quarters behind Shanghai). So the extra BIWs, drive units and packs get shipped to GF4, and the Shanghai process repeats.
Tesla's messaging has been consistent: these are products that they need to offer a lifetime warranty on, with a 30 year warranty on electricity generation; they need to make damned sure they're going to last in the real world (and use the meantime to refine the installation mechanism to be as cheap as possible). So while Tesla has done a limited rollout to a small number of houses, they don't want to enter bulk production until they're ready.
That said... IMHO, there's no question that the half year delay in the Model 3 ramp consumed a lot of cash that they would otherwise have put into GF2. I'm sure we'd be a lot further into the ramp - warranty periods or no - had this not happened. GF2 is behind schedule on hiring. They're now planning for a big rampup in production in Q1. A good indicator would be to watch their hiring late in Q4.
Only if management actually believes said study. At any large organization, there will exist some people people who believe that any given schedule is too optimistic, and will say so. To argue that because some people in an organization expressed concern about a schedule, but management overruled them, that this is criminally actionable, would be to argue that almost any delayed project where anyone protested is actionable. What matters is whether the decision makers believed their own schedules. Aka, the case would be to argue that Musk has no record of excessive optimism about schedules.
Yeah, good luck with that. We're talking about a guy who literally just the other day just fired his Starlink managers because he felt their schedules were too pessimistic.
A great example of the above was the attack series launched by UAW-tied organization "Reveal". First they alleged a high injury rate (with a bunch of BS about beeping forklifts and yellow caution tape being banned) - but Tesla rebutted it by pointing out that they're using old data, that they're around the industry average now, and that the plant used to be the highest injury-rate plant in the US before they bought it. So Reveal switched gears to arguing that they were "hiding" injuries off the books. They even got CAL-OSHA to investigate, and the latter's investigation concluded just recently: the biggest problem they found was an extension cord to a fan that could pose a trip hazard, and one injury whose date was wrong. Vs. its competitors which actually have been found to be hiding injuries off the books, and fined.
Each time the Reveal reports came out, the news was picked up widely. The actual facts? Crickets. Scandal sells. "Wait, there wasn't actually a scandal" doesn't.
In case you're curious, the full context of that quote:
Kara: "You pick fights with the press over Twitter, and then you have all your fans, of which there are many. Are you aware of what they do once you start them off?"
Elon: "Well, I have to say, my regard for the press has dropped quite dramatically."
Kara: "Explain that, please."
Elon: "The amount of untruthful stuff that is written is unbelievable. Take that Wall Street Journal front-page article about, like, “The FBI is closing in.” That is utterly false. That’s absurd. To print such a falsehood on the front page of a major newspaper is outrageous. Like, why are they even journalists? They’re terrible. Terrible people."
Kara: "I get that, but do you understand the mood in this country around the press and the dangers of attacking, especially when the president is doing that? In quite an aggressive, “enemy of the state” and everything else. It’s disturbing when someone like you as a leader does that, too, or goes along with it."
Elon: "The answer is for the press to be honest and truthful, and research their articles and correct things properly when they are false. Which they don’t do."
Kara: "Okay. But I’m asking if you understand where it goes to."
Elon: "Yes, of course I do."
Kara: "What do you think of that? Are you worried about unleashing a dangerous cycle that a lot of the press are worried about? Justifiably."
Elon: "I suggest the press take it to heart and do better."
Kara: "What about what Donald Trump does, about “enemy of the people”? Do you look at it that way?"
Elon: "No."
Kara: "Just that you don’t like falsehoods."
Elon: "Yeah. There are good journalists and there are bad ones, and unfortunately the feedback loop for good versus bad is inverted, so the more salacious that an article is, the more salacious the headline is, the more clicks it’s gonna get. Then somebody is not a journalist, they are an ad salesman."
Kara: "What about things that are just critical of you that you don’t like? Do you think you’re particularly sensitive?"
Elon: "No. Of course not. Count how many negative articles there are and how many I respond to. One percent, maybe. But the common rebuttal of journalists is, “Oh. My article’s fine. He’s just thin-skinned.” No, your article is false and you don’t want to admit it."
Just more "Slashdot's typical terrible coverage".
The criticism of the WSJ article was that it recycled old information and presented it as new. The fact that there had been a DOJ investigation was not news; Tesla confirmed a Bloomberg story on it in September. The request for documents from Tesla happened over a month ago. WSJ made this big front-page "DOJ is closing in!" article based on the fact that... the FBI sought documents and testimony from some former employees. It caused the stock price to plunge, but by the end of the day it had almost fully recovered (and surged past that the next day) as investors realized that they were just recycling a story. Then after the 10-Q repeated the news that broke in, I'll repeat, September (that the DOJ had requested, and been given, documents related to the production ramp), a number of outlets ran prominently with the exact "Tesla confirms DOJ investigation!" article, as if this was actual, new news. They're milking the heck out of this.
FYI: the DOJ case was launched simultaneously with a civil case on the exact same issue. Tesla already won the civil case. Obviously. Seriously: if missing projections while publicly describing what's going on as "production hell" is actionable, then virtually every company in the United States would be bankrupt.
1) The sun will not go supernova :)
2) The sun actually does lose significant mass in its red giant phase
3) There's a wide variety of stellar processes that affect orbits of objects around them (although the larger the body, the less effect these processes have)
Surprisingly enough, it doesn't really matter what you siphon off. In a star the mass of our sun, there's relatively little inflow of new fuel into the core. Smaller stars are fully convective, in that everything can cycle through the core. So just by simply "lightening" the star by any means, down to a red dwarf (note: not a brown dwarf!), you let all of that new fuel get in. Also, the higher mass of the sun increases the reaction rate in the core, so reducing the mass slows that down significantly. And red dwarfs are strictly hydrogen-burning; there's never a helium flash, no triple alpha process.
Red dwarfs never turn into giants. Instead, they're predicted to evolve into blue dwarfs. Although since it takes orders of magnitude longer than the age of the universe for this to happen, there are no blue dwarfs in the universe yet to observe!
Even before the sun's red giant phase it will have doubled in luminosity. Assuming no feedback effects, that would increase Earth's equilibrium temperature by 19% on an absolute temperature scale. So if you assume that feedback mechanisms remain the same, you're talking at least 50 degrees celsius temperature increase.
Of course, that's far too simplistic of an approach to take; feedback levels will change, and the details of that are a complex modeling task. Runaway greenhouse effects are quite possible (such as: loss of crustal water = reduce crustal viscosity = reduced / eliminated large-scale plate tectonics = Venus-like geology).
Of course, the biggest question is whether any sort of sentient life would exist in the system at that point in time. If so, it would likely be so far advanced (billions of years of technological development) that building an orbital solar reflector would be a laughably trivial task, and even relocating the planet might be within their reach. The ultimate achievement would be if they were to develop technology to siphon off matter from the sun over billions of years, ultimately reducing its mass to under 0,3Msol. Then it would not only burn slower, but also be fully convective - greatly extending its lifespan. Very low mass main sequence stars can potentially burn for trillions of years.
Fun fact: Sgr A* got its "star" postfix based on a nerdy joke: in atomic physics, excited states are denoted with asterisks, and Robert Brown found the signal coming from it "exciting" ;)
Regardless of what I say or do, we (the human species) will be covering the Earth in extensive amounts of concrete every year.