Of course, don't forget that lithium phosphate batteries are made from a small amount of a lithium salt (~$5/kg; even from seawater, it's only ~$30/kg), a bulk electrolyte, and various ingredients you'd find in a can of coke or around the house (phosphoric acid, sugar, iron, graphite, a PVC membrane, and an aluminum casing). They're only expensive because they're not mass produced yet like conventional laptop li-ion batteries are (conventional laptop batteries being price limited largely by the cost of the cobalt in the cathode, with LiP eliminates).
Titanates, phosphates, and spinels can take a charge in 5-10 minutes.
This alone will severely hamper the adoption of purely electric vehicles until the charging technology improves.
You mean like the 60kW PosiCharge fast chargers already installed around Oahu? Or the 250kW chargers made by the same company (Aerovironment)? Or any of the fast chargers made by other companies, such as Epyon?
It's okay; most people aren't aware of how far EV tech has gotten since the 90s.:)
Error in your logic: Electricity has already undergone Carnot losses. Gasoline hasn't. The average ICE is only about 20% efficient. The average li-ion EV is about 80% efficient when fed already-generated electricity.
Don't take my word for it. Take the word of a peer-reviewed study from PNL conducted for the DOE. We already have enough electric infrastructure for 84% of our existing vehicle fleet to switch. Of course, not as though it's somehow *harder* to build electric infrastructure than develop new oil fields and pipelines. Just the opposite, actually -- that's largely why electricity is so much cheaper per joule.
Ack, the post got messed up... I should have previewed. Replace that second paragraph with:
Okay, so these are the outlets found all across the country. The RV ones are especially interesting, since RV parks can often be found in even the most remote places, and I'm sure your average RV park owner would love a new revenue stream, what with RV travel down due to high gas prices. Now, let's take an upcoming EV like the Aptera Typ-1e -- 2+1 seating, 120 miles@55mph, 70 miles@80mph, 90mph top speed, 0-60 in under 10 sec, 15.9 cubic feet of cargo space, etc for $27k. It has a 10kWh battery pack. Charger efficiency isn't known, but 93% or so is standard for slow charging (i.e., charging in more than half an hour or so). Li-ion batteries range from 96% (fast charging) to 99.9% (trickle charging) efficiency. Let's say 99%. Let's ignore the slowdown at the end, since that's more significant with .
For ~2 hours worth of moderate speed driving or ~1 hour of high-speed driving, and assuming an appropriate onboard charger, you get the following charge times: NEMA 5-15R (15A): 6.2h NEMA 5-15R (20A): 4.6h NEMA TT-30R: 3.1h NEMA 10-30R or 14-30R: 1.5h NEMA 10-50R or 14-50R: 0.92h
Now, these are with standard outlets that you can already find across the country. Thanks to modern batteries and chargers, fast charging is not only possible, but already available in places, such as Oahu. They use 60kW PosiCharge fast chargers by Aerovironment. Aerovironment already makes them as big as 250kW.
Okay, well, first let's look at some common outlets in the US. Your standard NEMA 5-15R has a 15A breaker and, while there's a nominal delivery voltage of 120V, you'll probably get 117V or so out of it. That's 1.755kW. Kitchen outlets generally have a 20A breaker, so 2.34kW. The NEMA TT-30R, the standard low-power RV outlet, is also a nominal 120V, so assuming 117V still, that's 3.51kW. Dryer outlets are split-phase, either NEMA 10-30R or 14-30R (the 14-30 ones are properly grounded; the 10-30s are grounded through the neutral). They're able to feed a nominal 240V (we'll say 234V) at 30A. That's 7.02kW The higher power equivalents, the 10-50R and 14-50R, are the standards for range outlets. The 14-50R is also the standard high-power RV socket. This is 11.7kW.
Okay, so these are the outlets found all across the country. The RV ones are especially interesting, since RV parks can often be found in even the most remote places, and I'm sure your average RV park owner would love a new revenue stream, what with RV travel down due to high gas prices. Now, let's take an upcoming EV like the Aptera Typ-1e -- 2+1 seating, 120 miles@55mph, 70 miles@80mph, 90mph top speed, 0-60 in Oahu. They use 60kW PosiCharge fast chargers by Aerovironment. Aerovironment already makes them as big as 250kW.
To get an idea of what sort of driving distances you can get in a given length of time and how those compare to gasoline, there's always this convenient spreadsheet. Adjust the EV pararmeters to those of the EV of your liking. Explanations of the formulae and parameters are at the bottom.
Oh, and as for Mercedes? Who wants to bet that they'll make one or two EV/PHEVs, one fuel cell vehicle, and do the cheap/lazy thing and simply make all of the rest of their vehicles flex-fuel capable?
Perhaps computer interfaces may be a bit of a stretch, but the potential for custom DNA sequences, whether it's to make new drugs or do nanoengineering for things like solar panels or battery components, is tremendous.
While I doubt it would work with artificial bases, since I doubt you could readily get DNA made of artificial bases to reproduce inside an organism one of my favorite potential uses for "ordinary" custom DNA sequences is to eradicate invasive species. You need to make "greedy" (parasitic genes that mess with the normal inheritance process, changing the odds of being passed down from 50% to nearly 100%), recessive, lethal alleles and introduce them into a wild population. According to simulations, they'd steadily spread until the entire population had them, wherein the entire population would be unable to breed and would die off. While I initially heard this proposed to eliminate certain kinds of malaria-carrying mosquitoes, it sounds like a perfect solution to, for example, get rid of non-native rats and snakes from islands where they're killing off native species.
Which is what made the story so ridiculous. Iraq already *had* large amounts of yellowcake. It was produced as a byproduct of phosphate mining back in the 70s and 80s, back when they actually had a nuclear program. The concept that they were going to buy more was transparently idiotic to anyone who had actually studied the Iraqi nuclear program. Which is why there was such an international uproar: because a lot of people actually *had* studied the Iraqi nuclear program.
The same thing with the aluminum tubes. Iraq's centrifuges called for flow-formed maraging steel rotors. Unless they had *entirely scrapped all of their previous progress that they spent ages developing*, an aluminum that's ill-suited for welding and would easily have snapped under the centripetal force wouldn't have done a darned thing for them. On the other hand, it was the exact same type of tubing known to be used for small Iraqi military rockets. The concept was widely mocked by the international community and the international press. In the US, not so much. In fact, they mocked the concept that it would be used for Iraqi rockets (despite us knowing about said rockets), talking about how even we use poorer alloys than that for our rockets, and completely ignoring the fact that the Iraqis used a higher quality aluminum to compensate for lower manufacturing quality.
I didn't say that they'd convert it; I just converted the numbers to gasoline since that's what Americans are most used to mpg figures for. Comparing gasoline mpg figures to diesel mpg figures without adjusting for the difference in density isn't an accurate comparison. That said, if VW wants to be able to sell in California and any states that adopt CA's environmental regulations, they'll probably have to switch. Aptera was disappointed to discover that they couldn't find a single diesel engine as small as they needed it to be that met CA clean air regulations; that's why the Mk1 pre-production model switched from diesel. The problem is that the CA regulations are based on emissions per gallon rather than emissions per mile.
Really points out that the Neo Freerunner isn't really a bad deal, like some people were trying to claim in an earlier thread. Hardware capabilities almost as good as or matching an iPhone, and *no* contractual obligations, for $400. If $600-$700 is what they'd need to sell an iPhone for when the "locked into a contract" subsidy is removed, it sounds like the Freerunner is at a very reasonable price point, just ignoring all of the "open" aspects to it.
Of course, statistics can be misleading. In this case, the vehicle actually got 285mpg in a test run. However, thus run was at 45mph rather than a more typical 55mph; there's 1 1/2 times the aerodynamic drag at 55mph. Rolling losses will be higher by 1.2x. Let's say an overall 1.4x higher, since aerodynamic drag dominates at higher speeds; converting, we get 203mpg. Next, this wasn't a normal drive cycle, but a person trying to optimize their ride. Let's be generous and only cut it to 180mpg. It's a diesel, and diesel is about 15% more dense than gasoline, and emits about 15% more CO2; cut it to 155mpg for a gasoline-equivalent. The production version is going from a 1 cylinder to a 2 cylinder mild hybrid, since the 1 cylinder has poor acceleration. This won't hit it as much as normal, since the car operates on an acceleration/coasting system of maintaining sped, but it should at least hit it a little; let's say 145mpg. The production version is also going to be getting heavier, since this version omitted all of the standard things like airbags and so on. Let's say 130mpg to be generous. And if they widen it to make it more stable (it's quite narrow), it'll get more aerodynamic drag and go lower still. Same if they try and reinforce that frame and skin -- carbon fiber is great, but they're not using much of it, and magnesium (which makes up the bulk of the frame) is even weaker than aluminum. And if they try to make it more affordable by, say, swapping the carbon fiber and magnesium for aluminum and kevlar or fiberglass or whatnot (it's current projected *subsidized* price is, if I recall correctly, something like $40-60k USD), that'll drop further still. Also, since it only has a rather limited regen capability, its city mileage will be lower than its highway mileage.
Now, even with all of this, it's still one darned efficient vehicle. It's just not as impressive as the original claims. It's easy to manipulate numbers to try and make a vehicle look more efficient than it is. For example, with the Aptera. You generally see two numbers for it: 230mpg and 300mpg. Both are bogus. 230mpg was what the Mk0 got at 55mph. However, it too was a shell, and was not as safe or full of the things needed to meet legal requirements as the Mk1. It was also a diesel. Converting to the Mk1 pre-production model, its charge sustaining mileage went all the way down to 130mpg. However, they generally cite 300mpg, under the excuse that most people don't go on long trips very often, so it'll usually run just on electricity, which they don't count. It's still misleading; many people I've talked to thought you could go cross-country on 300mpg. Nope, not without charging every hundred miles or so. Mind you, Aptera is hardly alone in doing this; virtually all of the PHEV makers do it, and some are a lot worse offenders than others. I remember seeing an article about an SUV that got "150mpg". If you look at how they did their numbers, they were assuming that only something like 1/7th of its miles ran on gasoline, and only counting the gasoline.
In short: before you believe inflated mileage claims, look into the numbers.
On the subject of Aptera vs. 1L car: it's interesting the approaches taken by Aptera and the 1L car. The 1L car doesn't take streamlining as far. They move the rear wheels close together, but not so far as to make it a three wheeler. They lift the rear a little off the ground to eliminate ground turbulence, but not nearly as much as the Aptera -- nor do they use cabin air to fill in their wake. Overall, their drag coeff is 0.19, compared to 0.11 for the Aptera. However, while Aptera decided to make one significant compromise on efficiency -- requiring side-by-side seating to make it more acceptable to the general public -- Volkswagen did not. Their tandem seating arrangement reduces frontal area. While there are some downsides to tandem seating, it would be interesting to see a vehicle that takes a combined approach, with the extreme streamlining of an Aptera, along with its hig
Water does indeed compress... perhaps not easily, but it does. Search Google... I'm too bored to do so.
Water is known as an incompressible fluid. Technically, it does compress a little, but by a small enough amount as to be negligible in most applications.
And of course, needing to replace them after so many cycles isnt efficient either (and is very costly for situations such as this that would require a lot of battery).
Almost no multiuse battery variety uses anywhere near as much energy to make as it stores and discharges in its lifespan -- all li-ions included. Furthermore, only traditional li-ion and li-poly have short lifespans. The new varieties, such as the titanates, phosphates, and spinels have extremely long cycle lives -- especially the titanates. AltairNano's have been tested to over 25,000 cycles. They're so durable that at least one power company is considering using them for load leveling applications.)
Compressed air is extremely inefficient -- compressors generally only get 10-20% efficiency. Now, since these compressors would need to be monstrous in scale, they've probably got a bunch of stages and are doing everything possible to recover waste heat, so they'll probably do much better than that, but nonetheless, there's going to be a huge degree of loss here. This isn't a problem for incompressible fluids such as water.
Batteries (as another poster mentioned) are extremely efficient. Li-ion, for example, ranges from 95%-99.9% depending on the variety and the rate of charge. The problem is not the efficiency of batteries but their cost. One hope is that flow batteries may improve the situation.
I wasn't meaning to compliment the Chinese system of mining by any stretch:) I was just pointing out that if we *wanted* to, we could mine coal a heck of a lot faster. Coal is so readily mined that it's dirt cheap. Quite literally -- a short ton of powder river basin coal will only set you back $15. The most expensive coal in the US is only about $70 a ton.
Rents are unrelated to the cost to propel the ship. We're talking about the rent, not the operations cost.
You completely misunderstood the article you posted. One, it's from 2004. Early 2004, at that. Way outdated. Also, oil demand growth today (I.e., not 2004) is rather low due to the high prices. Here's a more recent article.
Oh really. Now explain to me what you think is limiting our production capacity by -- oh, let's say, coal liquefaction. Steel, with all of those steel mills shuttered across Appalachia? Unskilled labor, with huge unemployment in said regions and elsewhere? Engineers, with huge numbers in places like India and China trying to get visas? Rates of coal extraction, when China is mining through their their more-difficult-to-get reserves mostly by manual labor three times faster than we are (on a percentage basis)? Tell me, what do you think is the limiting factor?
Here's some things that should clue you in on oil prices. Oil companies aren't being valued by the market as though oil was $140+ a barrel; they're being priced as though it was $50-70 a barrel. Oil companies aren't betting on projects with expected oil prices at $140+ a barrel; the most expensive I've seen them undertake are the Bakken (~$50/barrel) and Greenland (~$50/barrel), and in the former case, it's only small oil companies, and in the latter case, it's only very preliminary work. The people who should know what they're talking about are *not* betting on these prices being sustained, or anythign close to them. Only the futures market is way up. Now, if that doesn't look like a standard commodities bubble, I don't know what does. Well, that and perhaps this: have you checked out prices of rents in oil exploration and transportation? Drilling ship rents are 3-4 times what they were a year ago. Fine, that's to be expected. Rig rents are 3-4 times what they were a year ago. Again, that's to be expected. But *tankers*, too, are renting at 3-4 times what they were a year ago. Go on, explain that one under the "scarcity" theory. If there's a scarcity, where's all of this oil coming from? Iran and Venezuela are both known to be renting tankers and just storing oil in them. In Iran's case, a slowdown in demand in India has lead a refiner there to stop buying their sour crude, only needing their more local sweet crude. They're looking for a new buyer, and in the meantime, they're stockpiling. The situation is such that a company with oil in a tanker, even with the current high prices, is paying less on the rent for the tanker than they're gaining by holding onto the oil as prices rise.
The exact same thing happened in the last oil spike. When prices collapsed, they all rushed to port to unload as fast as possible, furthering the price fall. Bubbles work that way.
The Simon-Ehlrich Wager wasn't a fluke. For more detail, I've written a fair bit on the concept of peak oil (w/references).
That contradicts the linked article. Not saying that one is right, just that there seems to be some dispute. The wiki also says 400MHz, while this says 500MHz.
Thanks! Hadn't seen that yet. Did they have to sacrifice anything for it? Modern phones are extremely space-limited, so you usually need to cut something to add something else. For example, for the Neo to support WiFi, they had to cut a speaker.
You KNOW that they are not going to use the same engine for SS3
SS3 is vaporware. It's probably had about as much design work done on it as a spacecraft I designed a while back. And if they don't start taking safety more seriously and end up killing paying passengers just once, it'll stand just as much of a chance of actually being built.
For any SS3 to actually work, they would have to literally start over. On virtually everything. Almost nothing they've developed and almost none of the experience they developed will apply to it, apart from a better understanding of dealing with transsonic and supersonic flight (which they could have just hired people for). the materials are wrong, the engines are wrong, the propellants are wrong, the staging is wrong, and on and on, and they haven't even touched on 95% of the actual challenges of real orbital spaceflight. What they built is far closer to a supersonic airplane than it is to an orbital spacecraft.
None of this means that they *can't* do SS3. What I've been pointing out is that SS3 is essentially starting over. SS1/SS2 is a technological dead-end as far as reaching orbit is concerned, and it doesn't retire or even begin to approach the overwhelming majority of the challenges involved.
Blowing up wealthy passengers isn't exactly an attractive business model, no matter what waivers you make them sign. And if the current disregard toward safety continues, that's exactly what's going to happen.
Oh, and by the way, please elaborate on the proven viability of SS2.
For years, I was warning people that Scaled was playing fast and loose with safety. I wrote this in 2006 (and updated with the latter link in early 2007, before the accident):
"Rutan, on the other hand, nearly killed his test pilot by launching in high wind shear conditions, and launching before resolving the cause of wild rolls at rocket ignition. With just a small handful of flights. On a task that is incredibly easy compared to reaching orbit. Some view the rocketplane tourism industry as a disaster waiting to happen."
1) Falcon 9 is far closer to "completing a successful test flight" than SpaceShipTwo. It has completed four static test firings, compared to a resounding zero for SS2.
2) No, it is not a "cargo rocket"; it's designed for either cargo *or* the Dragon spacecraft, which is scheduled to launch in Q1 of next year. You see, back in the real world of orbital rocketry, there's this little thing called "staging" that you have to deal with. And no, the tiny bit of extra altitude and speed from the White Knight hardly counts. In real, orbital rocketry, you can't generally afford to be hauling around the mass of what got you there.
will put space within reach
Count "2" for the number of times that "space" and "orbit" have been predictably treated as though they're roughly equivalent, when they're not even close.
which has already PROVEN its viability with several successful test flights.
Just the first stage of Falcon 1 gave more delta-V in a single launch than all of SS1's flights combined. It was only the second stage that failed, and really, it only "failed" in that the engine shut down early due to a slosh, which has been corrected in two different ways. Even the payload separated normally.
You're comparing a Segway with an EV1 here. The flight envelope of SS1 and SS2 isn't even remotely, slightly, trivially comparable to that of the Falcon series.
They're hardly comparable are they! Slashdot readers are far more interested in something which will take PEOPLE into space, rather than yet another satellite lifter that's only interesting because it's cheaper to make.
Apparently you've never heard of the Dragon. The Falcon series is designed to lift cargo *and* people to orbit. Unlike the shuttle, they made the wise (IMHO) decision to not require people to be on every liftoff; you include people when you want to lift people, and not otherwise. The first Dragon flight is scheduled for early next year. Both Falcon and Dragon have passed every NASA COTS review so far (example).
Also, once again, the old fallacy of "being in space is roughly equivalent to being in orbit" rears its ugly head. Sadly, this happens in pretty much every thread about SS1/SS2.
Apart from anything, SpaceShipOne/Two just simply looks WAY cooler!
Slashdot Mirror
Of course, don't forget that lithium phosphate batteries are made from a small amount of a lithium salt (~$5/kg; even from seawater, it's only ~$30/kg), a bulk electrolyte, and various ingredients you'd find in a can of coke or around the house (phosphoric acid, sugar, iron, graphite, a PVC membrane, and an aluminum casing). They're only expensive because they're not mass produced yet like conventional laptop li-ion batteries are (conventional laptop batteries being price limited largely by the cost of the cobalt in the cathode, with LiP eliminates).
How long does it take to charge batteries?
Titanates, phosphates, and spinels can take a charge in 5-10 minutes.
This alone will severely hamper the adoption of purely electric vehicles until the charging technology improves.
You mean like the 60kW PosiCharge fast chargers already installed around Oahu? Or the 250kW chargers made by the same company (Aerovironment)? Or any of the fast chargers made by other companies, such as Epyon?
It's okay; most people aren't aware of how far EV tech has gotten since the 90s. :)
Error in your logic: Electricity has already undergone Carnot losses. Gasoline hasn't. The average ICE is only about 20% efficient. The average li-ion EV is about 80% efficient when fed already-generated electricity.
Don't take my word for it. Take the word of a peer-reviewed study from PNL conducted for the DOE. We already have enough electric infrastructure for 84% of our existing vehicle fleet to switch. Of course, not as though it's somehow *harder* to build electric infrastructure than develop new oil fields and pipelines. Just the opposite, actually -- that's largely why electricity is so much cheaper per joule.
Ack, the post got messed up... I should have previewed. Replace that second paragraph with:
Okay, so these are the outlets found all across the country. The RV ones are especially interesting, since RV parks can often be found in even the most remote places, and I'm sure your average RV park owner would love a new revenue stream, what with RV travel down due to high gas prices. Now, let's take an upcoming EV like the Aptera Typ-1e -- 2+1 seating, 120 miles@55mph, 70 miles@80mph, 90mph top speed, 0-60 in under 10 sec, 15.9 cubic feet of cargo space, etc for $27k. It has a 10kWh battery pack. Charger efficiency isn't known, but 93% or so is standard for slow charging (i.e., charging in more than half an hour or so). Li-ion batteries range from 96% (fast charging) to 99.9% (trickle charging) efficiency. Let's say 99%. Let's ignore the slowdown at the end, since that's more significant with .
For ~2 hours worth of moderate speed driving or ~1 hour of high-speed driving, and assuming an appropriate onboard charger, you get the following charge times:
NEMA 5-15R (15A): 6.2h
NEMA 5-15R (20A): 4.6h
NEMA TT-30R: 3.1h
NEMA 10-30R or 14-30R: 1.5h
NEMA 10-50R or 14-50R: 0.92h
Now, these are with standard outlets that you can already find across the country. Thanks to modern batteries and chargers, fast charging is not only possible, but already available in places, such as Oahu. They use 60kW PosiCharge fast chargers by Aerovironment. Aerovironment already makes them as big as 250kW.
Okay, well, first let's look at some common outlets in the US. Your standard NEMA 5-15R has a 15A breaker and, while there's a nominal delivery voltage of 120V, you'll probably get 117V or so out of it. That's 1.755kW. Kitchen outlets generally have a 20A breaker, so 2.34kW. The NEMA TT-30R, the standard low-power RV outlet, is also a nominal 120V, so assuming 117V still, that's 3.51kW. Dryer outlets are split-phase, either NEMA 10-30R or 14-30R (the 14-30 ones are properly grounded; the 10-30s are grounded through the neutral). They're able to feed a nominal 240V (we'll say 234V) at 30A. That's 7.02kW The higher power equivalents, the 10-50R and 14-50R, are the standards for range outlets. The 14-50R is also the standard high-power RV socket. This is 11.7kW.
Okay, so these are the outlets found all across the country. The RV ones are especially interesting, since RV parks can often be found in even the most remote places, and I'm sure your average RV park owner would love a new revenue stream, what with RV travel down due to high gas prices. Now, let's take an upcoming EV like the Aptera Typ-1e -- 2+1 seating, 120 miles@55mph, 70 miles@80mph, 90mph top speed, 0-60 in Oahu. They use 60kW PosiCharge fast chargers by Aerovironment. Aerovironment already makes them as big as 250kW.
To get an idea of what sort of driving distances you can get in a given length of time and how those compare to gasoline, there's always this convenient spreadsheet. Adjust the EV pararmeters to those of the EV of your liking. Explanations of the formulae and parameters are at the bottom.
Oh, and as for Mercedes? Who wants to bet that they'll make one or two EV/PHEVs, one fuel cell vehicle, and do the cheap/lazy thing and simply make all of the rest of their vehicles flex-fuel capable?
Perhaps computer interfaces may be a bit of a stretch, but the potential for custom DNA sequences, whether it's to make new drugs or do nanoengineering for things like solar panels or battery components, is tremendous.
While I doubt it would work with artificial bases, since I doubt you could readily get DNA made of artificial bases to reproduce inside an organism one of my favorite potential uses for "ordinary" custom DNA sequences is to eradicate invasive species. You need to make "greedy" (parasitic genes that mess with the normal inheritance process, changing the odds of being passed down from 50% to nearly 100%), recessive, lethal alleles and introduce them into a wild population. According to simulations, they'd steadily spread until the entire population had them, wherein the entire population would be unable to breed and would die off. While I initially heard this proposed to eliminate certain kinds of malaria-carrying mosquitoes, it sounds like a perfect solution to, for example, get rid of non-native rats and snakes from islands where they're killing off native species.
Which is what made the story so ridiculous. Iraq already *had* large amounts of yellowcake. It was produced as a byproduct of phosphate mining back in the 70s and 80s, back when they actually had a nuclear program. The concept that they were going to buy more was transparently idiotic to anyone who had actually studied the Iraqi nuclear program. Which is why there was such an international uproar: because a lot of people actually *had* studied the Iraqi nuclear program.
The same thing with the aluminum tubes. Iraq's centrifuges called for flow-formed maraging steel rotors. Unless they had *entirely scrapped all of their previous progress that they spent ages developing*, an aluminum that's ill-suited for welding and would easily have snapped under the centripetal force wouldn't have done a darned thing for them. On the other hand, it was the exact same type of tubing known to be used for small Iraqi military rockets. The concept was widely mocked by the international community and the international press. In the US, not so much. In fact, they mocked the concept that it would be used for Iraqi rockets (despite us knowing about said rockets), talking about how even we use poorer alloys than that for our rockets, and completely ignoring the fact that the Iraqis used a higher quality aluminum to compensate for lower manufacturing quality.
"Green gasoline" is renewable, too. It's made from using the Fischer-Tropsch process on syngas derived from incomplete combustion of biomass.
I didn't say that they'd convert it; I just converted the numbers to gasoline since that's what Americans are most used to mpg figures for. Comparing gasoline mpg figures to diesel mpg figures without adjusting for the difference in density isn't an accurate comparison. That said, if VW wants to be able to sell in California and any states that adopt CA's environmental regulations, they'll probably have to switch. Aptera was disappointed to discover that they couldn't find a single diesel engine as small as they needed it to be that met CA clean air regulations; that's why the Mk1 pre-production model switched from diesel. The problem is that the CA regulations are based on emissions per gallon rather than emissions per mile.
Really points out that the Neo Freerunner isn't really a bad deal, like some people were trying to claim in an earlier thread. Hardware capabilities almost as good as or matching an iPhone, and *no* contractual obligations, for $400. If $600-$700 is what they'd need to sell an iPhone for when the "locked into a contract" subsidy is removed, it sounds like the Freerunner is at a very reasonable price point, just ignoring all of the "open" aspects to it.
Of course, statistics can be misleading. In this case, the vehicle actually got 285mpg in a test run. However, thus run was at 45mph rather than a more typical 55mph; there's 1 1/2 times the aerodynamic drag at 55mph. Rolling losses will be higher by 1.2x. Let's say an overall 1.4x higher, since aerodynamic drag dominates at higher speeds; converting, we get 203mpg. Next, this wasn't a normal drive cycle, but a person trying to optimize their ride. Let's be generous and only cut it to 180mpg. It's a diesel, and diesel is about 15% more dense than gasoline, and emits about 15% more CO2; cut it to 155mpg for a gasoline-equivalent. The production version is going from a 1 cylinder to a 2 cylinder mild hybrid, since the 1 cylinder has poor acceleration. This won't hit it as much as normal, since the car operates on an acceleration/coasting system of maintaining sped, but it should at least hit it a little; let's say 145mpg. The production version is also going to be getting heavier, since this version omitted all of the standard things like airbags and so on. Let's say 130mpg to be generous. And if they widen it to make it more stable (it's quite narrow), it'll get more aerodynamic drag and go lower still. Same if they try and reinforce that frame and skin -- carbon fiber is great, but they're not using much of it, and magnesium (which makes up the bulk of the frame) is even weaker than aluminum. And if they try to make it more affordable by, say, swapping the carbon fiber and magnesium for aluminum and kevlar or fiberglass or whatnot (it's current projected *subsidized* price is, if I recall correctly, something like $40-60k USD), that'll drop further still. Also, since it only has a rather limited regen capability, its city mileage will be lower than its highway mileage.
Now, even with all of this, it's still one darned efficient vehicle. It's just not as impressive as the original claims. It's easy to manipulate numbers to try and make a vehicle look more efficient than it is. For example, with the Aptera. You generally see two numbers for it: 230mpg and 300mpg. Both are bogus. 230mpg was what the Mk0 got at 55mph. However, it too was a shell, and was not as safe or full of the things needed to meet legal requirements as the Mk1. It was also a diesel. Converting to the Mk1 pre-production model, its charge sustaining mileage went all the way down to 130mpg. However, they generally cite 300mpg, under the excuse that most people don't go on long trips very often, so it'll usually run just on electricity, which they don't count. It's still misleading; many people I've talked to thought you could go cross-country on 300mpg. Nope, not without charging every hundred miles or so. Mind you, Aptera is hardly alone in doing this; virtually all of the PHEV makers do it, and some are a lot worse offenders than others. I remember seeing an article about an SUV that got "150mpg". If you look at how they did their numbers, they were assuming that only something like 1/7th of its miles ran on gasoline, and only counting the gasoline.
In short: before you believe inflated mileage claims, look into the numbers.
On the subject of Aptera vs. 1L car: it's interesting the approaches taken by Aptera and the 1L car. The 1L car doesn't take streamlining as far. They move the rear wheels close together, but not so far as to make it a three wheeler. They lift the rear a little off the ground to eliminate ground turbulence, but not nearly as much as the Aptera -- nor do they use cabin air to fill in their wake. Overall, their drag coeff is 0.19, compared to 0.11 for the Aptera. However, while Aptera decided to make one significant compromise on efficiency -- requiring side-by-side seating to make it more acceptable to the general public -- Volkswagen did not. Their tandem seating arrangement reduces frontal area. While there are some downsides to tandem seating, it would be interesting to see a vehicle that takes a combined approach, with the extreme streamlining of an Aptera, along with its hig
Water does indeed compress... perhaps not easily, but it does. Search Google... I'm too bored to do so.
Water is known as an incompressible fluid. Technically, it does compress a little, but by a small enough amount as to be negligible in most applications.
And of course, needing to replace them after so many cycles isnt efficient either (and is very costly for situations such as this that would require a lot of battery).
Almost no multiuse battery variety uses anywhere near as much energy to make as it stores and discharges in its lifespan -- all li-ions included. Furthermore, only traditional li-ion and li-poly have short lifespans. The new varieties, such as the titanates, phosphates, and spinels have extremely long cycle lives -- especially the titanates. AltairNano's have been tested to over 25,000 cycles. They're so durable that at least one power company is considering using them for load leveling applications.)
Compressed air is extremely inefficient -- compressors generally only get 10-20% efficiency. Now, since these compressors would need to be monstrous in scale, they've probably got a bunch of stages and are doing everything possible to recover waste heat, so they'll probably do much better than that, but nonetheless, there's going to be a huge degree of loss here. This isn't a problem for incompressible fluids such as water.
Batteries (as another poster mentioned) are extremely efficient. Li-ion, for example, ranges from 95%-99.9% depending on the variety and the rate of charge. The problem is not the efficiency of batteries but their cost. One hope is that flow batteries may improve the situation.
I wasn't meaning to compliment the Chinese system of mining by any stretch :) I was just pointing out that if we *wanted* to, we could mine coal a heck of a lot faster. Coal is so readily mined that it's dirt cheap. Quite literally -- a short ton of powder river basin coal will only set you back $15. The most expensive coal in the US is only about $70 a ton.
Rents are unrelated to the cost to propel the ship. We're talking about the rent, not the operations cost.
You completely misunderstood the article you posted. One, it's from 2004. Early 2004, at that. Way outdated. Also, oil demand growth today (I.e., not 2004) is rather low due to the high prices. Here's a more recent article.
Oh really. Now explain to me what you think is limiting our production capacity by -- oh, let's say, coal liquefaction. Steel, with all of those steel mills shuttered across Appalachia? Unskilled labor, with huge unemployment in said regions and elsewhere? Engineers, with huge numbers in places like India and China trying to get visas? Rates of coal extraction, when China is mining through their their more-difficult-to-get reserves mostly by manual labor three times faster than we are (on a percentage basis)? Tell me, what do you think is the limiting factor?
Here's some things that should clue you in on oil prices. Oil companies aren't being valued by the market as though oil was $140+ a barrel; they're being priced as though it was $50-70 a barrel. Oil companies aren't betting on projects with expected oil prices at $140+ a barrel; the most expensive I've seen them undertake are the Bakken (~$50/barrel) and Greenland (~$50/barrel), and in the former case, it's only small oil companies, and in the latter case, it's only very preliminary work. The people who should know what they're talking about are *not* betting on these prices being sustained, or anythign close to them. Only the futures market is way up. Now, if that doesn't look like a standard commodities bubble, I don't know what does. Well, that and perhaps this: have you checked out prices of rents in oil exploration and transportation? Drilling ship rents are 3-4 times what they were a year ago. Fine, that's to be expected. Rig rents are 3-4 times what they were a year ago. Again, that's to be expected. But *tankers*, too, are renting at 3-4 times what they were a year ago. Go on, explain that one under the "scarcity" theory. If there's a scarcity, where's all of this oil coming from? Iran and Venezuela are both known to be renting tankers and just storing oil in them. In Iran's case, a slowdown in demand in India has lead a refiner there to stop buying their sour crude, only needing their more local sweet crude. They're looking for a new buyer, and in the meantime, they're stockpiling. The situation is such that a company with oil in a tanker, even with the current high prices, is paying less on the rent for the tanker than they're gaining by holding onto the oil as prices rise.
The exact same thing happened in the last oil spike. When prices collapsed, they all rushed to port to unload as fast as possible, furthering the price fall. Bubbles work that way.
The Simon-Ehlrich Wager wasn't a fluke. For more detail, I've written a fair bit on the concept of peak oil (w/references).
FYI, the "enviro-radicals" tend to hate corn ethanol. It's mainly the farmers who love the stuff.
That contradicts the linked article. Not saying that one is right, just that there seems to be some dispute. The wiki also says 400MHz, while this says 500MHz.
Thanks! Hadn't seen that yet. Did they have to sacrifice anything for it? Modern phones are extremely space-limited, so you usually need to cut something to add something else. For example, for the Neo to support WiFi, they had to cut a speaker.
To do a side-by-side rundown with the iPhone (correct me if I get anything wrong):
Category: Neo FreeRunner / iPhone
Price: $400 / $200-$400 plus specific service requirements
Screen res: 640x480 / 480x320
Screen size: 4.3" / 3.5"
CPU: Samsung S3C2442 500MHz / 620 MHz ARM 1176, underclocked to 412 MHz
GPU: SMedia 3362-based 3D graphics acceleration / PowerVR MBX 3D
Ram: 128MB / 128MB
Onboard flash: 256MB / 4, 8, or 16GB
Card support: MicroSD (64MB to 8GB) / None
Bluetooth: 2.0 / 2.0
Wifi: 802.11b/g / 80211b/g
USB: 1.x / 1.x
Camera: None / 2.0 megapixel
GPS: AGPS / None
3D accelerometers: 2x / 1x
Touch: Single / Multi
Cellular: 2.5G tri-band / 2G quad band (just this month, now 3G)
Freedom: Open / Closed
Looks like a fair competitor.
You KNOW that they are not going to use the same engine for SS3
SS3 is vaporware. It's probably had about as much design work done on it as a spacecraft I designed a while back. And if they don't start taking safety more seriously and end up killing paying passengers just once, it'll stand just as much of a chance of actually being built.
For any SS3 to actually work, they would have to literally start over. On virtually everything. Almost nothing they've developed and almost none of the experience they developed will apply to it, apart from a better understanding of dealing with transsonic and supersonic flight (which they could have just hired people for). the materials are wrong, the engines are wrong, the propellants are wrong, the staging is wrong, and on and on, and they haven't even touched on 95% of the actual challenges of real orbital spaceflight. What they built is far closer to a supersonic airplane than it is to an orbital spacecraft.
None of this means that they *can't* do SS3. What I've been pointing out is that SS3 is essentially starting over. SS1/SS2 is a technological dead-end as far as reaching orbit is concerned, and it doesn't retire or even begin to approach the overwhelming majority of the challenges involved.
Blowing up wealthy passengers isn't exactly an attractive business model, no matter what waivers you make them sign. And if the current disregard toward safety continues, that's exactly what's going to happen.
Oh, and by the way, please elaborate on the proven viability of SS2.
For years, I was warning people that Scaled was playing fast and loose with safety. I wrote this in 2006 (and updated with the latter link in early 2007, before the accident):
"Rutan, on the other hand, nearly killed his test pilot by launching in high wind shear conditions, and launching before resolving the cause of wild rolls at rocket ignition. With just a small handful of flights. On a task that is incredibly easy compared to reaching orbit. Some view the rocketplane tourism industry as a disaster waiting to happen."
I would rather have been proven wrong.
1) Falcon 9 is far closer to "completing a successful test flight" than SpaceShipTwo. It has completed four static test firings, compared to a resounding zero for SS2.
2) No, it is not a "cargo rocket"; it's designed for either cargo *or* the Dragon spacecraft, which is scheduled to launch in Q1 of next year. You see, back in the real world of orbital rocketry, there's this little thing called "staging" that you have to deal with. And no, the tiny bit of extra altitude and speed from the White Knight hardly counts. In real, orbital rocketry, you can't generally afford to be hauling around the mass of what got you there.
will put space within reach
Count "2" for the number of times that "space" and "orbit" have been predictably treated as though they're roughly equivalent, when they're not even close.
which has already PROVEN its viability with several successful test flights.
Just the first stage of Falcon 1 gave more delta-V in a single launch than all of SS1's flights combined. It was only the second stage that failed, and really, it only "failed" in that the engine shut down early due to a slosh, which has been corrected in two different ways. Even the payload separated normally.
You're comparing a Segway with an EV1 here. The flight envelope of SS1 and SS2 isn't even remotely, slightly, trivially comparable to that of the Falcon series.
They're hardly comparable are they! Slashdot readers are far more interested in something which will take PEOPLE into space, rather than yet another satellite lifter that's only interesting because it's cheaper to make.
Apparently you've never heard of the Dragon. The Falcon series is designed to lift cargo *and* people to orbit. Unlike the shuttle, they made the wise (IMHO) decision to not require people to be on every liftoff; you include people when you want to lift people, and not otherwise. The first Dragon flight is scheduled for early next year. Both Falcon and Dragon have passed every NASA COTS review so far (example).
Also, once again, the old fallacy of "being in space is roughly equivalent to being in orbit" rears its ugly head. Sadly, this happens in pretty much every thread about SS1/SS2.
Apart from anything, SpaceShipOne/Two just simply looks WAY cooler!
You hit the nail on the head.