Yes -- orders of magnitude are used to indicate an approximate sense of scale when you're dealing with an exponential distribution. "Over 2 orders of magnitude": that means "approximately over 100 times as much"
I do calculations to show it relative to cellulosic ethanol (which is much better than corn ethanol) elsewhere in this thread, if you're interested. No need for me to repeat them here. Plants are very inefficient converters of solar energy to fuel, and electric motors are much more efficient converters of electricity to motion than internal combustion engines are at converting fuel to motion.
You're linking to a book. I'm referring to official US transportation casualty statistics. I can dig them up again if you'd like. SUVs have, on average, have a lower per-passenger-mile fatality rate than cars. But there is a much greater difference between models than between class; the safest cars are far safer than the least safe SUVs.
Their numbers are clearly wrong. You're not going to get greater "thermochemical" efficiency than electricity generation efficiency (esp. the way they're doing it -- you have thermolysis losses, CO2-splitting losses, and then Fischer-Tropsch losses). Also, and gasoline engines turn gasoline into motion with less than a quarter the average efficiency as EVs turn electricity into motion. So.... Ref for your numbers, please? I wouldn't be surprised if I could guess what's wrong with those numbers, too. I bet they're assuming that they get all of the energy from the sunlight hitting a given amount of land, when in reality, solar plants of any type are mostly empty space (because of shadowing at times other than noon, plus roads, etc). They might also be using an unreasonable capacity factor.
And where do you get the water to produce the algae in the desert? Even when you use enclosed tanks, some of the water still ends up as fuel, and some gets wasted in the fuel production process.
Pointing a gun at someone else's head is a very different kind of argument. But aim an ordinary pistol from several hundred yards away and I'll feel fairly comfortable calling you anything I please becuase "F=mA" can't begin to measure all the "F" factors involved over such a trajectory.
Which the error bars on such a calculation would indicate.
Ugh, don't get me started on bumpers. My (now) wife got into a 5mph accident that caused $3k worth of damage to our car. She hit a jacked up pickup that was still within the legal range; his bumper wasn't even close to ours. His trailer hitch cut right through the hood and engine compartment.
It's unfathomable to me that we mandate bumpers but don't require that they meet up.
The idea that the models are "complete" is like saying that physics was "complete" when Isaac Newton discovered F=MA. There's a lot that goes on in the details.
If I aimed a gun at you and showed you the calculations that said that if I shot it, the bullet would hit you (based on F=MA): would you sit there and insist that we need to take relativity into account, or would you move?
We have error bars. The results from historical simulations fall within the error bars. The future results are disastrous no matter where it falls within the error bars.
What really matters is what the resulting cost is.
1) Land use absolutely *does* matter. As does water use, fertilizer use, etc. It matters for wildlife habitat (incl. rainforest), for food production, for algal blooms, for countless things.
2) From a cost perspective, solar thermal wins there, too. EVs are really cheap to run. Even if cellulosic ethanol could manage to sell for the same price as gasoline (and note that 30mpg ethanol is notably better than 30mpg gasoline, in the above calculations) -- say, $3/gal -- it would be 10 cents per mile. Even if you had to pay 20 cents per kWh for the solar thermal (most next-gen solar thermal is predicting less than that), rather than the US national average for electricity of 10 cents per kWh residential (and notably less for industrial power), that would be five cents per mile.
Smoke belching vehicles? How about electric car companies blowing smoke? Electric cars have been vaporware for years; they keep predicting that they'll bring an affordable one to the general market in "a year or two".
What the heck are you talking about? Who's been saying that, apart from NEV manufacturers?
Typically tanks of water, you anonymous coward. Exposed to air, your optimal fuel-producing species end up being attacked by predators and diluted by species that produce less (or no) fuel.
I mentioned the worst and the best. Do I really need to spell out all of the midpoints?
Cellulosic ethanol is estimated at up to 1,500 gallons/acre/year. At 30mpg, that's 45,000 miles/acre/year.
Ausra's proposed 177MW Carrizo solar thermal plant was to be situated on 640 acres. That's 277kW/acre. Assuming a capacity factor of about 0.3 (clear skies, heliostat), that's about 727,000,000 Wh/acre/year. At 250Wh/mi, that's ~2,900,000 miles/acre/year.
The problem is, a typical gas nozzle runs about a megawatt. Theres 20 of them at my local quickie-mart or whatever its called. Sometimes all are in use. Often half are in use. Even in the middle of the night at least one is in use. "Trickle Charge" is still going to be a couple megawatts, and in an area without that kind of service.
Oh, certainly -- your "gas station" has to be able to "average" the amount of power it feeds out, plus losses -- there's no way around that. Of course, running counter to this is that since the vast majority of charging is done at home (and to a lesser extent, work), you don't actually need that many rapid chargers nationwide. Most of the lower-end rapid chargers (~40kW is sort of the cutoff for what's considered rapid charging) don't typically use battery banks, and these are typically installed just one charger per location to spread the load around (although the charger may have multiple connectors on it; when two EVs are hooked up, each charges at half-rate). There are very few of the higher power rapid chargers out there right now, so it's hard to draw generalizations, but one would expect you'd average several per location to better take advantage of a common battery bank. Probably nothing like the 8-16 pumps at your typical gas station. Gas stations load so many pumps into each location because of the not inconsiderable expense of excavation to install the fuel tanks, plus fuel delivery costs.
While studies suggest little to no need for new macro-scale infrastructure for mass adoption of EVs, there may be some local infrastructure improvements required, esp. if rapid charging for long, daytime EV trips takes off.
The net result is a single mass moving in the direction the Hummer was, at 20mph.
That should read, "at 10mph". Also, re-reading your post, you were postulating Hummer vs. Hummer and Civic vs. Civic, not Civic vs. Hummer. Sorry about that.:)
If Hummer would be willing to release their full crash test results breakdown, that'd be easier to evaluate.
Really, it's not that simple. All you can say is that the Civic will *decelerate faster* than the Hummer. But then again, you can say the same thing about a Hummer hitting a bus. No matter what size vehicle you are on the road, unless you're a bus or a semi, there are much heavier vehicles out there than you. Which means that you need to be able to withstand sudden deceleration.
But let's look at the Hummer/Civic crash. Let's put two vehicles heading toward each other at 30mph, with a completely inelastic collision, and say that the Hummer weighed twice as much as the Civic (both vehicles loaded). The net result is a single mass moving in the direction the Hummer was, at 20mph. The Hummer suffers a net deceleration of 20mph, while the Civic suffers a net deceleration of 40mph.
Now let's look at a Hummer vs. an ultralight vehicle that weighs a quarter as much as the Hummer. Same crash situation. The Hummer suffers a net deceleration of 12mph, while the ultralight suffers a net deceleration of 48mph.
So by making the ultralight half the weight of the Civic, it only decelerates 20% more in the accident than the Civic. Not what you might expect (twice as much). The same thing applies to a Hummer and a bus. The difference in deceleration between a Hummer hitting a bus and a Civic hitting a bus isn't much at all.
Now, what does this deceleration distance mean? That's the 10-million dollar question. What it means varies *dramatically* from vehicle to vehicle. First off, you have the length of your crumple zone. A longer crumple zone means more room to crush when an accident happens. The Hummer, with its steeply raked windshield and relatively short front end, doesn't leave you with all that much. Secondly, you need to look at how resistant the passenger compartment is to penetration. This varies tremendously.
There's one additional issue. Right now we're talking about head-on collisions. But that's not the only type of accident damage. For example, SUVs are famously bad in rollover accidents. Roof crush strength needs to be proportional to the weight of your vehicle, so making your vehicle heavier makes that a lot harder, since you don't want massive pillars holding up the roof (that'd look ugly, and SUVs are all about style).
So what do car accident statistics say? Statistically, last I checked, your odds of survival are best in a mid-sized SUV. The large SUV class actually had a lower survival rate than the mid-sized class did. However, most notably, there was a lot more variation *within* classes than *between* them. That is, to say, the safest cars were a heck of a lot safer than the least safe SUVs.
One final note: most vehicles today are steel-frame construction. But composites completely change the picture. Composite vehicles are both lighter but much better in accidents. Furthermore, they don't irreversibly deform, so there's no getting trapped in the car. This is ultimately the direction the auto industry will go.
There is also the issue of having an electrical grid that can handle that. Charging a battery in minutes with enough power to get you hundreds of miles takes a non-trivial amount of power, no matter how good your battery is.
You don't draw it from the grid. You draw it from a battery bank. The battery bank is in turn trickle-charged from the grid.
And in case anyone's curious, yes, they do make extremely high power chargers. TARDEC got one last year that does 800kW. I don't know how much that one cost, but ones in the ~250kW range are typically ~$125k-ish (and about the size of a vending machine). That may sound like a lot, but then again, a gas station generally costs $1-2m to build, and you have to pay for tear-down at end of life (tearing down a charger is a net gain, from scrap). Plus, expect prices to fall over time.
Chargers that big generally require that their connectors or even their cables be cooled. Which makes me wonder when we'll see the next logical step in that evolution -- having the charger provide coolant for the battery pack instead of the EV providing it. After all, why make the EV haul around a powerful cooling system when your charger already has one and is already bringing coolant all the way to the vehicle? All the vehicle should need is a connector for the coolant and ducting for it to travel through. If you use something like supercritical CO2 as a coolant, you won't even have to worry about coolant contamination or residual coolant being left over in the system.
The current fast-charging pseudo-standard, TESCO, doesn't do that, though. But in the future, I expect we'll ultimately see it.
Biofuels are not a long-term solution. Corn ethanol is over two orders of magnitude more land-intensive than solar thermal. Algae is just under one order of magnitude more land intensive. Plus, biofuel creation requires water, fertilizer, processing, etc. And the combination of needing "lots of water" and "lots of sun" can be rather mutually exclusive, as the sunniest places in the country are desert. Solar thermal is closed loop.
If your goal is to turn solar energy into propulsion, pure electric is the way to go.
Although the long recharge time is part of it
That's what rapid charging is for.
the main part is that you do not want to buy more battery than you are going to be using since the battery will be one of the most expensive parts of the car.
Indeed, the real issue is price. But that will fall significantly with mass production. And the operating cost advantage will remain, so eventually, even if sticker shock remains an issue for prospective buyers, seeing a lease price that's significantly cheaper than a gasoline car's lease plus the cost of gasoline that month should eventually drive the point home.
Furthermore, the main point to oversized gas tanks is to make it so that you don't have to fill up too often in your daily lives. Filling up is, after all, a pain; who wants to drive out of their way to pay for the privilege of pumping carcinogens in the middle of a blizzard? One of your average EV driver's favorite benefits is the fact that you start each day with a full charge. You don't even have to think about it in your daily life. The only time range comes into play is when you take long trips. But what's the point of having 700-800 miles on a long trip? Dear god, if you drive 700-800 miles without stopping to rest or eat, please don't do it when I'm on the road!
Lastly: In 1989, a new top of the line battery hit the market: the nickel metal hydride cell. It boasted 45Wh/kg energy density. Today, just over two decades later, commercially available li-ion cells boast up to 220 Wh/kg -- almost five times higher -- plus an order of magnitude higher power density. This trend shows no signs of slowing down; rather, it appears to be accelerating. So take that into account when talking about range for the future.
I really hope we get this electric car thing figured out soon because I am just about sick of following smoke belching vehicles every day.
The tech is here. Modern batteries can rapid charge in minutes (given adequate cooling) and yield hundreds of miles of range. The issue is cost. For most EVs, battery packs are generally limited in size by price, not volume or weight. And not just battery cost that's the problem; quality AC drivetrains are expensive as heck right now. You can't even use a lot of mass-produced accessories with EVs if the conventional accessory requires a gasoline engine to be running. The good news is that it's all about volume. Your typical LFP or manganese li-ion pack combined with an AC drivetrain uses almost no rare or expensive raw materials. You have lithium salts ($4-8/kg), phosphoric acid (in the case of LFP), iron powder, a porous plastic membrane, graphite, etc in the battery pack; your motor optimally uses copper windings, but can also use aluminum; the inverter also uses copper or aluminum, plus things like silicon carbide for thyristors; etc. The expenses are primarily the huge amounts of labor and capital costs per unit because of very low volumes and because of the lack of production process refinement.
BTW, the article summary is wrong (and partly the article, too). What they're talking about is not a battery; it's a capacitor. Which means that even if the whole body is made of the stuff, it's not going to be enough energy capacity for reasonable range. Plus, you have to consider how it'll change your vehicle's weight, structural strength, etc. There is always a cost-benefit analysis to consider.
Still, it could potentially be useful for making less-critical structural elements (say, the bellypan) to use for buffering (rather than energy storage).
1. Beautiful job attacking the messenger, not the message. I linked it so I wouldn't have to retype the same content. 2. RealClimate is a site run by ten climate scientists, plus guest columnists. Only one of them was related to SwiftHack, and was not the author of the linked article. 3. Keep pushing that SwiftHack "scandal", because the claims you deniers make about it are patently ridiculous.
Your first article isn't about changes in solar input; it's about improving the model of gas and temperature exchange with the atmosphere by breaking the ocean surface into discrete layers affected by wind and time. It's just a refinement over the existing models, which means it'll reduce the 95% error bars. And your second article is something that has been known pretty much since climate science first began to be studied -- warmer oceans = more evaporation.
No. Water vapor is the largest greenhouse gas factor by a large margin.
True as far as net GHG effects go (over double that of CO2). But irrelevant in terms of forcing, because water vapor has an extremely short atmospheric residency. Water vapor, hence, can only act as feedback, not forcing. And the numbers above list the net climate response from human activities, including feedbacks. Water vapor *is* included, as I showed you.
It completely swamps any possible CO2 contribution because, unlike CO2, which remains generally stable regardless of atmospheric temperature change (that's most of the basis for the claim that CO2 will incur warming, in fact), the evaporative cooling process accelerates enormously when the atmosphere warms.
That's a naive approach. Water vapor has both positive and negative feedbacks. It's a GHG, but it also creates clouds, which raise the planet's albedo, thus providing cooling. Whether you're talking about tropospheric or stratospheric water vapor plays a huge role, and thus transport models need to come into play. This is not a science for naive approaches to be taken. That's why we have peer-reviewed papers -- something you've clearly never read.
The real question here, especially after the scandals of the tweaked data
There was no tweaked data.
the lockout of contrary input
There is no lockout of contrary input. If you can pass peer review, you can get published. If peers find major flaws in your work, that means you have major flaws in your work.
the use of glacial statistics that were entirely false
1) Oooh, one place in a 3,000 page report wherein two digits were reversed! Heavens to betsy! 2) That was in WG2. WG2 is not about the science. WG1 is about the science (in particular, Ch. 02 is the primary document on forcings). WG2 is more of a news report, and isn't nearly as heavily reviewed.
the unforgivable falsification of the "hockey stick"
Oh, get over it. First off, it wasn't "falsification". There was no made-up data. If you're going on about the "hide the decline" thing, that just marks you as completely ignorant on the subject. The original paper that that dendrochronology line came from *explicitly stated* that the data was invalid after that point. And what idiot would trust dendrochronology data over thermometer data?
Second, there were three major reviews of Mann's paper. Two were largely supportive, one was largely critical. In your world, that means "unforgivable falsification".
Third, there have been a number of climate reconstructions since then, using different methods -- both refined dendrochronology reconstructions and borehole reconstructions (boreholes being much less opaque than dendrochronology climate reconstructions). They all follow the same general curve.
Fourth, Mann's paper is over a decade old. So get over it.
Fifth, historic climate reconstructions are a single line out of dozens related to global warming.... the real question is: Can we call AGW good, established science?
97% of actively publishing climate scientists say yes. Random posters on slashdot who've never read a peer-reviewed paper on the subject to save their life say no. Hmm, who to believe, who to believe...
But the answer to that is a resounding no. We have this stall in temperature rise
There is no stall in temperature rise. God, you people are like a whack-a-mole game sometimes. For the 1,827th time:
1) To come up with this "stall", you have to cherry-pick a starting point of 1998, which was one of the strongest El Nino events on record. El Nino means that the Walker circulation weakens, meaning less upwelling of cold water in the East Pacific, meaning that you have a swath of hot water across the equatorial pacific, warming the atmosphere). There is a massive, widely recognized (even by deniers) correlation between El Nino events an
That's the problem with nuclear. It's great on paper. Heck, on paper, it's way overbuilt and will undercut every fuel source on price. But it's been a magnet for "unforeseen complications". You've got a core being bombarded with a high neutron flux that weakens its structure, you have daughter products leeching out, you have products being bred from the neutron flux, etc. So your core and primary coolant loop is basically doing its best to damage itself. This then combines with the fact that a leak in the core or primary coolant loop is a Bad Thing(TM). Then you have the fact that you need (in order to be economical) to maintain a very high capacity factor (unlike, say, NG). This means you need to rush maintenance through. Then you have the fact that decommissioning cost estimates keep rising as we keep finding new expenses. The same thing happens with spent fuel. And bugs... in a conventional power plant, if something significant goes wrong, your plant shuts down and you have to fix it. The public never even hears about it In a nuclear power plant, if something significant goes wrong, your plant shuts down, you have to do a much bigger fix, you get a ton of bad press, you have to do an expensive cleanup operation, and if it's really bad, people get sick and/or die.
It's just a really tough situation to deal with. And even the most modern designs, like the CANDUs, keep having their own share of problems. It's the risk that's driving investment away, that's causing Moody's to downgrade nuclear power investments. Not so much direct, immediate health risks -- economic risk and liability risks. And don't underestimate the economic risks; even in the construction phase, nuclear power plant cost overruns have proven to be far too common.
No. They're not. Oceanic effects of solar radiation alone, and their effects on climate, are filled with some very complex models that are _not_ complete
It's you versus the peer-reviewed literature on the subject. Hmm, who to believe, who to believe...
The *direct* result of CO2 warming is only about 10% of observed warming
The *direct* result of CO2 is a +1.66 +- 0.17 W/m^2 forcing "solely due to increases in atmospheric CO2". The total forcing from human-added GHGs is +2.63 +- 0.26.
Let's run down the forcings from other human influences and from feedback effects. Stratospheric ozone forcing is -0.05 +- 0.10 W/m^2. Tropospheric ozone forcing is +0.35 (-0.1,+0.3). Stratospheric water vapor from CH4 is +0.07 +- 0.05. Total direct aerosol is -0.50 +- 0.40. Direct sulphate aerosol is -0.40 +- 0.20. Direct fossil fuel aerosol (organic carbon) is -0.05 +- 0.05. Direct biomass burning aerosol is 0.03 +- 0.12. Direct nitrate aerosol is -0.10 +- 0.10. Direct mineral dust aerosol is -0.10 +- 0.20. Cloud albedo effect is -0.70 (-1.1, +0.4). Surface albedo (land use) is -0.20 +- 0.20. Surface albedo (carbon black on snow) is 0.10 +- 0.10. Persistent linear contrails is 0.01 (-0.007, +0.02). Solar irradiance is 0.12 (-0.06, +0.18).
The biggest non-GHG factor by far is cloud albedo, and unfortunately, it's not well constrained because cloud modelling is a very difficult process. We get better at it each year, including since the AR4 reports, but there's still a good ways to go. So we'll go with the AR4 number, -0.70 (-1.1, +0.4) W/m^2. However, GHGs are by far the largest factor, and of those, CO2 is the largest.
What's the point of all this? Let's just sum up: Your "10% of observed warming" number is garbage.
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Yes -- orders of magnitude are used to indicate an approximate sense of scale when you're dealing with an exponential distribution. "Over 2 orders of magnitude": that means "approximately over 100 times as much"
I do calculations to show it relative to cellulosic ethanol (which is much better than corn ethanol) elsewhere in this thread, if you're interested. No need for me to repeat them here. Plants are very inefficient converters of solar energy to fuel, and electric motors are much more efficient converters of electricity to motion than internal combustion engines are at converting fuel to motion.
You're linking to a book. I'm referring to official US transportation casualty statistics. I can dig them up again if you'd like. SUVs have, on average, have a lower per-passenger-mile fatality rate than cars. But there is a much greater difference between models than between class; the safest cars are far safer than the least safe SUVs.
Their numbers are clearly wrong. You're not going to get greater "thermochemical" efficiency than electricity generation efficiency (esp. the way they're doing it -- you have thermolysis losses, CO2-splitting losses, and then Fischer-Tropsch losses). Also, and gasoline engines turn gasoline into motion with less than a quarter the average efficiency as EVs turn electricity into motion. So.... Ref for your numbers, please? I wouldn't be surprised if I could guess what's wrong with those numbers, too. I bet they're assuming that they get all of the energy from the sunlight hitting a given amount of land, when in reality, solar plants of any type are mostly empty space (because of shadowing at times other than noon, plus roads, etc). They might also be using an unreasonable capacity factor.
And where do you get the water to produce the algae in the desert? Even when you use enclosed tanks, some of the water still ends up as fuel, and some gets wasted in the fuel production process.
Pointing a gun at someone else's head is a very different kind of argument. But aim an ordinary pistol from several hundred yards away and I'll feel fairly comfortable calling you anything I please becuase "F=mA" can't begin to measure all the "F" factors involved over such a trajectory.
Which the error bars on such a calculation would indicate.
Ugh, don't get me started on bumpers. My (now) wife got into a 5mph accident that caused $3k worth of damage to our car. She hit a jacked up pickup that was still within the legal range; his bumper wasn't even close to ours. His trailer hitch cut right through the hood and engine compartment.
It's unfathomable to me that we mandate bumpers but don't require that they meet up.
The idea that the models are "complete" is like saying that physics was "complete" when Isaac Newton discovered F=MA. There's a lot that goes on in the details.
If I aimed a gun at you and showed you the calculations that said that if I shot it, the bullet would hit you (based on F=MA): would you sit there and insist that we need to take relativity into account, or would you move?
We have error bars. The results from historical simulations fall within the error bars. The future results are disastrous no matter where it falls within the error bars.
What really matters is what the resulting cost is.
1) Land use absolutely *does* matter. As does water use, fertilizer use, etc. It matters for wildlife habitat (incl. rainforest), for food production, for algal blooms, for countless things.
2) From a cost perspective, solar thermal wins there, too. EVs are really cheap to run. Even if cellulosic ethanol could manage to sell for the same price as gasoline (and note that 30mpg ethanol is notably better than 30mpg gasoline, in the above calculations) -- say, $3/gal -- it would be 10 cents per mile. Even if you had to pay 20 cents per kWh for the solar thermal (most next-gen solar thermal is predicting less than that), rather than the US national average for electricity of 10 cents per kWh residential (and notably less for industrial power), that would be five cents per mile.
Smoke belching vehicles? How about electric car companies blowing smoke? Electric cars have been vaporware for years; they keep predicting that they'll bring an affordable one to the general market in "a year or two".
What the heck are you talking about? Who's been saying that, apart from NEV manufacturers?
there is a limited supply of Lithium and other elements used in these batteries.
No, there isn't. Not in a practical sense.
Typically tanks of water, you anonymous coward. Exposed to air, your optimal fuel-producing species end up being attacked by predators and diluted by species that produce less (or no) fuel.
I mentioned the worst and the best. Do I really need to spell out all of the midpoints?
Cellulosic ethanol is estimated at up to 1,500 gallons/acre/year. At 30mpg, that's 45,000 miles/acre/year.
Ausra's proposed 177MW Carrizo solar thermal plant was to be situated on 640 acres. That's 277kW/acre. Assuming a capacity factor of about 0.3 (clear skies, heliostat), that's about 727,000,000 Wh/acre/year. At 250Wh/mi, that's ~2,900,000 miles/acre/year.
The problem is, a typical gas nozzle runs about a megawatt. Theres 20 of them at my local quickie-mart or whatever its called. Sometimes all are in use. Often half are in use. Even in the middle of the night at least one is in use. "Trickle Charge" is still going to be a couple megawatts, and in an area without that kind of service.
Oh, certainly -- your "gas station" has to be able to "average" the amount of power it feeds out, plus losses -- there's no way around that. Of course, running counter to this is that since the vast majority of charging is done at home (and to a lesser extent, work), you don't actually need that many rapid chargers nationwide. Most of the lower-end rapid chargers (~40kW is sort of the cutoff for what's considered rapid charging) don't typically use battery banks, and these are typically installed just one charger per location to spread the load around (although the charger may have multiple connectors on it; when two EVs are hooked up, each charges at half-rate). There are very few of the higher power rapid chargers out there right now, so it's hard to draw generalizations, but one would expect you'd average several per location to better take advantage of a common battery bank. Probably nothing like the 8-16 pumps at your typical gas station. Gas stations load so many pumps into each location because of the not inconsiderable expense of excavation to install the fuel tanks, plus fuel delivery costs.
While studies suggest little to no need for new macro-scale infrastructure for mass adoption of EVs, there may be some local infrastructure improvements required, esp. if rapid charging for long, daytime EV trips takes off.
Just caught a typo:
The net result is a single mass moving in the direction the Hummer was, at 20mph.
That should read, "at 10mph". Also, re-reading your post, you were postulating Hummer vs. Hummer and Civic vs. Civic, not Civic vs. Hummer. Sorry about that. :)
If Hummer would be willing to release their full crash test results breakdown, that'd be easier to evaluate.
Really, it's not that simple. All you can say is that the Civic will *decelerate faster* than the Hummer. But then again, you can say the same thing about a Hummer hitting a bus. No matter what size vehicle you are on the road, unless you're a bus or a semi, there are much heavier vehicles out there than you. Which means that you need to be able to withstand sudden deceleration.
But let's look at the Hummer/Civic crash. Let's put two vehicles heading toward each other at 30mph, with a completely inelastic collision, and say that the Hummer weighed twice as much as the Civic (both vehicles loaded). The net result is a single mass moving in the direction the Hummer was, at 20mph. The Hummer suffers a net deceleration of 20mph, while the Civic suffers a net deceleration of 40mph.
Now let's look at a Hummer vs. an ultralight vehicle that weighs a quarter as much as the Hummer. Same crash situation. The Hummer suffers a net deceleration of 12mph, while the ultralight suffers a net deceleration of 48mph.
So by making the ultralight half the weight of the Civic, it only decelerates 20% more in the accident than the Civic. Not what you might expect (twice as much). The same thing applies to a Hummer and a bus. The difference in deceleration between a Hummer hitting a bus and a Civic hitting a bus isn't much at all.
Now, what does this deceleration distance mean? That's the 10-million dollar question. What it means varies *dramatically* from vehicle to vehicle. First off, you have the length of your crumple zone. A longer crumple zone means more room to crush when an accident happens. The Hummer, with its steeply raked windshield and relatively short front end, doesn't leave you with all that much. Secondly, you need to look at how resistant the passenger compartment is to penetration. This varies tremendously.
There's one additional issue. Right now we're talking about head-on collisions. But that's not the only type of accident damage. For example, SUVs are famously bad in rollover accidents. Roof crush strength needs to be proportional to the weight of your vehicle, so making your vehicle heavier makes that a lot harder, since you don't want massive pillars holding up the roof (that'd look ugly, and SUVs are all about style).
So what do car accident statistics say? Statistically, last I checked, your odds of survival are best in a mid-sized SUV. The large SUV class actually had a lower survival rate than the mid-sized class did. However, most notably, there was a lot more variation *within* classes than *between* them. That is, to say, the safest cars were a heck of a lot safer than the least safe SUVs.
One final note: most vehicles today are steel-frame construction. But composites completely change the picture. Composite vehicles are both lighter but much better in accidents. Furthermore, they don't irreversibly deform, so there's no getting trapped in the car. This is ultimately the direction the auto industry will go.
There is also the issue of having an electrical grid that can handle that. Charging a battery in minutes with enough power to get you hundreds of miles takes a non-trivial amount of power, no matter how good your battery is.
You don't draw it from the grid. You draw it from a battery bank. The battery bank is in turn trickle-charged from the grid.
And in case anyone's curious, yes, they do make extremely high power chargers. TARDEC got one last year that does 800kW. I don't know how much that one cost, but ones in the ~250kW range are typically ~$125k-ish (and about the size of a vending machine). That may sound like a lot, but then again, a gas station generally costs $1-2m to build, and you have to pay for tear-down at end of life (tearing down a charger is a net gain, from scrap). Plus, expect prices to fall over time.
Chargers that big generally require that their connectors or even their cables be cooled. Which makes me wonder when we'll see the next logical step in that evolution -- having the charger provide coolant for the battery pack instead of the EV providing it. After all, why make the EV haul around a powerful cooling system when your charger already has one and is already bringing coolant all the way to the vehicle? All the vehicle should need is a connector for the coolant and ducting for it to travel through. If you use something like supercritical CO2 as a coolant, you won't even have to worry about coolant contamination or residual coolant being left over in the system.
The current fast-charging pseudo-standard, TESCO, doesn't do that, though. But in the future, I expect we'll ultimately see it.
Biofuels are not a long-term solution. Corn ethanol is over two orders of magnitude more land-intensive than solar thermal. Algae is just under one order of magnitude more land intensive. Plus, biofuel creation requires water, fertilizer, processing, etc. And the combination of needing "lots of water" and "lots of sun" can be rather mutually exclusive, as the sunniest places in the country are desert. Solar thermal is closed loop.
If your goal is to turn solar energy into propulsion, pure electric is the way to go.
Although the long recharge time is part of it
That's what rapid charging is for.
the main part is that you do not want to buy more battery than you are going to be using since the battery will be one of the most expensive parts of the car.
Indeed, the real issue is price. But that will fall significantly with mass production. And the operating cost advantage will remain, so eventually, even if sticker shock remains an issue for prospective buyers, seeing a lease price that's significantly cheaper than a gasoline car's lease plus the cost of gasoline that month should eventually drive the point home.
Furthermore, the main point to oversized gas tanks is to make it so that you don't have to fill up too often in your daily lives. Filling up is, after all, a pain; who wants to drive out of their way to pay for the privilege of pumping carcinogens in the middle of a blizzard? One of your average EV driver's favorite benefits is the fact that you start each day with a full charge. You don't even have to think about it in your daily life. The only time range comes into play is when you take long trips. But what's the point of having 700-800 miles on a long trip? Dear god, if you drive 700-800 miles without stopping to rest or eat, please don't do it when I'm on the road!
Lastly: In 1989, a new top of the line battery hit the market: the nickel metal hydride cell. It boasted 45Wh/kg energy density. Today, just over two decades later, commercially available li-ion cells boast up to 220 Wh/kg -- almost five times higher -- plus an order of magnitude higher power density. This trend shows no signs of slowing down; rather, it appears to be accelerating. So take that into account when talking about range for the future.
I really hope we get this electric car thing figured out soon because I am just about sick of following smoke belching vehicles every day.
The tech is here. Modern batteries can rapid charge in minutes (given adequate cooling) and yield hundreds of miles of range. The issue is cost. For most EVs, battery packs are generally limited in size by price, not volume or weight. And not just battery cost that's the problem; quality AC drivetrains are expensive as heck right now. You can't even use a lot of mass-produced accessories with EVs if the conventional accessory requires a gasoline engine to be running. The good news is that it's all about volume. Your typical LFP or manganese li-ion pack combined with an AC drivetrain uses almost no rare or expensive raw materials. You have lithium salts ($4-8/kg), phosphoric acid (in the case of LFP), iron powder, a porous plastic membrane, graphite, etc in the battery pack; your motor optimally uses copper windings, but can also use aluminum; the inverter also uses copper or aluminum, plus things like silicon carbide for thyristors; etc. The expenses are primarily the huge amounts of labor and capital costs per unit because of very low volumes and because of the lack of production process refinement.
BTW, the article summary is wrong (and partly the article, too). What they're talking about is not a battery; it's a capacitor. Which means that even if the whole body is made of the stuff, it's not going to be enough energy capacity for reasonable range. Plus, you have to consider how it'll change your vehicle's weight, structural strength, etc. There is always a cost-benefit analysis to consider.
Still, it could potentially be useful for making less-critical structural elements (say, the bellypan) to use for buffering (rather than energy storage).
1. Beautiful job attacking the messenger, not the message. I linked it so I wouldn't have to retype the same content.
2. RealClimate is a site run by ten climate scientists, plus guest columnists. Only one of them was related to SwiftHack, and was not the author of the linked article.
3. Keep pushing that SwiftHack "scandal", because the claims you deniers make about it are patently ridiculous.
Your first article isn't about changes in solar input; it's about improving the model of gas and temperature exchange with the atmosphere by breaking the ocean surface into discrete layers affected by wind and time. It's just a refinement over the existing models, which means it'll reduce the 95% error bars. And your second article is something that has been known pretty much since climate science first began to be studied -- warmer oceans = more evaporation.
No. Water vapor is the largest greenhouse gas factor by a large margin.
True as far as net GHG effects go (over double that of CO2). But irrelevant in terms of forcing, because water vapor has an extremely short atmospheric residency. Water vapor, hence, can only act as feedback, not forcing. And the numbers above list the net climate response from human activities, including feedbacks. Water vapor *is* included, as I showed you.
It completely swamps any possible CO2 contribution because, unlike CO2, which remains generally stable regardless of atmospheric temperature change (that's most of the basis for the claim that CO2 will incur warming, in fact), the evaporative cooling process accelerates enormously when the atmosphere warms.
That's a naive approach. Water vapor has both positive and negative feedbacks. It's a GHG, but it also creates clouds, which raise the planet's albedo, thus providing cooling. Whether you're talking about tropospheric or stratospheric water vapor plays a huge role, and thus transport models need to come into play. This is not a science for naive approaches to be taken. That's why we have peer-reviewed papers -- something you've clearly never read.
The real question here, especially after the scandals of the tweaked data
There was no tweaked data.
the lockout of contrary input
There is no lockout of contrary input. If you can pass peer review, you can get published. If peers find major flaws in your work, that means you have major flaws in your work.
the use of glacial statistics that were entirely false
1) Oooh, one place in a 3,000 page report wherein two digits were reversed! Heavens to betsy!
2) That was in WG2. WG2 is not about the science. WG1 is about the science (in particular, Ch. 02 is the primary document on forcings). WG2 is more of a news report, and isn't nearly as heavily reviewed.
the unforgivable falsification of the "hockey stick"
Oh, get over it. First off, it wasn't "falsification". There was no made-up data. If you're going on about the "hide the decline" thing, that just marks you as completely ignorant on the subject. The original paper that that dendrochronology line came from *explicitly stated* that the data was invalid after that point. And what idiot would trust dendrochronology data over thermometer data?
Second, there were three major reviews of Mann's paper. Two were largely supportive, one was largely critical. In your world, that means "unforgivable falsification".
Third, there have been a number of climate reconstructions since then, using different methods -- both refined dendrochronology reconstructions and borehole reconstructions (boreholes being much less opaque than dendrochronology climate reconstructions). They all follow the same general curve.
Fourth, Mann's paper is over a decade old. So get over it.
Fifth, historic climate reconstructions are a single line out of dozens related to global warming. ... the real question is: Can we call AGW good, established science?
97% of actively publishing climate scientists say yes. Random posters on slashdot who've never read a peer-reviewed paper on the subject to save their life say no. Hmm, who to believe, who to believe...
But the answer to that is a resounding no. We have this stall in temperature rise
There is no stall in temperature rise. God, you people are like a whack-a-mole game sometimes. For the 1,827th time:
1) To come up with this "stall", you have to cherry-pick a starting point of 1998, which was one of the strongest El Nino events on record. El Nino means that the Walker circulation weakens, meaning less upwelling of cold water in the East Pacific, meaning that you have a swath of hot water across the equatorial pacific, warming the atmosphere). There is a massive, widely recognized (even by deniers) correlation between El Nino events an
That's the problem with nuclear. It's great on paper. Heck, on paper, it's way overbuilt and will undercut every fuel source on price. But it's been a magnet for "unforeseen complications". You've got a core being bombarded with a high neutron flux that weakens its structure, you have daughter products leeching out, you have products being bred from the neutron flux, etc. So your core and primary coolant loop is basically doing its best to damage itself. This then combines with the fact that a leak in the core or primary coolant loop is a Bad Thing(TM). Then you have the fact that you need (in order to be economical) to maintain a very high capacity factor (unlike, say, NG). This means you need to rush maintenance through. Then you have the fact that decommissioning cost estimates keep rising as we keep finding new expenses. The same thing happens with spent fuel. And bugs... in a conventional power plant, if something significant goes wrong, your plant shuts down and you have to fix it. The public never even hears about it In a nuclear power plant, if something significant goes wrong, your plant shuts down, you have to do a much bigger fix, you get a ton of bad press, you have to do an expensive cleanup operation, and if it's really bad, people get sick and/or die.
It's just a really tough situation to deal with. And even the most modern designs, like the CANDUs, keep having their own share of problems. It's the risk that's driving investment away, that's causing Moody's to downgrade nuclear power investments. Not so much direct, immediate health risks -- economic risk and liability risks. And don't underestimate the economic risks; even in the construction phase, nuclear power plant cost overruns have proven to be far too common.
No. They're not. Oceanic effects of solar radiation alone, and their effects on climate, are filled with some very complex models that are _not_ complete
It's you versus the peer-reviewed literature on the subject. Hmm, who to believe, who to believe...
The *direct* result of CO2 warming is only about 10% of observed warming
The *direct* result of CO2 is a +1.66 +- 0.17 W/m^2 forcing "solely due to increases in atmospheric CO2". The total forcing from human-added GHGs is +2.63 +- 0.26.
Let's run down the forcings from other human influences and from feedback effects. Stratospheric ozone forcing is -0.05 +- 0.10 W/m^2. Tropospheric ozone forcing is +0.35 (-0.1,+0.3). Stratospheric water vapor from CH4 is +0.07 +- 0.05. Total direct aerosol is -0.50 +- 0.40. Direct sulphate aerosol is -0.40 +- 0.20. Direct fossil fuel aerosol (organic carbon) is -0.05 +- 0.05. Direct biomass burning aerosol is 0.03 +- 0.12. Direct nitrate aerosol is -0.10 +- 0.10. Direct mineral dust aerosol is -0.10 +- 0.20. Cloud albedo effect is -0.70 (-1.1, +0.4). Surface albedo (land use) is -0.20 +- 0.20. Surface albedo (carbon black on snow) is 0.10 +- 0.10. Persistent linear contrails is 0.01 (-0.007, +0.02). Solar irradiance is 0.12 (-0.06, +0.18).
The biggest non-GHG factor by far is cloud albedo, and unfortunately, it's not well constrained because cloud modelling is a very difficult process. We get better at it each year, including since the AR4 reports, but there's still a good ways to go. So we'll go with the AR4 number, -0.70 (-1.1, +0.4) W/m^2. However, GHGs are by far the largest factor, and of those, CO2 is the largest.
What's the point of all this? Let's just sum up: Your "10% of observed warming" number is garbage.
The cites. The citations are almost all (if not all) from peer-reviewed sources. Browse them yourself if you don't believe me.