Non-crowd-sourced chargers are no bette; check out EVChargerMaps some time. But the advantage of crowd sourcing with a trust network is you can get an idea of how much you can trust it. And with contact information for the owner, you can call up in advance. Our system is also designed to send followup emails every three months to station owners asking them to verify that their charger is still working and to follow a link to confirm it.
1)I don't have an outlet in my parking space. Not even the home one, much less at lots near work. Most people in dense urban areas don't.
Unless your landlord is a jerk, offer to install one, and tack a couple hundred dollars onto the purchase price; problem solved.
1a)I don't always park at home even over night. Sometimes I'm at a girlfriend's, sometimes I'm at a hotel in another city. Neither would have an outlet even if I had one in #1.
Your girlfriend doesn't have a *power outlet*? Where does she live, a cave? Or are you talking about someone who doesn't have a garage and won't run an extension cord, and you really have to charge every time -- and even then, electricians can be found everywhere..
2)When there's an accident on a bridge, I can take 2 hours to drive home. I wouldn't trust it to keep a charge for that long idling.
Huh? Unlike with cars, the slower EVs drive, the *more* range they get. They don't "idle". You'll use more accessory power, but not nearly as much as you save in terms of aero drag. This doesn't apply to gas cars, as they're inefficient at low speeds and don't regen.
3)I want the option of being able to drive farther. I want to be able to drive an hour or two out of the city on a weekend, or take a road trip. This car doesn't have that. So I'll need another car anyway. I don't have room for two in my garage. So add 100-150 a month for a parking spot to the price.
Wait, you have a garage... but you don't have a power outlet? Huh? Who has a garage without a power outlet? How do you use power tools? Do you charge them indoors?
How often do you drive that far? I need a cargo van once or twice a year, but I don't go out and buy one. I just rent. It'd be stupid to make a cargo van my daily commuter just because I occasionally need it. Why wouldn't you apply the same logic to your drivetrain?
If it's *really* a problem for you, that's what PHEVs are for.
4)I don't always drive to work. Occasionally I drive to work (20 mi), to a concert venue after work (40 mi), then home (30 mi). That's cutting it too close.
You'd be amazed at how accomodating most employers are. And furthermore, you're in *Seattle*. Your city is building a network of charging stations. An EV may actually get you a better parking space at the concert.
5)I'm forgetful. If I forgot for even 1 evening to plug it in I'd be in trouble. That's not acceptable. It needs to be able to go at least a week without plugging in.
How often do you forget to shut the front door? Because it's that obvious of a thing. Talk to any EV owner. Forgetting to charge an EV is essentially a non-issue; it just becomes a 15 second part of your daily routine. And lets you avoid having to randomly add 10-20 minutes to your weekly schedule to go out of your way to fill up your gas car; it eliminates the, "oh damn, I need to stop for gas" moments.
I'd prefer 500 mi, so I can take it on a real road trip.
Huh? You drive 8 hours nonstop without a break? Wow. Please let me know when you're taking a road trip and what roads you'll be on so I can avoid you.
The other issue is availability of charging. A car like this needs extensive infrastructure that just doesn't exist. The only viable solution is to make it rechargable on the go- removable batteries or the like.
50A/240V outlets already crisscross the country -- RV parks. Numerous cities are building EV-specific charging networks, including yours, Seattle. And your state is considering a statewide rollout.
Most upcoming EVs use about 200Wh/mi pack to wheels, ~225Wh/mi wall to wheels. The average person pays about $0.10/kWh. That's a little over 2 cents per mile in energy costs. How does that compare to what you pay for gas? At $3/gal, it'd take over 130mpg to beat that. And that's assuming you don't get time-of-use rates, since EVs typically charge off-peak.
And it's not all energy costs, too. It's also maintenance. EV drivetrains have about a tenth as many moving parts as gas drivetrains. And contrary to the stereotypes promoted by lead-acid EVs, if you look at the failure rate on Prius packs, they're very low. Heck, GM is *warrantying* the Volt pack for 10 years. And no shock, when hybrid packs were mass produced, the prices went way down. Hybrid packs nowadays are typically $2-2.5k. That's no worse than replacing a transmission (EVs are generally direct drive and thus don't have transmissions). Expect the same sort of longevities and price reductions with EV packs as with hybrid packs. People aren't exactly yet mass producing, say, large format manganese spinel battery packs.
Nissan's price estimate is $20-$33k (they haven't really locked it down yet). That's before the $7,500 tax credit, but also doesn't include the battery. It sounds like they're going with the PBP model; if so, the battery can be rented (at a cost that even after paying for rental + electricity, is less than what your typical driver pays on gasoline) or purchased outright. The battery cost is estimated by Nissan at $10k. This will drop over time, of course; large format manganese spinels batteries aren't exactly mass produced currently.
Back to low speeds and AC: low speeds are *great* for EVs; their ranges increase dramatically at low speeds. The Tesla Roadster can go over 400 miles at a steady 20mph. AC is relevant, but not *that* relevant. The issue is that unlike gasoline cars, EVs are efficient at all speeds, so you're most efficient at low speeds, since there's little aero drag. Plus, all EVs come with regen, and thanks to the big li-ion pack, it's a lot more efficient than in a small-pack NiMH hybrid (60-70% instead of ~30%).
Yeah, it's a neat concept; take it when you need it, leave it behind the rest of the time. I wish more companies were considering it. You wouldn't even need to own it; being so small and simple, it'd lend itself quite readily to low-cost rental or sharing programs.
I'm starting a company to do just that -- Celadon Applications, LLC. We already have a fully functional prototype and are in the middle of raising money to add some more features and polish to make it into a commercial product (the prototype is a bit cluttered and could use to be more user-friendly). The prototype makes use of weather forecasts, 10-meter altitude data with a vertical resolution of 4 inches, and so forth, along with driver behavior modeling and physics calculations every several meters to determine how much charge you'll have at each point along the trip. The final version will have a very powerful crowd-sourced, trust network-validated charger database overlay on the map as well (it's coded, but is currently being debugged). So you find your route won't make it to your destination, no problem -- you drag it over to a charging station. And you can click on the station, get pictures, reviews, find what there is to do in the area, etc. It'll initially be populated with not just "known" recharging stations, but also "likely" recharging places, such as RV parks and so forth -- as well as phone numbers and email addresses to contact their owners. And you can add your own charging stations, even just a high-power outlet in your garage -- and list a fee for it if you want.
We've done some accuracy validation on the simulator part with a Tesla Roadster. Of 7-ish legs that we tested, all but one of them were in the 2-4% error range. The last one was on surface streets and was about 12% error because Google was way off on how much traffic there was going to be (they said 40 minutes, it actually took closer to 25); when we hard-coded it to get the amount of traffic right, it fell back into the normal error range. To counter that issue, we're going to add real-time traffic forecasts in wherever available. Oh, and this is so far without any of Tesla's help. If we can get more detailed hardware specs, we can do even better.
The market forecasts range wildly, but they range from a million or two EVs up to 32.7 million shipped by 2015 (Wintergreen Research). Either way, it's a massive market, and even with just a couple percent penetration, there's huge profit potential and the potential to create a lot of jobs. And it should help open up the EV market to a lot of people who wouldn't otherwise consider them. And most of our competition is way behind -- the standard approach, you'll find, is just to draw a circle around the car and say this is how far you can drive (as though you can go just as far over the top of Mount Whitney as you can over flat land on good roads).
Don't forget that E=mc^2. A little bit of lithium will go a long, long way. 1kg of lithium burned at 5% net efficiency (after wasted lithium/tritium, generator inefficiencies, and the fact that only part of its mass becomes energy) is ~1.25 terawatt hours, enough to power almost 120,000 homes for a year.
And really, lithium isn't actually that rare. That's a myth. It generally costs between $4 and $8 per kilogram of lithium carbonate (the commonly traded form). Not exactly hard to come by. We can get it for seawater for $22-$32/kg. Meanwhile, 1-2kg of lithium carbonate go into your typical li-ion battery, which costs perhaps $100 per kilogram in bulk.
This whole thing is burying the lede, and you're right on the money. Efficient green LEDs are the panacea of LED room lighting. The human eye isn't very sensitive to red or blue, which we can efficiently make with LEDs; its primary sensitivity is in the green spectrum. Hence LED lighting lumens per watt isn't as impressive as you'd think (lumens are a scale based on the sensitivity of the human eye). This can completely change that picture. They're basically stating that they closed the "green gap".
Wait, so having your code take up a bunch of wasted space and having to make you change a lot of code when structures or functions change is somehow a good thing in terms of development time and maintenance?
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Spend $10,000 to buy new batteries every 100,000 miles
Um, no. The Volt, for example, has a pack that *currently* costs $7-8k, and that's not in mass production. And it's *warrantied* for 10 years. And how much do you think it'll cost ten years from now? Probably $3k or so, judging from how the price on the battery packs for conventional hybrids dropped from their initial values.
Ooh, *another* round of "Lies, Damned Lies, and Miles Per Gallon"! (see further down for the first installment this thread).
When a manufacturer cites an efficiency figure for an engine, that is at a single specific torque and RPM condition with no powertrain losses. In the real world, where torque and RPM are often far from the optimal band and where powertrain losses can be significant, modern gasoline vehicles average about 20% tank-to-wheels efficiency and modern diesels 25%.
No not really. A 5-seat Lupo 3L gets 88mpg on the highway. The new VW 2-seater arriving after Christmas gets 250mpg on the highway.
Ugh. Time for another round of, "Lies, Damned Lies, and Miles-Per-Gallon". First, the Lupo 3L
1) "Comparing different drivecycles": The Lupo 3L is measured on the NEDC, not the US06 and FTP drivecycles we're used to. European mileages for the same vehicle are generally about 15% higher than US combined mileages.
2) "Comparing non-equivalent vehicles": The Lupo 3L is a four seater with no trunk (you have to fold the rear seats down to get trunk space, making it into a two-seater) that does 0-60 in 17 seconds in its "economy" mode that is used to get that NEDC mileage figure.
3) "Comparing different fuels": Diesel is a fuel that is nearly 15% denser than gasoline, contains that much more petroleum energy, and releases about that much more CO2 when burned.
Now for the VW 1L car, which is even worse:
1) "Comparing different drivecycles": That figure isn't even for an official drivecycle -- it's for a steady-state 45mph on the highway. Good luck coming close to that in any kind of real-world driving.
2) "Comparing non-equivalent vehicles": The 1L car not only has two seats and no trunk space and is low enough to conveniently wedge itself under a semi, it has virtually nothing you'd expect in a car. Like, for example, an air conditioner. Enjoy all of that greenhouse over your head in the summer!
3) "Comparing different fuels": Also diesel. Divide by 1.12 or so to get a gasoline equivalent in terms of petroleum consumption.
There are, mind you, two more big fallacies that they didn't use:
4) "The PHEV Game": Only applies to plug-in hybrids. You make up a ratio of how much gasoline to how much electricity your average driver will use, then only count the gasoline towards the MPG. By picking whatever ratio you want, you can make the MPG figure be anything you want.
5) "Wrong gallons": Reporting miles per imperial gallon instead of miles per US gallon. Imperial gallons are ~30% bigger.
As for your last sentence, that doesn't even make sense. What are you talking about, and who the heck is "Greenercars.org"? There have been dozens of *peer-reviewed* studies on the subject (including from the DOE/PNNL), and essentially all of them state that even on our current grid, for the same vehicle, an electric drivetrain is notably lower emission. In the US, about 30% less CO2, somewhat more particulate matter, about the same SOx, somewhat less NOx, and almost no CO or VOCs -- with all of those emissions being moved away from ground level/population-dense areas and up to high altitude stacks in remote areas where they affect people less. And to top it all off? The grid is getting cleaner while oil is getting dirtier. Even *without* cap and trade, 42% of new power added to the grid last year was wind, and most of the rest, natural gas. Meanwhile, oil production is getting dirtier, increasingly turning to syncrude (ultra-heavy, bitumen, shale, coal, etc), unconventional high-extraction-energy structures (such as the Bakken), remote areas (deep sea, arctic, etc), isolated pockets, poor quality crude, and so forth.
Given that it only does 0-60 in 9 seconds, it's not a very powerful motor. But is surprisingly heavy for its output. And furthermore, your entire premise is wrong. Unlike with a gasoline car, the more powerful the powertrain you put in an electric vehicle, the *less* energy it uses for the same driving profile. Having higher peak torque/horsepower capabilities means fatter, lower resistance wires, which means that when you're not making use of that extra capacity, you're encountering less resistance.
Now, if your driver starts actually making use of that extra capability, sure, they'll burn more power. But for the same driving profile, no.
They could start by being better educated about the market. They don't know of any that have fast recharge out there? Really? Say, the BYD F3DM, the Mitsubishi MiEV, or the Subaru R1e, all of which are on the market right now? The Phoenix SUT, the Lightning GT, the Shelby Ultimate Aero EV, and about a dozen others currently under development? Various fast charging conversions that have been in test fleets for over a decade?
Perhaps I am mistaken (it certainly wouldn't be the first time) but that indicates to me a (relatively) small additional fuel requirement to bring the ET fully to orbital velocity.
The OMS only has 305m/s delta-V (getting to LEO generally takes 9-10k, depending on aero drag), and much of that OMS delta-V is needed to deorbit. The Space Shuttle is rated to take 25,000kg payload to LEO. Since the ET has a massive cross section, it'd need to be a high LEO, at least as high as the ISS. The original ET was over 35,000kg. The lightest version available today is a 26,330kg lithium-aluminum version. It holds 730,000kg of propellant, a couple percent of which will remain in the tank even at complete burnout -- say, 20,000kg, which would have to be vented over time once up in orbit. So that's pretty much double the shuttle's rated payload capacity, needing to go to a fairly high LEO orbit.
That said, only part of the shuttle's max payload is dictated by the OMS; with no payload in the payload bay, the SRBs and ET can give it more initial delta-V and loft it up higher. But it's still a major payload for the shuttle to haul around.
For political or practical reasons?:o)
The most powerful "political" force in NASA today is the Space Shuttle Program. Anything to encourage further development of its components would win political brownie points.
1) Orion launched from the surface is essentially a no-go; the amount of contamination and then the EMPs is simply unworkable.
2) Orion is obsolete; it's been superceded by better atomic bomb-based designs that are more efficient, lighter weight, and expose the crew to less radiation and shock. For example, Medusa. The paradigm is inversed -- instead of being pushed by the bombs, you're pulled. The spacecraft trails way behind a "parachute" that the bombs are detonated under. The tethers and "chute" itself provide a very long compression stroke, there's a significant distance between the bombs and the crew, and since structures are in tension instead of compression, they can be built lighter. And the whole craft need not be built as large (although it still can be).
3) If you don't care about spewing dangerous amounts of radiation out the back, why not just go with something like a nuclear saltwater rocket? If you're not familiar with the design, it involves a concentrated, enriched uranyl nitrate solution kept in a tank broken up into channels by neutron absorbers. When it gets injected into the "combustion" chamber, it reaches criticality and rapidly expands out the nozzle.
4) Realistically though, if what you care about is *getting off the surface*, and you want to go nuclear, you need a nuclear-thermal rocket, wherein a closed fission reactor in the chamber heats up hydrogen and expels it out the nozzle. Kind of tricky to have such a small, lightweight reactor release so much power in a safe, controlled manner, but it should be workable. As for cost, who knows. Before we can get to that point, though, I'd think we'd at first want to master nuclear-thermal aircraft engines, as the engineering constraints on them aren't as extreme.
5) The most radical cost reduction methods for getting off the surface don't involve fission or fusion at all (except possibly in power plants); they're electric. Some here are big fans of space elevators, but honestly, the material constraints are not only extreme, but they may be outright impossible. I personally favor the Launch Loop design, wherein a rigid tube maintains a vacuum and magnetically levitates and accelerates an iron ring inside of it, whose centrifugal force suspends the structure as a giant ramp. Craft can accelerate magnetically using the energy from the rapidly spinning iron ring.
6) For cargo, there may be some merit to the "giant gun" approach, whether traditional, light gas, ram accelerator, rail, coil, or whatnot. For humans, the G forces required to have a reasonable length track pretty much rule out this approach.
What's exceptional about SpaceX is that it's essentially a from-scratch system. They were able to take advantage of all that we've learned that we've done wrong with rocket design over the past century -- hence their impressive performance and low cost. Sea Launch just launches slightly modified Zenit rockets, which are modified Energia boosters. The Pegasus by OSC is closer to being a fully privately developed rocket, but they were fully funded by NASA (instead of just winning a COTS contract but mostly relying on private customers, like SpaceX) and its engines are modified versions of existing engines by ATK (the manufacturer of the Space Shuttle SRBs and many NASA spacecraft kick stages). Also, the Pegasus design is unfortunate in that it can't evolve much beyond where it stands right now, as it has low Isp but has to be light enough to be air-launched. And all of its design choices put together make it a rather expensive system.
Their current schedule, while IMHO overly ambitious, is to have an empty Dragon dock with the ISS in 2010, with crew delivery to follow on later missions.
SpaceX certainly aims to beat Ares 1 for a tiny fraction of the development and per-launch costs. And they may well succeed.
And how do you arrive at that conclusion? The Apollo astronauts repeatedly saw flashes of light on their trip from cosmic rays impacting on their retinas. This is no trivial amount of radiation. And if you face a strong radiation storm without a very well shielded shelter, the crew won't even reach their destination alive. Literally. You *have* to shield against solar radiation. As for GCR, while it's a lower dose, it's incredibly hard to shield against, but if you don't, your crew has unacceptably high odds of cancer, infertility, and other such problems by the time they get back to Earth.
People aren't studying this issue for the heck of it.
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Non-crowd-sourced chargers are no bette; check out EVChargerMaps some time. But the advantage of crowd sourcing with a trust network is you can get an idea of how much you can trust it. And with contact information for the owner, you can call up in advance. Our system is also designed to send followup emails every three months to station owners asking them to verify that their charger is still working and to follow a link to confirm it.
1)I don't have an outlet in my parking space. Not even the home one, much less at lots near work. Most people in dense urban areas don't.
Unless your landlord is a jerk, offer to install one, and tack a couple hundred dollars onto the purchase price; problem solved.
1a)I don't always park at home even over night. Sometimes I'm at a girlfriend's, sometimes I'm at a hotel in another city. Neither would have an outlet even if I had one in #1.
Your girlfriend doesn't have a *power outlet*? Where does she live, a cave? Or are you talking about someone who doesn't have a garage and won't run an extension cord, and you really have to charge every time -- and even then, electricians can be found everywhere..
2)When there's an accident on a bridge, I can take 2 hours to drive home. I wouldn't trust it to keep a charge for that long idling.
Huh? Unlike with cars, the slower EVs drive, the *more* range they get. They don't "idle". You'll use more accessory power, but not nearly as much as you save in terms of aero drag. This doesn't apply to gas cars, as they're inefficient at low speeds and don't regen.
3)I want the option of being able to drive farther. I want to be able to drive an hour or two out of the city on a weekend, or take a road trip. This car doesn't have that. So I'll need another car anyway. I don't have room for two in my garage. So add 100-150 a month for a parking spot to the price.
Wait, you have a garage... but you don't have a power outlet? Huh? Who has a garage without a power outlet? How do you use power tools? Do you charge them indoors?
How often do you drive that far? I need a cargo van once or twice a year, but I don't go out and buy one. I just rent. It'd be stupid to make a cargo van my daily commuter just because I occasionally need it. Why wouldn't you apply the same logic to your drivetrain?
If it's *really* a problem for you, that's what PHEVs are for.
4)I don't always drive to work. Occasionally I drive to work (20 mi), to a concert venue after work (40 mi), then home (30 mi). That's cutting it too close.
You'd be amazed at how accomodating most employers are. And furthermore, you're in *Seattle*. Your city is building a network of charging stations. An EV may actually get you a better parking space at the concert.
5)I'm forgetful. If I forgot for even 1 evening to plug it in I'd be in trouble. That's not acceptable. It needs to be able to go at least a week without plugging in.
How often do you forget to shut the front door? Because it's that obvious of a thing. Talk to any EV owner. Forgetting to charge an EV is essentially a non-issue; it just becomes a 15 second part of your daily routine. And lets you avoid having to randomly add 10-20 minutes to your weekly schedule to go out of your way to fill up your gas car; it eliminates the, "oh damn, I need to stop for gas" moments.
I'd prefer 500 mi, so I can take it on a real road trip.
Huh? You drive 8 hours nonstop without a break? Wow. Please let me know when you're taking a road trip and what roads you'll be on so I can avoid you.
The other issue is availability of charging. A car like this needs extensive infrastructure that just doesn't exist. The only viable solution is to make it rechargable on the go- removable batteries or the like.
50A/240V outlets already crisscross the country -- RV parks. Numerous cities are building EV-specific charging networks, including yours, Seattle. And your state is considering a statewide rollout.
Most upcoming EVs use about 200Wh/mi pack to wheels, ~225Wh/mi wall to wheels. The average person pays about $0.10/kWh. That's a little over 2 cents per mile in energy costs. How does that compare to what you pay for gas? At $3/gal, it'd take over 130mpg to beat that. And that's assuming you don't get time-of-use rates, since EVs typically charge off-peak.
And it's not all energy costs, too. It's also maintenance. EV drivetrains have about a tenth as many moving parts as gas drivetrains. And contrary to the stereotypes promoted by lead-acid EVs, if you look at the failure rate on Prius packs, they're very low. Heck, GM is *warrantying* the Volt pack for 10 years. And no shock, when hybrid packs were mass produced, the prices went way down. Hybrid packs nowadays are typically $2-2.5k. That's no worse than replacing a transmission (EVs are generally direct drive and thus don't have transmissions). Expect the same sort of longevities and price reductions with EV packs as with hybrid packs. People aren't exactly yet mass producing, say, large format manganese spinel battery packs.
Nissan's price estimate is $20-$33k (they haven't really locked it down yet). That's before the $7,500 tax credit, but also doesn't include the battery. It sounds like they're going with the PBP model; if so, the battery can be rented (at a cost that even after paying for rental + electricity, is less than what your typical driver pays on gasoline) or purchased outright. The battery cost is estimated by Nissan at $10k. This will drop over time, of course; large format manganese spinels batteries aren't exactly mass produced currently.
Back to low speeds and AC: low speeds are *great* for EVs; their ranges increase dramatically at low speeds. The Tesla Roadster can go over 400 miles at a steady 20mph. AC is relevant, but not *that* relevant. The issue is that unlike gasoline cars, EVs are efficient at all speeds, so you're most efficient at low speeds, since there's little aero drag. Plus, all EVs come with regen, and thanks to the big li-ion pack, it's a lot more efficient than in a small-pack NiMH hybrid (60-70% instead of ~30%).
You mean like this?
Yeah, it's a neat concept; take it when you need it, leave it behind the rest of the time. I wish more companies were considering it. You wouldn't even need to own it; being so small and simple, it'd lend itself quite readily to low-cost rental or sharing programs.
I'm starting a company to do just that -- Celadon Applications, LLC. We already have a fully functional prototype and are in the middle of raising money to add some more features and polish to make it into a commercial product (the prototype is a bit cluttered and could use to be more user-friendly). The prototype makes use of weather forecasts, 10-meter altitude data with a vertical resolution of 4 inches, and so forth, along with driver behavior modeling and physics calculations every several meters to determine how much charge you'll have at each point along the trip. The final version will have a very powerful crowd-sourced, trust network-validated charger database overlay on the map as well (it's coded, but is currently being debugged). So you find your route won't make it to your destination, no problem -- you drag it over to a charging station. And you can click on the station, get pictures, reviews, find what there is to do in the area, etc. It'll initially be populated with not just "known" recharging stations, but also "likely" recharging places, such as RV parks and so forth -- as well as phone numbers and email addresses to contact their owners. And you can add your own charging stations, even just a high-power outlet in your garage -- and list a fee for it if you want.
We've done some accuracy validation on the simulator part with a Tesla Roadster. Of 7-ish legs that we tested, all but one of them were in the 2-4% error range. The last one was on surface streets and was about 12% error because Google was way off on how much traffic there was going to be (they said 40 minutes, it actually took closer to 25); when we hard-coded it to get the amount of traffic right, it fell back into the normal error range. To counter that issue, we're going to add real-time traffic forecasts in wherever available. Oh, and this is so far without any of Tesla's help. If we can get more detailed hardware specs, we can do even better.
The market forecasts range wildly, but they range from a million or two EVs up to 32.7 million shipped by 2015 (Wintergreen Research). Either way, it's a massive market, and even with just a couple percent penetration, there's huge profit potential and the potential to create a lot of jobs. And it should help open up the EV market to a lot of people who wouldn't otherwise consider them. And most of our competition is way behind -- the standard approach, you'll find, is just to draw a circle around the car and say this is how far you can drive (as though you can go just as far over the top of Mount Whitney as you can over flat land on good roads).
Don't forget that E=mc^2. A little bit of lithium will go a long, long way. 1kg of lithium burned at 5% net efficiency (after wasted lithium/tritium, generator inefficiencies, and the fact that only part of its mass becomes energy) is ~1.25 terawatt hours, enough to power almost 120,000 homes for a year.
And really, lithium isn't actually that rare. That's a myth. It generally costs between $4 and $8 per kilogram of lithium carbonate (the commonly traded form). Not exactly hard to come by. We can get it for seawater for $22-$32/kg. Meanwhile, 1-2kg of lithium carbonate go into your typical li-ion battery, which costs perhaps $100 per kilogram in bulk.
One neat thing that they didn't mention: having lithium exposed to a high radiation flux will breed more tritium. It makes its own fuel.
A "keyboard"... how quaint.
This whole thing is burying the lede, and you're right on the money. Efficient green LEDs are the panacea of LED room lighting. The human eye isn't very sensitive to red or blue, which we can efficiently make with LEDs; its primary sensitivity is in the green spectrum. Hence LED lighting lumens per watt isn't as impressive as you'd think (lumens are a scale based on the sensitivity of the human eye). This can completely change that picture. They're basically stating that they closed the "green gap".
Wait, so having your code take up a bunch of wasted space and having to make you change a lot of code when structures or functions change is somehow a good thing in terms of development time and maintenance?
Yep -- several hundred m/s delta-V down, only ~9,000 more to go.
Forget about type safety... just give me the "auto" variable type. :P
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(Personally, I much prefer the amusement of quote nazis)
Last I checked, the US grid had a 92.8% transmission efficiency.
Spend $10,000 to buy new batteries every 100,000 miles
Um, no. The Volt, for example, has a pack that *currently* costs $7-8k, and that's not in mass production. And it's *warrantied* for 10 years. And how much do you think it'll cost ten years from now? Probably $3k or so, judging from how the price on the battery packs for conventional hybrids dropped from their initial values.
Ooh, *another* round of "Lies, Damned Lies, and Miles Per Gallon"! (see further down for the first installment this thread).
When a manufacturer cites an efficiency figure for an engine, that is at a single specific torque and RPM condition with no powertrain losses. In the real world, where torque and RPM are often far from the optimal band and where powertrain losses can be significant, modern gasoline vehicles average about 20% tank-to-wheels efficiency and modern diesels 25%.
No not really. A 5-seat Lupo 3L gets 88mpg on the highway. The new VW 2-seater arriving after Christmas gets 250mpg on the highway.
Ugh. Time for another round of, "Lies, Damned Lies, and Miles-Per-Gallon". First, the Lupo 3L
1) "Comparing different drivecycles": The Lupo 3L is measured on the NEDC, not the US06 and FTP drivecycles we're used to. European mileages for the same vehicle are generally about 15% higher than US combined mileages.
2) "Comparing non-equivalent vehicles": The Lupo 3L is a four seater with no trunk (you have to fold the rear seats down to get trunk space, making it into a two-seater) that does 0-60 in 17 seconds in its "economy" mode that is used to get that NEDC mileage figure.
3) "Comparing different fuels": Diesel is a fuel that is nearly 15% denser than gasoline, contains that much more petroleum energy, and releases about that much more CO2 when burned.
Now for the VW 1L car, which is even worse:
1) "Comparing different drivecycles": That figure isn't even for an official drivecycle -- it's for a steady-state 45mph on the highway. Good luck coming close to that in any kind of real-world driving.
2) "Comparing non-equivalent vehicles": The 1L car not only has two seats and no trunk space and is low enough to conveniently wedge itself under a semi, it has virtually nothing you'd expect in a car. Like, for example, an air conditioner. Enjoy all of that greenhouse over your head in the summer!
3) "Comparing different fuels": Also diesel. Divide by 1.12 or so to get a gasoline equivalent in terms of petroleum consumption.
There are, mind you, two more big fallacies that they didn't use:
4) "The PHEV Game": Only applies to plug-in hybrids. You make up a ratio of how much gasoline to how much electricity your average driver will use, then only count the gasoline towards the MPG. By picking whatever ratio you want, you can make the MPG figure be anything you want.
5) "Wrong gallons": Reporting miles per imperial gallon instead of miles per US gallon. Imperial gallons are ~30% bigger.
As for your last sentence, that doesn't even make sense. What are you talking about, and who the heck is "Greenercars.org"? There have been dozens of *peer-reviewed* studies on the subject (including from the DOE/PNNL), and essentially all of them state that even on our current grid, for the same vehicle, an electric drivetrain is notably lower emission. In the US, about 30% less CO2, somewhat more particulate matter, about the same SOx, somewhat less NOx, and almost no CO or VOCs -- with all of those emissions being moved away from ground level/population-dense areas and up to high altitude stacks in remote areas where they affect people less. And to top it all off? The grid is getting cleaner while oil is getting dirtier. Even *without* cap and trade, 42% of new power added to the grid last year was wind, and most of the rest, natural gas. Meanwhile, oil production is getting dirtier, increasingly turning to syncrude (ultra-heavy, bitumen, shale, coal, etc), unconventional high-extraction-energy structures (such as the Bakken), remote areas (deep sea, arctic, etc), isolated pockets, poor quality crude, and so forth.
Given that it only does 0-60 in 9 seconds, it's not a very powerful motor. But is surprisingly heavy for its output. And furthermore, your entire premise is wrong. Unlike with a gasoline car, the more powerful the powertrain you put in an electric vehicle, the *less* energy it uses for the same driving profile. Having higher peak torque/horsepower capabilities means fatter, lower resistance wires, which means that when you're not making use of that extra capacity, you're encountering less resistance.
Now, if your driver starts actually making use of that extra capability, sure, they'll burn more power. But for the same driving profile, no.
They could start by being better educated about the market. They don't know of any that have fast recharge out there? Really? Say, the BYD F3DM, the Mitsubishi MiEV, or the Subaru R1e, all of which are on the market right now? The Phoenix SUT, the Lightning GT, the Shelby Ultimate Aero EV, and about a dozen others currently under development? Various fast charging conversions that have been in test fleets for over a decade?
Perhaps I am mistaken (it certainly wouldn't be the first time) but that indicates to me a (relatively) small additional fuel requirement to bring the ET fully to orbital velocity.
The OMS only has 305m/s delta-V (getting to LEO generally takes 9-10k, depending on aero drag), and much of that OMS delta-V is needed to deorbit. The Space Shuttle is rated to take 25,000kg payload to LEO. Since the ET has a massive cross section, it'd need to be a high LEO, at least as high as the ISS. The original ET was over 35,000kg. The lightest version available today is a 26,330kg lithium-aluminum version. It holds 730,000kg of propellant, a couple percent of which will remain in the tank even at complete burnout -- say, 20,000kg, which would have to be vented over time once up in orbit. So that's pretty much double the shuttle's rated payload capacity, needing to go to a fairly high LEO orbit.
That said, only part of the shuttle's max payload is dictated by the OMS; with no payload in the payload bay, the SRBs and ET can give it more initial delta-V and loft it up higher. But it's still a major payload for the shuttle to haul around.
For political or practical reasons? :o)
The most powerful "political" force in NASA today is the Space Shuttle Program. Anything to encourage further development of its components would win political brownie points.
1) Orion launched from the surface is essentially a no-go; the amount of contamination and then the EMPs is simply unworkable.
2) Orion is obsolete; it's been superceded by better atomic bomb-based designs that are more efficient, lighter weight, and expose the crew to less radiation and shock. For example, Medusa. The paradigm is inversed -- instead of being pushed by the bombs, you're pulled. The spacecraft trails way behind a "parachute" that the bombs are detonated under. The tethers and "chute" itself provide a very long compression stroke, there's a significant distance between the bombs and the crew, and since structures are in tension instead of compression, they can be built lighter. And the whole craft need not be built as large (although it still can be).
3) If you don't care about spewing dangerous amounts of radiation out the back, why not just go with something like a nuclear saltwater rocket? If you're not familiar with the design, it involves a concentrated, enriched uranyl nitrate solution kept in a tank broken up into channels by neutron absorbers. When it gets injected into the "combustion" chamber, it reaches criticality and rapidly expands out the nozzle.
4) Realistically though, if what you care about is *getting off the surface*, and you want to go nuclear, you need a nuclear-thermal rocket, wherein a closed fission reactor in the chamber heats up hydrogen and expels it out the nozzle. Kind of tricky to have such a small, lightweight reactor release so much power in a safe, controlled manner, but it should be workable. As for cost, who knows. Before we can get to that point, though, I'd think we'd at first want to master nuclear-thermal aircraft engines, as the engineering constraints on them aren't as extreme.
5) The most radical cost reduction methods for getting off the surface don't involve fission or fusion at all (except possibly in power plants); they're electric. Some here are big fans of space elevators, but honestly, the material constraints are not only extreme, but they may be outright impossible. I personally favor the Launch Loop design, wherein a rigid tube maintains a vacuum and magnetically levitates and accelerates an iron ring inside of it, whose centrifugal force suspends the structure as a giant ramp. Craft can accelerate magnetically using the energy from the rapidly spinning iron ring.
6) For cargo, there may be some merit to the "giant gun" approach, whether traditional, light gas, ram accelerator, rail, coil, or whatnot. For humans, the G forces required to have a reasonable length track pretty much rule out this approach.
What's exceptional about SpaceX is that it's essentially a from-scratch system. They were able to take advantage of all that we've learned that we've done wrong with rocket design over the past century -- hence their impressive performance and low cost. Sea Launch just launches slightly modified Zenit rockets, which are modified Energia boosters. The Pegasus by OSC is closer to being a fully privately developed rocket, but they were fully funded by NASA (instead of just winning a COTS contract but mostly relying on private customers, like SpaceX) and its engines are modified versions of existing engines by ATK (the manufacturer of the Space Shuttle SRBs and many NASA spacecraft kick stages). Also, the Pegasus design is unfortunate in that it can't evolve much beyond where it stands right now, as it has low Isp but has to be light enough to be air-launched. And all of its design choices put together make it a rather expensive system.
By that time, the ISS will have been de-orbited.
Their current schedule, while IMHO overly ambitious, is to have an empty Dragon dock with the ISS in 2010, with crew delivery to follow on later missions.
SpaceX certainly aims to beat Ares 1 for a tiny fraction of the development and per-launch costs. And they may well succeed.
Space radiation problems are overrated.
And how do you arrive at that conclusion? The Apollo astronauts repeatedly saw flashes of light on their trip from cosmic rays impacting on their retinas. This is no trivial amount of radiation. And if you face a strong radiation storm without a very well shielded shelter, the crew won't even reach their destination alive. Literally. You *have* to shield against solar radiation. As for GCR, while it's a lower dose, it's incredibly hard to shield against, but if you don't, your crew has unacceptably high odds of cancer, infertility, and other such problems by the time they get back to Earth.
People aren't studying this issue for the heck of it.