Yup, there are electric trucks. I know people with electric versions of the Ford Ranger and the Chevy S-10. I drive an EV1 instead because I rarely need a truck, and I can always borrow or rent one if I really need to.
The main point is that while EVs can't displace every gasoline or diesel vehicle, they don't have to. A very high percentage of total vehicle miles are short trips that are well within the range of existing EVs. Many people who originally get an EV as a "secondary" car quickly make it their "primary" car and use their gasoline car only for the occasional long trip. Many of these gasoline cars sit undriven for so long that they often have trouble starting up again!
The numbers are even better here. You've got pretty cheap electricity; our rates in San Diego are more like US $0.14/kWh, or about GBP 0.09 at current exchange rates. Compact fluorescent bulb prices vary a lot depending on brand, store and quantity; I see local quotes both above and below your figure. However, the lifetimes are usually specified at 10,000 hr vs your 5,000 hr figure, which would help the CF economics even more if true.
In any event, compact fluorescents are a no-brainer here.
I know this is a naughty, but I am really curious. Do you have any references on this? Do you mean that electric cars are more energy efficient (total energy cycle) than equivalent gasoline powered cars?
Yes, that's what I mean. And yours is a perfectly reasonable question.
Here are some figures.
The NiMH model of the EV1 is rated to consume about 370 watt-hours AC per mile. The PbA version was more efficient, about 270 WhAC/mi. I've driven both models, and I've confirmed these figures. (The NiMH model is worse mainly because of GM's kludgey use of the air conditioner to cool the battery pack during charging. A good liquid-cooled design would be much more efficient.)
Gasoline is about 125,000 BTU/gallon, or about 36.6 kW-hr. So a car that gets 25 mpg consumes about 1464 watt-hours/mile, or about 4 times that of the EV1.
So if the efficiency of the power grid, from primary fuel to customer, is greater than about 25%, then the EV1 wins on overall energy efficiency. Large combined-cycle gas-fired turbines now yield efficiencies in excess of 50%, large alternators are practically 100%, and the grid efficiency in California is about 96%. So the EV1 wins.
It's even better than that, because I've ignored the energy used in the production of gasoline from crude oil. And the EV also has the qualitative advantage of being able to use electricity from any primary source, while the gasoline car can only run on petroleum (although it could be converted to run on compressed natural gas.)
As far as solar, again it depends on a lot of things. And, the cost per kw (if you ignore unreasonable subsidies, such as California and Arizona laws that force the power companies to buy your unreliable power back at your whim by running your meter backards) is much, much higher.
Even without subsidies, solar is within a factor of two. That may qualify as "much, much higher", but the long-term trend on solar prices is steadily down while the trend on fossil fuels is steadily up. Eventually, they'll cross. So it seems reasonable to get started now, and to use subsidies to help the economies of scale kick in.
My PV power is quite reliable -- whenever the sun shines, I get power. It has kept my house going several times when the utility failed (though I had to "spill" the excess generation.)
Net metering is hardly "unreasonable" when you consider that the effect of my generation is to slightly lower the net consumption of my neighborhood. When net-metered photovoltaic becomes a significant fraction of grid capacity, then we can reconsider net metering. I'd be happy to have that problem.
I note that electricity demand is usually greatest exactly when the sun is shining, because of heavy air conditioner use. I take advantage of this fact by having a time-of-use meter; I generate most of my PV electricity during peak periods when it is most valuable, and I buy it back at night at lower rates.
My home, in the summer, runs about 15kW for about 18 hours a day!
Did you really mean to say that you average about 15 kilowatts? The typical US home consumes about 1kW (or less) on average, so you're way above that.
I would also be interested in the 2 year energy cost payback on cells in the southwest. Not that I disbelieve you, but I would love a source.
I typed "photovoltaic payback" into
Google and immediately got several pages of links with that information. It seems to be a popular topic of study. A particularly detailed analysis is
here
I just don't see that fuel cells have any major advantages in common consumer applications like laptops and cell phones.
Remember that a fuel cell is just a battery that stores its fuel externally. Also, fuel cells are seldom designed to be reversible, i.e., you can't apply electricity and produce fuel.
The usual proposal is to store the fuel in some sort of cartridge that you replace when it's used up. Presumably you'd have to go to the local store to buy these cartridges.
But isn't that what you already do now with devices that use primary (non-rechargeable) batteries? This is exactly why secondary (rechargeable) batteries are so popular. It's a lot more convenient to just plug your depleted batteries into a charger where they'll be ready by morning. No store trip required.
So the only advantage I can see for the fuel cell is when the device requires so much energy that conventional (primary or secondary) batteries are too heavy or bulky, and you don't have frequent access to external power for recharging. This may be the case for some laptop users, but is it really that hard to carry a few spare batteries and swap them out as needed?
Sure, I'd like to see a safe, inexpensive consumer fuel cell on the market. But it will have to compete more with primary (nonrechargeable) batteries than with secondary (rechargeable) batteries. And primary battery chemistries (e.g., lithium) are already available that have much higher energy densities than any secondary battery. So unless those fuel cartridges are a lot cheaper (and no less safe) than alkaline or lithium batteries, they won't have much of a market.
Edison invented a light bulb that will last 10x longer than even today's four and five year bulbs. You can go to the Smithsonian [smithsonian.org] and see it for yourself. But why won't GE and Sylvania, or even Philips, spit one out on the consumer market? Because then they couldn't rope us into buying the nasty bulbs that don't last very long at all. We buy more, they make more money.
Now this is bullshit. You can make any incandescent lamp last much longer by simply reducing the voltage. You can already get bulbs rated for 130V that will last a long time on 120V circuits.
So why aren't they widely used? Simple. A typical incandescent bulb costs much less than the electricity it consumes over its lifetime, and operating a bulb below its voltage rating drops its efficiency considerably. So you're much better off just running at the higher voltage. The bulb will burn out more quickly, but you'll get more lumen-hours per dollar spent on both bulb and electricity.
The only place to use these long-lived bulbs is where bulb replacement is difficult or expensive.
Of course, if you really want to save money, use compact fluorescents. They cost much more than incandescents, but they last so much longer and use so much less electricity that your overall costs are far lower than for any incandescent.
Until there is a major break through in battary technology battary devices will always be crippled compared to those drawing energy for either AC or petro fuels
I believed this myth too, until I got an EV1 and actually drove it every day. And you know what? Given the incremental advances over the past few decades in power semiconductors, motor controllers, aerodynamic vehicle design and low rolling resistance tires, the fact is that you can now make an entirely practical EV without any major breakthroughs in battery technology. Even good old lead acid batteries are perfectly useful.
The problem is that everyone is still fixated on range-per-charge. You have to actually drive an EV on a daily basis to know what a red herring it is. Even the California Air Resources Board
(CARB has fallen into the trap. They've greatly increased the costs of EVs by mandating unnecessarily high ranges that still require exotic new battery technologies.
EVs cannot replace every gasoline car, but they don't have to. The fact is that well-designed EVs with readily available batteries can already meet the daily needs of a great many people, provided that charging facilities are available where these cars are routinely parked.
"Poor acceleration"? You've obviously never ridden in an EV1.
You really should gather some facts on your own instead of simply repeating the "conventional wisdom" you've heard in oil and auto industry propaganda.
the power load of the required air conditioning (5 kW) reduces the range even more.
The peak drain of the air conditioner in my EV1 is about 2kW, and it seldom runs at that level for very long. Even on hot days, the effect on range is not all that significant.
Both systems are energy inefficient (although I suppose electric cars are worse).
Actually, electric cars already have the edge. Despite there being more energy conversion steps in the EV, the overall energy efficiency is still greater than the gasoline car.
But the real win is in emissions. EVs charged by California power plants are about 97% cleaner than the average gasoline car.
BTW... anyone who wants to use electricity as either a primary (electric cars) or secondary (hydrogen cars) had better be an advocate of nuclear power.
I actually agree with this. I love the reaction I get from my fellow EV enthusiasts when I, a EV1 driver and a solar power user, advocate nuclear power as well.
Oh, and solar.... fuggetabout it. It takes too much land area, produces unreliable power which must be stored somehow (probably inefficiently, even more reducing the energy efficiency of the system), and most solar cells take more energy just to produce and install than they will deliver in their lifetime!
Wrong. I have a 2.4kW system on my roof here in San Diego, and it produces most of what we need. The economic payback, at current electric rates, is approximately a wash. While I do have a battery bank, I only use it during outages; during normal operation, I pump my excess PV power back into the power line, spin the meter backwards, and collect a credit from the power company towards electricity I use at night.
The truth is that in the southwest US, a typical solar panel will take only about 2 years to pay back the energy used to manufacture it. For the rest of its typical 25-year lifetime, you're ahead.
I did a similar measurement and computation a while back. I timed a random gasoline pump and got a figure of 20 megawatts.
That's the heat power you'd get if you completely burned the gasoline as it came out of the nozzle. That's a lot!
But for a more reasonable comparison we should multiply 20MW by the average efficiency of a car engine, say 15%. That gives us 3 MW, still a lot. (EV efficiencies are much higher; 70-85% is typical, and that's dominated by the battery since motors and inverters are so efficient).
So it's clear that EVs will never have charge times that approach the refueling times for gasoline cars, unless the batteries are physically swapped.
But is this really a problem? My EV1 spends most of its time parked in one of two places: my driveway, and the parking garage at work. I can charge in either place, and I have plenty of time to do it. So as long as I can get through a typical day's driving on two charges
(one overnight at home and another during the day at work), I really don't have a problem.
Actually, I hardly ever charge at home anymore. And the electricity at work is free.
As an EV1 driver for the past four years, I will say that charging speed is the biggest drawback of the current generation of EVs. (In fact, it's the only drawback even worth mentioning.) I would very much like to see charging powers increased from the present 4-6kW range to perhaps 15-20kW, which can still be managed in most homes. But given the considerable convenience of being able to charge at home or at work without ever having to go to visit a gas station, there's just no compelling need for charging speeds comparable to those of gasoline cars, at least for cars used for routine commuting and shopping.
For long road trips, use a gasoline car. But for everyday driving, EVs are already entirely practical.
The end result, an electric car just moves the pollution it creates from the car to the power plant, and the power plant is very very dirty.
It's amazing how this myth persists given how easy it is to disprove. In California, the emissions from existing power plants associated with EV charging are far below those of even the cleanest gasoline cars. The approximate figure is a 97% reduction in per-mile emissions, but the actual figures depend on the specific pollutant.
See
my analysis for the details.
Cars fueled by natural gas are the only internal combustion engines that even come close to the cleanliness of an EV.
>1: How am i going to charge it in my parking lot at work? at my dorm?
I charge my EV1 in the parking garage at work every day. I have a charger at home too, but I seldom have to use it. UCSD has installed chargers on campus.
>2: It just wont get me very far here in Kansas
It'll get you farther in flat Kansas than here in hilly San Diego. About 100 miles/charge here, which is plenty for my needs.
>3: Lack of speed. When I need to merge, I need to get up and GO damn it.
The EV1 does 0-60 in less than 8 seconds. Faster acceleration than any gasoline car I've ever had.
>4: Small. I like big cars, or better yet Trucks. You cant have an electric Truck - it just makes no sense unless you haul barbie furniture
Really now, how often do you haul stuff around, vs just yourself?
I wonder how much of the problem has to do with differing map datums? For those who don't know, there are actually dozens of reference grids for latitude and longitude, all slightly different. The "WGS-84" datum native to GPS is only one of them. Which datum the receiver displays is a setup option. Until the 1980s, most US maps used "NAD-27" (North American Datum 1927), and it differs by as much as a few hundred feet from WGS-84 (and the very similiar NAD-83) over much of the continental US. The differences are primarily in the east-west direction, which may be relevant to the border dispute between Connecticut and Rhode Island.
Last summer, my wife and I visited the Old Greenwich Observatory near London, site of the 0 degree longitude line. Naturally, I took my GPS. I found that the true (WGS-84) line lies in the park several hundred feet east of the ceremonial line marked at the observatory. The true line is not marked in any way, nor do you need to pay admission to stand on it. Switching to older British map datums brought the discrepancy down, but still didn't eliminate it completely. In fact I got better matches between the older datums and their older reference lines at the observatory than I did for the "modern" datum and reference line.
AC motors are starting to displace DC in electric traction, thanks to modern power semiconductors that can replace mechanical commutators.
Think of it this way: every motor is really an AC motor. The so-called "DC motor" is really an AC motor that performs an internal DC->AC conversion, usually mechanically. So the change is not from DC to AC, but from mechanical to solid-state DC->AC conversion.
My EV1 electric car uses a 3-phase AC induction motor driven by a variable frequency, variable voltage inverter that uses IGBTs (insulated gate bipolar transistors), a hybrid between bipolar transistors and MOSFETs.
On routine driving around San Diego, regeneration gives me back maybe 10-20% of the energy I move from the batteries to the car. It's not a large percentage, but every little bit helps, and it's not hard to do.
>you can waste the energy as heat (uncomfortable), use it to charge batteries (wasteful, since the efficiency is low, probably less than 50% for the round trip), pump water uphill (might be problematic in NYC, might not be very efficient), or spin up a flywheel attached to a generator
You left out another alternative. You can pump the regenerated energy back into the AC power grid, thereby offloading (for a moment) some of the grid's generating capacity.
>DC->AC requires big switches and transformers. It's not terribly efficient, and it's heavy and expensive.
It's getting easier all the time with modern power semiconductors. Very high power DC->AC converters have been used for quite some time in DC power transmission, e.g., on the 3+ GW DC Pacific Intertie that runs from the Columbia River to LA. DC power transmission is also common in Europe, e.g., under the English Channel.
Look at it this way: if the claim of $20M annual savings in electricity is accurate, that's $20M worth of electricity that won't be dissipated as heat in the subway tunnels.
This explanation makes as much sense as any. But still, why the flywheel? Why work with a new, bulky and quite likely hazardous technology instead of replacing those AC->DC rectifiers with bidirectional inverters that allow excess DC power to be pumped back to the AC side? The grid is the best stationary flywheel there is.
Inverters that do this already exist, at least at lower power levels. The Trace SW4048 in my grid-tied PV system is an example.
And so is mine. I just set up a new machine for her with Debian. All she does is use Mozilla to do mail and to occasionally search the web, so it really didn't matter to her what OS she ran. But it mattered a great deal to me, as I can remotely administer a Linux machine far more easily than a Windows machine. And Linux is far more stable.
I logged the power generated by my photovoltaic system during today's eclipse. Since I'm in San Diego where the eclipse reached 80%, the dip is quite noticeable.
Well, I'm certainly willing to try alternatives. Especially if they're non-Microsoft.;-)
I was surprised how quickly I adapted to the Natural keyboard: no more than a few hours. So I already know that just because a keyboard looks weird, it's not necessarily hard to learn.
BTW, I'm convinced that my heavy use of EMACS for the past 25 years directly contributed to my tendonitis. My problem was in the tendons that actuate the left little finger, which in EMACS gets a lot of use on the control and escape keys.
I now make a point of avoiding these keys whenever possible, especially for scrolling and cursor movement where alternatives exist such as the arrow keys and especially the wheeled mouse.
My Natural keyboard is the only Microsoft product that I can, in good conscience, recommend to others. I suffered from chronic tendonitis in my left arm before I got it for both home and work. Then my pain faded away over several months.
It recurred more recently because I had taken to often using my laptop on the couch instead of my desktop machine with the natural keyboard. So in my case at least, the natural keyboard definitely works.
I happened to sit next to Stephen Jay Gould on a flight from San Diego to Minneapolis in March 2001. He seemed perfectly healthy, albeit showing his age, so I was quite surprised to see his obituary today.
After I introduced myself, I told him how much I had enjoyed his guest appearance on The Simpsons. He laughed and said that he still got occasional $20-$30 checks from Fox for residuals for appearing on that show. Not bad for just a few minutes' work, he said.
Over the Grand Canyon, he had his nose pressed to the window. I couldn't resist. "You know, all that was carved out in just a few days by the Great Flood", I said. He grinned broadly and joined in. "Yeah, just imagine all that water! Wow! Must have been quite a sight!" I kept it going. "Yeah! All that water just appeared out of nowhere, did all that -- but only that -- and just vanished!"
We talked much of the rest of the flight. He seemed as interested in my work as I was in his. It was definitely one of the more memorable plane rides I've ever had. He's always been one of my heroes for his good-natured ability to stand up to the forces of ignorance and superstition, and having had the chance to talk with him personalizes the great loss that the forces of reason suffered today.
Inventors make their livings breaking physical limitations.
Sorry, but they don't. Inventors make their living doing things that are possible, but just haven't been done yet. The successful ones start with a good scientific background so they won't waste time and money trying to do the impossible.
That is, unless their "business plan" is to con gullible investors out of their money.
Re:Shannon's law is still safe from Townsend...
on
The Magic Box Hoax
·
· Score: 3, Informative
Is this technically breaking Shannon's Law? I am not sure enough to make the bold statement that it is.
Nope, it's not breaking the Shannon limit, because nothing can break it. It's impossible. So if somebody does manage exceed the "Shannon limit" on some channel, it can only be because it was incorrectly calculated.
The Shannon capacity in bits/sec of a noisy, band-limited channel is C = B*log2(1+SNR).
So to compute the Shannon limit, you need to know both the bandwidth and the signal-to-noise ratio of the channel. Both numbers can vary quite a bit for plain copper pairs. The signal-to-noise ratio is affected by things like attenuation, crosstalk from other pairs and transmit power limitations to avoid crosstalk to other pairs. And bandwidth is affected by the length of the cable, its insulation and wire gauge, the presence of loading coils, etc.
That's why DSL speeds vary so much from one place to another, and why it's no big deal to send at much faster rates than DSL over short (a few hundred meters max) twisted pairs that have been carefully constructed (i.e., Cat 5 cable).
Slashdot Mirror
The main point is that while EVs can't displace every gasoline or diesel vehicle, they don't have to. A very high percentage of total vehicle miles are short trips that are well within the range of existing EVs. Many people who originally get an EV as a "secondary" car quickly make it their "primary" car and use their gasoline car only for the occasional long trip. Many of these gasoline cars sit undriven for so long that they often have trouble starting up again!
In any event, compact fluorescents are a no-brainer here.
Here are some figures.
The NiMH model of the EV1 is rated to consume about 370 watt-hours AC per mile. The PbA version was more efficient, about 270 WhAC/mi. I've driven both models, and I've confirmed these figures. (The NiMH model is worse mainly because of GM's kludgey use of the air conditioner to cool the battery pack during charging. A good liquid-cooled design would be much more efficient.)
Gasoline is about 125,000 BTU/gallon, or about 36.6 kW-hr. So a car that gets 25 mpg consumes about 1464 watt-hours/mile, or about 4 times that of the EV1.
So if the efficiency of the power grid, from primary fuel to customer, is greater than about 25%, then the EV1 wins on overall energy efficiency. Large combined-cycle gas-fired turbines now yield efficiencies in excess of 50%, large alternators are practically 100%, and the grid efficiency in California is about 96%. So the EV1 wins.
It's even better than that, because I've ignored the energy used in the production of gasoline from crude oil. And the EV also has the qualitative advantage of being able to use electricity from any primary source, while the gasoline car can only run on petroleum (although it could be converted to run on compressed natural gas.)
Even without subsidies, solar is within a factor of two. That may qualify as "much, much higher", but the long-term trend on solar prices is steadily down while the trend on fossil fuels is steadily up. Eventually, they'll cross. So it seems reasonable to get started now, and to use subsidies to help the economies of scale kick in.
My PV power is quite reliable -- whenever the sun shines, I get power. It has kept my house going several times when the utility failed (though I had to "spill" the excess generation.) Net metering is hardly "unreasonable" when you consider that the effect of my generation is to slightly lower the net consumption of my neighborhood. When net-metered photovoltaic becomes a significant fraction of grid capacity, then we can reconsider net metering. I'd be happy to have that problem.
I note that electricity demand is usually greatest exactly when the sun is shining, because of heavy air conditioner use. I take advantage of this fact by having a time-of-use meter; I generate most of my PV electricity during peak periods when it is most valuable, and I buy it back at night at lower rates.
Did you really mean to say that you average about 15 kilowatts? The typical US home consumes about 1kW (or less) on average, so you're way above that.I typed "photovoltaic payback" into Google and immediately got several pages of links with that information. It seems to be a popular topic of study. A particularly detailed analysis is here
Remember that a fuel cell is just a battery that stores its fuel externally. Also, fuel cells are seldom designed to be reversible, i.e., you can't apply electricity and produce fuel.
The usual proposal is to store the fuel in some sort of cartridge that you replace when it's used up. Presumably you'd have to go to the local store to buy these cartridges.
But isn't that what you already do now with devices that use primary (non-rechargeable) batteries? This is exactly why secondary (rechargeable) batteries are so popular. It's a lot more convenient to just plug your depleted batteries into a charger where they'll be ready by morning. No store trip required.
So the only advantage I can see for the fuel cell is when the device requires so much energy that conventional (primary or secondary) batteries are too heavy or bulky, and you don't have frequent access to external power for recharging. This may be the case for some laptop users, but is it really that hard to carry a few spare batteries and swap them out as needed?
Sure, I'd like to see a safe, inexpensive consumer fuel cell on the market. But it will have to compete more with primary (nonrechargeable) batteries than with secondary (rechargeable) batteries. And primary battery chemistries (e.g., lithium) are already available that have much higher energy densities than any secondary battery. So unless those fuel cartridges are a lot cheaper (and no less safe) than alkaline or lithium batteries, they won't have much of a market.
Now this is bullshit. You can make any incandescent lamp last much longer by simply reducing the voltage. You can already get bulbs rated for 130V that will last a long time on 120V circuits.
So why aren't they widely used? Simple. A typical incandescent bulb costs much less than the electricity it consumes over its lifetime, and operating a bulb below its voltage rating drops its efficiency considerably. So you're much better off just running at the higher voltage. The bulb will burn out more quickly, but you'll get more lumen-hours per dollar spent on both bulb and electricity.
The only place to use these long-lived bulbs is where bulb replacement is difficult or expensive.
Of course, if you really want to save money, use compact fluorescents. They cost much more than incandescents, but they last so much longer and use so much less electricity that your overall costs are far lower than for any incandescent.
I believed this myth too, until I got an EV1 and actually drove it every day. And you know what? Given the incremental advances over the past few decades in power semiconductors, motor controllers, aerodynamic vehicle design and low rolling resistance tires, the fact is that you can now make an entirely practical EV without any major breakthroughs in battery technology. Even good old lead acid batteries are perfectly useful.
The problem is that everyone is still fixated on range-per-charge. You have to actually drive an EV on a daily basis to know what a red herring it is. Even the California Air Resources Board (CARB has fallen into the trap. They've greatly increased the costs of EVs by mandating unnecessarily high ranges that still require exotic new battery technologies.
EVs cannot replace every gasoline car, but they don't have to. The fact is that well-designed EVs with readily available batteries can already meet the daily needs of a great many people, provided that charging facilities are available where these cars are routinely parked.
You really should gather some facts on your own instead of simply repeating the "conventional wisdom" you've heard in oil and auto industry propaganda.
But the real win is in emissions. EVs charged by California power plants are about 97% cleaner than the average gasoline car.
I actually agree with this. I love the reaction I get from my fellow EV enthusiasts when I, a EV1 driver and a solar power user, advocate nuclear power as well. Wrong. I have a 2.4kW system on my roof here in San Diego, and it produces most of what we need. The economic payback, at current electric rates, is approximately a wash. While I do have a battery bank, I only use it during outages; during normal operation, I pump my excess PV power back into the power line, spin the meter backwards, and collect a credit from the power company towards electricity I use at night.The truth is that in the southwest US, a typical solar panel will take only about 2 years to pay back the energy used to manufacture it. For the rest of its typical 25-year lifetime, you're ahead.
That's the heat power you'd get if you completely burned the gasoline as it came out of the nozzle. That's a lot!
But for a more reasonable comparison we should multiply 20MW by the average efficiency of a car engine, say 15%. That gives us 3 MW, still a lot. (EV efficiencies are much higher; 70-85% is typical, and that's dominated by the battery since motors and inverters are so efficient).
So it's clear that EVs will never have charge times that approach the refueling times for gasoline cars, unless the batteries are physically swapped.
But is this really a problem? My EV1 spends most of its time parked in one of two places: my driveway, and the parking garage at work. I can charge in either place, and I have plenty of time to do it. So as long as I can get through a typical day's driving on two charges (one overnight at home and another during the day at work), I really don't have a problem.
Actually, I hardly ever charge at home anymore. And the electricity at work is free.
As an EV1 driver for the past four years, I will say that charging speed is the biggest drawback of the current generation of EVs. (In fact, it's the only drawback even worth mentioning.) I would very much like to see charging powers increased from the present 4-6kW range to perhaps 15-20kW, which can still be managed in most homes. But given the considerable convenience of being able to charge at home or at work without ever having to go to visit a gas station, there's just no compelling need for charging speeds comparable to those of gasoline cars, at least for cars used for routine commuting and shopping.
For long road trips, use a gasoline car. But for everyday driving, EVs are already entirely practical.
It's amazing how this myth persists given how easy it is to disprove. In California, the emissions from existing power plants associated with EV charging are far below those of even the cleanest gasoline cars. The approximate figure is a 97% reduction in per-mile emissions, but the actual figures depend on the specific pollutant. See my analysis for the details.
Cars fueled by natural gas are the only internal combustion engines that even come close to the cleanliness of an EV.
>1: How am i going to charge it in my parking lot at work? at my dorm?
I charge my EV1 in the parking garage at work every day. I have a charger at home too, but I seldom have to use it. UCSD has installed chargers on campus.
>2: It just wont get me very far here in Kansas
It'll get you farther in flat Kansas than here in hilly San Diego. About 100 miles/charge here, which is plenty for my needs.
>3: Lack of speed. When I need to merge, I need to get up and GO damn it.
The EV1 does 0-60 in less than 8 seconds. Faster acceleration than any gasoline car I've ever had.
>4: Small. I like big cars, or better yet Trucks. You cant have an electric Truck - it just makes no sense unless you haul barbie furniture
Really now, how often do you haul stuff around, vs just yourself?
The brothers are watching Flounder, a pledge, take severe abuse in his ROTC class.
Otter [highly indignant]: "They can't do that to our pledges!"
Boon: "Only we can do that to our pledges!"
Last summer, my wife and I visited the Old Greenwich Observatory near London, site of the 0 degree longitude line. Naturally, I took my GPS. I found that the true (WGS-84) line lies in the park several hundred feet east of the ceremonial line marked at the observatory. The true line is not marked in any way, nor do you need to pay admission to stand on it. Switching to older British map datums brought the discrepancy down, but still didn't eliminate it completely. In fact I got better matches between the older datums and their older reference lines at the observatory than I did for the "modern" datum and reference line.
I really should post my photos to my website...
Think of it this way: every motor is really an AC motor. The so-called "DC motor" is really an AC motor that performs an internal DC->AC conversion, usually mechanically. So the change is not from DC to AC, but from mechanical to solid-state DC->AC conversion.
My EV1 electric car uses a 3-phase AC induction motor driven by a variable frequency, variable voltage inverter that uses IGBTs (insulated gate bipolar transistors), a hybrid between bipolar transistors and MOSFETs. On routine driving around San Diego, regeneration gives me back maybe 10-20% of the energy I move from the batteries to the car. It's not a large percentage, but every little bit helps, and it's not hard to do.
>you can waste the energy as heat (uncomfortable), use it to charge batteries (wasteful, since the efficiency is low, probably less than 50% for the round trip), pump water uphill (might be problematic in NYC, might not be very efficient), or spin up a flywheel attached to a generator
You left out another alternative. You can pump the regenerated energy back into the AC power grid, thereby offloading (for a moment) some of the grid's generating capacity.
>DC->AC requires big switches and transformers. It's not terribly efficient, and it's heavy and expensive.
It's getting easier all the time with modern power semiconductors. Very high power DC->AC converters have been used for quite some time in DC power transmission, e.g., on the 3+ GW DC Pacific Intertie that runs from the Columbia River to LA. DC power transmission is also common in Europe, e.g., under the English Channel.
Look at it this way: if the claim of $20M annual savings in electricity is accurate, that's $20M worth of electricity that won't be dissipated as heat in the subway tunnels.
This explanation makes as much sense as any. But still, why the flywheel? Why work with a new, bulky and quite likely hazardous technology instead of replacing those AC->DC rectifiers with bidirectional inverters that allow excess DC power to be pumped back to the AC side? The grid is the best stationary flywheel there is.
Inverters that do this already exist, at least at lower power levels. The Trace SW4048 in my grid-tied PV system is an example.
And so is mine. I just set up a new machine for her with Debian. All she does is use Mozilla to do mail and to occasionally search the web, so it really didn't matter to her what OS she ran. But it mattered a great deal to me, as I can remotely administer a Linux machine far more easily than a Windows machine. And Linux is far more stable.
Phil
The URL is http://people.qualcomm.com/karn/pv/daylife.html
I was surprised how quickly I adapted to the Natural keyboard: no more than a few hours. So I already know that just because a keyboard looks weird, it's not necessarily hard to learn.
BTW, I'm convinced that my heavy use of EMACS for the past 25 years directly contributed to my tendonitis. My problem was in the tendons that actuate the left little finger, which in EMACS gets a lot of use on the control and escape keys.
I now make a point of avoiding these keys whenever possible, especially for scrolling and cursor movement where alternatives exist such as the arrow keys and especially the wheeled mouse.
It recurred more recently because I had taken to often using my laptop on the couch instead of my desktop machine with the natural keyboard. So in my case at least, the natural keyboard definitely works.
Phil
After I introduced myself, I told him how much I had enjoyed his guest appearance on The Simpsons. He laughed and said that he still got occasional $20-$30 checks from Fox for residuals for appearing on that show. Not bad for just a few minutes' work, he said.
Over the Grand Canyon, he had his nose pressed to the window. I couldn't resist. "You know, all that was carved out in just a few days by the Great Flood", I said. He grinned broadly and joined in. "Yeah, just imagine all that water! Wow! Must have been quite a sight!" I kept it going. "Yeah! All that water just appeared out of nowhere, did all that -- but only that -- and just vanished!"
We talked much of the rest of the flight. He seemed as interested in my work as I was in his. It was definitely one of the more memorable plane rides I've ever had. He's always been one of my heroes for his good-natured ability to stand up to the forces of ignorance and superstition, and having had the chance to talk with him personalizes the great loss that the forces of reason suffered today.
Here's a good one for you:
www.crank.net
Sorry, but they don't. Inventors make their living doing things that are possible, but just haven't been done yet. The successful ones start with a good scientific background so they won't waste time and money trying to do the impossible.
That is, unless their "business plan" is to con gullible investors out of their money.
Nope, it's not breaking the Shannon limit, because nothing can break it. It's impossible. So if somebody does manage exceed the "Shannon limit" on some channel, it can only be because it was incorrectly calculated.
The Shannon capacity in bits/sec of a noisy, band-limited channel is C = B*log2(1+SNR).
So to compute the Shannon limit, you need to know both the bandwidth and the signal-to-noise ratio of the channel. Both numbers can vary quite a bit for plain copper pairs. The signal-to-noise ratio is affected by things like attenuation, crosstalk from other pairs and transmit power limitations to avoid crosstalk to other pairs. And bandwidth is affected by the length of the cable, its insulation and wire gauge, the presence of loading coils, etc.
That's why DSL speeds vary so much from one place to another, and why it's no big deal to send at much faster rates than DSL over short (a few hundred meters max) twisted pairs that have been carefully constructed (i.e., Cat 5 cable).