Discussion in 'General Science & Technology' started by moementum7, Aug 10, 2006.
This is a good thing.
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Nothing is more efficient than an EV. Electric motors are 95% efficient.
The electric grid is 95% efficient (far more efficient than sending fuel by TRUCK to a gas station near you).
Battery storage is 88% efficient.
Thanks to the wide powerband, regerative braking and transmissionless design of most EVs, most of that power gets right to the road. An ICE car starts out with a 25% efficient engine, and after losses to idling, braking and time spent running outside of it's most efficient powerband, maybe 10% of the energy is actually utilized.
References: I have used at least two sources for each point, and government, corporate, or university sources whenever possible.
Electric motor efficiency
Public Service of New Hampshire
Chart showing that 25+ horsepower electric motors have efficiencies between 90 and 96%
Transmission line efficiency
Paper: 'Economic and engineering constraints on the restructuring of the electric power industry'
(points out that the industry standard is 95% efficiency)
From greenhouse to green house
(figure given is 3% transmission loss per 1000 km.)
News story about utility overcharging. Figure given is 3% transmission loss (97% efficient)
Says transmission losses in 1995 were 7.2% (92.8 efficient)
Paper says 88% efficient (over the usable charge-discharge range)
Arizona Wind and Sun
"Typical efficiency in a lead-acid battery is 85-95%.
Gas engine efficiency
http://www.everything2.com/index.pl?node=internal combustion engine
Argonne national laboratory
Whatever generating technology is used some thought should be given to the idea of using waste heat to warm the batteries if they are below the optimum temperature for charging. There is a nasty curve of charging inefficiency when battery temperatures approach the freezing point.
The larger the battery, the less heat produced (less internal resistance) and thus a better EMF transmission.
Electric cars are a better for the environment than petrol cars, when the advantages are weighed with disadvantages. They are also better for health reasons.
In low voltage generating setups the inefficiency of the rectifiers can cause some inefficiencies too, and some significant ones. Two silicon rectifiers in series in a 15 volt charging circuit can cut about 10 percent of the efficiency. That's like another 30 cents per gallon for your gas. There is such a thing as a perfect rectifier where a circuit switches power MOSFET transistors cutting the losses to nearly zero. That's one of the reasons why the hybrid cars favor high voltage systems too.
I would say that the real drawback is the fact that it costs over $100k.
It's actually a very clever idea for marketing an electric car - since it's going to cost many tens of thousands of dollars more than a regular car, package it as a sports car. Then you're competing against other cars that are already stupidly overpriced, so it's much more competitive.
That's true, it does have a nasty price tag. They are competing against other sports cars, porsche, ferrari, lamborghini, vector, and the like, so in that market, they may find a niche.
The high cost, however, is due to the need to recoup their factory and tooling costs. If it were in LARGE scale production, the cost would certainly be about the same, or a little less, as for an ICE. Most of the cost for conventional cars is for the body, chassis, electric windows, sound-system, seats, dash, air-bags, and all the other things to make a car other than the engine. Actually, the electric motor should, under mass production, cost quite a bit less than an ICE motor. Likewise, the transmission is somewhat less expensive. The addition of braking regeneration (to recover braking energy losses) should pay for itself in the long run due to the amount of energy saved. The batteries currently are about $20,000 of the cost, but that too should come down with mass production. If replaced by capacitors, they might cost far less.
Hey, maybe I should get a job as a PR guy at Tesla!
Here are some great pics of the Tesla launch demo:
So I'm wondering how much money a typical commuter would save over a ten year period, paying one cent per mile for electricity?
Right now they'd be paying $13,400 every ten years at current gas prices.
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The Future of Cars is Electric
by Martin Eberhard
CEO of Tesla
published Wednesday, August 16th, 2006
Not too long from now, most cars will be electric. Why? Two reasons: because electric cars are far more efficient than any other kind of car, and because they are the ultimate multi-fuel cars. Sound bold, maybe crazy? Read on.
The May 2006 issue of Popular Mechanics magazine got it right in its typical easy-to-understand way. The article was about biofuel, but they compared many technologies in the centerfold sidebar: gasoline, ethanol, methanol, biodiesel, compressed natural gas, hydrogen fuel cells, and, of course, electric cars. They compared the cost of a cross-country drive for each of the cars, all of similar size. The benchmark drive cost is $212 in a Honda Civic. The VW Diesel Golf came close at $230. E85 ethanol (85% ethanol, 15% gasoline) came in at $425; methanol cost $619; the hydrogen fuel cell drive cost a whopping $804! Compressed Natural Gas looked pretty good at $110. And the electric car? $60. And the article wasn’t even about electric cars…
Cost per mile is a reasonable approximation of energy consumption. (I set about doing a direct energy consumption comparison in our white paper, but money is a whole lot easier to understand.)
The neat thing about electricity is that pretty much any burnable fuel can be converted to electricity efficiently. Sure, there are quite a few inefficient old power plants from the ‘50s still running, but modern, readily-available technology means that even coal can be gasified and burnt cleanly and very efficiently in a combined cycle plant. This is nice to know, considering that we are sitting on an enormous reserve of coal. If there ever was an OCEC (Organization of Coal Exporting Countries), we’d be Saudi Arabia, so to speak.
General Electric makes an advanced, combined-cycle natural gas generator called the H-System Generator that measures in at 60% efficiency. This plant could easily burn “biogas” produced from biomass (corn or switchgrass, take your pick). If we powered our electric cars this way, the same acreage of fuel crop would transport an electric car four times as many miles than if we made ethanol out of the stuff and burnt it in a piston engine car. Should we decide to allow our cars’ fuel to compete for cropland with food, this difference matters!
But the true beauty becomes apparent when you realize that we can make electricity in so many different ways. I’m putting solar panels on the roof of my house to power my car. Many people have pointed out that nuclear power produces no greenhouse gasses. The shot of the Tesla Roadster in the movie, Who Killed the Electric Car, was taken at Altamont Pass, right in front of a huge windmill farm. We don’t need to decide now which is the “right” technology. Indeed, the answer will likely be a mix of these, combined with some amount of fossil fuels, depending on where in the world we are generating power.
Note, by the way, that we can put a million solar panels on our roofs, we can cover the coastlines with windmills, we can invent amazing tide-powered generators, or clean nuclear power plants, and we will not reduce our dependence on oil by one drop unless we can use that electricity to power cars. Why? Because we don’t use oil to make electricity, so all those cool electric generating technologies do not offset our oil consumption. The fact is that the vast majority of our oil consumption is used for transportation. Trains, planes, and automobiles, folks.
So what’s wrong with electric cars? Why not switch over today? Quite a few of you have nailed it in your comments to this blog already: recharge time. Even with a Tesla Roadster, you would need to stop for a couple of hours on a trip from LA to SF. Even the longest-range EV is not suitable for long road trips quite yet.
You all have proposed several solutions: quick-charging, battery pack swapping, and a gasoline (or whatever) powered auxiliary generator. Though appealing, each of these ideas has very significant technical problems that I will not attempt to lay out here. But there is another alternative suggested by some of you: simply increase the driving range enough. We can’t do it today: 250 miles range was hard enough! But the capacity of batteries – particularly lithium ion type batteries – has increased steadily by about 8% per year for the last couple of decades. All indications are that this will continue into the future, doubling in capacity every ten years. (And there are hints of breakthrough technologies that might speed things up for us.)
Think about it. If your car can go – say – 500 miles on a charge, who cares about stopping for a charge? A 500 mile drive is about 10 hours’ solid driving – more than enough for even a serious road trip. (I know: some of you will talk about crazy trips like I used to take, making it from Chicago to San Luis Obispo in 42 hours flat, but you’ve got to admit that this kind of drive is way down the pointy end of the bell curve!)
Do you remember when your cellphone wouldn’t last through the day? I do. In those days, we were acutely aware of the charge time because we had to recharge while driving in our cars or at work. I remember plugging in to get a bit of charge for my phone in a VC’s conference room while I was pitching a startup idea! But today I bet most of you have no idea how long your phone takes to charge. Is it 3 hours? 4 hours? Who cares? You come home, plug it in, and forget about it. In the morning, you unplug it and go. We just don’t need to charge up during the day so charge time isn’t an issue.
Electric cars will be the same. Once the driving range is enough to make it through the day, we will only ever charge while we sleep. The Tesla Roadster is like that already for most of us, except when we want to take a long road trip. With a 500 mile range, even road trips are covered.
And that means charging stations, like gas stations, are soon to be as obsolete as cigarette lighter chargers for our phones. We will need a charger in our garages, at hotels, and at campgrounds. And that’s it. Nice side business for Hyatt Hotels and KOA, by the way…
There will be electric cars, but it's no solution to the energy crisis we will be facing in the near future. We have been so brainwashed by the automobile industry and culture, that it's hard to think outside this paradigm. Car culture has created an unsustainable pattern of development called suburbia which has no future.
And what's the cost of one of these electric cars? What's the maintenance cost?
The market for EV is limited because when most people (like me) lay down more than $500 US for a vehicle we want it to do everything: 5 day road trips, 300+ mile range, refuel in mins, etc, basically they want all the _flexibility_ of a gas or diesel car/truck.
Now the fact that the majority of trips are less than 30 miles and total use during the day is less than 50 miles is irrelevant, people want the ability to go long distance whenever they want to and refuel in the middle of Nebraska (for example) if they need to.
So, until an electric car can go 300+ miles, be recharged in mins, and at a reasonable cost, people just will not buy one. I wouldn't
I disagree. I think that the advancements in communications bandwidth makes suburbs still viable even under increased energy prices. Although the "remote employee" work arrangment is not yet typical, it is becoming much more common.
I think it is more likely for cars to disappear than suburbs. The problem is that cars have gotten Americans used to being able to go wherever they want whenever they want without worrying about schedules other than their own. Any serious alternative to the car will have to address that reality and match that capability.
You can't send vegetables by e-mail or go to the doctor using fiber optics.
Vegetables are much cheaper to ship than people, and there is a lot of research in telemedicine right now.
I am not saying that everything can be done remotely, but you were specifically discussing suburbs as being impossible in a future with high energy costs. In terms of energy consumption the main problem with suburbs is not the location of grocery stores and doctors, but the location of work. Remote employment can dramatically reduce that for a potentially large number of suburban employees.
I do agree that it is difficult to think outside the automobile paradigm. I also agree that the automobile is fundamentally problematic and, ideally, should be eliminated. I just don't think that implies the end of suburbia.
I can show you an electric car for any price you can name. I drive a (very old) EV that I bought off eBay for $2000. The lead-acid batteries in my car limit the range to about 50 miles, so I don't think my car has the value a modern EV would have. But I still use it every day to commute to work. Aside from the money I invested to fix the car up when I got it, maintenance is virtually nil. Electric motors need no regular maintenance (only one moving part.) The major cost is battery replacement. My pack of 16 lead-acid batteries costs about $800, and can last me up to 8 years, if I take good care of it. That's $100 per year, about what I would otherwise spend on oil changes. More modern cars powered by NIMH or Li-Ion packs don't even have this expense: they have batteries that can last 100,000 miles or longer.
A few interesting inexpensive EVs are:
- the ZAP, for $10,000. Unfortunately it tops out at 40mph.
- The NMG from Myers Motors. It does freeway speeds, but looks pretty funny. It costs $25,000
- The Miles XS200. This car, a Chinese import, won't be available until next year, but it presents an unmatched value proposition: a 200 mile range, 80mph top speed, and a price of $28500.
I'll be buying stock in electric car companies.
Great post AW!
What do you make of Martin Everhard's little essay up top...middle of this page?
Yes, I had read that. I think the next few years could be exciting for EVs. I have never been aware of so many advanced battery projects going on at once.
There's a curious set of common assumptions about electric cars that will gradually fade. We have never seen a serious attempt at marketing such a car. I hope we do soon.
Whatever motive the Detroit car companies have had for playing along with the oily people, I hope they wake up soon. The presence of ANY old halfway practical EV on the market will cause gas prices to plummet. Then they can sell SUVs and pickups again.
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