Volt tester: GM engineers have incorporated the propulsion system for the GM Volt into one of their other vehicles for testing.
Technology Review
The electric propulsion system for GM's new plug-in hybrid gives a silent yet powerful ride.
As part of a marketing plan for its Volt plug-in hybrid, which is slated to go on sale by the end of 2010, GM has been taking the unusual step of allowing journalists to drive test vehicles. The test cars, called "mules," have the same basic propulsion system that the Volt will have, but not the same body. Here's what it feels like to be behind the wheel.
The Volt will be electrically powered, its wheels driven exclusively by an electric motor. For the first 40 miles, that motor will be powered using energy stored in a large battery pack. After that, an onboard gasoline- or ethanol-fueled generator with provide the electricity (with the battery acting as a buffer to improve the generator's efficiency).
The test drive was meant to show off only the electric drive system, not the car's handling (since it does not have the Volt body and chassis), nor the performance of the car once the generator kicks in (since GM prefers to emphasize the electric-only portion of the driving experience). Unlike other plug-in hybrid designs, in which a gas engine is connected to the wheels and used to supplement the electric motor, the Volt gets all of its acceleration from the electric motor.
The key distinctive feature of electric drive is the instantaneous response of the motor. Electric motors deliver their maximum amount of torque right away, whereas conventional internal combustion engines have to work up to it. As a result, the car accelerates faster. Frank Weber, the GM executive in charge of the Volt program as well as vehicles that will use the Volt's underlying propulsion technology worldwide, says that this means the car feels as though it's powered by a 250-horsepower engine, even though the motor is only rated at about 150 horsepower. The car certainly felt more powerful than a typical compact car. Accelerating from 40 to 80 kilometers per hour seemed effortless. And because there is only one gear, the acceleration is smooth.
The engineers have designed the control system to mimic conventional cars in several ways. Taking your foot off the accelerator in a conventional car causes the vehicle to slow down quickly due to engine braking, a phenomenon that drivers are used to and count on to slow down when approaching a car on the freeway, for example. If you cut off power to an electric motor, it can still spin freely, so the car doesn't slow down much. So the engineers have programmed the control system to start using the motor to recharge the battery when the driver lifts up on the accelerator, which slows the car down. They've also included a setting that increases the amount of this recharging, which slows the car down faster. In the future, these settings might be user-configurable, although Weber says that the amount of control would probably be limited to a few presets.
The engineers also decided to program in a small amount of vehicle creep. When conventional cars are stopped, a driver can edge forward by releasing the brake without depressing the accelerator. The same thing is programmed to happen in the Volt propulsion system. This was done not just to make the car feel like a conventional car, but also to give drivers some feedback that the car is on. Because the motor is silent, it would be easy for a driver to get out of the car without realizing that it is on.
The car is an engineering achievement, but it could easily be even more appealing.
The next few years will show whether the batteries in electric cars from GM and Nissan are safe and reliable.
As Nissan and GM prepare to ship flagship electric vehicles, Toyota is taking another road.
The author should have noted that Toyota sells each Prius at a loss. The Volt will be a GM design & engineering success, but it won't be competitve with the weight of the UAW in tow.
Performance test done with a charged battery aren't all that interesting. I want to read a performance test done after 50 open road miles - after the battery is depleted.
Also note the continuing evolution of battery tech. I expect, as Li/Sulphur batteries or Na/Sulphur battery tech becomes market ready, we will see an explosion in electric vehicle offerings.
Imagine a Volt able to go 200 to 300 miles on the same mass of batteries. That would be a real winner,,,
Gary 7
What fraction of the total production cost of the volt is attributable to the battery pack?
The Volt is too expensive. It could be $10,000 cheaper and have better performance if they instead used NiMH batteries. To do this the US government need to overturn Chevron's patent rights on the NiMH battery as a matter of national security, and force them to relinquish those rights to allow carmakers to use NiMH batteries in their cars.
If not, this will automatically happen by default by 2014 when Chevron's patent expires and cheap, high quality electric cars flood the market and finally lay the ICE car into its rightly deserved death bead and solve the energy crisis, at the same time hopefully killing the oil industry.
The article mentions programming the Volt to act like a gas car with an automatic transmission, where the car creeps forward when the brake is released, supposedly to let the driver know the car is on. Unfortunately, this logic is backwards. My Prius has the same "feature", and I see this is a safety defect and wish I could disable it. A few times after stopping, getting distracted with something else I didn't realize the car was on, opened the door and stepped out. The car warning beep goes off, then the cars starts driving away with no-one in the seat! Fortunately, I was able to get back in and step on the brake before long. Once, I had passengers in each seat, I completely closed the door, then had to run after the car to get back in. Certainly, the car should disable creep if the door is open! (Driving with the door open could still be possible by stepping on the accelerator, e.g. in case you need to see the white line of the parking stall.)
The other UI problem with the Prius is that the "off" button is ignored until 1-2 seconds after the vehicle is stopped, and there is no audio feedback that the car is on or off (like PCs make sounds during boot and shutdown). The car should remember the off button was pressed for a few seconds, then shutdown. Otherwise for impatient people, occasionally the car ignores "off" and drives away on it's own. If it beeped, e.g. . - for on and ... for off, drivers would know what the setting is instead of trying to look at the lights.
Most of the ergonomics of the Prius are excellent, so it surprises me for UI blunders like this.
Re: Automatic Transmission Creep
I agree. I use a new forklift that disables the transmission when the seat senses no rider. This seems to be easy to do. They might at least give us the 'option' for the 'deadman' lockout.
Re: Automatic Transmission Creep
I was almost rundown by my Prius due to the "automatic" creep. I arrived at gate at night in a rainstorm with a keypad that was too far to reach. I opened the door and was distracted by the rain and did not notice that the car was rolling. When my foot hit the ground I lost my balance and luckily was able to pull myself back into the car by grabbing the steering wheel. The car hit the gate and put a scratch on the bunper just as I was able to get my foot on the brake. Emailed Toyota and the dealer and received a "thank you for bothering me" response from each.
Dear jwer,
The Tesla is not the product of a "toy" car company! At least the Mercedes folks don't think so. They just bought into Tesla with a huge cash infusion!
The Tesla is for real! I drive one!! 60 miles/day commute, and the car does very very well. The irony: You sit there in your roadster and experience a silent, seamless surge of power that makes you wonder why it took so long for someone to get there. I look up at the rows of rumbling 6,000 pound monsters called SUV's idling away on our choked freeways everyday, and it occurred to me that I wasn't part of the crowd any more! I am criticized for having a vehicle that only transfers the pollution to the power plant, but really, I would rather control the pollution at the point of power generation rather than try to control the emissions from millions of dripping, belching hunks of metal called internal combustion engines. We pay the price every time it rains and washes that garbage down to the beach. You cant go in there for a week after!
I charge my razor for every day's use, and this is no different. Every morning, the roadster is waiting there to rush me off to work.
I just can't tell you any more about the experience, just that you got to try one out for yourself. It is spooky fantastic!
For the battery tech guys, look at it this way: Apply Moore's law to battery technology. The ability to store energy in a rapid charge battery system is evolving every day in the labs around the world. You said it! When these packs become available, the electric car will become common place. Park it, plug it in, go get your roll and cup of coffee, come back and unplug it, and your good for another 300 miles down the pike! Check out EESTOR.com along with the other technologies and see why the military is looking at electrics - - no more gas turbine with a gigantic heat signature on our tanks, only the insane power of a silent electric drive train. That is some heavy lifting!
You are one of the lucky few who has a collector's item. This car is expensive, but because of its historical significance its value will only go up! I suggest you look into installing a rooftop solar panel system on your house to almost completely shift your energy consumption for driving your car away from fossil fuels. I assume that since you have the money to buy a Tesla Roadster, you could probably also justify the expense for such a system. Then tell everybody about it and help end the oil industry's choke-hold on society by exposing their lies!
You're right, I should not have called it a "toy" company, it's actually a "vanity" car company...
The reason it took so long for someone to get there has been pointed out amply in other comments, and should be apparent every time you think about what you paid for your Tesla: they HAVEN'T gotten there yet. A $100K+ car that has only 500 examples is not a mass-production vehicle, nor is it a practical solution. A $30-40K car that can be built by a company with capacity isn't really either, but it's a heck of a lot closer.
I live in Baltimore city, with unpredictable street parking and zero prospect of a reliably available charger. The Tesla or any other plug-in electric vehicle is useless to me. The Volt would not be. Toyota and Honda resist full electrics for the same reasons.
I am not casting aspersions on the performance or ride quality, although it's my understanding that you are alone in your opinion that it's comfortable enough for a prolonged commute. I was merely addressing unfair GM/Tesla comparisons.
errata on tesla, wrt moore's law
Moore's law does not apply to battery technology; batteries are still evolving, especially thanks to nano-tech, but they aren't doubling in efficiency -- actually quite the opposite... volumetric capacity has been improving but you still only get about 50% of the juice you put in, back out for use by the system. Add that to electro-mechanical losses in the drive system, and well, you get the picture.
Unless we come up with a truly non-polluting way of generating the electricity in the first place, I'm afraid that all we are doing is shifting the pollution into somebody else's back yard.
No matter how you try and dress it up, personal automobiles are extremely wasteful commodities.
Re: errata on tesla, wrt moore's law
This is totally untrue. You get about 90% back of the energy you put into electric car batteries, if not more. I could look up actual numbers for you but I don't feel like it.
Furthermore, with electric cars available, the public will then have an incentive to put rooftop solar panel systems on their houses. I think they cost about $10,000 now, but if they catch on and Moore's law applies, then they will come down dramatically in price. With a rooftop solar power system on your house, hooked up to charge your electric car, you could go anywhere from 30 to 400 km a day, depending on the weather and where you live. This completely bypasses fossil fuels, except for that needed for the manufacture of the car and the solar panels. You get the equivalent of about 2000 miles per gallon. This is the obvious and inevitable solution to the world's energy crisis. It will solve itself, beginning significantly in 2014 when Chevron's electric car battery patents expire.
This is the undeniable fact of physics that the oil industry does not want the public to realize, because no matter how hard they try they will never be able to patent sunshine on your roof to keep it away from you. And all we need for this is solar panels and electric cars. We have both of these technologies right now! Right now this combination is only 2-4 times more expensive than the competition, so watch out oil!
Re: errata on tesla, wrt moore's law
I don't know what to say to that, other than, you are simply wrong. In the briefest possible terms: To charge a typical median use-life battery to 70%-80% capacity takes a 1C charge for 1.5h, with additional top-off time required to acheive 100% charge. Total power in, at the battery terminals, is nearly 200% of total battery capacity (give or take 10-15% depending on battery chemisty). Efficiencies decrease from there with losses in the charger, losses in energy transmission system, etc.
wrt to solar panel solution, the power consumed in manufacturing the panel is currently many times what the panel will produce in it's entire usable lifetime. the power to produce the panel inevitably comes from fossil based fuels -- often very dirty one's in the far east.
I'm not trying to rain on the parade here -- but the auto industry is being less than honest when they sell hydrogen or PHEV's as a 'solution' to what is a highly inefficient means of travel. Part of the unsustainable living plan we've developed over the past century or so.
Re: errata on tesla, wrt moore's law
Well it's good we don't disagre on principles, just specific numbers.
wrt life cycle carbon emissions, solar panels are quite low. Apologies in advance, but I'm going to use Wikipedia as a reference because I don't feel like doing more research right now. I'm sure it's reasonably accurate.
http://en.wikipedia.org/wiki/Photovoltaics#Environmental_impacts
"Life cycle greenhouse gas emissions are now in the range of 25-32 g/kWh and this could decrease to 15 g/kWh in the future.[84] For comparison, a combined cycle gas-fired power plant emits some 400 g/kWh and a coal-fired power plant 915 g/kWh and with carbon capture and storage some 200 g/kWh. Only nuclear power and wind are better, emitting 6-25 g/kWh and 11 g/kWh on average. "
wrt efficiency, the Tesla Roadster gets about 90% efficiency battery to wheel. I believe they have some proprietary technology they are using to make the efficiency so high. Also, a slow charger is going to be more efficient than the 2 hour charge you mention.
http://en.wikipedia.org/wiki/Tesla_roadster#Energy_efficiency
"The Roadster's motor efficiency, battery-to-wheel, is 92% on average and 85% at peak power.[74] For comparison, internal combustion engines have a tank-to-wheel efficiency of about 15%.[75]"
It gets 174 Wh/km plug-to-wheel mileage and 135 Wh/km battery-to-wheel mileage, so therefore in charging you lose (174-135)/174 = 22.4 %, and therefore charging efficiency is 78%.
It's still better than an ICE. And Hydrogen. There's a WWF report on this, just google it.
AND it's an enabler for renewables to one day replace fossil liquid fuels.
I bet people had a similar reaction to the first mobile phone, 'it's too bulky, the batteries run out too fast, it's ugly....'
I've perhaps not communicated my point properly; I'm not saying that electric isn't the better way to go; or because it isn't perfect now we should give up on it: I am saying that to make it the solution that we need it to be, we need to solve the bigger problem of how to make the electricity that powers it in a clean, abundant, and sustainable way.
Also, we have to stop being enablers for our own bad habits, 'cause they are going to kill us and a good chunk of our fellow earth inhabitants if we don't.
Yes, it's called nuclear energy where the waste is reprocessed.
I drive an 8 year old Honda Insight and would certainly be open to a better solution. Just cannot see anything on the horizon yet. Energy is just going to have to get much more expensive before alternatives start being really used.
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kearns
30 Comments
Errata concerning Tesla
The author cites Tesla motors as having only one tiny sports car costing over $100,000 and that the Volt will sell for $40,000. This is incorrect. Tesla has introduced the S class which is a sedan selling for $48,000. Please visit their website at http://www.teslamotors.com for more information.
Reply
gabrielg01
450 Comments
Re: Errata concerning Tesla
the Tesla website says that "Model S Signature" will only be available in 2011, and limited to 100 cars.
The regular Model S will only be available in 2012.
So, I would not call this a market ready car.
Reply
jwer
7 Comments
Re: Errata concerning Tesla
Also, that "$48,000" price is only after the $7500 tax credit for buying an electric car, which would bring the Volt to around $32,500.
Apples and oranges; Tesla is a very impressive toy car company kept afloat by a man with lots of money and an insistent vision. GM is a huge multinational car company with a hundred years' building cars. Yes, GM has been forced into bankruptcy, but Tesla has been desperate for funding after only a couple years. Strangely, the press is a lot kinder to Tesla than to GM.
Reply
Null Hypothesis
10 Comments
Re: Errata concerning Tesla
The press is nicer to Tesla because they are actually doing something productive with their limited funds, something GM was unwilling to do with its billions and mass production factories. As such, they embody the American Dream of starting from scratch and finding better ways of doing better things for less money and therefore progressing society forward, at the same time putting giant dinosaurs like GM out of business, were it not for billions of taxpayers' bailout dollars.
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jwer
7 Comments
Re: Errata concerning Tesla
Tesla's "limited funds" do not need to be offset against 100 years of pension obligations or poor model receptions.
I am not suggesting that GM is blameless, far from it, I just think it's silly to compare a 100-year-old car company to a startup with 500 built examples of one model, esp. when all they really did was secure venture capital to bolt a bunch of laptop batteries into a Lotus Elise.
GM tried to make an electric car, and tried to make a hydrogen car, but the reasons that they failed had as much to do with the EV-1's 12-mile range with the AC on as they did with GM's internal squabbles. The technology was not ready. It's not really ready yet, but it's close enough to start trying.
Yes, the Tesla is amazing, but it's not THAT amazing. It still costs more than many people's houses. The EV-1 was far more groundbreaking when it came out, it just came out too soon and was not pursued, which is something that current GM management has publicly regretted.
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