Posted on 12/11/2010 3:38:13 PM PST by editor-surveyor
Vlado Bevc
Synergy Research Institute, P.O.Box 561, San Ramon, California 94583
The promotion of General Motors Chevy Volt by three mayors (Contra Costa Times, November 6, 1010) merits some mundane evaluation from the energy standpoint. Electric vehicles with an internal combustion engine assist are compared to a typical car using 13 cents of $3.00/gallon gasoline per mile, that is one that makes 23 miles per gallon. (13/300 = 0.0433 gallon/mile)
In a conventional car 25 percent of 37 kWh from a gallon of gasoline gets into traction (because of losses in the engine and drive train). Conventional car thus uses 0.4 kWh/mile and so does any comparable car.
Reader Coughlan (CCT, November 13, 2010) correctly pointed out that at residential electric rates of 40 cents/kWh the energy cost is about 10 cents/mile rather than 3 cents/mile (above calculation shows 16 cents/mile). Moreover, Chevy Volt has a 435-pound battery costing $8,000 which wears out after 100,000 miles. That adds 8 cents to the energy associated operating cost of the electric car.
PG&E also has an experimental tariff designed for users of electric cars through which all of us are subsidizing electric vehicle owners.
Electric power plants supplying energy require from 3.5 to 4 kWh of thermal energy to generate 1 kWh or electrical energy. Thus the 0.4 kWh used by the electric car requires 1.6 kWh to generate. Energy wise we are at the same place as with an internal combustion engine.
About 70 % of electric power generating plants America use coal. At heating value of 3 kWh/lb, 1.3 pounds of coal is needed to generate 1 kWh. As coal is 80% carbon 3 pounds of carbon dioxide is emitted in generating 1 kWh of electric energy. In other words, electric vehicles cause production of 1.25 pounds of carbon dioxide per mile. On the other hand, an equivalent conventional car using 0.0433 gallon/mile emits 0.78 pounds of carbon dioxide per mile. Electric cars thus cannot reduce emissions of carbon dioxide to which climate changes are wrongly attributed.
The mayors say 500,000 electric vehicles in the Bay area would reduce costs and emissions dramatically. As shown no cost reduction can happen. Moreover, if 500,000 electric vehicles using 500 gallon/year producing 4 tons of carbon dioxide each were eliminated, there would be 2 megatons of carbon dioxide emissions less. This would be only 0.4 percent of the annual fluctuation (48,000 megaton) of carbon dioxide in the atmosphere which totals about 3 million megatons, an insignificant amount.
Particularly unreasonable is the hint that electric vehicles while parked in employee parking lots could be running their gasoline engines to feed energy it back to the network. Efficiency of any electrical generator is proportional to the fourth power of its dimensions, hence a number of small power generating stations would waste more energy than a normally sized electric power plant.
Vlado Bevc
925 683 9254
> “Is that what coal burning electical generating plants emit?”
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Never open a liberal’s eyes!
“Particularly unreasonable is the hint that electric vehicles while parked in employee parking lots could be running their gasoline engines to feed energy it back to the network.”
What????
Who (what idiot) thinks employees are gonna run their engines, using their gas, to feed energy back into the system? Furthermore, leaving you car engine running all day is rarely a good idea, except in maybe really cold climates.
Even the idea of employees recharging their batteries at work is not gonna please the employer. His higher utility bills will ultimately force him to charge for a charging.
“I’m not 100% opposed to taiffs. I think they have their place. But I am opposed to subsidies.”
Tariffs are best used as a temporary measure to help an ailing industry. As an example, the Voluntary Import Restraint Act was passed in 1981 on imports of Japanese cars. In addition, a 25% tariff was put on all imported trucks and a 3% tariff on imported cars. By 1985, the American auto industry was healthy again, the VIR was no longer needed, and it was thus repealed.
However, the above-mentioned tariffs still exist. Thus, Japanese SUVs like the Toyota Land Cruiser never sold well due to being substantially more expensive than their American competition.
To put all this in perspective if you are planning a commute in your electric car of 30 miles with temperatures around freezing with slushy snow requiring the use of wipers, heater and defroster I would not be listening to the stereo and would have cab fare ready.
I know where you are going and don’t disagree. My arguement(if I were to play both sides of the fence) is what is the ratio of dangerous emission from coal power plants vs emissions from all of the vehicles.. I’m not sure... I worked at Florida Power at a coal powered power plant. It was nasty stuff. The emissions into the Gulf were nasty. Makes for good fishing(warmer water) but the ash and dust was a bugger.
> “His higher utility bills will ultimately force him to charge for a charging.”
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Many are planning to do exactly that, at a profit too!
What these blindly stupid people overlook is that they also hate coal. As the article states 70% of this nations electricity is generated by coal. They also hate Nuclear Power. About 23% of our electricity is generated by Nuclear.
So these electric cars are 93% evil just on there electric power consumption. Unless some fool has a wind turbine in his back yard to charge his electric car he better surrender his Green Peace membership card. And if he does have that wind turbine he better be ready to commit seppuku when that turbine purées its first bird.
These idiots want to drive these cars to feel holier than thou and yet every thing about these cars is actually more harmful to the environment than the most gas guzzling SUV on the market.
If we could build a couple of hundred nuclear power plants that would make electric cars practical.
One thing I didn’t mention earlier is the loss of electricity while traveling over the lines. As a former power plant worker, you ought to know more about that then me. If someone really wants an “electric car,” the best bet would be a hybrid that generates its own electricity.
Unfortunately, I’ve yet to find one that will tow a 35’ 5th Wheel Toy Hauler.
True...but not likely.
It will be a wonderful world when the Libs are done with it.
> “ My arguement(if I were to play both sides of the fence) is what is the ratio of dangerous emission from coal power plants vs emissions from all of the vehicles”
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Vehicular emissions have been no problem, except for urban canyons and basins like LA where they are trapped, and become concentrated.
The biggest problem is the catalytic converter that emits sulphuric acid.
> “Unfortunately, Ive yet to find one that will tow a 35 5th Wheel Toy Hauler.”
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A one ton rated 300 HP, 6500 lb truck? As a hybrid? Heh, heh...
We do need to build the Nukes but it would take quite a bit more than that.
We would also need to make huge upgrades to the nations electric grid.
Most people would be plugging in their cars at home and charging the battery over night.
The cars I have read about would need a 220 volt hook up to charge the battery overnight. Most houses do not have a 220 V outlet available in their garage (possible exception of cloths dryer).
If more than a few homes in a given neighborhood started charging their cars at night it might become necessary to add additional transformers and higher voltage power lines to their neighborhood.
Considering that the California power grid is already over taxed and under powered it can hardly afford to be pushing electric cars at this time.
i bet there were electric “car” prototypes before the internal combustion ones. the unfettered free market therefore has already told us that electric cars couldn’t be as efficient, but it’s nice to see it proven analyically here. thanks to the author and for this post. this is why it’s great to be an engineer.
> “There is a significant amount of energy recovered when an electric motor operates as a generator to slow down and stop the vehicle.”
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Yes, but it is limited. You will get back about 30% of what it took to accelerate to the point that you began to decelerate, except that the process ends, and the friction brakes engage at about 8 MPH in mild braking, but at a much higher speed on panic braking.
Also, he was discussing the Volt, which doesn’t work that way.
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