MrRodgers
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quote:
ORIGINAL: MercTech
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ORIGINAL: MrRodgers
quote:
ORIGINAL: MercTech
Battery based electric cars, due to inefficiencies in generation and in motors; end up causing more fuel to be burned than an internal combustion engine.
Not according to my sources. If I understand you correctly.
$60 month less
HERE
The Department of Energy’s eGallon provides a quick and simple answer to this question and allows electric vehicle (EV) drivers to see how much they can save on fuel by using electricity instead of gasoline.
We take the average distance that a gasoline-powered vehicle can drive on a gallon of gas (28.2 miles for comparable 2012 model year cars), and then calculate how much it would cost to drive the average EV that same distance.
Because electricity prices are a little different state to state, our eGallon tool shows how much an eGallon costs in your state, and compares it to the cost of gasoline. As you can see, on average, fueling your car with gasoline costs roughly 3 times more than fueling with electricity.
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No one was talking a dollar price but the amount of fossil fuel burned. Most of the electricity in the U.S. still comes from fossil fuel.
The touts ignore the conversion losses in going from chemical to mechanical to electrical to storage to motor to wheels as opposed to chemical to mechanical to drive train. The maximum 28 percent efficiency of mechanical to electrical conversion or electrical to mechanical is a horrendous amount of power thrown away. You never get as many amp hours out of a battery as you put in. And the more steps from source to end use allows for losses along the way.
For a given number of horsepower-hours; an electric care will result in having to generate more power than an internal combustion car uses. Trying to jigger a set of numbers to make a grant application or an investment prospectus look good is far removed from an objective look at a total system.
Given, the efficiency of Li-ION storage cells has made battery technology much better than it was even a decade ago. But the inefficiencies of electric motors and electric generators still makes battery electric systems a poor overall choice compared to internal combustion. For electric cars to be other than a boondoggle that doesn't cure what it claims to: some technical breakthroughs need to be made to alleviate all the system losses inherent in the design.
Electric engines can be more than 90% efficient and even up to 98% efficient while combustion engines are 30 to 45% efficient.
The motor itself is fantastically efficient, but that’s in terms of the electricity being delivered to it from the batteries. That conversion is not direct the batteries provide DC power but the motor uses AC, so you need to use an “inverter” to change it from one to the other. Modern inverters are about 95% efficient.
In a gasoline car, the fuel that’s pumped into your tank is used directly in the engine. That’s not the case in an electric car, where the “fuel” is AC power from your home, and the tank is a battery full of DC power. So we have to convert from AC to DC using a charger which is also about 95% efficient.
That’s right – we start with AC, turn it into DC, back into AC, and then into motion. That doesn’t sound great, does it?
And finally, we need to consider leakage. When I charge the battery, not all of the power ends up stored, some of it is used up pushing the electrons through the battery. Typical numbers here are about 85 to 90% efficient.
So, a rough estimate of the total round-trip tank to wheel efficiency is:
0.90 (motor and drivetrain) x 0.95 (inverter) x 0.90 (battery) x 0.95 (charger) = 73%
This number jives quite well with the claims of Tesla, which quotes a 75% round-trip efficiency. Tesla and Leaf owners report slightly lower real-world charging numbers, with the charger and battery portions of the cycle on the order of 80 to 85%. If we use those numbers we get:
0.90 (motor and drivetrain) x 0.95 (inverter) x 0.8 (battery and charger) = 68%
This isn’t a huge difference, so we’ll split it and call it 70%. How does this compare to a conventional car? Quite well in fact. A normal gasoline car has a tank-to-wheel efficiency of 16%.
That’s right, an electric car is over four times as efficient at turning energy into motion.
HERE
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You can be a murderous tyrant and the world will remember you fondly but fuck one horse and you will be a horse fucker for all eternity. Catherine the Great
Under capitalism, man exploits man. Under communism, it's just the opposite.
J K Galbraith
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RE: Look for gas and oil...to go down. - 
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