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The $50,000 is not quite the impediment that availability is. The Type S is vaporware; it will be available as early as 2012.

If all cars in LA were electric right now, there would be more than 12,000,000 on the road each day (estimate on Wikitravel). If they all travel 60 miles per day, then 100,000 tons of coal would be burned every work day to accommodate those 12,000,000 cars. And that’s just LA in 2009. I’m not sure how much coal is burned each day, but that seems like an astonishing amount, even if it is only burned at night for this purpose. For a 500 megawatt plant, that’s 7% of the load just for LA’s cars. But not trucks.

I’ve always wondered about this too. I’m an environmentalist, but I am not tied to any one solution. I’d like to see a qualified scientist, like an MIT engineering professor, comment on this. If electric motors are 80% efficient, does that mean that 80% of the chemical energy in the coal is converted to motion indirectly through electricity, or merely that 80% of the electricity that goes into the engine directly is converted to motion?

I always thought of electric cars are cars that will be green, once we’ve developed a clean, renewable source of electricity, which we keep getting closer to.

Technology is not always the whole solution. One partial solution is for employers to have small but more numerous facilities located in various parts of the same metropolitan area, strategically located to be closer to where their employees live. For example, why do financial corporations always locate their offices in big city downtown areas, when most of their employees live in the suburbs?

While we do have American-made mercury scrubbing technology that works very well, both Congress (under Republican AND then under Democratic control) and the president (both the last one, who came from the energy industry, and the current one, who has been sponsored by the coal industry for his entire political career) have failed to require coal companies to use them. Mercury is a neurotoxin, and driving less and reducing heating and air conditioning is well worth it to preserve our nation’s dwindling brain power. (The world’s largest number of college graduates, 90% of them with degrees in English literature and Art History.)

It means 80% of the electricity released by the batteries is converted into motion. You then have to add on the efficiencies of the charger, the electricity transmission system, and the conversion of coal to electricity at the power plant. All togethter, I’d bet it’s 30%-40% or so.

I’m not betting. I’m waiting to hear from the professor.

OK-dokie. A little time researching yields these facts:
“fossil fuel power plants can achieve 36?40% efficiency” (Wikipedia)
“U.S.-wide transmission and distribution losses were about 5% in 1970, and grew to 9.5% in 2001” (DOE)
So 38% X 90% = 34% (coal energy to energy at your plug)
34% X 80% = 27% (coal energy to vehicle motion).

So I was a bit high.

BS/MS eng.

Recently, most research has zeroed in on the development of super-efficient burning methods so that plants can extract more electricity from less coal. The average pound of coal contains about 10,000 Btu. Most coal-fired plants capture about a third. Newer ones like the Polk County facility can extract 37%, and Berry sees that rising to 40% within 10 years. The Energy Department has set an efficiency goal of 60% by 2025.

Thanks for your answer Docnick. However I am also interested in the generation, transmission, transformation losses in the use of electricity. As well as the losses in charging these vehicles. Each step of the way requires a loss…
I just don’t believe these electric vehicles are as clean as the promoters would like one to believe after all the losses are computed.

Yes, the numbers are astonishing. Figure how many gallons of gasoline are being burned each day for the same number of autos probably averaging a generous 20mpg. With all of the traffic backups, it’s probably much, much lower. But an EV doesn’t consume anything when it’s sitting idle (assuming you don’t have an HVAC demand).

The losses vary all over the map. As others point out, you can generate heat and electricity in the same plant, giving an overall efficiency of nearly 85 %. The heat is used in process plants. Korea Electric has a GE designed gas fired combined cycle plant the has 52% overall efficiency.

When comparing to gasoline, we have to count:

  1. The energy required to get the oil out of the ground
  2. The energy required to transport it, by pipeline, tanker or both.
  3. The energy to refine the oil into gasoline, at least 10-15% of the energy in the oil.
  4. The energy required to transport the gasoline to the service station.
  5. The very low efficiency of the gas engine at part load, no more than 15%.
  6. The energy losses in the transmission (not required for an electric motor)

If we add all these up, you can see that even the best gasoline system is very inefficient. With any luck only 5-10% of the original energy in the oil ends up propelling the car.

For a coal fired plant, we have “mine mouth” generation; the coal is mined right where it is burned in many cases. Electric transmision is more efficient than pipelines. There are no “refining losses” only the conversion losses from coal to electricty. The electric car motor is about 80-90% efficient, and there are no automatic transmission losses. So I would guess a “mine to car” efficiency of .4x.8x.8=25.6%

As you can see, that is much better than an oil/gasoline based system.

However, you must be concerned with CO2 emissions, and few people know that in oil production much associated gas is flared off, creating large amount of CO2. Nigeria still flares most of its gas in the production of light crude.

If we assume a pessimistic level of CO2 from coal burning at twice the amount of oil/gasoline, we still come out ahead of oil to gasoline. And with cleaner downtown air.

The real problem is the US depending on imported oil(70%) and the econmic and political consquences. The US has a 700 year supply of coal at least, so that should be a comfort factor.

My local university is conducting a CO2 lifetime inventory of different forms of energy. Imported oils from Africa and the Midle East do not come out too well, in spite of their high quality. It’s mostly the waste in production and the energy used in transportation.

I agree that electric vehicles are not as clean as promoted, but they are at least twice as clean with respect to CO2, and squeaky clean with respect to tailpipe emissions. If you live in Washington state, your electric power is from hydroelectic generators,and your efficiency would be 64% or more while generating no air pollution whatsoever.

Docnick, BSc,MBA,PE

Doc, you’re right about the flaring, especially in the past. Today, however, Nigeria is probably one of the few countries where that’s occurring on a large scale. Gas is now valuable enough to be conserved, both for local electricity generation and for LNG production. Flaring of gas is the exception now, and most countries forbid it.

Edit - I stand corrected, there are still several countries flaring large amounts of gas. In 2007 these were the amounts for the big ones: Russia 50 BCM (billion cubic meters), Nigeria 17 BCM, Iran 11 BCM, Iraq 7 BCM, Libya 4 BCM, Saudi Arabia 3 BCM, Qatar 3 BCM. The rest are 2 BCM or less.

Here’s a video showing it using Google earth: '

The OP’s question is interesting and valid, and there’s been lots of good discussion of the issue, however I’d like to add a point…the post is premised on the assumption that the electricity to power EVs will be produced by fossil fuels. I have a more optimistic view of the future.

Projects to look for alternative sources abound. Geothermal, solar, wind, tidal energy, nuclear (nucular if you prefer), and even oceanic farming (weed farms) are all being explored as sources of fuel to produce electricity. And thene there’s hydroelectric. It’s been estimated that there are tens of thousands of hydroelectric sites either idle or operating with obsolete, low efficiency equipment. There are numerous sources both existing and potential to generate electricity without the use of fossil fuels.

Also, we alreadyy have an electrical infrastructure in place, although it would likely need enhancing if EVs became common. Garages could easily add charging stations, meter the amount of electricity used to recharge, and allow patrons to recharge while taking a break. A nice diner would supplement the activity.

I’m particularly enthused about Tesla, because they’ve demonstrated thet EVs can be desirable cars, and can have the range to be practical as daily drivers. And the prices of the roadster and the Model S are comparable to other cars with their level of performance and luxury.

Sure, there are still some challanges, and still some unknowns. But no more so than when we set our sites on landing on the moon.

Good thinking-out of the box-Kevin

I know this one…
Heat engines are by definition, maximum efficiency of 68% (Carnot)
Most heat engine power plant approach 60% or a bit better.

IC’s vary from 5% in your lawn mower, to about 20% in your auto if you’re lucky…

even if you use an 80% efficient electric motor in your car .8*.6 = .48
nearly twice the efficiency of your car…

note that this doesn’t apply to fuel cells (chemical converters).

When plugged up, converted EVs will use 400 watts of grid electricity per mile driven. So 40 miles will be 16kw hours of grid electricity. 16 kwh of 100% coal fired energy in 2005 produced .016 lbs NOX, .0224 lbs SO2, .0016 lbs PM and 35.2 lbs of CO2(if CO2 is now considered a pollutant?)Clean coal would be much lower 8.4 lbs CO2.
An ICE powered car?
.130 lbs of NOx and 36.6 lbs of CO2
EV= 35.2 lbs CO2 or 8.4 lbs of CO2 (clean)
ICE= 36.6 lbs of CO2


It’s not the CO2 from coal power I’m worried about, rather the Hg and the H2SO4. Also, the “clean coal” numbers–are those being realized anywhere right now? Not to belittle, but “bird in the hand” and all…

I guess what bothers me is how e- cars are viewed as an ecological Godsend, when most of what they do is “outsource” pollution from the cities…or in CommieSpeak, “…a petit-bourgeios urbanite ploy to unfairly burden the rural proletairat…” (knew Sociology was good for SOMETHING :wink:

Cant those huge Waukashaw engines burn the flare gas to generate electricity-they use them to burn landfill methane?-Kevin

The natural gas is burned at the well head because they do not have customers for it.

To really get the Greenie points, you buy an electric car and you also cover your south-facing roof with solar panels to produce enough electricity to power the car and perhaps the house too…Don’t laugh, people are doing this and it works. Right, it does not work very well in New England, but that’s another issue…It works GREAT in Tempe, Arizona…There are lots of incentives to do this, including the fact that the local utility will buy your excess electricity allowing the system to pay for itself over time, while you drive a “solar powered” car…