Reply #58: But I notice you ignore Electrical to Battery loss, nor the loss of Coal to electricity, [View All]

[happyslug]

A ton of Coal produced only 2000 Kilowatt-hours of Electricity.
http://www.blm.gov/ut/st/en/prog/energy/coal/electricity_conversion.html

Thus according to the US Government, 1 pound of coal produces 1 KWH of electricity NOT 1.3 as the author claims. Now the 1.3 may probably includes Hydro, Wind and Natural Gas generation, but it is 1 KWH per Pound of coal if only coal is being used.

Once you have the 1 KWH, the question is how much is lost just charging a battery. If that number is 50% (Which seems to be the number) you are down to .5 KWH before you even get to the issue of loss in battery to engine (only a 10% loss) but that put you into about .45KWH per pound of coal

50% Battery Efficiency:
http://wiki.xtronics.com/index.php/Sealed_Lead_Acid_Battery_Applications

Battery Charge Time Efficiency Calculator:
http://www.csgnetwork.com/batterychg2calc.html

According to the EIA you produce 2.117 pounds of CO2 per 1KWH of electricity if coal is the sole source of power.
http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2report.html#electric

Thus to provide power in a car (.45 KWH) you are producing 2.117 pounds of CO2.

Now the EIA also points out Gasoline produces 19.4 pounds of CO2 per gallon
http://www.epa.gov/oms/climate/420f05001.htm

The problem is we can NOT compare these two numbers directly. We are discussing we different ways to move people. The real test is how far can you go with .45 kwh? And how far can you go, in the same size vehicle, with 1 gallon of gasoline? Another way to look at this is how many KWH does it take to go the same distance in a Gasoline powered car?

Now the EIA has numbers for Gasoline and CO2, but those are for electrical generation, but in out hypothetical we are NOT using gasoline to produce electrical power, instead it is a direct drive mechanism so that number is NOT valid for out comparison.

Wikipedia gives 5 mile per Kwh:
http://en.wikipedia.org/wiki/Electric_vehicle_battery

Remember one pound of coal produces .45 KWH and 2,117 pounds of CO2. To get to 1 kwh you have to double the CO2 to 4.234 pounds (and the actual number is greater for by doubling I am using .5 not the .45 I mentioned above). Then to get to 20 miles (what the average American car gets) you have to increase the CO2 level by 4 or 16.896 pounds of CO2.

Another way to look at this is to take the 20 mpg American Car and reduce by a 1/4 (or 4.85 pounds of CO2 to go 5 miles compared to the 4.234 if electrical generation is used).

Now, most electric cars are much smaller then the average American car, thus the numbers are NOT as good as I am making them out to be. Most cars that are the same size as most electric cars get 30-40 mpg, which clearly shows you produce less CO2 with a gasoline engine then with an electric car if the source of electricity is Coal.