I wanted to compare the energy usage of the Leaf to a Prius and to the "average U.S. passenger vehicle". I did some research and a little bit of calcula-mation and here's the result:
There are two categories of calculations: "fuel economy" and cost per mile, and CO2 emission per mile. (I did not attempt to quantify the carbon footprint of the manufacturing process of each car, nor the carbon footprint of each car's maintenance: battery used, oil used for lubrication, coolant use, etc.)
Fuel Economy and Cost of Operation
"Fuel economy" for the Leaf is
(Edit Mar 9, 2011) based on
real-world data points averaging 4.06 miles/kWh, which is
136 mpg or 0.2463 kWh/mile.
The Prius gets an average of 50 mpg. Assuming that gasoline has an energy contents of 35.1 kWh/gallon (note 2), the Prius requires
0.7 kWh per mile.
For the "average ICE (Internal Combustion Engined) car, I used data from two tables from the Bureau of Transportation Statistics:
Table 4-11: Passenger Car and Motorcycle Fuel Consumption and Travel and
Table 4-12: Other 2-Axle 4-Tire Vehicle Fuel Consumption and Travel (including "light trucks", which include vans, pickup trucks, and sport utility vehicles).
In 2008, those vehicles average 20.5 mpg.
(I did not use data from the
Table 4-9: Motor Vehicle Fuel Consumption and Travel (which shows the average US vehicle getting 17.4 MPG) because I think that figure includes big commercial trucks and things like that.)
That works out to
1.7 kWh per mile.
Austin Engergy charges an average of 6.92 cents per kWh (3.55 cents per kWh for the first 500 kWh) (note 3).
Nissan Leaf:
1.66 cents/mile
Toyota Prius: 0.7 kWh/mile = 4.84 cents/mile (
5.5 cents/mile given $2.75/gal gasoline)
Average U.S. passenger vehicle (2008): 1.7 kWh/mile = 11.76 cents/mile (
13.4 cents/mile given $2.75/gal gasoline)
CO2 Emission
The CO2 emission calculation is a bit more long winded because I want to account for the approximately 6.5% loss in transmission of electricity (note 4).
The CO2 estimate is also pessimistic against the Leaf because the data on CO2 emission from electricity generation is from 1999.
In 1999, 50.9% of electricity was produced from coal, 19.71% from nuclear and 15.058% from natural gas.
By 2009, it was 44.456% from coal, 23.313% from natural gas and 20.225% from nuclear (note 5).
So it's reasonable to think that the current level of CO2 emission from electricity generation is lower that in 1999.
Also,
not included in this calculation is CO2 emission resulting from exploration, retrieval (coal mining, oil drilling,
waste gas burn-off at well head, transportation (from well to refinery, from coal mine to coal electricity plant), refining, and delivery of gasoline to pump.
In 1999, total CO2 emission by the electric power industry was 2,244,804 thousands metric tons (note 6).
The total amount of electricity generated was 3,691,073 millions kilowatts-hour.
That works out to an average of 1.34 lbs of CO2 per kWh (0.60817 kg/kWh).
Assuming 6.5% transmission losses, each kWh at my wall plug requires generation of 1.07 kWh at the source, producing 1.43314 lbs of CO2.
Since the Leaf consumes 0.24 kWh per mile (see above), it therefores is responsible for
0.34395 lbs of CO2 per mile.
One gallon of gasoline results in 19.4 lbs of CO2, calculated by molecular weights, that is under ideal conditions.
Given that, the Prius generates
0.39 lbs of CO2 (431.07g) per mile.
(Note that this does not include CO2 emission of the discovery, drilling, distillation, and transportation of gasoline.)
The average U.S. passenger vehicle (in 2008) generates
0.95 lbs CO2/mile (431.07 g).
Note 1:
Leaf's range and battery capacity.
Note 2:
Energy content of gasoline is the average from four sources:
36.6 kWh/US gal,
36.4 kWh/gal,
33.6 kWh/gal, and
33.7 kWh/gal, averaging 35.1 kWh/gal.
Note 3:
Austin Energy's rate schedule.
Note 4:
Transmission losses in transmission of electric power: 6.5%, in 2007.
Note 5:
Net Generation by Energy Source by Type of Producer.
Note 6:
Electric Power Industry CO2 Emissions and Generation Share by Fuel Type. This does not include CO2 emission of the discovery, mining, and transportation of fuel (coal, petroleum, natural gas, etc.)
Edit: text-editing error (damn vim's control-X!) on Leaf's cost-per-mile: it's 1.66 cents/mile not 0.66 cents/mile.
Edit: include caveat about omission of CO2 emission of discovery, mining, and transportation of fuel.
While I am retired military, IndyLeaf is the 'retired military officer' that you quoted.
