Wednesday, June 6, 2012

Electric Vehicles Vs Internal Combusion Engine: Total Cost Of CO2

Further to the Total Cost of Energy for a vehicle, how much CO2 do Internal Combustion Engine (ICE)  vehicles make, versus Electric Vehicles (EV)?

The total weight of C02 that an ICE vehicle emits into the atmosphere over 200K miles is at least 50 times the car's weight! Wow!

On CO2 emissions, electric vehicles easily beat internal combustion engines, usually by orders of magnitude.

How MUCH Carbon Dioxide Does Your Car Produce?

So, how much CO2 do ICE vehicles produce over their lifetime? First, consider how much CO2 is produced by burning a gallon of gasoline.

According to,, the average fuel economy for cars sold in 2005 is about 25.2 MPG (Source: National Highway Traffic Safety Administration).

"How much CO2 is produced from 1 Gallon of Gas? 1 GALLON OF GAS = 19 LBS. OF CO2. If a gallon of gasoline weighs about 6 pounds, how can it produce three times that much greenhouse gas? The carbon from the gasoline mixes with oxygen from the air. … The eight molecules of CO2 weigh about three times more than the one molecule of octane you started with. That doesn't mean you've violated the law of conservation of mass; instead, you've added the weight of the oxygen from the air to the weight of the carbon from the gasoline."


Burning a Single Tank Of Gas Will Create More Carbon Dioxide Than Most People Weigh! 

Assuming 15 gallons of gas in a car's gas tank: 
15 gallons * 19 Pounds Of Co2
= 285 pounds of CO2 per tank of gas!

When you burn 15 gallons of gas in your tank, you are creating 285 pounds of CO2! 

Think of that number in terms of how much you personally weigh.  


Burning Gasoline Over 200K Miles Will Produce Dozens Of Tons Of Carbon Dioxide:

At 25 MPG, and assuming that this figure also applies to 15 MPG: 
1 Gallon Of Gas = 19 Pounds Of Co2

8,000 gallons of gas in the car's lifetime of 200K miles

8,000 Gallons * 19 Pounds Of Co2
= 152,000 pounds of C02
= 152,000 pounds / 2000 pounds in ton
= 76 Tons of C02 over the car's lifetime

Assuming the car weighs 1 ton (2000 pounds), the 25 MPG car will produce 76 times its weight in carbon dioxide in its 200K mile lifetime!

A vehicle that gets 35 MPG will produce 54 tons of CO2. A car gets 15 MPG will produce 127 tons of CO2. 


How Much CO2 Emissions Do Electric Vehicles Make? 

Of course, with CO2, we mean, "How much CO2 do EVs INDIRECTLY emit?". Of course an EV produces no direct CO2 whatsoever, in the same way your cell phone produces no direct emissions. Unless you consider the noise pollution that comes out of your cell phone.  :)

There have been many expressing a big OPINION that because electric vehicles use electricity that has been generated by coal plants, it produces "just as much" pollution as gasoline ICE vehicles do. But they usually don't give any numbers or analysis.

So let's run the numbers using some relatively simple math. 

How Much Carbon Is Used To Create A KiloWatt Hour?

CO2 Emissions in grams per KWH (life cycle analysis)

Worst case is coal: 800 to 1050 grams of carbon dioxide per KWH
Best case is Hydro Electric Power: 4 grams of carbon dioxide per KWH

Using, Exhibit 1.1 

Worst case: 1000 grams of carbon dioxide per KWH, using coal
Best case: 4 grams of carbon dioxide per KWH, using hydro electric

Notice the difference? Producing electricity from coal produces 250 times more CO2 then using hydro electric!  Wow! 

From a carbon standpoint, does it make sense to build more hydro electric power plants, and phase out the coal plants? Would that have more benefits than building expensive infrastructure for carbon sequestration? 

Consider how heavy 1000 grams is. It is a kilogram, which is 2.2 pounds. 

Using 100% coal, for every KWH of electricity produced, 2.2 pounds, or one kilogram of CO2 is produced. Could you carry on your back, the weight of CO2 that generated the electricity you used in a day?

Best case:
Mitsubishi MIEV
6.25 miles per kwh

Average Case:
Nissan Leaf Best case/Tesla Roadster are very similar
Use 4.5416 miles per kwh

Worst case:
Nissan Leaf at -30 celcius:  
1.9583 miles per kwh

Put the numbers into a spreadsheet, the worst case scenario using coal, and an EV with reduced range in cold winter weather. 

1000 grams of carbon per kwh
453.59 grams in a pound

= ( (200,000 miles / 1.958  miles per kwh) * 1000 grams of CO2 per kwh) / 453.59 grams per pound
= 225,153 pounds 
= 225,153 pounds / 2000 pounds in a ton
= 112.6 tons of carbon over 200K miles in an EV

Note the dramatic difference between coal and hydro. If 100% Hydro electric power is used to charge the EV, over the entire 200K miles, an EV driving in winter weather will not even create half a ton of carbon dioxide!  

This is in contrast to ICE vehicles, which will produce 54 to 127 tons of CO2 over a 200K lifetime.


Comparing EV and ICE CO2 emissions side by side, we get:  

For the Best and Average cases, using 100% coal to charge the EVs, the CO2 produced is only about 2/3rds (64%) of the CO2 that ICE vehicles emit.  

This puts to rest the idea that charging the vehicles with coal would produce "just as much" CO2 as internal combustion engines.  

If 100% Hydro electric power is used to charge the EVs, over 200K miles, the worst case scenario with Evs (.45 tons of CO2) would be over 100 times better than the best case with ICE (54 tons). 


Notes on The Worst Case Scenarios: 

Even in the worst case scenario of using 100% coal, EVs still produce fewer carbon emissions, although not as dramatically at 89% of ICE emissions.  

For today's EVs to get such a short range for their charge, it is typically because they are working 100% of the time in a very cold winter environment, such as -30 Celcius (-22 Fahrenheit).  

However, how long are any vehicles driven consistently in such cold weather? Even in Canada, the winter ends, and the warm temperatures of spring and summer follow. In cold Winnipeg, Manitoba, Canada, the average temperature is below freezing only from November until March, 5 months of the year.  
In such a cold climate, it's not uncommon for even ICE vehicles to also get worse overall mileage. While they get 15 MPG in the summer, they will get fewer MPG in the winter. Part of this is due to the time spent idling just to warm the vehicle up. Another factor is the colder air used for combustion. Lower winter gas mileage would also increase the CO2 emissions for ICE vehicles. 

What Power Sources Are Used To Generate Electricity?

In the USA, different power sources are used to generate electricity. According to, about 48% of the USA's electricity is generated from coal. 

What Is The Weighted Average Of CO2 Per KWH In The USA?  

USA: 0.61 Kilograms of CO2 per KWH

= .61 Kilograms * 2.2 pounds in kilogram * 453.59 grams in a pound
= 608.7 grams of CO2 per KWH
= Approximately 1.3 pounds of CO2 per KWH

Multiplying the EV's CO2 numbers by .61, we get:

In the Best and Average cases, the CO2 emissions from charging the EV, are only about 39% of what an ICE vehicle produces. In the worst case, they are 54%. 

In Canada, where the colder weather would produce the higher electricity use for EVs, about 59% of electricity is produced by Hydro electricity.  See:

And in some provinces, over 90% of the electricity is generated by hydro electricity: British Columbia, Manitoba, Quebec, Newfoundland.  

So, in the worst climate for CO2 emissions from EVs, there are actually the cleanest energy sources to charge the vehicle. 

The weighted average of CO2 per KWH in Canada is about 1/3 of what it is in the USA:

Canada:  0.22 Kilograms per KWH
= 220 grams of CO2 per KWH
= 220 grams / 453.59 grams in a pound
= Approximately 1/2 pounds (.484 pounds) of CO2 per KWH

Using the Canadian weighted average of 220 grams of CO2 per KWH, the difference is even more dramatic.

Using the best and average case scenarios, EV CO2 emissions are about 1/7 what an ICE vehicle produces. In the worst case, EV CO2 emissions are about 1/5.



Running the CO2 numbers, a few things really stood out.  

One, the many tons of CO2 produced by internal combustion vehicles over a lifetime of 200K miles. For a vehicle that gets 35 MPG, over 50 tons of CO2 is produced! 127 tons for a vehicle that gets 15 MPG! 

Two, how very dirty coal is for producing electricity. Coal produces over 250 times the amount of CO2 that hydro electric does! Just one KWH of electricity created by a coal plant produces .85 to 1 kilogram of C02!  

You have to wonder just how "clean", is "clean coal"? 850 grams of CO2 per KWH? That's only a 15% reduction from 1000 grams per KWH. Not very compelling. Perhaps that's a topic for another post. 

Three, from a CO2 perspective, the most dramatic thing we can do to reduce CO2 is to move from ICE to EVs. That would make a dramatic difference. In the USA, it would reduce emissions to less than half of what they are. In Canada, such a move would reduce emissions from 1/7 to 1/5 of what they currently are. 

Four, it is really striking when you start to consider the CO2 emissions from coal and ICE vehicles in terms of your own weight. It starts to put the total emissions of the whole population into perspective. 

Five, as far as public policy is concerned, if reducing C02 is the priority, almost anything that can move away from coal would seem to be a good idea. Again, an idea for another post. 


How about you?  Any thoughts or ideas? 


  1. I'd like to see energy and cost figures for the entire cars. It seems to me that the cost to manufacture the batteries used in plug in and hybrid vehicles is substantial in both energy use, cost, and impact to the environment (both when constructed and when they need to be disposed of). Also, an ICE car will go 200k miles without a rebuild, but I believe that the batteries need to be replaced at around 100k miles. The battery replacement is frequently glossed over both as an additional cost of ownership and cost to the environment.

    Car and Driver (I believe) did a comparison of the total cost of ownership of a hybrid versus a ICE some years ago (they used the Toyota Echo and Prius as the basis for comparison). My recollection is that it would take more than eleven years of ownership based on $5/gal of gas before the hybrid became less expensive.

    Have you seen any data / sources to help me with my quest?


    1. Terry,

      We have a 2007 Camry Hybrid with 140,000 miles and the batteries have shown no sign of failure whatsoever. Also, the difference in our gasoline consumption from our first Camry has averaged over 10 mpg improvement. With our vehicle use, we recovered our cost differential in four years.

  2. HI Terry,

    You can calculate:

    Direct to Direct costs
    Indirect to Indirect
    Full life cycle to full life cycle.

    And measure one of: energy, dollars, CO2, or something else.

    In this particular post I was measuring CO2 in pounds and tons. Not currency.

    What bothers me is when so many suddenly question indirect costs for EVs. But never for the ICE. It's a double standard.

    Just what are the "indirect" costs for oil changes over the life of the ICE? And radiator changes? And timing belt replacements? In dollars? Indirect costs of CO2? Energy? The numbers please. Not idealogy.

    I've run other numbers on dollars at:

    And costs on the battery at: Hummer Vs Prius

    I question a lot of the "numbers" coming out of magazines. Many of them are way, way off. Saying that EVs are only slightly better than ICE. But it's not true. Where did they get their numbers, and how did they calculate them? They don't say. Nor do they answer when I ask.

    Check this review. It's the first I've seen to consider EV vs ICE in energy efficiency:
    The top 5 are all EVs. Cool!