Here’s An Easy Way To See How Clean Your Electric Car Really Is

FEB 17 2016 BY MARK KANE 44

How Clean is Your Electric Vehicle?

How Clean is Your Electric Vehicle?

2015 Nissan LEAF

2015 Nissan LEAF

The Union of Concerned Scientists released a tool that shows CO2 emission per mile for plug-in electric cars – How Clean is Your Electric Vehicle?

Their average results nationwide are:

  • ICE: 381 g CO2 per mile
  • PHEV: 209 g CO2 per mile
  • BEV: 154 g CO2 per mile

If you insert a model (not all are available for comparison) and location, then you get particular results.

As always, the results are specific for “today”, and do not consider the anticipated going forward, increased cleanliness of electricity production in the United States.   Therefore in almost all cases, any petrol car compared to a plug-in vehicle would be a comparison of the gas vehicle on its newest (and cleanest) day, to the plug-in’s worst day.

We grabbed a few models and checked results for Auburn, California. Feel free to show us in comments how much it differs where you reside:

How Clean is Your Electric Vehicle? - examples

How Clean is Your Electric Vehicle? – examples

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44 Comments on "Here’s An Easy Way To See How Clean Your Electric Car Really Is"

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So, the Tesla Model X in this example is cleaner than the Volt, but can seat 7 versus the Volts 5 or 4 seats. And this doesn’t even consider charging the Tesla on Solar!

In Michigan a Model X P90D is as dirty as a 34 MPG car, maybe thats why Michigan doesn’t want Teslas?

But how many high performance 7 seaters get 34mpg

None, but its still interesting to see how much influence your location has on your carbon footprint. Not only with EVs, but also the electricity you use in general.

So you’re saying there are no solar options for charging an EV in Michigan ? In southern California there are lots of solar charging options , our Wal-Mart has charging stations run off solar during the day , even the San Diego zoo has solar charging in the parking lot and so do some of the malls now .

Just had look at the spread and I would suggest that the problem is Michigan not the model X or for that matter the volt. you drive either of those cars in 12201 (New York state?) things look much better. I would suggest buying electric cars and then fixing the grid. There is no way that level of inefficiency can be justified.

The answer is maybe until we can figure out what UCS uses as their Utility factor for the Volt.

“Total distance between charge events determines how much of the driving is performed in each of the two fundamental modes. An equation describing the portion of driving in each mode is defined. Driving statistics from the National Highway Transportation Survey are used as inputs to the equation to provide an aggregate “Utility Factor” (UF) applied to the charge-depleting mode results.”

I often find UCS studies hiding the parameter used in their study.

What is the UF used for Volt? Until we find that, we won’t know for sure.

Volt’s EV mode efficiency are higher than Tesla. So, if you are 90% EV in the new Volt, I seriously doubt the Model X would be better.

After digging further, the only UF I found vs EV range is 0.7 for about 50 miles of EV. If we assume that is the number the UCS uses, then it is grossly underestimate for the new Volt. The Gen 1 Volt with only 35-38 miles of range had a 67% fleet average, there is no way the 53 miles Volt will only do 70%.

If you are higher than that UF number, then your emission is significantly better.

I hope UCS adjust their calculator to allow PHEV owners to put in their own EV/Gas ratio.

According to, the Volt 1.0 averages 71% EV miles, or 0.71 to use your math. I think it’s a bit optimistic to assume 90% for the Volt 2.0. I’d guess about 85%, but we’ll both have to wait to see what the actual data shows.

The 90% number wasn’t a fleet average as the 71% for the Gen 1. It is really a projection based on my personal case.

The problem with the calculation is that their assumption is very low relative to what real world fleet data says. So, the UCS calculator actually made Volt looking worse than it actually is or capable of.

That is why I think UCS should “disclose” the condition or parameter it used to reach those estimates and maybe even better to allow user to put in that information.

Last I looked i couldn’t break down Voltstats by model year. So, the 2010-2012 35 AER cars miles will be weighted highest as they have been on the road the longest. Besides being on the road longer, 2012 sales were the highest while the 40 AER 2015 was much smaller. What makes a bigger difference is weighting the total ev vs total miles which skewes numbers toward the highest mileage, typically older cars.

It would be great to see how much difference the bump in range for 2013-2014 does, the 2015 bump does, and most of all the 2016-2017 jump does.

If I am wrong, and there is a place this is broken down I’d love to see it!

My guess is if we had numbers just by model year the 3 and 2 mile range bump ups would make little measurable difference. Also, the Gen II jump in range would be closer to 80% than 85%, due to the factors where gas is used doesn’t always depend much on AER (away multiple days on trips w/out charging, comfort heating in cold weather, fleet/dealer cars not plugged in for periods of time).

Still, wish we had the numbers broken down better.

“So, the Tesla Model X in this example is cleaner than the Volt, but can seat 7”

Yea, but the emissions go up considerably on the way back from the taco bell.

’14 ELR in DFW = 282. Pretty high for NG+wind+60%-EV.

It shows 188g/mile for my LEAF. Seems high, like what you said. Still twice as good as a gas car. Better for DFW during our summer smog alerts.


Refined fuel from Texas is very bad. They fuel their refineries with brown coal.

If you’re doing regional impact analysis, you should include the variable impact of fuel as well.

Yep, looks like they use the national average GREET model for gasoline CO2 impact.

I wonder if they could pull in more regional data?

Good, so that shows that even fueling the car from a power plant burning roadkill is almost twice as efficient than a gas car.

I.e., the worst case proves the rule.

Nice. What about the resource cost for creating a BEV vs. an ICE?

Word. Thanks.

great link – thanks!

It’s hard to tell how they came up with the figure, but EV would do far better in city (low speed in traffic) than rural (high speed). I tried inner city zip code and rural zip code, and they both came back with same numbers. Gas cars would do far worse in city, something to keep in mind when comparing to EV.

Very true.

The UCS should have included a category for hybrid cars and also allowed you to calculate the CO2e for specific model hybrid and conventional ICE cars in their emissions tool, instead of just giving one figure for a 29 mpg gasoline-only car.

I guess the reason they didn’t included regular hybrids is that it would not suite their agenda very well :/ Not very scientific approach.

These CO2 emission figures are already well defined in DOE website for each particular car, no need to invent a bicycle really.

Nation wide averages speak for themselves..

“not suite their agenda very well” says who? Tell us about YOUR agenda will you? 😉

This is why solar city is up double digits percentage wise today – you can’t win against Elon and the new age of electric energy. Join us instead.

and, in other news, the time it took to write this article India opened two new coal power plants, as did China,..negating the entire output of Tesla for the next century. Oh, and Russia just opened another one,..there goes every Bolt that will ever be sold. (I grew up with “the Coming Ice Age” environmental hysteria, then the “Global Warming” hoax, so please excuse my skepticism over the current tax-the-rich scheme called “Climate Change”..) I can just see Gore hopping out of his personal heated outdoor Olympic pool and into his Tesla 3,..saving the blessed planet yet again.

In the U.S. alone, pollution from coal-fired power plants are estimated to kill between 15,000 and 30,000 Americans ever year. Obviously worldwide, it’s far worse… especially in China.

I’d think that even someone who thinks global warming is a “hoax” could see the advantage of reducing air pollution. Don’t cut off your nose to spite your face.

Now, as to your apparent belief that if plug-in EVs can’t immediately stop 100% of worldwide industrial pollution or climate change, then there’s no point in pursuing them at all, I’m reminded of what one wise person said:

“I am only one, but still I am one. I cannot do everything, but still I can do something; and because I cannot do everything, I will not refuse to do something that I can do.” — Helen Keller

Did you know that %36 of statistics are made up on the spot?

That’s actually an old number. The latest is 42%.

“and, in other news, the time it took to write this article India opened two new coal power plants, as did China,..negating the entire output of Tesla for the next century”

I would like to see reference to back up that claim.

China isn’t building coal plants that fast anymore ever since the collapse of their real estate bubble…

Its better they burn it anyways, rather than dump in the rivers.

It’s perspective dude. I mean that coming ice age stuff lasted for about 6 months, had a few articles on it in the paper and magazines.
Now that the planet has been warming for decades, you can no longer
‘Rush Limbaugh,’ the facts, pretend as if they don’t exist, you resort too: what we do won’t matter because others will ruin the planet is just specious argumentation.

Sorry, not buying what you are selling.
If you buy the Republican or for matter any political parties take on things, hook, line and sinker, well then, you are just hopeless.

Old news, China has stopped all new coal mine projects just last month.

If you really don’t think that global warming is real by now, it’s unlikely that rational arguments can help much at this late stage. But just in case.

The average global surface temperature decreased slightly from 1940 to 1975. The main reason behind this mid-century cooling was global dimming due to anthropogenic sulfate aerosol emissions. That was global cooling.

I am really disappointed I can’t select and ICEs for comparison in this. There should have at least been 10 or 20 of the most common sold ICE vehicles to do a direct comparison.

You can compare Annual Emissions (lbs CO2) of almost all cars here ->

You can also breakout daily driving distance, and percentage that is highway miles.

I think we should also consider the other dangerous gases produced by ices:

U.S. Environmental Protection Agency estimates of average passenger car emissions in the United States for April 2000[5]
Component Emission Rate Annual pollution emitted
Hydrocarbons 2.80 grams/mile (1.75 g/Km) 77.1 pounds (35.0 kg)
Carbon monoxide 20.9 grams/mile (13.06 g/Km) 575 pounds (261 kg)
NOx 1.39 grams/mile (0.87 g/Km) 38.2 pounds (17.3 kg)

Vehicle, Light-Duty Truck, and Medium-Duty Passenger Vehicle—Tier 2 Exhaust Emission Standards (for Bin 5)[6]
Component Emission Rate Annual pollution emitted
NMOG (Volatile organic compounds) 0.075 grams/mile (0.046 g/Km) 2.1 pounds (0.95 kg)
Carbon Monoxide 3.4 grams/mile (2.1 g/Km) 94 pounds (43 kg)
NOX 0.05 grams/mile (0.0305 g/Km) 1.4 pounds (0.64 kg)
Formaldehyde 0.015 grams/mile (0.0092 g/Km) 0.41 pounds (0.19 kg)

I have solar and buy wind power so my LEAF emits zero.

Why is the leaf so sensitive to model year? The battery is the same and the range hasn’t changed in real terms by any great amount.

The CO2 produced per mile then to come from EPA data sets from 2009, or 2012. The do not take into account that:

1. Refineries have trended to use more dirty crude oil to make fuel in each year since 2011/12. (between 2010-2014 sweet crude was very expensive, and oil-sand crude came online, as more oil source from North Dakota)

2. Each year since 2009, the electric grid has gotten cleaner each year. In 2015 NG electric energy produced exceeded coal for each month of the year (US). Also in 2014/15 new electric energy sources were mostly from renewable sources … reaching 100% of new production be renewable in 2015. More coal plants were retired in 2015 as the overall demand for electric energy dropped, due to more efficient use of electricity. (thing mobile phones and LCD screens and LED bulbs vs. older energy hogging TV tubes)