Op-Ed: A Response to Climate Central’s EV Analysis


Climate Central's next report may suggest the space shuttle Discovery had a higher MPGe than a Nissan Leaf

Climate Central’s next report may suggest the space shuttle Discovery had a higher MPGe than a Nissan Leaf

A few days ago, one of our most dedicated and pro-EV writers, Eric Loveday, published a story about a recent Climate Central report that, in summary, made the claim that traditional hybrids remain more environmentally friendly in most states than today’s plug-in hybrids.  As Eric’s evil brother on the site (or perhaps just the other Eric on the staff), I thought I’d post an opinion article that discusses some of the fallacies in Climate Central’s report.

In my own state of New York, the Climate Central report says that electric vehicles are more climate friendly, yet there are many traditional hybrids in the list, and my Chevy Volt is absent. Odd considering that I’ve traveled roughly 200 miles in it for every gallon of gasoline I’ve burned, don’t you think?  This further reinforces how easy it is to play with statistics to reinforce one’s own opinion, regardless of what side of the story you’re on.

I readily admit that a Chevy Volt is not for everyone, especially those people that regularly travel over 100 miles daily. However, I burn no gas unless I make a 375 mile trip to visit my family, and even then I get better gas mileage on that trip than the best traditional hybrids on the market today.

I find it interesting (read: amusing) that the report sets out to make a very bold claim that traditional hybrid vehicles are generally more environmentally friendly, with a very fancy graphic depiction that may lead passers by to the same conclusion.  However, the report states in part:

“This reduction in carbon emissions [between 2010 and 2012] from electric power generation more than doubled the number of states where driving and charging a high-efficiency all-electric vehicle is better for the climate than a gasoline-powered Toyota Prius hybrid.”

The Union of Concerned Scientist's Report Contradicts Climate Central's

The Union of Concerned Scientist’s Report Contradicts Climate Central’s

That’s right: the same report that is seemingly trying so hard to discount today’s electric vehicles simultaneously acknowledges that, in a mere 2 years, their own analysis shows that the number of states where driving an electric vehicle is better than a traditional hybrid DOUBLED, between 2010 and 2012.  If this trend continues, then by their own analysis, even more states will be more conducive to electric vehicles from an emissions standpoint than even the cleanest traditional hybrids.  And yet, their graphics would suggest that would-be buyers of a new car are better off buying traditional hybrids.  Considering most people keep their vehicles for over 2 years, I would seriously question their motives in this whole report, as many of our readers here have also done.

While it’s easy enough to point out flaws in their conclusions while constraining ourselves to their own analysis, it’s easy to see that their analysis and data is also flawed in and of itself.  One of our avid readers, Thomas T., linked to an interesting blog post countering the Climate Central analysis, and rightly pointing out that no one state’s energy mix should be referenced when attempting to determine if a vehicle’s true emissions footprint.  For a detailed explanation of why, as well as other perceived flaws in Climate Central’s report, check out the blog post.

If Climate Central truly wants to do an analysis of what vehicle technology is the cleanest to buy today, they should look at:

  1. Energy mixes across an entire utility region
  2. Forecasted changes in the energy mix of our nation’s utility grid
  3. Forecasted increases in battery advancements (which should also result in a decreased carbon footprint per kWh of battery production)
  4. The percentage of charging that may be done overnight when electricity is plentiful (and the incremental pollution per additional kWh used is minimal)
  5. The carbon footprint of the energy distribution network (e.g. transporting fuel to power plants versus distributing fuel across the nation to gas stations)
  6. The carbon footprint of the military presence we maintain to secure and stabilize oil commodities across the world

I’d also settle for a WWE-style last man standing match between Climate Central and the Union of Concerned Scientists.

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35 Comments on "Op-Ed: A Response to Climate Central’s EV Analysis"

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There are certainly things in the report with which to take issue with. Principally, the assumed 50/50 split between gas and electric driving for *all* PHEV’s is clearly misguided for a vehicle with as long of an EV range as the Volt. And some if the state map graphics default to only 50,000 miles of driving, which is too short. But most of the report is sound. The fact that the grid is slowly getting cleaner is also compelling fact, but it’s not as though the study ignores it. They address it head on. I find it disconcerting how quick some readers of this site (and others) are to ascribe sinister motives, malice, and even corruption to the authors of any study that doesn’t put EV’s in the best possible light. Climate Central is a non-profit comprised of climate scientists and journalists. It’s not the freaking Big Oil Institute, as some have suggested. Bottom line: power plant emissions and manufacturing-related emissions are significant and can’t be ignored when assessing the environmental impact of EV’s. Some people would like to ignore these sources of pollution, but I’d rather get my analyses from scientists who are objective aren’t principally EV enthusiasts and… Read more »
Jeff hi, As a statistician who reads and writes research articles on a daily basis, I strongly disagree with your statement that “the report is sound”. In the way it is written, it is not. ( Besides that, over the past week I’ve followed my own fact-checking trail on this report, including numerous email conversations with researchers including the authors – and their numbers and conclusions themselves appear misguided – but that’s for a separate comment below ). I do agree with you that it is a bad idea to impugn motives unless there’s a smoking gun, and I’ve found none. Climate Central appears to be independent, and as interested in global warming mitigation as any of us. In other words, the old adage “never attribute malice when incompetence is a possible explanation” should hold here as well. So what is unsound in the way the report is written? 1. The lack of any reference to uncertainty and variability in the main presentation of data (i.e., the charts, maps and tables). In view of this, whatever mention of uncertainty is made in the article’s fine print is no more than lip-service. *All* research articles that the authors used, had at… Read more »

One should also add, that a huge chunk of their tables maps and figures are just a regurgitation and re-presentation of the very same number. Too much fluff, not enough substance.

Also, how is their “nationwide average” calculated? An average of states, is my guess. A population-based average would be far more plausible.

The biggest flaw in all these studies is that they look at average grid mix instead of the MARGINAL generation needed for EVs. At night, when demand goes down, natural gas plants idle. That’s where EVs will get the majority of their electricity from.

A state’s electricity can be 80% coal and 20% natural gas, but the coal is baseload and running at the same output day and night. Adding 10,000 EVs charging at night won’t increase the city’s peak demand nor result in any more coal being burned.

If any new generation capacity is needed to handle daytime charging, it most certainly won’t be from coal. But that’s going to be minimal for a long time, as even 10M EVs would only need 1% of US electricity generation.

Yeah a 50/50 split is silly. We have statistics on this now from Volt drivers and they drive much more on electricity.

I guess you could say that the low-AER PHEVs could have lower electric usage but those cars also sell less. The Volt is the best-selling PHEV. It outsells all the others combined.

It’s difficult to take Eric Loveday’s articles seriously given the sheer number of typos, spelling errors, and grammatical errors typically contained therein. Makes me wonder how much true investigative work he performs writing his articles.

distraction much Aaron?

give him a break. He has to publish 4 articles an hour. ..and that isn’t easy.

Aaron, it’s difficult to take your posts seriously when you, on at least two occasions, apparently didn’t know the facts before making a statement. On one occasion you attacked ICE-based BEVs, and I pointed out to you that your MiEV is ICE-based. Most recently, you attacked the Focus Electric for losing too much cargo space to its battery, and I pointed out that your MiEV has even less cargo space behind the rear seats than the Focus Electric. I don’t get it.

But, my gosh, your spelling and grammar is usually exemplary.

Eric – you kick butt. thanks to you, Jay, and the rest of the crew for keeping us informed.

I have cogitated over this seeming contradiction in EV use:…ie, if the source of electricity is from coal or oil then there are more emissions from my volt than from my Toyota Prius. I put together some simple numbers and it is true…….but you know what?

I don’t care. and most EV drivers don’t care. It is not our job to get the grid cleaned up. It is the grids job. As a transducer out Volts do their job to the best of their ability. What really needs to be pointed out is that if one charges from Solar PV or if someone is using hydro or (dare I say it) that horrible nuclear stuff then we kick butt on the Prius.

Good article ClarksonCote. I like the Bio that Eric and Jay include w/ the articles…and I truly appreciate readers writing articles. I’ve done it myself. It is time consuming and it pays very little (ha-ha that’s an understatement).

“I readily admit that a Chevy Volt is not for everyone, especially those people that regularly travel over 100 miles daily.”

Why? It’s fun to drive and gets better gas mileage in RE mode than all other traditional ICE cars. There’s only a handful of hybrids that beat it.

Yeah, that makes no sense. If you drive 100 miles, nearly half of that is on electricity and the rest is at a high MPG. And even though the Prius gets better MPG, the electric miles more than make up for that difference.

Well, take my situation as an example. For one, the Volt is too small for my family of four. I don’t care about the lack of 5th seat, but the trunk is practically non-existent. Second, my wife and I have two cars – a Leaf and a traditional hybrid. The trips done on the hybrid are either really short (my commute is <5 miles round trip) or really long (nearly every other weekend, we travel 400+ miles). I ran the numbers given my trips, and the plug-in prius would use less gas for me than a Volt. Plus, it would actually fit my family!

There will never be one car that works for everyone. Why would the Volt suddenly change that?

Cargo space, seating, etc., were not things I was concentrating on. It was the 100 miles comment i was responding to. The Volt is comfy for long trips, certainly 100 miles, and will still use less gas than the Prius at that distance. I’ll also mention that I (personally) would not want to drive long distances in a Prius.

The changing grid cannot be overstated. Last year the number one new source of electricity production was wind. Not coal, not natural gas . . . wind. Natural gas was number 2. And solar PV is currently growing like crazy. Yes, it is starting from nearly nothing but the growth rate is so big that utilities are now running scared and are trying to kill off net-metering and/or make solar people pay. Just do a search on “utility death spiral” (the name for this meme) and you’ll see lots of articles on this. Right now solar is not really a threat since the installation costs dissuade a lot of people. But with with the no-money-down solar leasing programs and self-installers like me, it is starting to put fear into utilities. For $5K in PV parts, a self-installer can eliminate most of the electric bill. For $12K in parts, I’m building a 6.12KW system that will provide all my home’s electricity AND all my EV’s electricity needs for the next 25+ years. Oh, there is a tax-credit so it is only $8.5K. Calculate the costs of your electricity bill AND gasoline bill for the next 25 years and you’ll see what… Read more »

My drive through central NY last week included seeing a new giant wind turbine being delivered to another site. Everytime I drive north between Philadelphia and Rochester NY, I see some parts to a new turbine being delivered. NY is a great state in terms of renewable power – wind has grown well and good old Niagara Falls (hello Nikola Tesla fans) kicked it all off and still has 2.4 GW of output on both sides of the niagara river since kicking off in the early 1960s. Hydro and Wind are not enough but together along with solar, are starting to amount to “something a bit more sustainable”.

Eric hi, Thanks for posting this. You beat me to the punch – I have just been in touch with the editors about writing some sort of debunk-ation here. You have pointed out some of the main issues with the report, but there are many more. Over the past week I have been in touch with the authors, as well as the authors of scientific articles they used as input. I can now say without doubt that the Climate Central report cherry-picked both information and assumptions, in a way that strongly biased the analysis against EVs. That said, I would not impugn their motives because there is no evidence for ill motives. In fact, the authors have so far responded to my inquiries in a very open manner (I am still waiting for a second answer from them though). Besides the presentation issues (see comment above), what is wrong with the numbers in the report? 1. The biggest issue – and the joker in the deck of anyone wishing to diss EVs for their GHG impact – is the battery footprint. Estimates in the literature vary widely, from 6kg CO2 / kg battery, to 22. The authors chose to use… Read more »
Ok, here are some major points about point-of-use. Others have made them, but let’s try to put numbers around them: 2. The fixed grid. It is counter-logical to present a “life-cycle analysis” over 50k or 100k miles, while assuming that the grid mix remains fixed. The authors themselves admit a 8% reduction in overall grid GHG in 2 years. So… assume 5 years for 50 miles – or 2.5 years for “the average driven mile”. The national grid should be on average 10% cleaner over these 50k miles than today. For the 100k mile analysis – almost 20% cleaner. They definitely should put uncertainty and sensitivity-analyses around these estimates, but assuming no improvement biases everything against EVs. Over 50k miles the Leaf becomes about 20% cleaner than the Prius on average on a per-mile basis (excluding production overhead), vs. only 12% in their Table 1. 3. Off-peak charging. It so happens that coal plants have to maintain some level of “production” 24/7, even if there’s no demand. It also so happens, that most EVs do (or can do) a substantial amount of their charging during those hours. But how much, and what’s the impact? In this book chapter, some work… Read more »


Since you, too, are looking at table 1. Please, before all you’ve written, state your assumptions about how CO2/kwh is arrived upon? You are making an inference, from their report, about how clean an EV is.


I’m very curious about the linear relationship assumed for CO2/kwh as well. Does the assembly line making Tesla batteries truly pump out significantly more CO2 when it’s a 85kWh battery on the line than when it’s a 60kWh battery? Does the bucket scooping out the ingredients at the mine expel that much more CO2 between the two different sized packs? It’s hard to imagine when visualizing the steps that the difference would be very great. Or linear. But the studies seem to be making that assumption. It seems that the effort of making ANY battery production line would be the lion’s share of the emissions, more so penalizing the difference in battery size.

Nice response, Eric!

I too would love to see a “WWE-style last man standing match between Climate Central and the Union of Concerned Scientists.”

Considering the whole energy mix thing.

There needs to be continued revelation (revealing?) of the fact that each gallon of gas contains spent electricity. So, if a gallon contains 3-4 kWh (I am yet unable to know exactly what it is) – then that is maybe 7-9 miles of energy that could have been routed to an EV. Sure, there are charging losses so I would have said 9-12 miles but with every gallon of gas pumped, you could be driving about 8 miles in an EV. This should be factored into these analysis reports and I don’t think they are.

The Climate Central report does factor in about 35% CO2 overhead for every unit of gasoline consume (35% of the net CO2 burned when the gas is used). They take that number from an ANL GREET article by Burnham et al. The number includes drilling, refinery and transport related energy. It does seem on the low side. One thing it (and all ICE overhead analysis) surely does *not* include is the extra GHG emitted due to military costs, wars, accident-caused disasters, etc. (Dr. Burnham confirmed that to me). So it is likely on the low side, but in principle some calculation is included.

In general, the Climate Central report has *Zero* new information. It is all numbers taken – or rather cherry-picked – from other studies, then simple arithmetic with those numbers and a lot of fancy maps and graphs whose main end result is to distract and confuse rather than inform and educate.

Not that uncommon whenever the mainstream media tries to convey research-based data, but I expected more from an environmental research NGO.

More to the point, they provide .52lb/mile CO2, for the Prius. At 52mpg, it’s 27lbs/gal. That’s 5-8lbs more than the conventional wisdom that each gallon of burned gas releases 19-22lbs of CO2. (Hmm 27/20 ~ 135%…uh, ok)

We’re in “well-to-wheels” land. A recent Congressional Research Study on Oil Sands, contrasted them against more easily extracted, standard light-crude forms, but still it yielded values 45-75% above 20 pounds, not 35%.


Both the authors, and the those republishing this story are duly impugned on each the oil, and the electric, side. Cherry picking is unethical. It’s a white Bronco that let’s you know what’s under the hood.

People, don’t struggle with this. They “picked” the car, understated the well-to-wheels, overstated the historic CO2/kwh, ignored today’s grid, dialed the life-cycle analysis, and then made this huge leap to a general “Hybrids are better in most states” tagline. This story seems not to have belonged on Climate Central, or Insideevs. It goes down along the lines of “baffle them with bullshit”. Be embarrassed. It’s OK. Move on.

It believe that it has been proposed that, if we simply ceased all gasoline production overnight, there would be enough electric capacity left over for EV transportation over the same or greater distance as had been achieved with ICE vehicles. (Assuming we could also magically convert all ICE vehicles into EVs overnight.)

This makes intuitive sense as it has been estimated that about 7 kWh of electricity (not to mention lots of other energy) is consumed in the production of 1 gallon of gasoline, on which the average ICE vehicle can travel about 25 miles. The average EV can travel at least 25 miles on the same 7 kWh directly.

Think of all the other energy that is *utterly wasted* in the extraction and transport of crude oil to the refinery, the refining process, and then the transport of the finished gasoline to the consuming ICE vehicles. How much energy has an ICE vehicle “consumed” before it has even moved one inch of its 25 measly miles per gallon? The whole situation boggles the mind.

Life Cycle Assessments are extremely complex when determining the true ‘carbon footprint’. By the time the Climate Central article’s superficial data was researched, tabulated, analyzed, and later printed, it was outdated albeit of some historical value. I feel the emphasis should be on the ‘in phase’ carbon footprint of EV’s which my research & experience indicates that OVERALL they are the most climate friendly on the road! I drive a LEAF which I power with a residential photovoltaic system as do many EV owners…no mention about the MINIMAL carbon footprint of this group.

Dear Eric and Eric,

The EPA has been releasing carbon dioxide data, by electric generation source for about a year. So, yes, in fact it is possible to gauge by state emissions this way. One can also look up by state emissions by looking at EIA.gov data for electric generation by fuel source, where (generally in terawatt hours) a breakout of fuels is reflected. It is not that hard to infer, and in my experience the end values aren’t far from the ranking of Climate Central’s report. But their values are curiously too high.

I pointed out MA was too high, as your critique now points out. Their Table 1 suggested ~.45lb, or so, per kwh, when fuel sources suggest .2-.3. And, with MA, it doesn’t matter how much you go back in time. Coal’s use was never enough to suggest .45lb/kwh (the table might say .43lb. I’m not at work). What Climate Central needs to do is attribute CO2 on the way to the plant, and at the plant, for all of us. They can pick one, or two states. I think they’re way off.

Coal will not be an issue in NY State a year from now. It is currently at best 3% of generation, and will probably be essentially 0% a year from now.

My personal concern is to keep my distance for the Ginna plant in Ontario, NY, (around 94 miles away), and Pickering east of Toronto (about the same). Other than those, I have no Nuclear plants extremely close to me.

Oops, just found Ontario Hydro’s Pickering complex (6 CANDU units, one of the largest Nuclear installations in the world), is about 60 miles from me. Recently, it has been admitted by the Canadians that their containments for these CANDU units are not so good. Horrors! But problems at any of these complex’s would surely be more of concern to tiny little cities very nearby, such as Toronto.

Ugh! Too early in the A.M. Darlington is east of Toronto, Pickering is West.

Many competent scientists argue that CO2 has little effect on climate, much less the small fraction of man made CO2. Google James Peden AGW to get a very cogent synopsis of the issue. I’m a life long electric car fan, but the attractiveness of EVs resides in the availability of an alternate and virtually inexhaustible energy source. In addition, EVs should eventually become simpler and more reliable than ICE-age machines. I’m gratified to see the success of the Leaf and Zoe and have my fingers crossed that improvements in battery technology will make EVs a primary source of motivation.