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Could Pure Electrics Emit More Than Hybrids?

A battery electric vehicle (shown as 'BEV240') could be responsible for more social damage in the form of emissions than a plug-in hybrid, largely as a result of battery size.   (Source: Carnegie Mellon University)
A battery electric vehicle (shown as "BEV240") could be responsible for more social damage in the form of emissions than a plug-in hybrid, largely as a result of battery size.
(Source: Carnegie Mellon University)

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Could Pure Electrics Emit More Than Hybrids?
JimBeals   11/16/2012 6:34:33 PM
The other elephant in the room is maintenance of the vehicles. The primary thing is the replacement/disposal of the battery(ies), they don't last forever. Then there is disposal of the vehicle at the end of its useful life. In other words the total life cycle of the vehicle.

The costs are good but the impact to the environment is the justification for the vehicles. Disposal of batteries, even creation of batteries, puts a lot of load on the  environement.  I'd like to see the analysis on that as well, it might be very enlightening.

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Enough short sightedness already!
SparkyWatt   11/16/2012 6:30:43 PM
Why can't people get it through their heads that the current crop of cars, both total EV and Hybrid, are bridge technologies.  Stop evaluating them as if they were the end.

The bottom line is this: We cannot stop burning fossil fuels while our cars burn fossil fuels.  The total electric vehicle is therefore a critical link in the chain required to free us from fossile fuels.  We cannot be free without them.  We must therefore support total EVs because they aren't going to get good enough if the R&D isn't done.

Hybrids, on the other hand, are an extension technology.  They make fossil fuels viable for a longer time.  Giving us the time we need to get the EVs perfected and the alternate sources of energy figured out.

Some people will say, "Why do we have to get free of fossil fuels."  Pick your answer:

- Fossil fuels are a finite resource.  Although fracking has made a new pool of these resources available, possibly extending their availability by 100 years or more, they will eventually run out.  Then gas cars and hybrids will be dead, and there will be nothing we can do about it.  Would you rather spend 50 years developing new technologies at a reasonable pace, or push the problem onto our grandchildren, who will be facing the same problem at short notice.  If you chose the latter, you are incredibly selfish and short sighted.

- The evidence is mounting in the face of the naysayers that Global Warming is caused by our addiction to fossil fuels, and that it isn't a good thing.  Although no one weather event can be attributed to Global Warming, the increasing pattern of extreme weather can.  The bottom line is that we are going to have to cope with an increasing number of large scale problems if we can't find another way to power our things.

The other thing that I don't understand in this debate is why nobody mentions Geothermal Energy.  We are sitting on top of millions of cubic miles of lava.  That is a whale of a lot of heat.  Figuring out a reasonably efficient way of putting it to use does not require fundamental research (as fusion energy does) and does not produce waste that will be toxic for thousands of years (as fission energy does) and does not require more land than we have (as biofuels do).  All it requires is digging a very deep hole and a few years worth of good old engineering creativity to solve the problems involved in the distances (a steam generator that is several miles long is no mean feat, but we already know everything that we need to know to figure it out).

Charles Murray
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Re: EV's ARE cleaner than Hybrids
Charles Murray   11/16/2012 5:21:07 PM
I'm not sure which numbers you're looking at, rainmaking. Professor Michalek's study is here.


The GREET numbers, mentioned in an earlier comment, were one of the sources of his study, but were not the study itself.

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Re: EV's ARE cleaner than Hybrids
rainmaking   11/16/2012 5:04:58 PM
Charles, in the chart you reference it is interesting how the only figure reported for BEV is US average while all other PHEV data is provided for with a few different regions. Also, the condition studied is "charge depleting" for some reason. As many engineers know this drastically affects the charge efficiency. The advantage you state for HEV is slim and would certainly be overturned in many regions and when more moderate usage conditions are considered.

Another thing everyone is forgetting about, the elephant in the room, is the economic beneift of reducing the billion dollar daily foreign oil spend.

Charles Murray
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Re: EV's ARE cleaner than Hybrids
Charles Murray   11/16/2012 4:18:43 PM
For those who want to learn more about GREET and see where the numbers came from, Professor Michalek sent the following:
  1. See this link for a summary of the GREET model. Well-to-wheels includes well-to-pump and pump-to-wheels. We include these estimates using GREET (GREET 1 Series) as well as the vehicle cycle (GREET 2 Series) that describes emissions associated with manufacturing the vehicles. We also included other higher-resolution data from eGRID about the location and emissions-intensity of power plant emissions.
  2. See this link for a GREET report on well-to-wheels analysis of plug-in vehicles. Note in the first figure (Figure ES.1) that even when we ignore manufacturing emissions, Argonne concludes that BEVs emit more GHGs in the operation phase than HEVs on today's average grid mix. When we include the emissions associated with manufacturing the battery pack, HEVs look better relative to BEVs. 

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Read the main source document for more info
JSNiles   11/16/2012 3:55:59 PM
There are more graphics beyond the one here in the original paper at http://www.pnas.org/content/early/2011/09/19/1104473108.full.pdf .  How the electricity is generated that recharges the batteries is very important in the life-cycle assessment.

Charles Murray
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Re: EV's ARE cleaner than Hybrids
Charles Murray   11/16/2012 3:15:00 PM
Thanks for your comment, cmdred. You are absolutely correct about the value of the GREET models, which is why Michalek and his colleagues used the GREET numbers (among others) in their studies. You are also correct that there is a "well to wheels" model, which is essentially a fuel model involving drawing the oil out of the ground, shipping it, processing it, taking it to the pump, delivering it to a vehicle and then burning it in the engine. That, however, is only one of the sets of GREET numbers that the researchers used. They also employed GREET numbers associated with the manufacturing of the vehicle and its parts, which gives them a better handle on the full life cycle of the vehicle. It's also worth noting that the team presented their findings at Argonne National Labs, where Michalek said he "received no disagreement." Finally, it should be said that the team's work was indeed peer-reviewed. Their 2011 paper was published by the National Academy of Sciences, a non-profit organization that advises the nation on science, engineering and medicine. So, yes, I agree that our readers should check out the GREET numbers. Or they can read Profesor Michalek's paper by clicking on the link in our story.

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Re: Makes total sense
shrimper53   11/16/2012 1:40:53 PM
The example of the hybrid is precisely an example of how technologies evolve, progress,and reach a level of acceptance and use based upon it's practicality, efficiency, and cost effectiveness.  No one including this author suggests "killing a technology in its infancy"; we need to foster and promote those approaches that work in the context of current infrastructure, supply and storage technologies, etc.... while at the same time, working towards improvements and advances that move the ball down the road.   Nothing in science or technology is static, nor should it be.  Subsidies of new technologies have their place; it is however important to know and recognize when you have a Solydra and avoid the massive waste of precious tax dollars with little to nothing to contribute to advancing the science.  

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EV's ARE cleaner than Hybrids
cmdred   11/16/2012 1:33:51 PM
Guys, I suggest checking out the Argonne National Laboratory site on this subject, which has been doing these evaluations for years.  They even have a free program you can use to do the trades yourself; it is called GREET, and you can download it for free. 

GREET does "well to wheels" analysis of energy consumption, efficiency, manufacturing losses, transportation costs, and even includes the makeup of the electric power grid and assesses various pollutants.

In all the analyses I've seen and run myself BEV's (battery electric vehicles) outperform all other vehicles in emissions, efficiency, and just about every other measure.  Even on pure coal fired electric grids the carbon output is lower than with hybrids.  The particulates and sulfur output is much higher for pure coal based power grids.  But most grids have more in the mix; and more and more power stations are moving to natural gas, which is much cleaner than coal.  Out here in california we have an even cleaner grid which uses nuclear, solar, wind, gas, and coal.

Even including the battery manufacture (which is still significant for hybrids) BEV's far outrank hybrids.  Hybrids both burn gas and use batteries.  EV's don't burn gas at all.

I urge you to check out the GREET model and run the numbers yourself.

As a driver of a Toyota RAV4 EV for the past 6 years, and the proud owner of a new Ford Focus EV I can tell you; its the best driving experience I've ever had; especially once you get over the range management (which is a psychological adjustment more than anything unless you really drive more than 40 miles a day) which took me about a month; and I've had Porsches and Volvos, Nissans and Toyotas in my day.  My monthly electric cost is about 1/4 of what the gasoline would cost, and frankly the lease deal on the new Focus (at $250/month!) makes the car practically free. 

Check out the GREET model and studies that have been done with it.  I'm not sure where this guy got his data but I am suspicious.  I'll have to check it out

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Re: Definitely time for biofuel
rainmaking   11/16/2012 1:22:25 PM

Sorry but I have to take some issue on that tract. Unfortunately any biomass that is consumed as a fuel still removes terrestrial carbon and puts it in the atmosphere. Industry advocates love to talk carbon neutrality and such but it just isn't so.

NH3 on the other hand is a carbon free fuel that can burn in engines with virtually no emissions (N2+H20 plus tiny NOx--less than fossil-fired counterparts). This is a viable alternative you can learn more about at http://nh3fuelassociation.org/

However, I still fully believe in BEV's for daily personal use. Especially considering we ARE cleaning up our electricity supply with more natural gas and renewables.

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