Electric drive vehicles have little impact on US pollutant emissions, study finds

Jan 21, 2014 by Matt Shipman
Toyota Prius plug-in hybrid car is shown on display at the 2012 Detroit Auto Show. The US auto industry remains unsold over the future of "green cars" such as electrics and hybrids, as carmakers struggle with the first steps in a market most agree shows promise over the long term.

(Phys.org) —A new study from North Carolina State University indicates that even a sharp increase in the use of electric drive passenger vehicles (EDVs) by 2050 would not significantly reduce emissions of high-profile air pollutants carbon dioxide, sulfur dioxide or nitrogen oxides.

"EDVs" is a catch-all term that includes hybrid, plug-in hybrid and battery electric vehicles.

"We wanted to see how important EDVs may be over the next 40 years in terms of their ability to reduce ," says Dr. Joseph DeCarolis, an assistant professor of civil, construction and environmental engineering at NC State and senior author of a paper on the new model. "We found that increasing the use of EDVs is not an effective way to produce large emissions reductions."

The researchers ran 108 different scenarios in a powerful energy systems model to determine the impact of EDV use on emissions between now and 2050. They found that, even if EDVs made up 42 percent of passenger vehicles in the U.S., there would be little or no reduction in the emission of key .

"There are a number of reasons for this," DeCarolis says. "In part, it's because some of the benefits of EDVs are wiped out by higher emissions from power plants. Another factor is that passenger vehicles make up a relatively small share of total emissions, limiting the potential impact of EDVs in the first place. For example, passenger vehicles make up only 20 percent of .

"From a policy standpoint, this study tells us that it makes more sense to set emissions reductions goals, rather than promoting specific vehicle technologies with the idea that they'll solve the problem on their own."

The energy systems model also showed that key factors in encouraging use of EDVs are oil price and battery cost. If batteries are cheap and oil is expensive, EDVs become more attractive to consumers. "That's consistent with results from other studies," DeCarolis says.

The paper, "How Much Do Electric Drive Vehicles Matter to Future U.S. Emissions?," is published online in Environmental Science & Technology. Lead author of the paper is Samaneh Babaee, a Ph.D. student at NC State. The paper was co-authored by Dr. Ajay Nagpure, a former postdoctoral researcher at NC State who is now at the University of Minnesota. The research was supported by National Science Foundation grant CBET-0853766.

Explore further: EU cuts CO2 emissions for vans by 28%

More information: "How Much Do Electric Drive Vehicles Matter to Future U.S. Emissions?" Published: online January 2014 in Environmental Science & Technology pubs.acs.org/doi/abs/10.1021/es4045677

Abstract
Hybrid, plug-in hybrid, and battery electric vehicles—known collectively as electric drive vehicles (EDVs)—may represent a clean and affordable option to meet growing U.S. light duty vehicle (LDV) demand. The goal of this study is twofold: identify the conditions under which EDVs achieve high LDV market penetration in the U.S. and quantify the associated change in CO2, SO2, and NOX emissions through mid-century. We employ the Integrated MARKAL-EFOM System (TIMES), a bottom-up energy system model, along with a U.S. dataset developed for this analysis. To characterize EDV deployment through 2050, varying assumptions related to crude oil and natural gas prices, a CO2 policy, a federal renewable portfolio standard, and vehicle battery cost were combined to form 108 different scenarios. Across these scenarios, oil prices and battery cost have the biggest effect on EDV deployment. The model results do not demonstrate a clear and consistent trend towards lower system-wide emissions as EDV deployment increases. In addition to the tradeoff between lower tailpipe and higher electric sector emissions associated with plug-in vehicles, the scenarios produce system-wide emissions effects that often mask the effect of EDV deployment.

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User comments : 12

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aksdad
5 / 5 (5) Jan 21, 2014
Interesting statement: "...it makes more sense to set emissions reductions goals, rather than promoting specific vehicle technologies..."

I suppose that's true if you average emissions across the entire country, however the problems are concentrated in a relatively few densely populated urban areas. When a high pressure system (inversion) traps pollutants (smog) on the ground, vehicular emissions cause most of the respiratory problems in those cities. Power plants are typically located far from urban areas.

FYI, nitrous oxide emissions and sulfur dioxide emissions have decreased steadily since 1980 as the EPA has documented here:

http://www.epa.go...gen.html
http://www.epa.go...fur.html

Most of the country is in compliance with regulations most of the time except some dense urban areas that are geographically constricted by hills or mountains during inversions. I'm not sure increased regulations will solve their problems.
AeroSR71
5 / 5 (4) Jan 21, 2014
It still makes sense to go fully electric as the efficiency is much higher, and thus the cost is much lower in the long-term. You're much better off losing 12% of your energy to the environment (excluding manufacturing, materials, transport, etc.) than losing 70% as is the case in ICE vehicles today!! It's like paying 100$ to fill your tank, but only 30$ of it is going to useful energy.
Skepticus_Rex
1 / 5 (2) Jan 22, 2014
Has anybody ever done a study on the amount of ozone that is generated by electric drive motors in electric vehicles? Somebody may also want to quantify the effects on ground level ozone by an increase of EDV deployment of 45%.
antialias_physorg
5 / 5 (4) Jan 22, 2014
In part, it's because some of the benefits of EDVs are wiped out by higher emissions from power plants

If you insist on producing the needed power via coal/oil/gas...Duh. EVs, however, give you the chance to switch over your power infrastructure to other modes of energy production. If you don't use that opportunity then you're missing out on the biggest boon that EVs can give you.

In any case - even if you insist on powering EVs with coal powerplants - you're moving pollution out of places where vehicles are concentrated (e.g. city centers). I.e. you're increasing air quality where it is currently the worst at the cost of decreasing it in places where it (potentially) doesn't matter as much.

EnricM
not rated yet Jan 22, 2014


In any case - even if you insist on powering EVs with coal powerplants - you're moving pollution out of places where vehicles are concentrated (e.g. city centers). I.e. you're increasing air quality where it is currently the worst at the cost of decreasing it in places where it (potentially) doesn't matter as much



If we recall (here in the UE at least) this was actually the whole point of the EV development before AGW came into play. Here in Europe we also have huge problems with pollution in urban areas which does cause an important impact on our healthcare budget. Germany for example has taken measures that may be seen as draconian by some such as limiting the areas were certain types of vehicles can ride (vehicles with high emissions are banned from certain urban areas). I have however no idea what the benefits are of this program (I live in Holland).
antialias_physorg
5 / 5 (3) Jan 22, 2014
Here in Europe we also have huge problems with pollution in urban areas which does cause an important impact on our healthcare budget.

The problem is augmented because we (Europe) don't have much in the way of unused land (so no real space to site powerplants away from population centers)

I have however no idea what the benefits are of this program

It's so and so. A problem is that about two thirds of communities don't perform any check on whether people stick to the rules. And also basically almost any vehicle gets the sticker.
Particulate matter has dropped in cities by only one percent. However, ultrafine particles - which are extremely toxic because you can't cough them up - and 'black carbon' (mainly from diesel engines) has been reduced by 30 percent.
It's an encouraging first step - but no substitute for going full EV.
Eikka
3 / 5 (1) Jan 22, 2014
If you insist on producing the needed power via coal/oil/gas...Duh. EVs, however, give you the chance to switch over your power infrastructure to other modes of energy production. If you don't use that opportunity then you're missing out on the biggest boon that EVs can give you.


In the mean while, while you don't have a pollution-free infrastructure, using electric vehicles doesn't make sense because they're more resource-intensive to make and more expensive overall. It's just throwing money in the wind.

As I've been saying many times, you need the clean energy first. Just building electric cars doesn't bring it about, because vehicles are such a small part of the whole energy sector problem. When you actually have clean energy, switching over to electric vehicles happens automatically if it's going to happen at all.

I still hold it more likely that we skip EVs completely for fuel cell vehicles running on synthetic hydrocarbons because it's easier to transition to.

antialias_physorg
5 / 5 (2) Jan 22, 2014
In the mean while, while you don't have a pollution-free infrastructure, using electric vehicles doesn't make sense because they're more resource-intensive to make and more expensive overall

You're playing chicken and egg here. You have to create a demand (EVs - which will lead users to demand that the energy for their EVs be produced in a clean way) in order to force a changeover. The changeover isn't going to happen by itself. No company is going to switch over to clean energy production until they are forced to (by demand or by law). They have their current powerplants already built and see no reason to invest in new ones just to replace an already cash-generating infrastructure.
kochevnik
not rated yet Jan 22, 2014
Anyone next to electric vehicle smells cleaner air. Stupid article
Howhot
not rated yet Jan 22, 2014
From the Article;
the benefits of EDVs are wiped out by higher emissions from power plants.

Well duuuhhhh. The whole point of an EDV is to push the energy source to the grid. If the local grid is powered by coal that isn't going to help. However the grid usually has several sources, blended and borrowed from each other, including some renewable's.

Currently renewables are about 14% of the US total grid energy. Coal in contrast is nearly 44%. If that is changed around, EDV are fantastic for the environment. Given gas prices, its also very affordable to go Electric Vehicle if your a commuter for less than 100 miles a day. I've seen big payoffs to EV owners that commute with EVs in the day and plug in at night. The trade off being expensive oil for nasty coal.

If enough people went EV, there is tipping point where the energy grid will need renewal and economies would favor renewables over fossil fuels and that isn't very far away.

Benni
not rated yet Jan 26, 2014
The only reason anyone should own a fully electric powered vehicle is its reduced maintenance cost.

If it turns out there is less manufacturing cost for producing EV's over combustion engines, then that is probably the only plus there is, so far it looks as if there is only a slight edge for EV's in that department & the best way to gauge this is by the weight of the vehicle versus power output, then comparing that to manufacturing costs.
Newbeak
not rated yet Jan 26, 2014
The only reason anyone should own a fully electric powered vehicle is its reduced maintenance cost.

No,there's also the saving in fuel costs,depending on local electric rates,and that warm,fuzzy feeling you aren't polluting when you drive.The biggest bottleneck to widespread adoption is lack of a reasonably priced battery.

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