Industry Market Trends

The Damage Done -- Electric Vehicles, the Green Way to Get Around?

Apr 03, 2012

Electric vehicles (EVs) are often touted as the environmentally friendly way forward for automobile transportation. But the thinking person has to wonder whether they are ultimately any cleaner than conventional gasoline and diesel vehicles.

EVs run on electricity, and if electricity in the U.S. and globally comes primarily from coal, don't electricity-powered vehicles bear the environmental stigma of that dirtiest of all energy sources? Obviously, that could change if electrical generation morphs from coal in the near term, to gas and nuclear in the medium term, to renewables in the longer term.

For previous articles in this "Damage Done" series, I've examined the environmental effects of petroleum fuels (gasoline and diesel), natural gas, and biofuels. Let's take a look now at the importance of EVs in transportation and their environmental impacts.

Electric Vehicles in the Big Energy Picture

Chevrolet VoltHow significant are EVs likely to become in the overall energy picture?

Actually, not very, if the U.S. Energy Information Administration (EIA) is to be believed. Even by 2030, according to EIA data projections, electricity in the U.S. will only be supplying 0.1 quadrillion Btus of transportation energy. That's compared to 29.7 quadrillion Btus for liquids, a ratio of, ahem, 297 to 1. I wanted to show you a pie chart, but at that puny proportion, I couldn't generate a pie chart that electricity would even show up on.

(Photo: Chevrolet Volt. Credit:, CC BY-ND 2.0.)

Globally, the EIA expects liquid fuels to dwarf electricity for transportation. By 2020, the agency expects electricity consumption for transportation worldwide to only reach 1.2 quadrillion Btus, compared to 114.6 quadrillion Btus for liquids, a ratio of 96 to 1.

A report from cleantech research firm Pike Research forecasts 2012 global EV sales to exceed 257,000 units, led by the Asia-Pacific region with 112,586 units sold, followed by North America (66,233), then Western Europe (61,169). Other research from Pikeprojects that "the annual market for hybrid electric [HE] and plug-in electric vehicles [PEV] will grow to 2.9 million vehicles by 2017," with a cumulative number of 13.9 electrified vehicles in the market.

EVs and the Environment

Charging an EVFor this "Damage Done" series, I have often referred to a study by the National Academy of Sciences (NAS), titled Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use. This is a useful study, as it covers all major sources of energy and evaluates their external environmental effects (externalities), often in ways that allow you to compare one energy source to the others.

(Photo: Charging a PHEV, Portland, Oregon. Credit: Parker Michael Knight, CC BY 2.0.)

In discussing the environmental ramifications of EVs, the NAS points out that the manufacturing processes for the vehicles are energy- and material-intensive and generate waste streams. However, this would really be the case for any kind of vehicle, so to compare the energy-related externalities between electric and gasoline vehicles, you would think the manufacturing side would be a wash. Nevertheless, the NAS finds that electric vehicles actually use more energy in their manufacturing and will continue to do so through 2035, as you can see in this table:

2035 Energy Use During Vehicle Manufacturing, Light-Duty Vehicles, gigaJoules per vehicle

(Source: NAS data)





Plug-In Hybrid (PHEV)


The NAS attributes the greater energy use to the manufacture of EV batteries.

Aside from the effects of manufacturing, the report's authors identify externalities from the actual use of EVs in two areas: emissions and battery disposal. Regarding pollution and emissions, they write:

Potential reductions in urban emissions and exposures (a positive externality) from the use of HEVs [hybrid electric vehicles] and PHEVs [plug-in hybrid electric vehicles] and the potential increases in emissions from grid electricity are expected... the gradual expansion of the use of these technologies will result in emissions being representative of the average grid emissions (rather than the peak)...

And about battery recycling and disposal:

With substantially increased use of batteries containing unusual metals, a key question will be where battery recycling and disposal will take place. In the United States and under U.S. regulatory requirements, improper emissions and worker exposures will probably be minimized (although at a minimum, there is a need for a review of current requirements to ensure their adequacy). If any significant portion of this activity takes place in the developing world, however, past experience suggests that there could be significant exposures of workers and even populations.

Necessarily, the NAS says, "The analysis of damages attributable to the operation of different electric technologies is highly dependent on the assumptions made about the energy mix and emissions from the electric utility system." Realistically, fossil fuels will continue to dominate U.S. electrical power production in the short- and medium-term. EIA data indicate that coal and natural gas generation will only decrease from 70 percent of generation in 2005 to 66 percent in 2035. At those percentages, environmental damages from EVs would actually be higher than those from gasoline vehicles. For EV damages to equal those of gasoline, fossil-fuel generation would have to drop to 37 percent of generation.

The following chart shows the NAS estimates of current health and non-GHG damages from EV technologies compared with damages from conventional gasoline vehicles:

Technology Full-Life-Cycle Mean 2005 Health and Other Non-GHG Damages ($/VMT, vehicle mile traveled) Mean Damages for Vehicle Operation Only ($/VMT)
Conventional Gas Vehicle



Grid-Independent HEV



Grid-Dependent HEV






Under the hood of the Nissan LeafWhen you consider the full energy life cycle, the grid-independent hybrid technology (such as the Toyota Prius) comes in with the lowest damages per vehicle mile traveled (VMT) in the comparison. Grid-dependent EVs (i.e., plug-in hybrids such as the Chevrolet Volt) and all-electric vehicles (such as the Nissan Leaf) rack up higher damages, because you're including the full-life-cycle damages from electricity generation. (Photo: Nissan Leaf. Credit: Tom Raftery, CC BY-SA 2.0.)

When you consider vehicle operation only, pure-electric EVs come in with the lowest damages. However, if you really want to understand the environmental externalities of the production and consumption of energy, I don't see great value in looking only at vehicle operation -- you've got to have a line-of-sight back to the electricity that was generated to run the vehicle.

What about the environmental effects of EV batteries? In a 2010 article published in Environmental Science & Technology, researcher Dominic Notter and colleagues did a life cycle assessment of one type of lithium-ion battery typically used in newer EVs. Notter uses assessment methods that take into account the product's global-warming potential (GWP), energy demand, resource depletion, atmospheric emissions, and toxic effects on human health and ecosystems.

Notter's article includes a detailed description of the manufacturing processes that go into producing a battery:

The main finding of this study is that the impact of a Li-ion battery used in BEVs [battery electric vehicles] for transport service is relatively small. In contrast, it is the operation phase that remains the dominant contributor to the environmental burden caused by transport service as long as the electricity for the BEV is not produced by renewable hydropower. This finding is in good accordance with other studies showing that the impact of operation dominates in transport service... In these studies, infrastructure, maintenance, and service have minor shares of the environmental impact imposed by transport services.

So, even Notter's results circle back to the same basic concern about electric vehicles: The environmental damage of the vehicle technology itself is not as great a concern as the source of the energy the vehicle consumes.

EV chargin stationThe first set of articles in this "Damage Done" series focused on the environmental effects of electrical generation. My article The Damage Done, Part 10 - Are Renewables Really Better for the Environment Than Fossil Fuels? gave an apples-to-apples comparison of both "green" and conventional sources of electrical generation -- coal, natural gas, nuclear, hydro, wind, solar, and geothermal. My analysis showed that, whether you considered carbon footprint or non-GHG effects, renewable energy causes less environmental damage.(Photo: EV Charging Station, Oregon. Credit: Oregon Department of Transportation, CC BY 2.0.)

Consider the following table, based on the NEEDS study (New Energy Externalities Developments for Sustainability, Project no. 502687, "External costs from emerging electricity generation technologies," March 24, 2009):

Quantifiable External Costs From Electricity Generation Technologies in Year-2000 Euro-cents () per kWh
Technology Health Impacts Biodiversity Crop Yield Losses Material Damage Land Use Total Non-Climate Cost
Coal - Lignite














Natural Gas Combined Cycle














Offshore Wind







Solar PV







Concentrating Solar







As you can see, nuclear power and all of the renewables perform better than coal for these non-GHG damages. All of the renewables also outperform natural gas, except for solar photovoltaic power because of its health impacts.

The following chart is based on an article in Energy Policy by Benjamin J. Sovacool. The chart tabulates GHG emissions for various sources of electrical power, expressing carbon footprint as carbon dioxide (CO2) equivalents per kilowatt hour (kWh):

Source/Technology Lifecycle CO2 Equivalents (gCO2eq/kWh)
Coal 960 to 1,050
Natural gas 443
Nuclear 66
Geothermal 38
Solar Photovoltaic (PV) 32
Hydroelectric 10 to 13
Wind 9

In this case, nuclear and all of the renewables undeniably beat out the fossil fuels when it comes to climate impact.

So, from all that I can tell, any future environmental benefits of electric vehicles will depend on the expansion of nuclear and renewable electrical generation.

Are EVs Feasible in Some Markets?

A world in which the greater volume of electrical power comes from renewables seems far off, given current trends.

But that might not be the case in some individual markets. For example, Germany plans to invest 200 billion euros in offshore wind farms "that will cover an area six times the size of New York City," according to Bloomberg News, in a bid to increase its renewables generation from 20 percent in 2011 to 35 percent in 2020. Bloomberg's Stefan Nicola comments: "Not since the allies leveled Germany in World War II has Europe's biggest economy undertaken a reconstruction of its energy market on this scale."

Various states in the U.S. have enacted renewable portfolio standards (RPS) that require power producers to generate certain percentages of electricity from renewable sources by specific dates. For example, California's RPS program "requires investor-owned utilities, electric service providers, and community choice aggregators to increase procurement from eligible renewable energy resources to 33% of total procurement by 2020," according to the state's overview of the program.

Efforts by particular governments, then -- whether nations, states, provinces, or other authorities -- might be able to establish micro-markets under which electric vehicles could gain an environmental edge over conventional gasoline vehicles.