Studies on Auto Emissions Favor Electric Vehicles

I know not everyone studies the well-to-wheels comparisons of fuel sources for transportation, and that there are people who harbor grave misunderstanding in the area.  Here, frequent commenter Glenn Doty writes:

With our current grid, nearly 100% of the energy used to power EV’s will be coal. That means that a Nissan Leaf will cause more than twice the emissions/mile as a Toyota Prius, and that’s only the marginal emissions. Once the initial capital emissions are considered, it will be significantly worse still.

In no way would EV’s be better for the environment than HEV’s – which are far less expensive.

EV’s will universally do far greater harm than ICEV’s if you compare similar size vehicles. So why are they being pushed as “green”?

All I can say in response is to request that he – and others who have similar beliefs – read one of the numerous studies on auto emissions that has been done recently on the subject, like this one by Sherry Boschert showing just the opposite.

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6 comments on “Studies on Auto Emissions Favor Electric Vehicles
  1. Mihai Grumazescu says:

    The problem is we got used to carry too much about other people’s business. Why don’t we simply let auto makers to focus on car emissions and efficiency and cost and let energy providers carry about power plants’ emissions, efficiency and energy cost? Let everyone do their job responsively and professionally. For more than 100 years auto makers were not concerned about how oil is extracted, refined and distributed while oil industry didn’t interfere into the auto industry.
    Over-thinking about the overall picture or well-to-wheel in this case, will paralyze any effort to build EVs and renewable sources of energy. This is what politicians love for not taking any action.

  2. Glenn Doty says:


    I have read Sherry Boschert’s study. I have read several DOE studies on the same issue, and I have looked through the data carefully. These studies share a basic flaw in their analysis: They assume that a “grid mix” of energy should be credited for a new marginal electric demand load (such as an EV).

    That is incorrect. The power companies are currently utilizing their available nuclear, hydro, wind, geothermal, and solar energy generation. There is no spare capacity for them to ramp up when new demand comes online (except in wind power, but curtailed wind power exists in remote rural areas of the wind belt, in which very few people will accept range-restricted EV’s).

    An easy way to think about it is to ask yourself what would happen in a grid if the EV were to stop being plugged in. Would the power companies respond by curtailing wind? Would they respond by withdrawing the rods from a nuclear reactor? Would they start spilling water over the dam?

    No. They would tamp back on their fossil fuel generation.

    This is because while the base grid has a “grid mix” that goes into a known mixture of sources for the electron impulses traveling through the grid… the reaction to new energy demand is very specifically known. There is no spare capacity in hydro, nuclear, biomass, geothermal, or solar. There is some spare capacity in wind, but that is regional and highly variable. In all of these cases, power companies cannot respond to a new marginal increase in demand by increasing energy production from these sources.

    The only spare capacity that is available is fossil fuel power, so that spare capacity is the only possible source that a power company can use to react to a new marginal increase in demand. If that demand increase were predictable, and were to occur nightly for many hours on a constant basis, there is no power company in the world which would choose natural gas over coal (remember these are the only choices with spare capacity).

    Currently, coal is suffering from a market dynamic which revolves around the fact that most coal plants have to tamp down their generators at night. This dramatically reduces the profitability of coal power. They would much rather leave the coal at a constant power production, but they have to tamp back enough so that there is not overgeneration, and they must leave enough dispatchable power online (natural gas, hydro) to accommodate demand fluctuation.

    But the prospect of hundreds of MWh of new, constant multi-hour demand would rectify this situation, as it would allow a high enough steady nighttime load that the coal companies would become far more profitable again. They would certainly choose to keep their coal plants burning at a steady capacity rather than tamping them down so that they could then use natural gas to fulfill the stable EV electricity demand.

    The idea that this will be fixed with new renewable power is also flawed. If you put solar panels on your roof, and sell that power to the grid, you are directly reducing the amount of fossil energy that is needed, or you are directly offsetting some fossil power (mostly natural gas). If you then plug your car in at night, the power companies would respond by tamping down their coal plants a little less each night – assuring that the balance of new energy demand represented by your car is met by coal. If you use home-based battery systems to store energy from your solar panels, and use that energy to power your car, then your solar cells cease their previous good work of reducing natural gas power production, so the balance of energy demand represented by your car is now met by an increase in the generation from natural gas plants (plus storage cycling losses).

    To put another way: After considering line loss and battery charging losses, ~120,000 EV’s would require ~1TWh/yr of energy from the grid. Let’s assume a hypothetical 100 TWh/yr local grid that has a grid mix similar to the U.S. average:

    43 TWh of coal, 23 TWh natural gas, 20 TWh nuclear, 8.2 TWh hydro, 3.2 TWh wind, 1.5 TWh biomass, 1 TWh of petroleum, 0.1 TWh solar.

    Then we’ll add 120,000 EV’s, all plugging in overnight, every night:
    44 TWh of coal, 23 TWh natural gas, 20 TWh nuclear, 8.2 TWh hydro, 3.2 TWh wind, 1.5 TWh biomass, 1 TWh of petroleum, 0.1 TWh solar.

    Anyone claiming that those 120,000 EV’s are using only 44% coal might be technically correct… because electron impulses cannot be individually controlled within the lines – they mix freely. But the grid increased its generation from coal by 1 TWh when the additional 1 TWh of demand from EV’s were plugged in.

    Any analysis that uses a “grid mix” to determine the environmental impact of a large marginal increase in electricity demand is deeply flawed to such an extent that it can be called completely baseless. Sherry Boschert’s analysis is simply wrong.

    Returning to our hypothetical grid, in 10 years we’ll see a rapid penetration of renewables. Let’s say in 10 years it’s 110TWh/year:
    40 TWh of coal, 30 TWh of natural gas, 18 TWh of nuclear, 9 TWh of hydro, 9 TWh of wind, 2 TWh of biomass, and 2 TWh of solar.

    Now if we have those same 120,000 EV’s on the grid, at that time, and all 120,000 EV’s are suddenly removed – not plugging in overnight… Then we have a reduction in grid use of 1 TWh, and our grid mix looks like this:
    39 TWh of coal, 30 TWh of natural gas, 18 TWh of nuclear, 9 TWh of hydro, 9 TWh of wind, 2 TWh of biomass, and 2 TWh of solar.

    So as you can see, the introduction of new renewable energy into the “grid mix” does nothing to change the fact that the EV’s marginal power needs are based on fossil fuels – especially coal.

    I know this is a long post. But I hope that you consider this carefully. The power companies will utilize every bit of renewable energy that they can regardless of whether EV’s are plugged in or not, which means that the only power that will be ramped up to provide the needed power for EV’s must be fossil sourced.

  3. Glenn Doty says:


    These are good points, although I believe you are overestimating the “waste” of coal ramping in most of the country (outside of the wind belt), as the gradual tamp-down/ramp-up cycle that coal power experiences nightly can be effectively balanced by pumped hydrostorage and gate fluctuation in hydropower dams… except in the vast plains state where neither hydrostorage nor hydropower have any viability.

    There are some countries in the world that genuinely do have excess (spare) carbon-neutral capacity. But these countries typically share grids with other countries. So France is producing plenty of excess carbon-neutral electricity, but it’s selling that to Germany. If it uses that carbon-neutral electricity to power its vehicles, then Germany must ramp up their fossil power in order to make up for the losses, so the only actual savings on energy are the line losses, and otherwise the effects still largely are a matter of an increase in coal energy generation equal to the energy requirements of the electric vehicles that are plugged in.

    The same is true of the Pacific Northwest, if Seattle starts plugging in thousands of EV’s, that reduces the amount of carbon-neutral electricity that can be transmitted to California, which would be forced to make up the deficit by importing more coal power from Nevada and Idaho.

    I’m not bringing this up to be a contrarion, I’m stating it because there is a fundamental oversight in the review of the environmental impact of electric cars which has led to policy that is not “green”. An EV would be quite “green” and quite helpful to the grid if it was connected to a smartgrid control with a rapid charge station in the Midwest… but the subsidies are not region specific, nor are the smartgrid controls or rapid-charge capability required in order to receive full funding for the vehicle itself – though without those additional installations the vehicle itself is far more polluting than a similar sized ICE vehicle.

    The policy must be more properly informed by actual environmental needs and impacts, or else we’re all just spending money without achieving any benefit… or at least without achieving a cost effective benefit.

    I see no reason to fear the impact of EV’s on our business model. There are practical limitations to the scale-up of EV’s, and there are practical limitations to the vehicle size that could be accomodated with EV’s. There should still be sufficient global demand for clean, carbon-neutral liquid fuels to allow our business to grow geometrically for decades even if all small vehicle demand was displaced by EV’s the world over. That is not the point of my concern. I was an environmentalist long before WindFuels were ever dreamed of, and I believe our current policy will cause more environmental damage… not less. This should be addressed by our advocacy.

    Thank you for considering my analysis, thank you for recognizing the potential benefit of WindFuels, and thank you again for being a constant advocate for the economic and environmental benefit that may be achieved through smart investment in greentech.

    • Craig Shields says:

      Thanks, Glenn. Interesting stuff; I’ll circulate this to some people who study this more closely.

      I look forward to meeting you sometime. I feel I’ve made fine friends in your parents; they’re both terrific people.

  4. Glenn Doty says:


    I certainly look forward to meeting you. My father speaks of you with respect, which is a mark of distinction in itself. Both he and mom seem to genuinely enjoy your company and friendship.

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