The Tesla Model S, as with all electric vehicles, has zero tailpipe emissions. We all know that, since there is no tailpipe, but what about emissions related to power production and battery manufacturing?
On the other hand, there are other emissions that we readily admit electric vehicles as having, such as the carbon dioxide and other environmentally harmful emissions involved in the production of the electricity that the Tesla Model S uses.
For example, according to Tesla Motors’ own calculator, carbon dioxide emissions are all over the chart, from a mere 26g/mi [grams per mile] of carbon dioxide in Idaho to an astonishing 310g/mi in West Virginia.
Even my own calculations have borne this out, and the reasoning is simple. Idaho is 79.6% hydro powered. Vermont is even better with a 73.6% wind power and 20.4% hydro power mix. West Virginia is the worst, by far, 96% coal powered. Depending where you live and what you drive, you could be better off simply switching to a more fuel-efficient vehicle, like the Toyota Matrix or Scion iQ.
An obvious opponent of Tesla Motors says to short sell stocks before they plunge, which just hasn’t happened yet, but goes on to attack efficiency claims by Tesla Motors regarding vehicle efficiency and charger efficiency. Author Nathan Weiss claims that inefficiencies add another 55% to Tesla Motors’ low-ball carbon dioxide estimates. David Noland of Green Car Reports suggests that Weiss’ assumptions are way off-base, such as Weiss’ use of lithium-ion battery production carbon dioxide estimates.
Weiss claims battery production emissions add another 39% to the Tesla Model S carbon footprint, but cites a study that is fairly well debunked online. Even so, there is a footprint here, though not as large as Weiss asserts. Tesla Motors’ batteries are actually constructed by the assembly of commodity Panasonic 18650 lithium-ion cells, which are possibly the most efficiently produced if you consider the economics of scale. A study in 2010 by American Chemical Society puts lithium-ion carbon dioxide emissions at 15%, a number corroborated by a 2012 study done by the California Air Resources Board [CARB].
All in all, Weiss’ article on Seeking Alpha, after a small adjustment, puts Tesla Model S carbon dioxide emissions at 346g/mi which is a little more than a Toyota Highlander. Weiss’ previous estimate of 547g/mi was more akin to the Jeep Grand Cherokee V8. If even the same author can change his opinion based on varying sets of data, then who is to say that all of this data and extrapolation isn’t a complete speculation?
Also, let’s not forget to include petroleum extraction and refining, which adds another 25% to the operational carbon footprint of a conventional vehicle, which would boost a Toyota Highlander’s carbon dioxide generation to 390g/mi.
What gets me is that Weiss wasn’t bothered to calculate the carbon dioxide emissions related to petroleum refining for conventional vehicles. For example, every oil refinery and even every petroleum extraction station has a flare, basically a blow-off valve that burns off excess gases. What do you get when you burn off excess gases during extraction and refining of petroleum but carbon dioxide and other emissions? If the known quantity of carbon dioxide emissions is adding 25% to conventional vehicles’ carbon footprint, then what about the unknown quantity?
Research done by the US Environmental Protection Agency admits that they have no idea how much excess petroleum is simply burned off. For example, it is estimated that Bakken Formation shale oil natural gas extraction operations burn off about 330,000 barrels of natural gas daily or about ⅓ of gross yield. Petroleum flares are similar, which doesn’t paint a pretty picture of emissions related simply to the extraction and purification of petroleum for use in vehicles.
What we need is an actual scientific explanation for all of this. Leave out the politics and include all the relevant data if you’re going to compare vehicles. Hopefully we can get more people to take an objective look, as according to Nolan’s calculations, driving his Tesla Model S in New York has about the same lifecycle emissions as a Scion iQ. Not bad!