2013 Tesla Model SEnlarge Photo
Does the supposedly clean, green Tesla Model S really pollute more than a gas-guzzling Jeep Grand Cherokee sport-utility vehicle?
That's what one analyst has claimed.
In an exhaustive 6,500-word article on the financial website Seeking Alpha, analyst Nathan Weiss lays out a case that the Model S actually has higher effective emissions than most large SUVs of both the greenhouse gas carbon dioxide and smog-producing pollutants like sulfur dioxide.
As a 2013 Tesla Model S owner, I was shocked and concerned by his claims.
Although carbon emissions were not a big factor in my decision to buy a plug-in car--I was more interested in performance, style, and low operating cost--the car's green cred was a nice bonus.
Now here's this Weiss guy, calling me a global-warming villain.
But I couldn't help but notice that in his role as financial analyst, Weiss had been advising his clients to "short" the stock of Tesla Motors [NSDQ:TSLA]--to bet against it. (Tesla stock price down = happy clients; Tesla stock up = very unhappy clients.)
And is it a coincidence that the article appeared the same day Tesla stock skyrocketed 30 percent, after Tesla's first-quarter earning report? (It's since risen another 30 percent.)
Weiss's motives aside, his claims deserve a close look on their merits.
Not only the tailpipe
Like all 100-percent electric cars, the Model S indisputably has zero tailpipe emissions.
But Weiss looks at emissions from the powerplants that supply the Tesla's electric "fuel," as well as the excess electricity consumed by the Model S due to charging inefficiencies and "vampire" losses.
These two factors, he concludes, give the Model S effective carbon emissions roughly equal to those of a Honda Accord.
Throw in the carbon emitted during production of the Model S's 85-kWh lithium-ion battery, says Weiss, and the Model S ends up in Ford Expedition territory.
Not so fast....
Although Weiss makes a number of valid points, I see several flaws in his argument. And he bases his carbon-footprint estimates of battery production on a single report that is far out of sync with previous research on the subject.
Furthermore, he fails to account for the carbon emissions resulting from the production of gasoline. If the carbon footprint of a Tesla's fuel counts against it, why shouldn't a standard car's fuel be subject to similar accounting?
So let's go through his analysis and his conclusions point by point.
*Power plant emissions count against electric cars
Virtually all electric car advocate agree that when toting up the environmental pros and cons of electric cars, it's only fair to include powerplant emissions.
When this has been done previously, the numbers have still favored electric cars. The Union of Concerned Scientists, for example, concluded in a 2012 report, "Electric vehicles charged on the power grid have lower global warming emissions than the average gasoline-based vehicle sold today."
The carbon-friendliness of the electric grid, of course, varies wildly from region to region, depending upon the type of powerplants there.