Thursday, September 16, 2010
X Prize: Electric Vehicles-Two, Biofuel Vehicles-One
The $10 million dollar X Prize was split between two electric car designs and a design that runs on biofuel (E85) called the Edison 2.
In the above video the Edison 2 is hyped by the guy who bankrolled it. He tells us the main reason the wheels stick out is to enhance crash safety. Actually, they stick out for stability and aerodynamic reasons as they did for the defunct Aptera and the popular Cessna 172 aircraft. To be more accurate, they are hoping the wheels will also act as a kind of bumper, unless the car striking you from the side happens to land between the wheels.
When you cut through the hype, there isn't really anything new about the Edison 2. Take a deep breath and ask any mechanical engineer worth her salt, "If allowed to compromise crash safety, acceleration, payload, and cost (a low-weight body costs more than a steel body), and if you bolted a modified single piston turbo charged motorcycle engine running on a high octane fuel using exhaust gas recirculation to reduce pumping losses to a very light aerodynamic body, would you get great gas mileage?"
Her answer would have been, "Duh?!"
The marketability of a car having these compromises has always been the only unknown, and remains unknown. And because the Edison 2 can't run on regular gas, you would be stuck looking for gas stations that sell E85 (assuming you could buy one of these cars today).
Every story written about this prize tells you that the Edison 2 gets 102 MPGe (although most laypersons have no idea what that means). Robert Rapier took the time to look at the formula for calculating MPGe and realized that the Edison 2 would only get 73 miles on a gallon of E85 (73 MPG). Confused? Well, I don't really blame you. You can download a spreadsheet to verify Rapier's epiphany "here".
To put this in perspective, an ordinary Prius gets 50 MPG running on E10, and it's a five-passenger, mid-sized hatchback, with power windows and air bags all over the place. And unlike the Edison 2 (assuming you could buy one of these cars today), which is not capable of running on regular gas, you would not be stuck looking for gas stations that sell E85.
Corn ethanol can't ever provide more than about 10% of our fuel. If it were all converted into E85, about one in ten gas stations could carry it. But the vast majority of available ethanol is blended into our gas already at much lower percentages, so in reality, only a fraction of a percent of gas stations will ever sell E85 (an 85 percent blend).
This is not a flex fuel car. It is a car optimized to run on a fuel that is not readily available (E85), which is kinda dumb for more than one reason, and it would actually get worse mileage if modified to run on gasoline. I am a big fan of smallish, lightweight, aerodynamically clean cars like the Edison 2 but would never buy one because of the fuel it burns.
If I had a choice, I would not use a fuel that exacerbates the negative ramifications of agriculture (corn ethanol). Few people understand the scale and scope of the damage being wrought by our global need to provide ourselves with food, fiber, and housing (agriculture). Adding fuel to that demand is just not very smart.
Had the MPGe formula taken into account the EROEI (energy returned on energy invested) of the fuel it uses, the Edison 2 would likely have been eliminated at the get go.
Put an electric drive train in it and I may reconsider, even with the additional cost and more limited range.
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