Eyes on the Prize

IEEE Spectrum sits in on energy equivalence debates--with millions of dollars for a "100 mpg car" riding on the results

Editor’s Note: We’d hoped to get this story up on 4 April, the day the X Prize Foundation released its draft rules for the Auto X Prize. Unwisely, we even promised to do so in a blog entry by our automotive editor John Voelcker . But even John couldn’t get a peek at the draft rules until just two days beforehand, so he chose to write a more thorough piece—at the cost of breaking his promise. We hope you’ll think it’s worth the wait.

Photo: John Shore/Automotive X Prize

Debate over energy equivalency metrics among (from left) Gale Banks of Gale Banks Engineering, Ian Wright of Wrightspeed, IEEE Spectrum 's auto editor John Voelcker, Jeff Alson of the U.S. Environmental Protection Agency, and Fujio Takimoto of Subaru.

The windowless, fluorescent-lit conference room exists for a single purpose: to provide a dedicated venue in which people from all over the world can gather to listen, learn, and debate. Even in the nicest locales, the focus is on the subject, not the surroundings.

On 9 February, two dozen world experts filed into one such room in otherwise-sunny Pasadena, Calif. Organizers of the Automotive X Prize (AXP) held the full-day session to help them craft rules for an upcoming race among ultra-high-efficiency, low-emission vehicles. Every participant was passionate and opinionated, even with the knowledge that a ringer was sitting among them: IEEE Spectrum was privileged to be the only media invited to the working group.

The impetus for the session—and the Auto X Prize itself—is the growing awareness of climate change. How to spur radically reduced energy use and carbon dioxide emissions? Offer people money! At least, that’s the theory behind the multimillion-dollar Auto X Prize, the latest privately funded incentive to encourage technology innovation (in a variety of disciplines)—all courtesy of the X Prize Foundation. The prize will go to the team that creates a production-capable vehicle that wins a long-distance stage race while achieving the equivalent of at least 100 miles per gallon (2.35 liters/100 kilometers or less) and staying within strict emissions limits.

It’s not an impossible goal. Several years ago, Volkswagen built a so-called "1-liter" car, with the goal of using no more than 1 liter of fuel per 100 km (235 mpg). It was a two-seat tandem with a single cylinder diesel engine. Unfortunately, for most auto buyers, it would be roughly as practical as a motorcycle. The discontinued Volkswagen Lupo, a ”3-liter car” (78 mpg) for the European market, sold poorly in the late ’90s, in part because it was expensive (roughly US $17 000) for its size. So the X Prize crafted its rules to encourage designs that offer the same user experience as today’s cars—engineered for volume production (no all-titanium structures or hand-built bodies)—with four times the efficiency.

But the devil is in the details. Among them: How should the relative importance of reducing CO 2 emissions be weighed against lower overall energy consumption? How will energy usage be measured among vehicles powered by gasoline, regular or biodiesel, ethanol, methanol, natural gas…and electricity? Whose grid is used to measure the greenhouse gases (GHGs) produced by generating that electricity? Should life-cycle energy consumption play a role? And so on.

It seems a propitious time for a contest such as the Auto X Prize. For several years, Europe has taken an aggressive public policy role in reacting to climate change. But North America has long consumed the most energy per capita for personal transportation. Its auto industry remains the world’s largest, and average fuel economy is worse than the average in either Europe or Japan.

The issue of climate change is now intertwined with a desire in the United States for energy independence, and that has led to a focus on nonpetrochemical fuels. With a recent Supreme Court decision affirming that the U.S. Environmental Protection Agency can and should regulate CO 2 emissions, automakers are bracing for another round of regulations that will affect the performance, weight, and features in the cars they offer. In the wake of the court ruling, General Motors went so far as to suspend work on a new large rear-wheel-drive ”platform” destined primarily for North American markets. And the Bush administration recently proposed that average vehicle fuel economy rise roughly 4 percent per year—potentially a very costly rate of change to achieve.

The foundation released its draft rules on 4 April, at this year’s New York International Auto Show. Comments are being solicited from all interested parties, including Spectrum readers, through 31 May. But behind the 37-page draft document lay several months of intensive debate over the complex and challenging issues of energy equivalency.

With the 4 April deadline nearing, Mark Goodstein, AXP’s cheerfully energetic executive director, guided the February session with the assistance of two able moderators (confusingly, named Kristin and Cristin). Though bloodshed was averted, the discussions ranged from spirited to contentious. Members represented a range of institutions, from automakers (Honda, Subaru), research labs (Argonne National Laboratory), and government agencies (U.S. Environmental Protection Agency) to environmental advocacy groups (Natural Resources Defense Council, Pew Center on Global Climate Change), with engineering firms (Gale Banks Engineering, Wrightspeed) and industry specialists (Auto Research Center) thrown in to leaven the mix.

One of the thorniest points of discussion was the source of electric power used in pure-electric or plug-in hybrid-electric vehicles. Might not an all-electric car whose power was generated by old Midwestern power plants running on high-sulfur coal generate more greenhouse gases in the complete wells-to-wheels cycle than a highly efficient gasoline-electric hybrid, say? Much discussion ensued on the value of publicizing lower-impact power-generation sources, as well as locations where such cars might first be adopted. Since more electricity on the California grid comes from natural gas (and renewable sources), and less from coal—and since Hollywood stars already love the Prius—should the California grid be overweighted?

The answer was no. The draft rules base GHG emissions from electricity on the current national grid—with a commitment to an education program that publicizes the impact of cleaner electricity production on total wells-to-wheels emissions.

In the end, the organizers chose to measure upstream (wells-to-pump) GHG emissions using average default values that reflect fuel production today and in the near future. The formulas, developed by the U.S. Department of Energy and Argonne National Laboratory, are known as the GREET model, standing for Greenhouse Gases, Regulated Emissions, and Energy use in Transportation.

What about lifecycle emissions from such nontransportation activities as manufacturing and shipping? The AXP chose to require simply that production of any competing vehicle create no more GHG emissions than today’s typical production vehicles, based again on the DOE-Argonne model.

Another issue was how to make a downstream (or pump-to-wheels) energy-consumption metric that was easily grasped by the public at large. Goodstein and the rest of the AXP team were blunt about the overall prize goals: massive publicity, quick comprehension, and an easy way for the public at large to imagine such advanced vehicles meeting their everyday transportation needs.

The result adopted by the organizers is ”MPG Equivalent” (MPGe), which calculates distance covered per unit of energy consumed. Both dynamometer testing (using the EPA fixed cycle) and real-world performance will be measured. At least two participants, Axel Friedrich of Germany’s federal environmental protection agency and power train engineer Gale Banks, argued that the chosen level—100 mpg—was too extreme to have a practical impact. Why not, say, double the current average of 20 to 30 mpg? After all, the EPA’s Jeff Alson pointed out, the savings aren’t proportional: raising fleet economy from 20 to 60 mpg gets 83 percent of the carbon savings of 100 mpg. But in the end, the rules as released stuck with 100 MPGe—an inspirational goal, if also a singularly challenging one to maintain in a four-seat vehicle.

Several panelists from the environmental side of the house expressed concerns over the propriety of a ”race” versus a straight competition on the numbers. Wouldn’t this prioritize speed over thrifty driving? Didn’t a race signify squealing tires and one-off cars rather than the sedan or minivan substitutes that the public could easily connect to? Answer: the organizers have always envisioned the race as a series of stages. The winning vehicle must now have the lowest overall time across all stages, in which weather, terrain, communities, and driving patterns would vary to simulate the variety of real-world uses to which North American vehicles are subjected.

To have a shot at the gold, however, all competitors must meet or exceed the threshold requirements: 100 MPGe, less than 200 grams per mile of GHG emissions, and compliance with the limits on criteria emissions (hydrocarbons, nitrogen oxides, carbon monoxide, and other substances) known as ”US EPA Tier II, bin 5” standards for sale in all 50 states.

In the end, the working group was knowledgeable, passionate, and respectfully civil. Now it’s up to the public at large. The organizers have already received well over 100 letters of intent to enter the contest. They hope to have a mix of known global brands (automakers, perhaps?), university teams, and maybe even a few teams of ”shade-tree mechanics” competing.

Meanwhile, you have roughly one month left to download, read, and comment on the draft rules. You can find them under ”Draft Guidelines” on the Auto X Prize site.

About the Author

JOHN VOELCKER has written about automotive technology and other topics for 20 years. He covered software and microprocessor design for IEEE Spectrum from 1985 to 1990.

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