The End of Fossilized Transportation
The SUV is in its heyday, and highway speed limits are back up to 1970s levels. It’s not an easy time for energy-efficiency advocates to effect social or policy change. But David Friedman ’92 (ME) has a turbocharged plan to free the United States from oil-dependent transportation, and he isn’t about to let fashion or status quo stop him.
As research director of the Union of Concerned Scientists’ Clean Vehicles Program, David Friedman delivers his message to Congress, industry leaders, and the public: The nation can turn the tide on global warming and a costly reliance on foreign oil. But time is running short.
The United States, says Friedman, already pays a high price for its oil-dependent autos and trucks, in both dollars and pollutants, for starters. Petroleum products comprised nearly one-quarter of the U.S. trade deficit in 2004, costing $250,000 a minute—a price that’s already doubled this year. Forty percent of this demand originates with cars and trucks.
While Americans dig deep to pay escalating petroleum prices, our vehicles cough up gasoline’s byproducts. One of those emissions, carbon dioxide, alters the blanket of gases in the earth’s atmosphere, trapping in the sun’s heat. The concentration of carbon dioxide in the atmosphere, Friedman notes, now hovers near 400 parts per million. “It will shoot to 450 ppm within three decades,” he says, “if we keep going the way we are. And if that happens, global average temperatures will rise more than two degrees centigrade by 2100, leading to significant negative effects on public health and the economy.”
But it doesn’t have to be that way. Friedman has mapped out a three-part plan to slow global warming and dramatically reduce the need for foreign oil.
First, he advises that we pump up vehicles’ fuel efficiency to 40 mpg from today’s paltry 24 mpg. Conventional but underutilized automotive technology would accomplish this without sacrificing vehicle size or power. We also should boost hybrid electric vehicle sales via government incentives and tighter standards. Those two moves would reduce greenhouse gases and level the rate of oil importation, buying the precious time required to realize hydrogen fuel cell technology. “We could decarbonize our energy systems within the next 50 to 60 years,” he says. “It just takes commitment, effort, and some investment.”
Friedman’s vision for a carbonless future is rooted in years of research that began at WPI. “I wanted to do my MQP on wind power,” he recalls. “But my mentor, Professor John Boyd [now professor emeritus, ME], suggested I research hydrogen. That project has guided my work ever since.” So, too, has WPI’s teaching philosophy. “WPI encouraged me to examine the impact of engineering on society.”
Friedman applied those lessons first at Arthur D. Little, where he researched hybrid and fuel-cell vehicles. Then, as a student at the University of California–Davis’ Institute of Transportation Studies, he helped convert a Ford Taurus into a 60-mpg electric hybrid.
While at UC–Davis, Friedman met Jason Mark, director of the UCS Clean Vehicles Program. “The decision to join UCS was easy. I love engineering, but if that’s all I do, I get bored. At UCS, I get to use my communications skills and still do research. It’s a great blend.”
Friedman communicates vigorously with Congress and industry that a 40-mpg conventional vehicle fleet would sacrifice neither performance nor safety and would save consumers money at the gas pump. But many lawmakers and automakers remain reluctant to effect change. “The government hasn’t stepped up to the plate with better fuel efficiency standards,” says Friedman. “And U.S. auto manufacturers often shelve technologies they could be using to improve fuel economy.”
Honda and other foreign manufacturers, meanwhile, have begun incorporating such innovations as lower-friction engines and variable valve technology into their models.
International automakers have also gotten a jump on hybrid electric vehicles, which have attracted U.S. consumer interest. Since 1999, when the Honda Insight arrived in this country, more than 200,000 hybrids have been sold. Toyota alone has sold nearly 143,000 Prius hybrids since 2000. The company has increased U.S. production to 100,000 units for 2005, but the wait list continues to grow. Ford, meanwhile, has introduced one hybrid model at a rate well below that of consumer demand. GM has announced plans for hybrid production, but not starting until 2007.
Hybrids are appealing because they require far fewer stops at increasingly pricey gas pumps—every 500 to 600 miles versus every 350 to 450 miles with conventional vehicles. “Also, hybrids’ acceleration is great on the highway,” says Friedman, “and especially in town.”
Hybrids also further fuel cell technology, as their manufacture relies on electrical innovations that fuel cell vehicles also need, such as high-voltage motors and power electronics. The hybrid uses an electric motor and battery in partnership with an internal combustion engine. The motor recoups energy in stop-and-go traffic through regenerative braking and idles off the engine at stoplights to save fuel. “As a result,” Friedman says, “a fleet of hybrid cars and trucks could average over 50 miles per gallon.”
“If we are to move forward responsibly as a society, we need to invest now in a variety of solutions ranging from near-term efficiency to long-term renewable energy.”
Hydrogen: It’s elemental
But with their engines still tied partially to petroleum, hybrids can take the nation only so far down the road to oil-independence, which is why Friedman’s ultimate goal is the fuel cell– powered vehicle, run by cleanly produced hydrogen.
Fuel cell–driven cars and trucks could run two to three times more efficiently than today’s average vehicles and produce zero harmful emissions. Their efficiency comes from hydrogen fuel cells that convert hydrogen directly into useable energy through electrochemistry, unlike internal combustion engines that must first convert gasoline’s chemical energy to thermal energy and then to mechanical power.
The fuel cell itself works by supplying hydrogen to the anode side, where a catalyst—typically platinum—separates it into electrons and protons (hydrogen ions). These ions pass through a filtering membrane and, again helped by the catalyst, mix with electrons and air-supplied oxygen on the cathode end, producing water. The electrons had to travel to the cathode through an external wire, since they cannot pass through the membrane. As they zip through the wire, they provide the electricity to power the motor.
Hydrogen is the fuel of choice for these engineering marvels because this simplest-known element—consisting of one proton and one electron—allows for simplicity in the components needed to get the fuel cell system to work.
Although hydrogen fuel cells are used today—by the U.S. space shuttle program, for example—the technology “has a way to go before it becomes commercially viable for autos,” says Friedman.
Hydrogen harvesting, for example, presents a challenge. Since it occurs only in conjunction with other elements, such as oxygen in water, hydrogen must be isolated before it can be used as fuel.
Nearly all hydrogen is produced today by “steam reforming” natural gas. In this high-temperature process—up to 1,470°F—natural gas reacts with steam and a catalyst, forming a hydrogen- rich gas. Oil refineries use this well-developed technology to alter crude oil’s chemical structure and produce gasoline.
“Natural gas is a finite resource, and not without its own heat-trapping carbon dioxide emissions,” says Friedman. “But steam reforming still gives us a good transition technology.”
Transition to wind and water, that is—a duo promising the cleanest hydrogen harvest. Wind-generated electricity, which Friedman notes “is quickly becoming a viable and economical source of commercial electricity,” can split water into hydrogen and oxygen.
“I see huge promise in fuel cells and hydrogen made from renewable energy sources, but this is not a silver bullet. If we are to move forward responsibly as a society, we need to invest now in a variety of solutions ranging from near-term efficiency to long-term renewable energy. Then we can have energy security, clean air, more jobs—everything we need to thrive.”email@example.com
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Last modified: Aug 25, 2005, 13:39 EDT