Take This Car and PLUG IT Eager Hybrid Owners Can’T Wait to Connect Their Cars to the Power Grid

CHARGING: Makers of the hybrid-electric cars that are on the road today call them “grid independent,” but making them chargeable from the grid could enormously boost their gasoline fuel efficiency. S

Take This Car And PLUG IT Eager hybrid owners can’t wait to connect their cars to the power grid

A funny thing has happened on what University, in Cambridge, Mass.— W U.S. policy makers thought was going to who have made tinkering with hybrids be the high road to a hydrogen economy. their primary extracurricular activity. Initiatives aimed at putting hydrogen Now, a derivative of hybrids that fuel cell–powered cars on the road by will improve fuel economy even more 2020—visualized by President George by maximizing the use of the electric W. Bush in his 2003 State of the Union motor is poised to make what is already address as the centerpiece of his plans an undeniably attractive concept to wean the country from fossil fuels— downright irresistible. Some of the most are taking longer than promised. At the eager owners of the Prius, the world’s time of the speech, hybrid-electric cars, most popular hybrid, have been hacking which offer higher fuel efficiency than the cars, swapping their 1.3-kilowatthour regular cars because of electric motors battery packs for bigger ones with that help drive the wheels, were seen in capacities as large as 9 kWh.

E the United States as but a minor detour The modifications also include the or way station en route to a world of addition of plugs so the new, bigger hydrogen fuel cells. battery packs can be recharged from But they suddenly are looking like wall outlets. The resulting machines, the main way to go, or even maybe the referred to as plug-in hybrids, can be ultimate destination. Models produced propelled exclusively by their electric by companies such as Toyota Motor motors for, in some cases, more than Corp., in Toyota City, Japan, and 30 kilometers without their gasoline Honda Motor Co., in Tokyo, are flying engines ever turning on. The factory- out of dealer showrooms. Among those built Prius can run on electricity only, who have been able to purchase hybrids but for just a kilometer or two. (usually after a two- to six-month This group of hackers and other wait) are some early adopters—like a technologists say that in a few years, we

group of physics professors at Harvard could have a car that, after its batteries CHRISTIE BRYAN

10 IEEE Spectrum | July 2005 | NA N plug-ins could lead to dramati- cally lower gasoline consumption and oil imports. Because of that promise, a strange-bedfellow alliance of environmentalists and security hawks has emerged. They are united by a conviction that the hybrid—not the futuristic fuel cell-driven hydrogen vehicle favored by the Bush administration in its FreedomCar program and other initiatives—is the way to cut both noxious emissions and oil dependence right now. In a manifesto issued last fall in the form of a letter to the U.S. public and then again last March as an open letter to President Bush, a group representing foreign policy intellectuals and advocates of clean energy called for the “technological transfor- mation of the transportation sector through what might be called ‘fuel choice.’” The group are topped up overnight via a supports increased reliance on wall socket, could handle a daily alternative fuels that are domes- commute using only electrons tically produced, such as gasohol for fuel—unlike the hybrids on and biomass, and on cars such as the market now, which still plug-in hybrids that can draw derive all their power from gaso- energy from the grid. line [see box, “Stretching the “The United States should Hybrid’s Electric Capabilities,” implement technologies that ex- and illustration, “Charging”]. ist today and are ready for wide- Dramatizing the potential of spread use,” the group said in its the plug-in during the Tour de core statement, “Set America Sol race from 13 to 16 May in Free.” In effect, the report pits a Schenectady and Albany, N.Y., a group that includes influential modified Prius equipped with a Republicans against a Republican fully charged 9-kWh lithium-ion president on the question of battery pack achieved 2.31 liters whether the country should con- High-Tech Fabergé per 100 km (102 miles per gallon) tinue to spend several hundred on a 240-km course. It is million dollars a year to promote PALO ALTO, CALIF., is recognized as the birthplace of Silicon representative of the modified far-off hydrogen vehicles when it Valley, but until now it lacked a public landmark commemorating hybrids that clean-car promoters could do more today to accelerate its fame. An effort to change that began in 2000 when the and hobbyists have been build- adoption of hybrid-electric and town’s art commission asked multimedia artist Adriana Varella ing, partly for fun, partly to alternative-fuel vehicles. to propose a project. She designed a giant egg, a Styrofoam show how wide adoption of sculpture covered in discarded circuit boards, only to see the BOLD IN ITS VISION, the “Set final product—obviously symbolizing birth—go up in flames America Free” report asserted in a warehouse fire. Undeterred, Varella selected about Researchers have that a plug-in hybrid with a 600 more circuit boards and distributed them to engineers, shown that battery 100-km-range battery could cut academics, and even a few homeless people, asking that each fuel consumption by 85 percent write a phrase about circuits on a board, which she then packs offering an and that conventional cars could collected and used to rebuild the sculpture. On 6 May, the effective electric be converted to run on alterna- 2.13-meter-tall sculpture was installed in Lytton Plaza, range of 32 km will tive fuels with the addition of a brick-paved public space abutting Palo Alto’s main commercial yield up to a control chips and fuel-line mod- street, University Avenue. It was to be formally unveiled a 50 PERCENT ifications costing less than month later, but after just two days a group of teens began to TEKLA S. PERRY S. TEKLA US $100. Combining advanced tear off the wrappings, bringing its gestation to a premature REDUCTION IN plug-in and flexible-fuel fea- end. Varella didn’t mind. "It was just curiosity," she says, PETROLEUM tures could ultimately yield a which of course is what she wants. — TEKLA S. PERRY CONSUMPTION vehicle capable of going 100 km

July 2005 | IEEE Spectrum | NA 11 STRETCHING THE HYBRID’S ELECTRIC CAPABILITIES

Conventional U.S.-market Prius The motor and battery pack in the Toyota Prius deliver bursts of power to the wheels, so that the gasoline engine operates in its most efficient revolution-per- minute range. The 30-kilowatt motor can accelerate the car from a dead stop to about 65 kilometers per hour. At that point the engine kicks in (if it hasn’t done so already) to keep the motor from running faster than 6000 r/min and to prevent the 1.3kilowatthour nickel-metal hydride battery pack from going below a state of 40 percent charged. Even if a driver put- Hacked U.S. Prius with Plug-in Capability ters along at 40 km/h or slower, the car’s Instead of having the motor mainly deliver peak Thebattery pack can be charged directly from an computerized control system will activate power to complement the gasoline engine, the ordinary wall socket, with inverters rectifying the the engine before this threshold is aim is to get as much distance as possible from ac current. The vehicle’s control system is modi- reached. When running, the engine shunts the electric drive train without the engine’s kick- fied to prevent the transfer of propulsion from 30 percent of its torque back to the ing in. To keep the motor going for more than motor to engine at the usual speed. But with this vehicle’s 15-kW generator, which keeps 30 km rather than just the 1 or 2 km of the con- tinkering come compromises: in its all-electric the battery pack topped up. Regenerative ventional Prius, the hacked versions [like the mode, when the motor and battery pack are doing braking captures additional energy that Tour de Sol model, above] boast battery packs the heavy lifting, the control system will not let otherwise would be lost as heat. with storage capacities on the order of 9 kWh. the vehicle reach highway speeds. on a mere 0.47 liter of gasoline signers of the report are hoping hydrogen economy cannot be and smog precursors by (500 mi/gal), the report claimed. that its points about hybrids realized for at least a couple of 15 percent. Their gains in fuel The environmentalists and and alternative fuels will make decades, a supposition that efficiency are even more security-minded luminaries it into the final version. emerges clearly from recent impressive: the Prius gets behind the report, such as “There’s very little doubt in my reports by organizations such 4.7 L/100 km (50 mi/gal) on Frank Gaffney, a senior defense mind that these sorts of steps as the National Academy of highways, compared with the official in Ronald Reagan’s will be taken at some point,” Sciences, in Washington, D.C., top-selling Toyota Camry’s administration, and R. James says Gaffney, founder and and the American Physical 7.1 L/100 km (33 mi/gal), and Woolsey, the hawkish director president of the Center for Society, based in College Park, does better yet in stop-and-go of the U.S. Central Intelligence Security Policy in Washington, Md. Until basic scientific traffic, when the battery powers Agency during President Bill D.C. “The question is [do we breakthroughs occur, the the car more of the time. Clinton’s first administration, take them] after we have reports concluded, the hydro- But make that car a plug-in, urged Bush to commit $1 billion realized the very unpleasant gen vision will do nothing to with a battery big enough to over the next five years to the national security crisis that liberate the United States from keep the vehicle in its electric establishment of a domestic we’re forecasting, or do we do energy dependence or improve mode for all daily errands and alternative fuels industry. In it in advance of that.” prospects for bringing down commuting, and the potential addition, they said, the federal Gaffney referred to what the greenhouse gas emissions. fuel savings become truly government should implement report called a “perfect storm” The other assumption is prodigious. Researchers have tax credits and other incentives of circumstances requiring that that U.S. consumers will be shown that battery packs offer- “to encourage rapid production “we effect over the next four willing, even eager, to pay a ing an effective all-electric and consumer purchase of years a dramatic reduction in premium of a few thousand range of 32 km will yield up to advanced vehicles like hybrids, the quantities of oil imported dollars to get cars that are a 50 percent reduction in gaso- plug-in hybrids, and flexible- from unstable and hostile more fuel efficient and envi- line consumption. And the fuel vehicles” and to produce regions of the world.” Other ronmentally friendly. Sales of hope is that in a few years, “more efficient vehicles across report signers include a Reagan conventional hybrid-electric when advanced batteries like all models.” national security adviser and a cars jumped 81 percent in the lithium-ion become cheap Eyeing the draft compre- Clinton chief of staff. United States last year and are enough, there will be plug-ins hensive energy bill, which expected to double this year. with an effective electric range once again is wending its way THE “SET AMERICA FREE” REPORT These grid-independent approaching 100 km. through the U.S. Congress after is based on two well-founded (non-plug-in) hybrids cut car- At that point, says Mark S.

being stalled for two years, assumptions. One is that the bon emissions up to 25 percent Duvall, manager of technology TECHNOLOGY VALENCE

12 IEEE Spectrum | July 2005 | NA NEWS

European/Asian Prius metal hydride battery packs With air pollution a strong factor in Asia and have become significantly Europe, the Prius version sold in those markets cheaper since Toyota began allows the driver to shut off the engine and run just producing the car for the on electricity, though the car is not a plug-in. The Japanese market in late 1997— electric-only capability is desirable when creeping power densities have gone up, along in the central districts of cities where internal allowing the car to get the combustion engines same acceleration with a smaller have been banned or battery pack. But energy strictly limited at cer- density hasn’t really improved, tain times. (Milan, so energy storage remains as Italy, recently ordered expensive as ever. cars, motorcycles, and On this point, CalCars’ trucks off the roads Gremban simply disagrees. He on alternate days, and claims that achieving higher other cities, including power densities is much more London, have also taken steps to curtail auto- expensive than maximizing motive traffic in their business districts.) energy storage, and he observes Press a button [above], and the Prius runs just on that with larger battery packs its battery at speeds less than 55 km/h for 1 or 2 km. storing much more energy, The electric-only setting is not locked in, however. At the higher power densities any speed greater than 55 km/h or with aggressive are not needed. Accordingly, acceleration, the vehicle’s control system will over- production-volume nickel- ride the driver’s selection and start the engine. metal hydride batteries might The button exists in U.S. models but is not con- cost car companies only on the nected to the car’s control system. order of $500/kWh—much closer to the $300/kWh price target, cited by EPRI’s Duvall, development for transportation larger battery packs is so high But the individuals and that will make it practical for a at the utility-sponsored Toyota could never make a groups like the nonprofit car company to offer a vehicle Electric Power Research profit selling them at a price CalCars—the California Cars with a 100-km all-electric range. Institute (EPRI), in Palo Alto, consumers would be willing to Initiative, based in Palo Alto— In any case, plug-in devel- Calif., the car will run on pay. And that’s just one hurdle, that have installed bigger opment is already in gear. electricity most of the time. says the Toyota engineer. battery packs and modified Duvall reports that his organi- Such a vehicle will use only the electronics in the Prius zation and DaimlerChrysler 10 to 15 percent as much liquid HERMANCE POINTS OUT not only have done so to show that AG, of Stuttgart, Germany, fuel as a conventional vehicle. that one Prius-hacking tinkerer turning the car into a plug-in are currently testing four Duvall points out that paid $15 000 for his lithium-ion hybrid is realistic. Sprinter vans built at a there’s really not that much battery pack, but that the Ron Gremban, the lead Daimler facility in Mannheim, difference between the systems added batteries make the car technologist on CalCars’ Prius+ Germany. If all goes according in the conventional hybrid cars heavier—by 68 kilograms in the project, concedes that the to plan, those four vehicles made by Toyota and Honda, or case of lithium-ion and nearly group’s modified Prius does will be the first plug-ins to be in Ford’s hybrid SUV, and those twice that for lead-acid. Thus, not perform as well as it might tested on U.S. roads. that would be needed to build a the car’s fuel economy is actu- and costs more than it would if “The project has really de- plug-in hybrid. Yet the compa- ally worsened when the gaso- produced by Toyota. But “a veloped nicely,” says Duvall— nies have not made plug-ins line engine is running. And company with the resources of so much so that EPRI is negoti- available and evidently don’t there’s also the matter of hav- a Toyota, Honda, or General ating the final details of an plan to do so anytime soon. ing to replace the battery pack Motors could build a more alliance of utility and fleet

LEFT:TOYOTA; RIGHT:GUOQIANG/IMAGINECHINA JI To take Toyota, the leader more often during the lifetime elegant, full-function version customers to fund and test of the pack: “The corporation of the vehicle because cycling a for far less money,” he believes. another 30 prototype vehicles is committed to hybrid tech- battery from fully charged to How much less is the that will hit U.S. roads begin- nology, but so far [only for 20 percent charged wears out subject of debate. Toyota’s ning next year. Asked when hybrids that] are grid inde- even advanced batteries. Hermance insists that, barring we’ll see a Daimler plug-in in pendent,” according to David “So you have a higher a spectacular breakthrough in dealer showrooms, Duvall said, Hermance, executive engineer up-front cost, a heavier vehicle battery chemistry, the cost of “If [Daimler] makes a produc- at the Toyota Technical Center that gets less fuel economy with nickel-metal hydride batteries tion decision to make this USA Inc., in Torrance, Calif. less performance, and the pro- will remain around $1100/kWh vehicle, it would enter the mar- Why? Hermance says the an- spect of replacing the battery for the foreseeable future. He ket sometime in 2008 or 2009.” swer is simple: the cost of the during [the car’s] life,” he says. concedes that the Prius’s nickel- —WILLIE D. JONES

July 2005 | IEEE Spectrum | NA 13