DRIVING THE SOLUTION THE PLUG-IN HYBRID VEHICLE by Lucy Sanna The Story in Brief As automakers gear up to satisfy a growing market for fuel-efficient hybrid electric vehicles, the next- generation hybrid is already cruis- ing city streets, and it can literally run on empty. The plug-in hybrid charges directly from the electricity grid, but unlike its electric vehicle brethren, it sports a liquid fuel tank for unlimited driving range. The technology is here, the electricity infrastructure is in place, and the plug-in hybrid offers a key to replacing foreign oil with domestic resources for energy indepen- dence, reduced CO2 emissions, and lower fuel costs. DRIVING THE SOLUTION THE PLUG-IN HYBRID VEHICLE by Lucy Sanna n November 2005, the first few proto­ vide a variety of battery options tailored 2004, more than half of which came from Itype plug­in hybrid electric vehicles to specific applications—vehicles that can imports. (PHEVs) will roll onto the streets of New run 20, 30, or even more electric miles.” With growing global demand, particu­ York City, Kansas City, and Los Angeles Until recently, however, even those larly from China and India, the price of a to demonstrate plug­in hybrid technology automakers engaged in conventional barrel of oil is climbing at an unprece­ in varied environments. Like hybrid vehi­ hybrid technology have been reluctant to dented rate. The added cost and vulnera­ cles on the market today, the plug­in embrace the PHEV, despite growing rec­ bility of relying on a strategic energy hybrid uses battery power to supplement ognition of the vehicle’s potential. A chief resource from an unstable part of the the power of its internal combustion concern is the prospectively higher cost of world continues to threaten national secu­ engine. But while the conventional hybrid the larger batteries required. Indeed, rity. Add to that the environmental con­ derives all of its propulsion energy from because the advanced batteries needed for cerns surrounding global warming: petro­ gasoline, the PHEV gains much of its PHEVs are currently produced on a lim­ leum combustion accounts for about 40% energy from the electricity grid. ited scale, prototype PHEVs are costly, of all U.S. CO2 emissions. Taken together, What does this mean for the consumer? but once batteries go into mass produc­ these three significant issues—fuel cost, At current U.S. energy prices—that is, tion, costs are expected to come down. national security, and the environment— with the cost of gasoline at $3 per gallon According to Robert Graham, manager gained momentum in September 2004 and the national average cost of electricity of EPRI’s Electric Transportation Pro­ when an unusual alliance of U.S. environ­ at 8.5¢ per kilowatthour—a PHEV runs gram, “We have the basic technology for mentalists and security hawks, the Set on an equivalent of 75¢ per gallon. And the PHEV—the electric drive system and America Free coalition, called on the Bush given that half the cars on U.S. roads are advanced batteries—and we have the in­ administration to cut U.S. oil consump­ driven 25 miles a day or less, a plug­in frastructure—home recharging. Our main tion in half over the next four years. with even a 20­mile­range battery could challenge is to optimize the design of The concern is not new. Anyone over reduce petroleum fuel consumption by the batteries and the integrated battery­ the age of 35 today will remember the so­ about 60%. engine control systems that will allow us called Arab Oil Embargo of 1973, which The PHEV combines the best of both to take full advantage of the superior fuel created a worldwide oil shortage. Six years electric vehicle and hybrid technologies. savings and emissions reduction potential later, the Iranian revolution underscored Like the electric vehicle, the PHEV is of this vehicle.” global energy vulnerability. Before the fueled by electricity generated from domes­ But is there a market? In a 2001 study, decade was out, world leaders and energy tic resources: it reduces carbon dioxide EPRI found that 30–50% of consumers experts alike sought ways to reduce oil (CO2) and urban pollutants, provides surveyed would choose a PHEV even if consumption. Energy conservation became utilities with a new, sustainable market it were priced up to 25% higher than a the watchword, and efficiency played a for off­peak electricity, and offers con­ $19,000 conventionally powered vehicle. major role in reducing overall energy use. sumers a clean, low­cost transportation What’s more, 63% of respondents pre­ Auto manufacturers developed smaller, fuel option. And like the hybrid, the ferred plugging in a vehicle at home to more­efficient vehicles, appliance manu­ PHEV can run on liquid fuel for unlim­ going to the gas station. At the time of facturers developed energy­efficient prod­ ited driving range. This combination that survey, the U.S. national average ucts, and utilities reduced the use of oil makes the PHEV more efficient in fuel price of gasoline at the pump was pro­ for generating electricity; in the United and total energy use than any vehicle of jected to be $1.65. Since then, the price States alone, oil used for electricity de­ comparable size and performance on the has nearly doubled. This ongoing trend creased from nearly 17% in 1973 to less road today. makes all types of hybrids—and espe­ than 3% today. Dr. Fritz Kalhammer, who beginning cially the PHEV—increasingly attractive. In recent years, however, auto manufac­ in 1973 established and directed EPRI’s Today, in fact, the market for fuel­effi­ turers have increased the power and size of programs for energy storage, fuel cells, cient vehicles has begun to escalate along cars and sports utility vehicles, thereby and electric vehicles, has advocated a shift with the price of oil. increasing oil dependence. Today because in focus to PHEVs for more than five two­thirds of all U.S. oil consumed goes years. “The PHEV is unique,” he states. Oil at a Boiling Point into cars, trucks, and buses, the focus in “It offers the optimal mix of power from Though the United States holds only 3% energy conservation is on transportation. the battery and the engine—of energy of global petroleum, Americans consume from the grid and the gas station—to con­ 25% of the world’s oil supply. According What’s Driving the Market? sumers with varying transportation needs. to the U.S. Department of Energy, that The internal combustion engine (ICE) is Auto manufacturers can eventually pro­ was 20.5 million barrels of oil per day in designed to start quickly and provide 10 EPRI JOURNAL power as soon as the driver demands it. “in urban driving, that idling translates EV1 served as a benchmark for electric But until the engine warms up, it runs to about 10–15% of total vehicle carbon vehicle technology development, but be­ quite inefficiently. It also idles at every emissions.” cause of its limited utility and driving stop, and according to Mark Duvall, One clean solution is the electric vehi­ range, it met with limited acceptance. manager of technology development for cle. In 1996, GM boldly entered the elec­ Early adopters—mostly environmental­ EPRI’s Electric Transportation Program, tric vehicle marketplace with its EV1. The ists ready to trade urban pollutants for a clean and quiet if limited ride—were gen­ erally enthusiastic about their EV1 expe­ U.S. Oil Consumption rience, but they didn’t constitute a large 20 enough consumer base to make the vehi­ cle profitable within the few years that it was available. 16 This being said, hundreds of electric Transportation oil use vehicles such as the Toyota RAV4, manu­ 12 factured for several years under Califor­ nia’s zero­emission mandate, continue to operate in communities such as Los Ange­ 8 les; and a variety of electric vehicles of Domestic production limited range and performance are now Million Barrels Per Day of Oil 4 successfully serving such niche markets as airports, retirement communities, city governments, and golf courses. These 0 1970 1980 1990 2000 2010 2020 2030 limited applications, however, cannot solve the problems of strategic vulnerabil­ ity and trade imbalance caused by depen­ While U.S. domestic production of oil has decreased 44% since the 1970s, the use dence on imported oil. of oil for transportation has increased 83%, and the gap is widening. Given a The hybrid electric vehicle is a move in continuation of this pattern, U.S. oil consumption is expected to grow 60% over the right direction. Its battery/electric the next 25 years, with consequential increases in transportation fuel costs, carbon emissions, and security vulnerability. (Source: Energy Information Administration) motor combination provides the quick starts, so when the vehicle is standing still, the gas engine can be shut off auto­ American Driving Patterns matically to prevent idling and conserve 100 fuel. In fact, the hybrid can achieve an increase in fuel efficiency of roughly 30%. 90 The battery also boosts the performance 80 of the ICE at takeoff and for passing. 70 The hybrid’s ICE uses fuel available 60 from any gas station, and the battery charges whenever the ICE is running. 50 The battery also charges when the driver 40 brakes to stop; in a process called regen­ 30 erative braking, the electric motor be­ comes a generator and converts otherwise 20 wasted kinetic energy into electricity. 10 Cumulative Percent of Personal Automobiles Hybrids are not designed to operate on 0 electricity alone, but if they run out of 0 30 60 90 120 150 >180 gas, most can go a short distance with Average Daily Travel Distance Per Vehicle (miles) extremely limited performance.