Importance of Hybrid Cars - Essay Example

s Hybrid Cars - Research Paper The new millennium is bringing a millennial change to the family car. A few years back, concerns about pollution -- and nagging worries about global warming and oil shortages -- led to a trickle of electric cars powered by batteries. Because the batteries were heavy and expensive, the cars didn't drive far enough between recharges. Government incentives failed to move many cars from the showroom to the street (Beaton 1995, pp.991). But batteries are not the only way to power an electric car. In 2000, Honda and Toyota both started selling "hybrid" electric cars that evade those bothersome range limits. You never plug in these cars to recharge the battery -- you simply fill the gas tank. The Toyota Prius, a five passenger hybrid about the size of a Corolla, gets 52 miles per gallon around town and 45 on the highway. The smaller Honda Insight gets 70 miles per gallon overall, making it the highest-mileage car ever to hit the mass market -- ideal for today's soaring energy prices. Hybrid technology also works on a larger scale. In 1999, five hybrid busses ran up to 18 hours a day in New York City. The 40-foot busses used a diesel engine running at constant speed. The hefty batteries were used to accelerate and recover energy from braking. Hybrids combine the best of electricity and gasoline. Instead of recharging through a plug, the batteries get their juice from a small, light gasoline or diesel engine. When you hit the brakes, kinetic energy is converted into electricity, and then stored in the battery. At a stop light, the engine shuts down entirely. Because the battery is not the cars sole source of support, so to speak, it can be much smaller than the weighty, costly monsters used for battery-operated cars. Hybrids sound good -- they are, for example, exempt from the range limitations of battery-powered cars. But even hybrids could seem passed by 2004, when major auto makers promise to start selling cars powered by fuel cells. Fuel cells make electricity without burning anything. They don't even have moving parts. In the effort to cut auto pollution, hybrids and battery cars are a step forward, assuming anybody will buy them. But they're far from perfect: Hybrids burn gasoline, making air pollution. Batteries run down, and even though battery cars are called "zero emissions" vehicles, they generally just move the pollution rather than eliminate it (Lovins 1995, pp.73). On the horizon, however, is a car where "zero emissions" meets truth-in-advertising. Bye-bye catalytic converters and associated pollution-control gadgetry. In fact, it will be so long to pollution entirely. In fuel-cell cars running on hydrogen, the waste products amount to water and heat. The fuel cell, furthermore, is a new kind of engine -- one without moving parts! Even if fuel cells burn alcohol or gasoline, they will be far more efficient than today's internal combustion engines, and will produce less carbon dioxide, the primary culprit in global warming. Fuel cells have been producing power since the start of the space age. But bulky, expensive and relatively weak, the cells seemed unlikely to find a place under the hood of Detroit's finest. Then, in the 1980s, Canadian engineer Geoffrey Ballard began tinkering with fuel cells in search of a cleaner way to move people and goods. Among the several possible varieties, Ballard selected the proton-exchange membrane, a technology that operates at low temperature and starts up quickly; making it suitable for a machine that would replace the Buick Road Master (Polokovic 2000, p.A1). Like batteries, fuel cells make electricity from chemical reactions. But while batteries have a limited supply of chemical energy, fuel cells get chemical energy from the fuel, so they drive until the tank runs dry. Like a battery, a fuel cell has a cathode, with a positive charge, and an anode, with a negative charge. The cell uses a catalyst -- often platinum -- to dissociate some electrons from atoms. These liberated electrons become the electric current that leaves the cell to do useful work. In Ballard cells, the anode and cathode are separated by a polymer membrane that acts as an electrolyte -- a substance that allows electrons to flow. As hydrogen enters the anode, it is broken into protons and electrons by the catalyst. The liberated electrons flow as a current through the external circuit to electric motors powering the wheels. The protons pass through the membrane to the cathode and combine with oxygen from air and electrons returning from the external circuit. If hydrogen is the fuel, the waste products are simply water and heat. When Ballard began, only bulky cells could produce a reasonable amount of power, so he began imprinting tiny channels on the membranes, allowing the fuel to move through thin cells that could be pan caked into a stack hefty enough to power a bus. Ballard's inventions dramatically raised the power density -- the amount of power available from a given volume of cells. As power density rose, Ballard began testing cells in various vehicles (Koppel 1999, pp.14). By the late 1990s, Ballard was attracting attention from the big wheels in the auto biz: Daimler Benz (now DaimlerChrysler) started testing cells in its cars and wound up buying part of Ballard. In 1999, Daimler claimed that the New Electric Car 4, a compact Mercedes, would go 90 miles per hour and get almost 280 miles on a tank of liquid hydrogen (not counting stops for traffic tickets...). The liquid hydrogen fuel was stored in a large thermos in the trunk; the fuel cells were stashed beneath the floor. While Daimler and Ford Motor Co. plan to sell fuel-cell cars in the 2004 model year, fuel cells don't need to go anywhere to be helpful: Several manufacturers are building stationary fuel cell stacks to power homes and businesses. In these stacks, the waste heat could warm water or air, increasing overall efficiency. As fuel cells approach the market, a key decision concerns fuel. Most of today's cells oxidize hydrogen, which is a clear winner in environmental terms, since the oxidation process produces H2O, AKA water. However, carbon-bearing fuels, including gasoline and methane, also contain lots of hydrogen. In August, 2000, General Motors and ExxonMobil, eager to maintain its future market announced a technology to extract hydrogen from gasoline (Jones 2000, pp.C1). Despite the environmental drawback -- the cell would produce the greenhouse gas carbon dioxide -- the gasoline supply is in place, while a new infrastructure would be needed to supply hydrogen. Ultimately, the best solution, from an environmental point of view, would involve finding a way to generate hydrogen from renewable energy. Toward that end, Iceland, which has the highest per-capita oil imports, is talking about establishing a "hydrogen economy." Whether powered by hydrogen or gasoline, the move toward fuel cells seems real. In August, Erhard Schubert, co-director of GM's Global Alternative Propulsion Center, told the Cleveland Plain Dealer that if we want future generations to enjoy the same kind of mobility we have become accustomed to, the fuel cell is now the only viable option in light of our planet's limited fossil fuel energy resources. If the history of fuel cells reflects the "lone-inventor-in-garage" paradigm, the story of battery-powered cars represents bureaucratic imperative driven by filthy air. Since 1990, the California Air Resources Board (CARB, the agency responsible for improving air quality), has been pushing the sale of "zero emissions" (translated: battery-powered) vehicles. Iceland is awash in renewable energy, and it plans to use geothermal heated water from the many volcanoes to drive the separation of water into oxygen and hydrogen to power fuel cells in buses and the nation's large fishing fleet (Howes 2000, pp.1). The move faced corporate opposition and technical problems. Under political pressure, Detroit begrudgingly made battery-powered cars that suffered from a combo of pedestrian Earth bound range and an astronomical price tag. The environmental benefits were never great enough to compel consumers to break down the doors for wheels that needed recharging after 100 miles. Still, on Sept. 8, 2000, the agency reaffirmed its commitment to zero-emissions vehicles and claimed that its mandates had been crucial in developing cars powered by batteries, fuel cells and hybrid engines. The debate over mandates has recently arisen in the controversy over vehicle rollovers caused by shoddy tires on top-heavy sports-utility vehicles, which helped fuel an explosion of rollover deaths in the last seven years. The blowout seems poised to overturn political attitudes toward regulation. The problem with batteries is simple to state, and gnarly to solve: They simply can't store much energy, compared to familiar gasoline. Although any comparison of power sources must note that battery cars use energy about three times as efficiently as gasoline cars, storage is the biggest obstacle facing battery vehicles. Critics say the agency is unwisely pushing auto manufacturers to make clean-vehicle technology that nobody wants, and that after the expenditure of billions of dollars on battery-powered cars, the cars still don't perform (Law 2000, pp.1F). Philosophically, critics also charge that instead of controlling air pollution, the agency is trying to "drive technology" by bureaucratic whim rather than marketplace demand. Yet government interference deserves credit for major advances in auto safety and pollution control. Without federal intervention, cars might lack the can't-live-without-'em improvements. Batteries are categorized by two key components: the electrolyte -- a chemical that conducts electricity -- and the electrode -- an electrical conductor through which an electric current enters or leaves an electrolyte or other medium. In a battery, the two components interact to produce a flow of electrons. In lead-acid batteries, the electrolyte is acid, and the electrodes are lead. Some exotic batteries use air to oxidize a metal electrode. Other can be recharged simply by dumping and replacing the fluid -- much as gasoline cars are "recharged" by adding fuel. But most exotic batteries are simply too expensive for production cars, and some operate at hundreds of degrees Celsius. The push for electric cars grew out of persistent air pollution in Southern California, which leads the state's air quality regulators to require that 2 percent of new vehicles sold in 1998 be "zero-emissions vehicles" -- meaning battery cars. That level was never reached, although the air regulators do plan to insist on the sale of more clean cars. Battery cars are expensive and don't drive very far. Hybrids are just entering the market, and fuel cells are still on the horizon. What can we do now to reduce pollution from transportation According to a study of highway pollution in California, the cheapest approach is to crack down on the cruddiest cars and trucks. Using a sensor to measure carbon monoxide and hydrocarbon as cars drove past; the scientists found that a few cars were to blame for most auto pollution. Most people assume that older vehicles are the worst polluters, because they lack sophisticated pollution controls. That's true to some extent, but the researchers found that deliberate destruction of pollution controls, and failure to maintain them, was a much bigger problem (Santini 2001, p.33). Repairing emissions controls may not be as glamorous as inventing electric vehicles, but it may offer the most bang for the buck. The researchers estimated that repairing emissions controls on the worst 20 percent of cars would cost $880-million -- an average cost of $200 per car. That would reduce California's vehicle carbon monoxide emissions by 61 percent and hydrocarbons by 50 percent. REFERENCES All Charged Up in Minutes Flat, Goss, Helen, New Scientist 147, July 15, 1995, pp. 23. Firms Told to Resume Making Electric Cars, Gary Polakovic, Los Angeles Times, Sept. 9, 2000, p. A1. Exxon, GM Report Major Fuel-Cell Technology Gain, Los Angeles Times, Terril Yeu Jones, Aug. 11, 2000, p. C1. Iceland Warms Up to Hydrogen Fuel, Daniel Howes, The Detroit News, 10 Sept. 2000, Business p. 1. Magnitude and Value of Electric Vehicle Emissions Reductions for Six Driving Cycles in Four U.S. Cities with Varying Air Quality Problems, Quanlu (Michael) Wang and Danilo Santini, Transportation Research Record 1416, p. 33-42. On-Road Vehicle Emissions: Regulations, Costs, and Benefits, Stuart P. Beaton, et al, Science, 268: 991-993 (May 19, 1995). Powering the Future: The Ballard Fuel Cell and the Race to Change the World, Tom Koppel, John & Sons, 1999. Reinventing the Wheels, Amory B. Lovins and L. Hunter Lovins, The Atlantic Monthly, January, 1995, p. 73-86. Read More