Hybrid technology in cars is really not a big thing today. During World War II, submarines ran on diesel engines while cruising at or just below the surface; the diesels charged banks of batteries that propelled the subs underwater, where the diesels are inoperable. Hybrid cars also integrate, through use of computer control, a gasoline engine, a set of batteries, and one or more electric motors. The engine charges the batteries, and the car can be propelled by the gasoline engine alone, the battery-powered electric motor(s), or the two together. Because batteries are charged by the operation of the vehicle, the hybrid does not draw charge from an electrical outlet, an inconvenience of conventional electric vehicles.
The hybrid vehicle concept squeezes miles from gasoline in other ways. The electric motor may grab energy typically squandered as heat in braking to charge the batteries in a concept called regenerative braking. Hybrids can shut down the gasoline motor when idling, for example, at a long stoplight.
Hybrids are lightweight and shaped to reduce aerodynamic drag. Some have a more efficient, electronically controlled variable-gearing transmission. Low-drag, stiff tires also increase fuel efficiency, but they may not be best for road adherence in snowy weather. Some of these concepts can and have been used in improving gas mileage in fully gasoline-powered vehicles. For example, Honda’s Insight and Civic and Toyota’s Prius travel over 50 miles per gallon in freeway use (Cole 36-40). Ford will soon be offering hybrid SUVs;
The Escape SUV by ford was recently released in 2004. Ford’s 2004 Escape SUV may deliver 40 miles per gallon in city driving (Wechter 17). General Motors offered their hybrid versions of their cars in 2006 when they offered Saturn VUE and later Chevrolet Malibu and Tahoe. Also General Motors distributed around 240 hybrid buses in Seattle. The basic purpose was to reduce the consumption of oil up to 65%. Other than these cities General motors offered Houston, Portland and Philadelphia with the same hybrid bus models (The Daily Herald).
Hybrid engines are being considered because of their low contamination levels and quiet operation. These engines operate smoothly, produce high torques at low speed, can tolerate a variety of fuels and exhibit superior cold weather starting performance. Steam generators now available practically eliminate the delayed starting problem which plagued earlier steam vehicles, and are entirely safe. At present, however, they are both bulky and costly. Since no major technical obstacles are foreseen in manufacturing suitable engines, costs no doubt would decline as production increased (Gilles 202).
Hybrid technology has been under development for most of the last decade but there is no standard system under the hood of each of these vehicles. Automakers are developing competing and sometimes complementary technologies for hybrid electric vehicle propulsion. One system uses a small gasoline-burning engine that directly drives an alternator to generate electricity. The electricity is stored in batteries or sent to an electric motor which in turn powers the wheels at all times.
A second system is configured with two power paths so that the gasoline engine, an electric battery pack or both may be used to produce the motive power to turn the wheels. The gasoline engine also is used to charge and recharge the electric batteries. Under this dual-power or parallel-power system, the vehicle is powered by the electric engine at lower speeds and switches to the gasoline engine for quick acceleration and once it reaches cruising speed.
Reducing the total weight of the vehicle is one of the most important factors in achieving greater fuel efficiency. Replacing steel engine and frame components with advanced aluminum, and strategic uses of other materials such as magnesium, carbon fiber and titanium has helped hybrids shave pounds for greater efficiency. Although these types of structural changes have been simultaneously developed and tested alongside hybrids, they will be equally applicable to use in conventional vehicles. (Ruffino 16-18)
Some may be concerned that lightweight materials used in hybrids could create safety concerns. Not so, according to Terry Penny “All materials on the hybrid vehicles have to meet structural and other performance requirements identical to conventional vehicles.” There is one other specific safety issue, says Penny. “Some people worry that in a rescue situation the ‘jaws of life’ could be electrifying if they cut into the vehicle’s high voltage line.” But others say that rescuers would be aware of the electric nature of hybrids and act accordingly in an emergency. (Penny 25)
Finally, one of the most attractive and intuitively pleasing features of having an electric motor onboard is a function called regenerative braking. As the brakes are applied under normal driving conditions, the HEV captures energy expended to slow the vehicle down. It is then routed to the battery pack, recycled and applied in the passing lane or in climbing that next big hill. In the near term for Ford Vehicles, the likeliest option for the fuel cell vehicle is an onboard converter that plucks hydrogen from natural gas. The technology does produce carbon dioxide emission, however, and its use would lead to questions about the possible security risks of an expanded role for natural gas. An added concern is the expansion of pipeline infrastructure for delivery of great quantities of natural gas. (Arnold 17)
For at least the next decade fuel cells unless their hydrogen is supplied through nuclear power, will not replace fossil fuels without major environmental and economic impact. Costly hybrid vehicles offered by Ford and General Motors may make transportation less affordable for fixed- and low-income households; subsidies for the vehicles would have economic costs and could even undermine petroleum conservation efforts.
Petroleum seems to be indispensable to prosperity, health, welfare, and a clean environment. Even as petroleum use has increased dramatically, the emissions of six important (criteria) pollutants monitored by the EPA have declined. Technological advances have continued to deliver greater economic output per amount of energy used. Technology may make reductions in carbon dioxide emission affordable. The National Academy of Engineering ranks the electrification of the United States as the greatest engineering achievement of the twentieth century. Following electrification are the automobile and airplane, energy-using achievements that have helped to generate prosperity. Those great achievements were made possible by fossil fuels, especially petroleum, as the largest share of energy supply for the United States and the world. The debt owed to petroleum is immense, as it has reduced the coarseness of nature and contributed much to the blossoming of humanity.
Works Cited
- Leon, Monroe Cole. Tomorrow’s Transportation: New Systems for the Urban Future. United States. Urban Transportation Administration. U.S. Government Printing Office. Place of Washington, DC. 1998.
- Wechter, Arnold. Ford Escape to Feature New Platform, Hybrid Engine. The Washington Times. 2000. 17.
- Daily Herald. General Motors Plugs into Hybrid Vehicles. Publication Date: November 28, 2005. 1.
- Ruffino, Norma Carr. The Hybrid Phenomenon: High Gas Prices and Shifting Consumer Sentiment Point to Bright Prospects for Hybrid Cars. The Futurist. Volume: 41. Issue: 4. 2007. 16.
- Gilles, Tim. Automobiles/ Maintenance and repair. Thomson Delmar Learning. 2003. 202-204
- Penny, Terry. Low Grade Heat Power Cycles. Amer Solar Energy Society. 1985. 25-27.
- Miller, John. Propulsion Systems for Hybrid Vehicles. Institution of Electrical Engineers. 125-128