Electric Vehicles | Electric Cars
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| 2005 RAV 4 Electric Vehicle
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This Toyota RAV4 electric vehicle was powered by 2 dozen batteries.
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The use of electricity to power vehicles, whether gas/electric hybrids or pure battery-powered cars, is an interesting technological problem for many automotive manufacturers. In most electric vehicles, an electric current is used to power a motor which then turns the wheels. Electric motors do not require transmissions, and in some cases it is possible to use a motor driving each individual wheel.
Applications And Environmental Impact
There are several different types of electric vehicle on the road today. The most common is the hybrid, which uses both a gas and an electric motor to move the vehicle. Usually the electric motor is the primary motive force, with the gasoline engine only running occasionally to charge the battery, or at speeds which cannot be maintained on battery power alone. The vehicle’s battery can also be recharged through a process called regenerative braking, which uses the energy of the spinning wheels to generate electricity as part of the braking process.
Pure electric vehicles are powered exclusively by a battery, and while some take advantage of regenerative braking technology, most rely on external electricity to charge their batteries. These types of vehicles must be plugged in to a power source in between drives in order to stay operational.
Pure electric vehicles do not produce any emissions, and neither do hybrid vehicles while operating off of the battery. They are also extremely quiet. However, the chemicals used to store energy in the batteries, such as lead, can be highly toxic. This can pose a problem when disposing of old power sources. In addition, the electricity that is used to re-charge electric cars in the United States generally comes from coal-burning power stations, thus negating a sizable portion of the vehicle’s emissions savings. However, even taking this into account, electric vehicles typically have a carbon footprint that is at least 50% smaller than their gasoline equivalents.
Performance
In some ways, electric vehicles are the equivalent of, or superior to traditional gasoline powered vehicles when it comes to performance. The torque curve of an electric motor is almost flat, meaning that maximum torque is produced very early, allowing for rapid acceleration. This enables electric motors to out-accelerate more powerful gasoline motors.
Performance comes at a price, however, and more aggressive driving in modern electric vehicles uses a significant amount of current. This battery drain can dramatically lower the range of a vehicle.
Downsides To Electric Vehicles
Most pure electric vehicles on the market have very short ranges, being able to travel only between 80 and 300 miles per charge, depending on battery type. The least expensive batteries, lead-acid, also provide the poorest range. Vehicles at the high end of the range spectrum tend to be very small and light, and use lithium-ion batteries, which are the most expensive. Battery life and cost are two of the biggest issues when it comes to building a practical pure electric vehicle, and the combination of low ranges and small cars have generally restricted pure electric vehicles to the role of city runabouts.
Batteries also eventually wear out, leading to issues regarding their safe disposal and also how to deal with the high cost of replacing them. Some lithium-ion batteries currently used in electric vehicles would cost up to $10,000 dollars to replace, making consumers wary of the costs of this type of car in the later stages of ownership.
Another important consideration when it comes to the wide scale adoption of electric cars is the necessary growth of the American power grid to match. If all gasoline powered vehicles were to be instantly replaced with pure electrics, then the result would be empty highways, as there is currently not enough electrical power being generated to charge millions of cars. Any increase in the use of electric cars necessarily entails the organic growth of power generation in the United States, and in order for that increased use to be environmentally relevant, the power grid will be required to shift away from burning coal.
The Future Of Electric Vehicles
Electric cars are undergoing somewhat of a renaissance in the United States as a result of new battery technologies that offer reduced weight and longer discharge times. This has prompted the increased research and development into pure electric vehicles by small start-up companies such as Tesla Motors and domestic automotive giants like Chrysler and General Motors. Most major automakers around the world have unveiled battery powered electrics at auto shows, and some, such as Dodge and Chevrolet, have pledged to actually begin selling these types of vehicles within the next 5 years. Hybrids have also become commonplace in showrooms across the country, and they represent an interim step between the current world of gasoline-powered cars and the future of pure electric vehicles.
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