What ever happened to the decades-old idea of an electric car? What are the newest designs for electric cars? What powers an electric car? What are the advantages and disadvantages of an electric car?

Insights

Electric cars offer many advantages when compared to gasoline-powered cars. Electric cars run without burning gasoline, and therefore, produce no exhaust pollution. They are relatively quiet during normal operation and nearly silent when idling; therefore, they produce much less noise pollution than gasoline-powered cars.

Electric cars don't have many of the parts that gasoline-powered cars do--parts that need continual upkeep at best, and that often fail (e.g., fuel injectors, carburetors, mufflers, distributors, water pumps, etc.). There are no tune-ups or oil changes for electric cars. Required battery maintenance is minimal. There is no emission-control system, which is one of the most complex and expensive parts of a car that uses gasoline. Most of the components in an electric car are electrical or solid-state, with no moving parts. The overall costs for maintaining an electric car average about 30% of that for gas-powered cars.

So, if electric vehicles are so great, why don't we see many around? There are several reasons for this, the primary one being the relative efficiency of gasoline as a fuel. Gasoline is fairly inexpensive to produce; because it's a liquid, it's cheap to store and transport; and it has a very high energy content per unit of weight. Batteries, by comparison, have a low energy content per unit of weight. Several hundred pounds of batteries are needed for some electric cars. These batteries store as much energy as a single gallon of gasoline, which weighs only about five or six pounds. In addition, an electric vehicle gets only about 100 miles to a charge and can take hours to fully recharge.

There are developments in electric cars that might eliminate some of the disadvantages. One example was seen in the Newton's Apple segment. This style of car is fueled by electrical metal strips laid within the roadbed. Electrical energy is provided from a central source through the metal strip. These electric cars do not require a battery source, only an electric motor.

The electric-vehicle industry continues to grow. By the year 2000, any manufacturer who wants to sell gas-powered cars in the state of California must also have electric cars available. The cost of an electric car is approximately $17,000. Many "do-it-yourselfers" are converting their gas-powered cars to electric cars, thus saving money.

Our dependence on the internal combustion engine is costing us in many ways, including monetarily and environmentally. Electric vehicles can bring us cleaner air and greater energy independence.

Connections

New technologies can have far-reaching impacts on our society. What are the consequences of a wider-use of electric cars in the U.S.? Environmental? Economic? Political? Safety?

Vocabulary

battery an electric cell or a group of connected cells that furnishes an electric current for the transfer of energy
electricity a form of energy that can be transferred by the movement of electrons and protons
electric motor a machine for converting electrical energy into mechanical energy
photovoltaic a solar cell that changes light energy into electric energy
recharge to supply with chemical energy again, as a battery for conversion to electrical energy

Resources

Colvin, R.L. (1991) "Electric-car buffs shift efforts into higher gear." In Los Angeles Times (February 11): Section B, pg. 3.

deLucenay, L.G. (1983) The electricity story. New York: Arco Publishing.

Traister, R.J. (1982) All about electric and hybrid cars, 1st ed. Blue Ridge Summit, PA: Tab Books.

Additional sources of information:

General Motors
Electric Vehicle Group
30200 Mound Rd.
Warren, MI 48090
(313) 556-5000

Solar & Electric Car Racing Association
11811 N. Tatum Blvd. Suite #3031
Phoenix, AZ 85028

Main Activity

Test different substances to determine whether they can produce an electrical current.

Part I

Materials

• #6 dry cell
  
• knife switch OR push button
  
• compass
  
• 15 feet of 28-gauge (or finer) insulated wire

1. Wind the insulated wire about 10 times around the compass at the north- and south-pole markings. The compass should be rotated so that the compass needle is also aligned in a north-south direction.
2. Connect the wires in a complete circuit.
3. Use the knife switch or push button to close the circuit only for a moment at a time.

CAUTION: Leaving the circuit closed will result in a short circuit with the wires becoming very hot!

4. Now make your own batteries using household items and test them in the next investigation. Use the "compass" galvanometer to detect an electric current after constructing it in steps 1 through 4.

Questions

1. What happened to the compass needle when the circuit was closed?

2. How do you know that the deflection of the compass indicates a current flow? Try showing that a straight wire can also cause the compass to deflect when near a current-carrying wire.

Part II

Materials

• lemon
  
• vinegar
  
• orange juice
  
• wire from Part I
  
• compass from Part I
  
• copper strip approximately 3/4" wide and 5" long
  
• zinc strip approximately 3/4" wide and 5" long
  
• wide-mouth glass jar

1. Carefully squeeze or roll on a hard surface the unpeeled lemon until it feels very soft. Be careful not to break or puncture the skin. Push the copper and zinc strips into the lemon.
2. Wrap the ends of the wires from the compass galvanometer around the metal strips as illustrated. What happened to the compass needle when the circuit was closed? Was the compass needle deflected? What does that indicate?
3. Now repeat the procedure using a jar of vinegar and then a jar of orange juice. Be sure to wash the metal strips with water before testing a new substance.

Questions

1. What would happen if you used a non-conducting liquid, such as milk? What needs to be present to cause a current to flow?

2. Look at and identify the parts of a battery. What components in your circuit correspond to these parts?

Investigate the various solar-electric-car races that have been held over the last few years. Compare the differences and similarities of a solar-electric car with a battery-electric car. Write a report on your findings.

Imagine you are a member of a debate team and you need to convince your audience that electric cars are better than gasoline-powered cars. Do research and present issues such as pollution, reliability, maintenance, operating costs, etc., to support your arguments.

Search literature about the history of science and technology for information about scientists who discovered ways of making and improving batteries. Develop a chart that includes the inventor and the contribution. Include such scientists as Alessandro Volta, Gaston Plante, Georges Leclanché, and Thomas Edison.

Newton's Apple is a production of KTCA Twin Cities Public Television.
Made possible by a grant from 3M.
Educational materials developed with the National Science Teachers Association.