Electricity & Magnetismat Work

Generating Electric Energy

Chapter 3

Section 2

Electromagnetic Induction

• An electric current will be produced in a conductor when the conductor moves across the lines of a magnetic field

AC/DC

• The flow of the induced current may be constant (direct), or it may change directions (alternating).

Alternating Current

• From power plant • A current consisting of charges that move back and forth

Direct Current

• Battery • Electrons move away from one end of the battery and into the other end

Generators

• Uses motion to produce an electric current

• A motor… run backwards

Turbines

• Flowing water from a dam, wind, steam from the burning of fuels, and even the ocean’s tides can be used to turn turbines

Generating Electricity

• Coal– 56.5%

• Nuclear– 21.9%

• Hydroelectric– 10.7%

• Natural Gas– 8.5%

• Petroleum– 2.2%

• Other– 0.2%

Renewable Resources

• Can be replaced in nature at a rate close to the rate at which it is used.

Nonrenewable Resources

• Exists in a fixed/limited amount

• Fossil Fuels

Coal

• Moderate Cost• Large Supply

• Damage from mining• Air Pollution (Sulfur)

Oil

• Moderate cost• Adequate supply

• Oil Spills

Natural Gas

• Moderate cost

• Adequate supply

Nuclear Power

• No air pollution • Expensive set-up• Radioactive waste• Terrorist target

Hydroelectricity

• Low costs• No waste

• Dam able rivers are rare• Disturbs wildlife

Wind

• Moderate cost• No wastes• Inexhaustible supply

• Winds are variable• Wind farms require

large areas of land

Sun

• No waste• Inexhaustible supply

• Expensive set up• Requires large area

of land• Sunlight varies with

weather and time of day

Geothermal Power

• Low operating costs • Moderate set-up costs

• Potential sites are uncommon

Tidal Plant

• No waste • Expensive set-up• Power varies with the

tides