KidWind / KnoW Energy
V. Introduction to
Magnetism and Electricity
Generation
Magnets are surrounded by
invisible lines of magnetic force
which make up a magnetic field.
Magnetic lines (made visible with iron filings)
connecting the poles of a magnet
Magnetic Poles
Magnetic Lines
When these magnetic lines of
force move near a wire, they
cause electrons to move in the
wire. This movement of
electrons is called electricity.
Atomic Structure
Nucleus
One of the simplest, homemade generators creates
electricity by spinning magnets
inside a coil of wire
Coil
Magnets
Shaft
Spinning a coil of wire inside a
magnet also generates
electricity.
Most power plants use the
same kind of generator as a
wind turbine
Power Plants
• Wind turns a shaft, which spins a coil of
wire inside magnets, which makes elect.
• Nuclear plants convert water to steam,
which turns a turbine, which spins wire
inside magnets, which makes elect.
• Hydroelectric dams use water to turn a
turbine, which spins . . . .
• Coal plants burn coal to turn water into
steam, which turns a turbine, which. . .
Wind Turbine
Nuclear Power Plant
Hydroelectric Dam
Coal-fired power plant
Types of Electricity
• Alternating Current
• Direct Current
Alternating Current
• Electrons alternate directions moving
“forward” and then “backward”.
• Most homes in America use alternating
current that changes directions 60 times
every second (60 cycles per second).
• Wind, hydro, nuclear, etc. turbines
generally produce Alternating Current.
Direct Current
• The electrons move in one direction from
an area of high concentration to an area of
low concentration.
• Batteries, solar cells, fuel cells, etc.
generally produce Direct Current
End of Part V.