Teddy Ferreira, age 12, of Dunwoody, Ga., for his question:

WHAT IS GEOTHERMAL POWER?

Geothermal power is generated whenever water comes into contact with heated underground rocks and turns into steam. Power companies drill into areas where underground steam is trapped and direct it into the blades of steam turbines.

In areas where underground steam does not exist naturally, man can create it by injecting water into hot rocks.

Geothermal power plants do not burn anything, and so no smoke pollutes the air. Some of these plants produce electricity more cheaply than do ordinary power plants.

Several countries, including New Zealand, Japan, Italy and the United States, had developed geothermal power plants by the mid 1970s.