|
|
Geothermal
power (which has been used
in some countries for thousands of years for heating and cooking) is
made from very hot rocks deep in the center of the earth. As you get to
the center of the earth the temperature rises, and because the heat is
so extreme rocks melt (molten rock). In order to harness this power, a
hole is dug where it is known that molten rock is close to the surface
of the Earth, then water (a little at a time as you do not want to cool
the rocks down too much) is pumped into a pipe that leads down into the
hole, steam is produced and comes up through a pipe and turns turbines
that turn generators that create electrical power. The advantages of
using geothermal power are; no fuel is needed, no pollution is created
and there is no contribution to the green house effect, the plants do
not take up much room, and once the plant is built the energy is
practically free. The disadvantages of using geothermal power are;
there are very few sites that geothermal plants can be built, sites
that have been used for years can become inactive and hazardous
minerals can sometimes come up from deep in the earth and can be very
difficult to dispose of. Because of the heat produced by the
center of the Earth geothermal power is considered a renewable source.
|