Earth^61
WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF NUCLEAR ENERGY?
Nuclear fuel does not release the same polluting gases as fossil fuels, and does not
use up the Earth’s natural resources. However, uranium and other nuclear materials
are radioactive – they give off radiation that can harm living things. This
means that great care must be taken when they are
processed and transported. Nuclear fuel is also
difficult to dispose of safely once used.WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF RENEWABLE ENERGY?
Renewable energy will last as long as the Sun shines,
winds blow, waves crash, and rivers flow. These
technologies are safe to use and do not pollute the
environment. However, renewable energy plants can
be expensive to build and may not produce enough
energy to meet local requirements.
Renewable energy is generated using the power of natural
forces such as sunlight. Fossil fuels release harmful waste
gases when burned, and they cannot be replaced when their
limited supplies are used up. Renewable energy, however,
will not run out and produces little pollution.
WHAT ARE THE SOURCES OF RENEWABLE ENERGY?
Most of the energy on Earth comes from the Sun.
Solar power uses the energy in sunlight directly.
Moving water (in the form of waves, tides, and
flowing rivers), and the wind also contain energy that
can be used to spin turbines to generate electricity.
Geothermal energy taps heat from inside the Earth.
In the 1930s, scientists discovered that huge amounts of energy
could be produced by splitting atoms (tiny particles) of a rare
mineral called uranium. The technology was first used to make
nuclear bombs. Later, it was used to generate electricity.SOLAR POWER 3
Each curved dish
at a solar power
station focuses
radiation from
the Sun onto a
thermoelectric
generator. A
computer steers
the dishes so
they always turn
to face the Sun
during
the day.NUCLEAR ENERGY
RENEWABLE ENERGY
1 GEOTHERMAL POWER
Geothermal power plants, such as this one near natural hot
springs in Iceland, pipe heat from the Earth’s hot interior
and use it to generate electricity.1 THE CHERNOBYL DISASTER
In 1986, a nuclear reactor at Chernobyl, in Russia, caught fire
and exploded, releasing a cloud of radiation. This image shows
the extent of the contamination six days after the accident.1 WIND POWER
Windmills have been used to power machines for centuries.
The spinning blades of modern wind turbines turn a shaft,
which generates electricity.
1 HYDROELECTRIC POWER
Fast-flowing river water can be used to spin turbines that
work electricity generators. A dam above the hydroelectric
plant controls the flow of water.FIND OUT MORE. Atoms 157 • Engines 198 • Fossils 76 • Industry 204 • Nuclear Energy 167