60 Earth
Energy is the force that makes things work. Over many
years, people have learned to produce energy from various
sources, including burning. FOSSIL FUELS and using
. NUCLEAR and. RENEWABLE ENERGYtechnology.
WHAT IS FUEL?
Fuel is something that can be burned to produce
energy in the form of heat or power. Fuels include
coal, oil, natural gas, and wood. Humans have been
burning wood for warmth, and to light homes and
cook food since civilization began. However, in some
parts of the world, so many trees have been cut down
for fuel that firewood is now scarce.HOW ARE FOSSIL FUELS USED
TO PRODUCE ENERGY?
Power stations burn fossil fuels to heat water and
produce steam. The steam pushes around turbines
in a generator, which then spin a series of magnets,
creating an electric current. Oil refineries process oil
to make fuel to run cars, trains, ships, and aircraft.Fossil fuels are made of the fossilized
remains of living things that died millions
of years ago. Coal, oil, and gas are the
most important fossil fuels. Today, they
provide most of the world’s energy.HOW DID OIL AND NATURAL GAS FORM?
Oil is formed from the remains of tiny plants and
animals that were buried and squashed on the seabed.
Natural gas forms in a similar way to oil and is found
trapped in underground reservoirs.1 COAL FORMATION
Plant remains decay to make brown, crumbly peat when they are buried
and squashed. Over many thousands of years, more layers build up on
top, and heat and pressure convert the remains first to lignite, then to
bituminous coal, and finally to anthracite, the highest grade of coal.Energy Resources
Hard, black anthracite is found
the deepest underground. Made
from more than 90 per cent
carbon, it burns the best
and is used in industry
and to heat homesFOSSIL FUELS
Bituminous coal
is found deeper underground.
This better-quality solid fuel
contains more than 80 per cent
carbon and is most commonly
used in industryLignite, or brown coal, is found
nearest the Earth’s surface. This
low-grade fuel contains up to
60 per cent carbon, along with
plant remains and moistureFROM WOOD TO FIRE 3
Wood provides fuel for cooking in
a remote part of China. Firewood
is the main source of fuel for half
the world’s population.4 USING ENERGY
A city blazes with light.
In developed countries, people
consume vast amounts of energy
in their daily lives.Coal is formed over millions
of years from rotting plant
material that accumulated in
warm, muddy swampsMoist, fibrous peat formed as
rotting plant remains were
buried and squashed. Peat gives
off heat when burnedHOW OIL FORMS- Heat and pressure
increase as the
sediments sink. The
organic remains
become oil and gas. - Decaying plants
and animals sink to
the sea floor, and
are buried by
layers of sediment. - Gas and oil rise
through porous
(holey) rock and
collect below a
layer of solid rock.
Fuels collect
under solid
rockPlants and
animal remainsNew layers
of sedimentOil and
gas rigsenergy
resources