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Energy Source
Energy resources
Renewable or non-renewable
Different energy sources
Comparing resources
Energy resources
There are different energy resources in the world and the amount of energy stored
by them varies greatly. For example, the amount of nuclear energy stored within 1 kg
of uranium is enormous, but the gravitational potential energy stored by many
thousands of tonnes of water held back by a dam is less.
Renewable or non-renewable
A renewable energy resource is one that is being (or can be) replenished as
fast (or faster) than it is used.
Renewable resources are replenished either by:
human action - eg trees cut down for biofuel are replaced by planting new trees
natural processes - eg water let through a dam for hydroelectricity is replaced
through the water cycle
A non-renewable energy resource is one that is not being replenished as it is being
used. It will eventually run out when all reserves have been used up.
Different energy sources
The table below shows the main features of the most common energy resources
used today.
Energy
Energy Source
Store
R or NR
Uses
Power
Output
Impact on
Environment
1
Energy
Fossil fuels
Nuclear fuels
Biofuel
Store
Chemical
Nuclear
Chemical
R or NR
Non-renewable
Non-renewable
Renewable
Uses
Transport,
heating,
electricity
generation
Electricity
generation
Transport,
heating,
electricity
Power
Output
High
Very high
Kinetic
Renewable
Electricity
generation
Releases
CO2 (causes
global
warming)
Radioactive
waste
(needs to be
disposed of
safely)
Medium
generation
Wind
Impact on
Environment
Carbonneutral so
low impact
Take up
large areas
that could be
used for
Very low
farming,
people say
windmills
spoil their
view
Local
habitats are
affected by
Hydroelectricity
Gravitational
potential
Renewable
Electricity
generation
Medium
the large
areas that
need to be
flooded to
build dams
Geothermal
Internal
Renewable
Electricity
generation,
Medium
Very low
heating
Energy Source
2
Energy
Store
R or NR
Uses
Power
Output
Impact on
Environment
Tidal
Tides
Kinetic
Renewable
Electricity
generation
Potentially
very high
barrages can
block
but hard
sewage
to
harness
which needs
to go out to
sea
Potentially
Sun
Nuclear
Renewable
Electricity
generation
very high,
but hard
to
Very little
harness
Water waves
Kinetic
Renewable
Electricity
generation
Low
Very low
Comparing resources
Power stations that use fossil fuels or nuclear fuel are very reliable sources of
energy. These two types of stations provide much of the UK’s electricity. They
operate almost continuously. When additional power is needed, gas power stations
are usually used because they will come on very quickly and start generating
electricity almost immediately.
The fuel for nuclear power stations is relatively cheap, but the power stations
themselves are expensive to build. It is also very expensive to dismantle,
or decommission, old nuclear power stations at the end of their useful life. The
highly radioactive waste needs to be stored for millions of years before the
natural activity will reduce to a safe level.
Water power eg tidal and hydroelectricity are reliable and predictable because of
the Moon causing the tides and rainfall filling reservoirs. These two types can also
be used to supply additional demand. But many of the renewable sources are
unreliable, including wind and solar energy, and cannot respond to increased
demand - sunny and windy weather cannot be guaranteed.
Renewable resources have no fuel costs, but the equipment used is expensive to
build.
Energy Source
3