1.2 Energy resources

Question 1

Renewable energy

Answer 1

Renewable resources will never run out. They can be or are being replenished as they are used.
Solar, wind, water waves, hydro-electricity, bio-fuel, tides, geothermal are renewable energy resources.
Most resources damage the environment. But renewable sources are less harmful than non-renewable sources.

Question 2

Non renewable energy

Answer 2

Non-renewable resources will run out one day.
Fossil fuels and nuclear fuel are non-renewable.
All non-renewable resources damage our environment.

Question 3

Uses of energy resources

Answer 3

Transport
Electricity generation
Heating

Question 4

Fossil fuels

Answer 4

Fossil fuels (such as coal and oil) are burned to heat a fluid (water), which creates steam and turns a turbine which turns a generator.

Advantages
Reliable, on-demand electricity.

Disadvantages
Not renewable.
Contributes to global warming.

Question 5

Geothermal energy

Answer 5

In volcanic places, magma (underground lava) has lots of internal energy. The magma heats rocks, which heat water in pipes. This rotates a turbine, which turns a generator.

Advantages
Renewable.
Reliable.
Does not produce greenhouse gases.

Disadvantages
Can only be used where there is volcanic activity close to the surface.
Geothermal plants can lead to the instability of the land surrounding it.

Question 6

Wind energy

Answer 6

When the wind blows, it rotates a wind turbine, which can turn a generator.

Advantages
Source of renewable energy.
They don’t take up much land space.
Relatively low cost.

Disadvantages
Unreliable, only produces power when wind blows.
Can be considered ugly or an eyesore.
Can cause noise pollution.

Question 7

Water energy

Answer 7

Water high above the ground is a store of gravitational potential energy. Hydroelectric dams trap water. Allowing it to fall rotates a turbine, which turns a generator.

Advantages
Renewable.
More reliable than wind and solar.
Capable of producing lots of energy.

Disadvantages
Hydroelectric dams often change the paths of rivers, which can move people out of houses and harm local wildlife.
Can be affected by droughts and variation in water flow over time.
There are fewer and fewer suitable places to build a dam.

Question 8

Tidal energy

Answer 8

The waves and tides in the sea are stores of kinetic energy. Tidal and wave power use this kinetic energy to rotate a turbine, which turns a generator.

Advantages
Renewable source of energy.
Does not produce greenhouse gases.
Tides are a predictable phenomenon.

Disadvantages
The creation of tidal turbines can damage fragile ecosystems in estuaries.
Does not produce electricity continuously.
Turbines must be built close to the shore, affecting communities that live there.

Question 9

Nuclear energy

Answer 9

In a nuclear reactor, the nuclear energy stored in atoms’ nuclei is released as kinetic energy. Some of this kinetic energy heats up graphite which then heats up a fluid (like water). This creates steam and rotates a turbine, which turns a generator.

Advantages
No greenhouse gas emission, so no contribution to global warming.
Reliable, on-demand electricity.

Disadvantages
Nuclear waste is radioactive and potentially dangerous if not disposed of properly.
Nuclear waste has a very long half-life, which will continue to be dangerous for a very long time.

Question 10

Solar energy

Answer 10

The electromagnetic waves emitted by the sun (e.g. light), transfer energy to the earth. Solar cells use heat from the sun to boil water, create steam and rotate a turbine, which turns a generator.

Advantages
Renewable.
Produces no greenhouse gases.
Produces no noise pollution.

Disadvantages
Only produces electricity when there is sunlight.
High cost of installation.
Solar cells are currently not very efficient at converting sunlight into energy.