Energy Resources

Energy resources can be classified as renewable or non-renewable.

Non-renewable energy resources will eventually run out (for example: coal, oil, and gas).

Renewable energy resources will not run out (for example, wind and solar power).

Renewable Energy Resources

Renewable energy resources include:

1. Hydroelectric
2. Wind
3. Solar
4. Tidal
5. Wave
6. Geothermal
7. Biomass

Hydroelectric

Hydroelectric generators use moving water to drive turbines. Large-scale hydroelectric power stations usually create a reservoir of water by building a dam. The water can then be released past turbines to generate electricity.

Advantages:

1. No gas emissions
2. Cheap to run
3. Renewable

Disadvantages:

1. Limited locations are suitable as there needs to be a supply of water and enough land to create a reservoir
2. Building a dam and reservoir has an impact on the local environment (i.e., animal habitats, farmland)

Wind

Wind turbines use the kinetic energy of the wind to generate electricity.

Advantages:

1. No gas emissions
2. No fuel costs
3. Renewable

Disadvantages:

1. Low power output from each turbine, so lots of turbines are needed
2. Unreliable supply – they only work when it is windy
3. Visual pollution – some people think that they spoil the landscape

Solar

Solar (photovoltaic) cells convert sunlight to electricity.

Advantages:

1. No gas emissions
2. No fuel costs

Disadvantages:

1. Expensive to produce the panels
2. Low power output
3. Unreliable supply – they do not work at night

Solar energy can also be used by solar heating panels to heat water that can be used to keep a building warm, rather than generating electricity.

Geothermal

Geothermal uses the heat that is naturally occurring below the surface of the Earth. Water can be pumped down into the Earth’s crust where it is heated up. The steam produced can be used to drive a turbine and generate electricity at the surface.

Advantages:

1. No gas emissions
2. No fuel costs

Disadvantages:

1. Expensive to build
2. Only suitable in areas with the right geological conditions

Wave

The motion of waves in the sea can be used to turn turbines and generate electricity.

Advantages:

1. No gas emissions
2. No fuel costs

Disadvantages:

1. Only suitable for use in coastal areas
2. Installing the turbines and generators can interfere with other coastal activities (fishing, swimming, etc.) and/or wildlife

Tidal

At the coast, the water level (tide) rises and falls twice a day due to the moon’s gravitational field. As the water moves in/out from the coastline, turbines can be used to generate electricity.

Advantages:

1. No gas emissions
2. No fuel costs

Disadvantages:

1. Only suitable for use in coastal areas
2. Installing the turbines and generators can interfere with other coastal activities (fishing, swimming, etc.) and/or wildlife

Biofuels

Biofuels are made from living or recently living organisms. Examples include methane from animal waste, rapeseed oil, ethanol from sugar cane, woodchips.

Advantages:

1. Renewable (as long as the source is replaced at the same rate it is used)
2. Suitable for use in remote/rural locations
3. Carbon neutral - the amount of carbon taken into the organism when it is living should equal the amount of carbon given out when it is burned

Disadvantages:

1. Biofuels release carbon dioxide when burned.
2. Low power output – only suitable for small-scale use

Non-Renewable Energy Resources

Fossil Fuels

Coal, oil, and gas are fossil fuels. They have been formed underground from the remains of ancient organisms over millions of years.

A power station can burn a fossil fuel to heat water, producing steam. The steam is used to turn a turbine, which turns a generator, producing electricity.

Advantages:

1. Fossil fuel power stations generate a high power output

Disadvantages:

1. Non-renewable
2. Carbon dioxide (and other pollutants) released into the atmosphere when burned
3. Large amounts of fuel needed

Nuclear Power

Nuclear power stations use the process of nuclear fission. Splitting a nucleus of uranium in the reactor generates large amounts of energy. This heat is used to produce steam. The steam is used to turn a turbine, which turns a generator, producing electricity.

Advantages:

1. No waste gases produced
2. Large power output from only a small amount of fuel

Disadvantages:

1. Radioactive waste produced
2. Power stations are expensive to build and decommission

Evaluating Energy Resources

When evaluating and comparing energy resources, consider the following factors:

1. Running Costs – includes fuel, transport, staff, maintenance
2. Lifecycle costs – building, decommissioning
3. Power Output
4. Environmental Impact
5. Efficiency
6. Renewable/Non-renewable

Worked Example

Compare the advantages and disadvantages of using fossil fuels and nuclear power to provide electricity to the UK:

Fossil Fuels

Advantages:

1. Quicker/cheaper to build the power station
2. Can respond quickly to changes in demand
3. Can be built anywhere

Disadvantages:

1. Carbon dioxide produced (contributing to climate change)
2. Non-renewable
3. Acid rain

Nuclear

Advantages:

1. No gas emissions
2. Small amounts of fuel needed
3. Smaller running costs
4. More plentiful supply (although not renewable)

Disadvantages:

1. Radioactive waste
2. Expensive/slower to build and decommission
3. Local public may not want it built in their location

In a power station, steam is often used to turn a __________?

turbine

What is the name for the category of fuels made from living or recently living organisms?

Your answer should include: biofuels / biofuel

What is the name of the energy resource that uses a dam to cause water to flow past turbines to generate electricity?

hydroelectric

What is the name of the energy resource that uses heat that occurs below the Earth's surface?

geothermal

Coal, oil, and gas are known as _______ fuels.

fossil