Renewable and non-renewable energy

In a nutshell

Non-renewable energy resources cannot be replenished whereas renewable energy resources can. Fossil fuels is the biggest energy resource but they are non-renewable and contribute to global warming. This means we have to become more reliant on renewable energy resources such as solar and wind energy.

Definitions

Key word	Definition
Carbon neutral	Equal amount of carbon that is getting emitted is also getting absorbed
Global warming	An increase in the temperature of Earth's atmosphere
Greenhouse gases	Gases which absorb and reflect energy in the atmosphere, causing global warming in the similar way to a greenhouse
Pollution	Substances released into the atmosphere which are harmful

Non-renewable energy resources

There is only a finite amount of non-renewable energy resources. Non-renewable means that they cannot be replenished, so (at some point) will run out. Most of our energy comes from fossil fuels.

Fossil fuels

The main sources of non-renewable energy resources are fossil fuels (coal, natural gas and oil). Fossil fuels take millions of years to form from dead organisms, and we have used them far quicker than the Earth is able to make them.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Advantages	Disadvantages
Reliable as there is currently enough to meet energy demand	Releases carbon dioxide when burnt into the atmosphere, contributing to global warming
Running costs of mining fossil fuels are (relatively) cheap	Sulphur dioxide is produced when coal and oil are burnt, which causes acid rain and damages plant life and habitats
Get a lot of chemical energy per kg of fossil fuel (which leads to a further reduced cost)	Oil spillages can have detrimental impacts on sea life

Nuclear energy

Using radioactive materials such as uranium and plutonium, nuclear energy is also used to generate electricity. There is a limited amount of uranium and plutonium, so one day nuclear energy will also run out.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

However, $1\ kg$ of nuclear fuel has $14,000$ times the amount of energy compared to $1\ kg$ of fossil fuel. Nuclear energy also does not produce harmful greenhouse gases. However the radioactive waste produced is very difficult to get rid of and can be very harmful to humans (and the environment) for millions of years.

Generating electricity using non-renewable resources

Non-renewable resources are burnt in order to create electricity. Fossil fuels transfer their chemical energy into thermal energy. Nuclear fuels transfer nuclear energy into thermal energy.

Power plant procedure

Below is a diagram of a power plant and the procedure for how they work.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

1.	Water from a reservoir or water tower is sent to be heated
2.	Fossil fuels are burnt to heat water into steam
3.	Steam turns a turbine
4.	The turbine turns a generator
5.	Generator converts kinetic energy into electrical energy
6.	Electrical energy is put into the national grid
7.	The steam from the turbine is cooled in a water tower

Renewable energy resources

Renewable energy resources do not run out. This means that as we use renewables, they can be replaced.

Most energy comes from fossil fuels. However countries around the world are trying to become more reliant on renewable energy, as fossil fuels deplete and global warming worsens.

Solar cells

Solar cells convert radiation from the Sun into electric currents. Examples of solar cells in every day uses are calculators. You can also see them on the roof of houses and 'solar farms' which are fields of solar cells.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Advantages	Disadvantages
After manufacturing, no pollution produced	Whilst manufacturing solar cells, greenhouse gases are produced
Very reliable source of energy in sunny places	In cloudier countries, like the UK, not always a very reliable source of energy especially in the winter
Once installed, little running costs	Very expensive to initially manufacture and install solar cells
	Solar cells are not very effective at nighttime due to the lack of sunlight

Wind power

Wind turbines use kinetic energy to turn a generator that produces electricity. Wind turbines are found in remote places (for example hills or off the coast in the sea) in order to be exposed to as much wind as possible.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Advantage	Disadvantages
After manufacturing, no pollution produced	Some pollution produced when manufacturing and installing
No fuel costs are needed	Need lots of wind turbines to produce the same amount of electricity as a coal-fired factory which can be an eye sore
	They can be very loud
	Wind turbines won't produce electricity if there is no wind, and will also stop working if it is too windy

Bio-fuels

Bio-fuels are made from plant products or animal poop and have a chemical energy store. Just like fossil fuels, they are burnt in order to generate electricity.

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Advantages	Disadvantages
They are carbon neutral when plants are grown at the same rate they are being burnt	Growing food for bio fuel has taken over space used for farming and growing food to eat
Crops only take a short amount of time to grow	Need water for bio-fuel to be sustainable, which takes water away from other crops and animals
Bio-fuels can be stored to be used at a later to point to keep up with demand	Habitats are being destroyed in order to make room for bio-fuel farms

Other non-renewable resources

There are many other non-renewable resources such as tidal, geothermal and hydro-electric. None of these produce greenhouse gases when up and running.

However they can only work in certain locations. For example, tidal energy needs to be built in the sea or a river and geothermal needs a volcano (none of those in the UK!).

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Science; Energy; KS3 Year 7; Renewable and non-renewable energy

Science; Energy; KS3 Year 7; Renewable and non-renewable energy