What are the key learning points about energy resources?
Renewable energy is defined as energy that is collected from resources that will never run out or which are naturally replenished within a human lifetime.
Examples of renewable energy include sunlight, wind, hydroelectricity, tidal, waves, wood and geothermal.
Using renewable energy resources can affect the environment, for example causing habitat destruction or visual pollution.
A non-renewable energy resource is one that has a finite (limited) supply and it will run out some time.
Fossil fuels such as oil, natural gas and coal are considered non-renewable because they cannot be replaced within a human lifetime.
Nuclear energy based on The splitting of a large nucleus to produce two smaller ones. Two or three neutrons are also released in the process. The energy from the neutrons powers a nuclear reactor. is also non-renewable since supplies of uranium ore will not last forever.
Using non-renewable energy resources can affect the environment, for example causing acid rain or global warming.
What are energy resources?
Energy resources are the different ways of supplying an energy form.
For example:
Chemical energy is an energy form.
- Food, oil, coal, gas, petrol, turf and wood are some of the resources which supply chemical energy.
Energy which an object possesses by being in motion. is an energy form.
- Waves, tides, wind and falling water are some of the resources which supply kinetic energy.
There are many different energy resources.
They can be split into A renewable resource will never run out or replaced by nature in less than a human lifetime. and A resource that will run out, e.g. oil, natural gas, coal. These sources cannot be replaced by nature in less than a human lifetime. resources.
What are renewable energy resources?
Key facts
Renewable energy is defined as energy that is collected from resources that will never run out or which are replaced by nature in less than a human lifetime.
Non-renewable energy is defined as energy collected from resources that cannot be replaced when they are used up, such as oil, natural gas or coal.
How is wind energy generated?
Wind is produced as a result of giant The motion of a liquid or gas caused by heating some part of that liquid or gas. in the Earth's atmosphere, which are driven by heat energy from the Sun.
This means that wind is a renewable energy resource providing kinetic energy - as long as the Sun exists, the wind will too.
Wind Revolving machine with blades that are turned by wind, water or steam. Turbines in a power station turn the generators. use the wind to drive turbines directly.
They have huge blades mounted on a tall tower.
The blades are connected to a The part at the top of the tower of a wind turbine. The blades of the turbine are joined to the nacelle, which contains gears linked to a generator., or housing, which contains gears linked to a generator.
As the wind blows, it transfers some of its Energy which an object possesses by being in motion. to the blades, which turn and drive the generator.
Several wind turbines may be grouped together to form a wind farm.
What are the advantages of wind energy?
- It is a renewable energy resource.
- There are no fuel costs.
- No harmful polluting gases are produced.
What are the disadvantages of wind energy?
- Wind farms are noisy and may spoil the view for people living near them.
- The amount of electricity generated depends on the strength of the wind; if there is no wind, there is no electricity.
- They can be a danger to birds or low-flying aircraft.
What are wave, tide and falling water energy resources?
Wave
Sea waves moving up and down can be used to drive turbines directly to generate electricity.
Energy which an object possesses by being in motion. of the waves → electrical energy.
WATCH: How wave power works and its impact
http://delta.bahce.site/bitesize/topics/znrwdp3/articles/zmpj8hv#z3dgr2p
Tides
Huge amounts of water move in and out of river mouths each day because of the tides.
The moving water has kinetic energy.
A tidal barrage is a barrier built over a river mouth to make use of the kinetic energy in the moving water.
The barrage contains electricity generators, which are driven by the water rushing through tubes in the barrage.
Kinetic energy of the moving water → electrical energy.
WATCH: How tidal power works and its impact
http://delta.bahce.site/bitesize/articles/z3hwkty#z2dbg7h
Hydroelectric power
Like tidal barrages, hydroelectric power (HEP) stations use the kinetic energy in moving water.
Often, the water comes from behind a dam built across a river valley.
The water high up behind the dam contains The energy an object possesses due to its position above the ground..
This is transferred to kinetic energy as the water rushes down through tubes inside the dam.
The moving water drives electrical generators, which may be built inside the dam.
Gravitational potential energy of the water → kinetic energy.
Kinetic energy of the falling water → electrical energy.
WATCH: How hydroelectric power works and its impact
http://delta.bahce.site/bitesize/topics/znrwdp3/articles/z9pwkty#zsxcr2p
What are the advantages of wave, tide and falling water energy resources?
- Waves, tides and hydroelectric power are renewable energy resources and there are no fuel costs.
- No harmful polluting gases are produced.
- Tidal barrages and hydroelectric power stations are very reliable and can be easily switched on.
What are the disadvantages of wave, tide and falling water energy resources?
- It has been difficult to make wave machines big enough to produce large amounts of electricity.
- Tidal barrages destroy the places where birds and fish live.
- Hydroelectricity dams flood farmland and can push people from their homes.
- The rotting vegetation underwater releases methane, which is a The gases responsible for global warming - carbon dioxide, methane, nitrous oxide and CFCs (chlorofluorocarbons)..
What is geothermal energy?
Hot water and steam from deep underground can be used to drive turbines: this is called Energy from the heat of the Earth. energy.
Geothermal and nuclear energy are the only energy resources that do not come from the Sun.
Geothermal power stations are located in places such as Iceland, California and Italy.
Hot rocks
In some places, the rocks are hot, but no hot water or steam rises to the surface.
In this situation, deep wells can be drilled down to the hot rocks and cold water pumped down.
The water runs through fractures in the rocks and is heated up.
It returns to the surface as hot water and steam, where its energy can be used to drive turbines and electricity generators.
The diagram below shows how this works.
What are the advantages of geothermal energy?
- Geothermal energy is a renewable energy resource and there are no fuel costs.
- No harmful polluting gases are produced.
What are the disadvantages of geothermal energy?
- Most parts of the world do not have suitable areas where geothermal energy can be exploited.
How is solar energy generated?
Solar energy is used to generate electricity and to produce hot water.
Solar energy is energy released by A type of nuclear reaction in which two lighter atoms are joined to make a heavier atom, releasing a large amount of energy in the process. in the Sun.
Solar cells
Solar cells are devices that convert light energy directly into electrical energy.
Small solar cells are used in calculators.
Larger arrays of solar cells are used to power road signs in remote areas, and even larger arrays are used to power satellites in orbit around Earth.
What are the advantages of solar energy?
- Solar energy is a renewable energy resource and there are no fuel costs.
- No harmful polluting gases are produced.
What are the disadvantages of solar energy?
- Space is needed for installing solar cells.
- Solar cells do not work at night.
Solar panels
Solar panels do not generate electricity, but rather they heat up water.
They are often located on the roofs of buildings where they can receive heat energy from the Sun.
The diagram outlines how they work:
- Cold water is pumped up to the solar panel, it heats up and is transferred to a storage tank.
- A pump pushes cold water from the storage tank through pipes in the solar panel. The water is heated by heat energy from the Sun and returns to the tank. In some systems, a conventional boiler may be used to increase the temperature of the water.
Advantages
- Solar energy is a renewable energy resource and there are no fuel costs
- No harmful polluting gases are produced
Disadvantages
- Solar panels may only produce very hot water in very sunny climates, and in cooler areas may need to be supplemented with a conventional boiler
- Although warm water can be produced even on cloudy days, solar panels do not work at night
What are non-renewable energy resources?
Fossil fuels
Fossil fuels include coal, oil and natural gas.
They were formed from the remains of living organisms (plants and animals) millions of years ago.
They have A type of stored energy. It is taken in when chemical bonds break, and given out when chemical bonds are made. stored within them and are non-renewable because they cannot be replaced within a human lifetime.
About three-quarters of the electricity generated in the UK comes from power stations fuelled by fossil fuels.
This diagram shows an energy transfer diagram for the generation of electricity from a fossil fuel such as coal.
What are the advantages of using fossil fuels?
- At the moment, fossil fuels are relatively cheap and easy to obtain. This may not always be the case.
- Much of our The basic structures needed for an area to function, for example roads and communications. is designed to run using fossil fuels.
What are the disadvantages of using fossil fuels?
- Fossil fuels are non-renewable energy resources. Their supply is limited and they will eventually run out.
- Coal and oil release sulphur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain.
- Fossil fuels release carbon dioxide when they burn, which adds to the The retention of heat in the atmosphere caused by the build-up of greenhouse gases. and increases global warming. Of the three fossil fuels, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least.
Key facts
A non-renewable energy resource is one that has a Something that has a limited number of uses before it is depleted. For example, oil is a finite resource. supply and it will run out at some stage. They are used faster than they can be replaced.
Fossil fuels such as oil, natural gas and coal are considered non-renewable because they cannot be replaced within a human lifetime.
How is nuclear energy generated?
The main nuclear fuels are uranium and plutonium.
In a nuclear power station, nuclear fuel undergoes a controlled chain reaction in the A piece of equipment in which nuclear fission or fusion takes place. to produce heat - nuclear energy is converted to heat energy:
Heat is used to change water into steam in the boiler.
The steam drives the A turbine is a machine that turns the movement of liquid or gas into energy that can be used. In a simple turbine water or air push against turbine blades and spin them round. The spinning blades turn a long pole called a shaft. The shaft can then turn other pieces of machinery, such as a generator that is used to produce electricity. (heat to Energy which an object possesses by being in motion.)
This drives the generator to produce electricity - kinetic to electrical energy.
Nuclear and geothermal energy are the only energy resources that do not come from the Sun.
What are the advantages of nuclear energy?
- Unlike fossil fuels, nuclear fuels do not emit The gases responsible for global warming - carbon dioxide, methane, nitrous oxide and CFCs (chlorofluorocarbons). such as carbon dioxide.
- Nuclear fuels do not emit gasses such as sulphur dioxide which cause Rain that contains dissolved acidic gases such as nitrogen oxides and sulfur dioxide..
- 1 kg of nuclear fuel produces fuel (such as uranium) produces 1 million times more energy than 1 kg of coal.
What are the disadvantages of nuclear energy?
- Like fossil fuels, nuclear fuels used for The splitting of a large nucleus to produce two smaller ones. Two or three neutrons are also released in the process. The energy from the neutrons powers a nuclear reactor., such as uranium ore, are non-renewable energy resources since supplies will not last forever.
- Although modern reactor designs are extremely safe, if there is an accident, large amounts of radioactive material could be released into the environment. Such an incident occurred at Chernobyl in Ukraine in 1986.
- Nuclear waste remains radioactive and is hazardous to health for thousands of years, so it must be stored safely.
- To deactivate or remove in a safe manner. a nuclear power plant is extremely expensive.
What are the different energy resources used today?
The table below shows the main features of the most common energy resources used today.
What are the environmental effects of air pollution?
Global warming and acid rain are often confused as they are both caused by air pollution from the combustion of fossil fuels and biofuels.
Global warming
Global warming is caused by the release of carbon dioxide (CO₂) from the burning of all fossil fuels (and biomass fuels as well).
This extra CO₂ and other greenhouse gases (such as methane) in the atmosphere, traps infra-red radiation (heat) resulting in an increase in the Earth’s temperature (the greenhouse effect) which causes melting of ice caps, flooding of low-lying land and extreme weather patterns known as climate change.
Acid rain
Rain that contains dissolved acidic gases such as nitrogen oxides and sulfur dioxide. is caused by the release of sulfur dioxide (SO₂) and nitrogen oxides (NOx) from the burning of coal and oil.
This sulfur dioxide and nitrogen oxides react with rainwater in clouds forming sulfuric acid and nitric acid which falls as acid rain.
This causes rivers and waterways to become acidic which can kill aquatic plants and animals.
It can cause defoliation of young trees and can also corrode buildings.
| Energy | Energy store | Renewable or non-renewable | Uses | Power output | Impact on environment |
|---|---|---|---|---|---|
| Fossil fuels (oil, coal and natural gases) | Chemical | Non-renewable | Transport, heating, electricity generation | High | Releases CO₂ (causes global warming) |
| Nuclear fuels | Nuclear | Non-renewable | Electricity generation | Very high | Radioactive waste (needs to be disposed of safely) |
| Biofuel | Chemical | Renewable | Transport, heating, electricity generation | Medium | Carbon-neutral so low impact |
| Wind | Kinetic | Renewable | Electricity generation | Very low | Take up large areas that could be used for farming, people say windmills spoil their view |
| Hydroelectricity | Gravitational potential | Renewable | Electricity generation | Medium | Local habitats are affected by the large areas that need to be flooded to build dams |
| Geothermal | Internal | Renewable | Electricity generation, heating | Medium | Very low |
| Tides | Kinetic | Renewable | Electricity generation | Potentially very high but hard to harness | Tidal barrages can block sewage which needs to go out to sea |
| Sun | Nuclear | Renewable | Electricity generation | Potentially very high, but hard to harness | Very little |
| Water waves | Kinetic | Renewable | Electricity generation | Low | Very low |
How do the different energy resources compare?
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.
How much do you know about energy resources?
More on Unit 1: Energy
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