Renewable energy Energy resources for the future

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Starter: 1 minute

End

How many energy sources are there in the picture?

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Aim

• Identify several examples of renewable energy resources.

• Explain what is meant by renewable energy. • Establish pros and cons of the renewable energy

resources.

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4 of 39 © Boardworks Ltd 2008

Governments and scientists are trying to develop alternative

sources of energy to replace fossil fuel power stations.

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Coal Oil Gas

Years left

Why are alternatives to fossil fuels needed?

Burning fossil fuels has many bad effects on the environment.

However,

environmental

damage is not the

only problem with

continuing to rely on

fossil fuels to supply

our energy needs.

What does this

chart show?

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What are renewable energy sources?

Renewable energy resources will not run out because they

can easily be generated anew. The photograph shows a

dam built for the generation of hydroelectric power.

Other examples of

renewable energy

resources are:

Only 4% of the UK’s energy comes from renewable sources.

Why do you think this is?

wind power

solar power

tidal power

biomass

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How can the wind generate electricity?

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There are a number of methods of generating

electricity from the Sun’s energy.

Solar panels convert sunlight

into electricity directly. They are

used on some new houses and

also on calculators.

Mirrors can be used to

focus sunlight onto pipes

containing water. The hot

water drives a generator.

How is solar energy used?

Passive solar heaters heat

water directly using sunlight.

Why are they black?

10.5 Renewable energy Let's look at some renewable energy forms in a little more detail...

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10.5 Renewable energy

Hydroelectricity

Water is collected in a dam high up a mountain. When the water is released downhill its kinetic energy turns a turbine below. The turbine turns a generator and electricity is generated.

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10.5 Renewable energy

Tidal energy

Tides flowing in and out of narrow spaces such as rivers could also be used to generate electricity.

The gates are opened to allow the tide in and then closed to trap the water.

This is then released in one big flow to turn the turbines and generate electricity.

Tidal energy is not being used yet but being planned.

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10.5 Renewable energy

Wave energy

The movement of waves out at sea can be used to generate electricity.

At the moment this is used for generating enough power for a flashing light on a buoy to warn ships of danger. But there are experiments going on to find out how to use power to make larger quantities of electricity for use on land.

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10.5 Renewable energy

Solar power

Solar panels convert light energy directly into electricity. This can be on a small scale, such as running a calculator, or on a large scale to supply a building.

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10.5 Renewable energy Biomass

Biomass is anything that is grown, such as straw, or produced by animals, like dung. It can be burned instead of fossil fuels and produces less carbon dioxide. More biomass can be produced easily.

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Geothermal

• Geothermal energy uses heat stored beneath the Earth’s surface to create steam. This is then used to power turbines.

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Other renewable energy sources

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Nuclear fusion

Fusion (joining atoms) is the opposite idea to fission

(splitting atoms). The Sun and all other stars are powered

by fusion reactions.

Fusion produces no

harmful waste and

generates enormous

amounts of energy.

Unfortunately, it needs

very high pressures,

and temperatures as

hot as the sun to get

it started.

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Hydrogen is now being used to

power cars in California, where

you can fill up with the gas just like

petrol. It is converted by the car’s

fuel cells into water and electricity.

At present however, the production

of hydrogen is expensive and often

requires a lot of energy.

Methane is a waste

product from animals and

from rotting plant and

animal material.

The gas can be collected

and burned in a power

station.

New ways of generating useful energy

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Plenary: Energy sources for the future

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Multiple-choice quiz

10.5 Renewable energy In pairs Create an A3 publisher poster on Energy Sources You need to include all forms of renewable and non renewable fuels You need to include: Advantages Disadvantages How they make electricity

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