Lesson 2 Running out of energy

Lesson aim: To understand why fossil fuels are non-renewable.

Lesson outcomes: • be able to explain the need for fuel conservation

and be able to suggest ways in which this could be achieved.

• use sources of information to extract relevant information, and then present the information in an appropriate way.

How coal was formed

About 300 million years ago, plants photosynthesized and stored the Sun’s energy.

Dead plants fell into swampy water and the mud stopped them from rotting away.

Over the years, the mud piled up and squashed the plants.

After millions of years under this pressure, the mud became rock and the plants became coal.

Coal Formation

How oil was formed

Oil is also biological in origin. Millions of years ago tiny animals lived in the sea. Like now their ecosystem was dependent on heat and light from the Sun and photosynthesis by plants. When they died they fell into mud and sand at the bottom of the sea but didn’t rot away.

Over millions of years, they got buried deeper by the mud and sand. The temperature and pressure (caused by the weight of the sediments and deep burial) changed the mud and sand into rock and the dead animals into crude oil and natural gas.

Oil formation

Energy resourcesWe all use chemical energy (food) to live and function. However, in a modern society we also use large amounts of energy from other sources.

Think of some activities requiring energy:

Traveling and communicating over long distances.

Controlling our environment - air conditioning / heating.

Manufacturing and building many kinds of materials and products – e.g. roads, cars, buildings, prepared food.

The pie diagram on the next slide shows where the energy comes from for some of these activities.

Energy supplies in Britain

35%

9%1%

30%

25%

coalnuclearhydro-electricoilnatural gas

These energy resources can be divided into two types:renewable and non-renewable.

Non-renewable energy sources

Oil Coal Natural gas

Oil, coal and natural gas are examples of fossil fuels. They were formed from biological deposits over the course of millions of years.

There is a finite amount of these materials on the Earth so they will run out eventually.

Once they are used up they cannot be regenerated and used again.

Spotlight 7 p 42

• Answer questions g and h

• In small groups suggest 5 ways in which you could reduce your use of energy obtained from fossil fuels. (make the link to fossil fuels clear. Eg. Turning off un-needed lights reduces the electricity we use so we need to burn less coal at power stations)

In your exercise books

• Write a definition of a non-renewable fuel

A fuel that took so long to form that when we use it all up we won’t get anymore.

• Write down your own examples of ways in which we can reduce energy use and conserve fossil fuels

Energy from plants 1

• Rotting plants can be used to produce a gas called methane. Methane can be burned to give heat energy.

• The methane is produced by microbes eating the plant material. They also produce some heat.

• It would be difficult to collect the methane in a school laboratory. You can tell that methane is being produced because the plants will get warm.

Your teacher will set up this apparatus

label the diagram

Complete the worksheet method

• Then in your exercise book make a prediction. Which flask will have the highest temperature after 7 days . Explain why