Let there be light!

This lesson for students aged 7–11 is about converting energy and doing work.

Lesson outline

Step 1: Engage and elicit. Starting the lesson by stimulating curiosity

Most pupils are familiar with a battery operated torch. Using an example ask them to demonstrate how the light comes on. Explain that because the battery has stored energy that allows the bulb to light. Ask them to consider: What if there wasn’t a battery but human effort had to make the torch work. Is it possible? Have a dynamo torch available? Compare the two torches. What happens if the winder stops moving? Is it hard work? How long can you keep the light on?

Step 2: Explain. Pupils recognise that movement is essential to generating electricity

Take a tour inside a power station by watching the clip from the CHRISTMAS LECTURES. Encourage the children to spot the named parts of a power station whilst watching the video. Challenge them to think about which parts are moving.

NB: The turbine needs to turn and this is a common factor whether the fuel is renewable or non-renewable. 

Step 3: Explore. Pupils create questions and categorise into those that can be answered from previous research compared to a scientific question that is testable

Use the slide stimulus to encourage the pupils to generate their own questions about windmills. Question stem cards can be useful to support identifying the range of question words – How, what, should, where, when, who, could, if… then, what if.

Review the questions to sort into two piles: ‘scientific explorers’ and ‘general knowledge’. This encourages the children to consider which questions could be classed as scientific. For example:

What is the most expensive windmill? Indicates a research based investigation.
Does a taller windmill turn faster? Is scientifically testable and would offer a pattern seeking investigation.
Where are the most windmills? Indicates a research based investigation
Do North facing windmills turn faster than South facing? Is a scientifically testable question and would offer a pattern seeking investigation.

Step 4 Experiment. Pupils make and test a windmill that could be used to turn a turbine

Pupils define a testable question for themselves, eg: Do bigger windmills turn faster? Do three blades turn more than four blades? Ask the pupils to plan, predict and carry out a comparative fair test to measure and record the efficiency of a windmill. The focus of the learning is to understand the difference between scientific questions and general questions but the opportunity to discuss control of variables will be relevant also. The more efficient electricity generation the longer the non-renewable sources will last.

Step 5: Elaborate. Pupils apply new learning to a design sketch

How can a super machine use several energy changing within it? There are clips within popular films such as ‘Chitty Chitty Bang Bang’ that could help pupils to understand the task. Search on the internet for such examples and perhaps watch a couple.

Ask pupils to label the drawing. Would it be possible to have over 100 energy changing points in one machine? Watch the CHRISTMAS LECTURES video clip Rube Goldberg machine running over several rooms! Challenge the pupils to spot the different types of energy sources. 


The underpinning big idea:
When energy is converted, work can be done.

Children will be able to work scientifically by:
NC Key Stage 2: planning different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary.

Children will learn:

  • To identify the range of common appliances that run on electricity (and rely on batteries)
  • To consider where electricity is generated and appreciate that movement is needed in all power stations regardless of the energy source
  • To understand the uses and implicationsof science, today and for the future

Cross-curricular opportunities:

  • Eco-sustainability and reducing energy waste

Video clips

Download the teachers' guide for instructions on how to use these clips:

A tour of a power station:

A huge Rube Goldberg machine:

Lesson material

Download the full teachers' guide.

You'll also need the PowerPoint presentation.

Watch the full lectures

View the full CHRISTMAS LECTURES, 'Supercharged: Fuelling the future', on the Ri Channel: richannel.org/christmas-lectures

Primary resources produced by the University of Manchester's Science & Engineering Education Research and Innovation Hub and the Primary Science Teaching Trust.