1. Date 4:Energy Diagrams Lesson Outcomes How I did Targets
Task 1:Describe some energy transfer in appliances.
Level 5
Task 2:Explain why transfer may not be 100%.
Level 6
Task 3: Calculate running costs of an appliance over time.
Level 7
Connector: (Level 4)
Name the different forms of energy.

2. BIG picture What skills will you be developing this lesson?
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
How is this lesson relevant to every day life? (WRL/CIT)

3. What’s the energy transfer?
Discuss the energy transfer involved in each appliance with the person next to you.

4. Energy transfer in electrical circuits
5 J transferred to bulb
as light energy
chemical energy from battery (e.g. 100J)
heat energy of bulb
95 J transferred to 4

5. Energy transfer in electrical circuits
Most of the energy from the battery does not produce light – most of it is wasted as heat!
5 J transferred to bulb
as light energy
chemical energy from battery (e.g. 100J)
heat energy of bulb
95 J transferred to

6. Is all the energy useful to us?
List the output energy as useful and wasted energy.

7. Discuss the energy transfer

8. Sankey diagram (Task 1)
15J 5J
35J
45J
100J

9. Draw the Sankey diagram (Task 1)

10. Task 1 (Level 5)
Explain why energy transfer may not be 100%.

11. How can I improve on task 1?
Task 1: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 1:
Level 5
Met?
Partly met?
Not met?
How can I improve on task 1?

12. Calculating energy efficiency
total energy input
useful energy output
%Efficiency = x 100
This bulb converts 200 J of chemical energy from battery into 10 J of useful light energy:
Efficiency of bulb = 10
200
= 5%
x 100
( )

13. New Information for Task 2
This radio converts 200 J of chemical energy from battery into 20 J of sound energy:
Calculate the efficiency of the Radio.
total energy input
useful energy output
%Efficiency = x 100

14. Task 2
This kettle converts 100 J of chemical energy from battery into 75 J of wasted sound and light energy.
Calculate the efficiency of the kettle.
total energy input
useful energy output
%Efficiency = x 100

15. New Information for Task 2
Calculate the efficiency of the fuel
total energy input
useful energy output
%Efficiency = x 100

16. Calculate it’s efficiency (Task 2)

17. Questions

18. How can I improve on task 2?
Task 2: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 2:
Level 6
Met?
Partly met?
Not met?
How can I improve on task 2?

19. Measuring electricity
Electricity is measured in KWh, this is sometimes called a unit

20. Questions 1.5 kW 0.08 kW A Unit. Energy transferred = power x time
= 2 kW x 3 h
= 6 kWh

21. Cost of energy transfer
How can we calculate the cost of energy transfer ?

22. Electrical cost

23. Questions 50 kWh 300 p or £3 The same: in both cases the number of
kilowatt-hours is 12.
36 p p

24. How can I improve on task 3?
Task 3: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 3:
Level 7
Met?
Partly met?
Not met?
How can I improve on task 3?

25. Homework Homework task: Due date: Criteria for level 5:

26. Review of lesson