1. Energy, Power & Climate Change
Topic 8
Energy, Power & Climate Change

2. Types of Energy

3. Types of Energy

4. Energy Flow diagrams
We can write energy flow diagrams to show the energy changes that occur in a given situation. Name the energy changes that occur when a car engages its brakes

5. Energy Flow diagrams Notice the size differences of the terms
Kinetic heat
sound

6. Another Example
Sketch an Energy Flow Diagram of a rocket launch

7. Rocket Launch
Chemical Kinetic Gravitational
heat
heat
sound

8. Energy degradation!
In any process that involves energy transformations, the energy that is transferred to the surroundings (thermal energy) is no longer available to perform useful work.

9. Energy transfer (change)
A lamp turns electrical energy into heat and light energy

10. Sankey Diagram
A Sankey diagram helps to show how much light and heat energy is produced

11. Sankey Diagram
The thickness of each arrow is drawn to scale to show the amount of energy

12. Sankey Diagram
Notice that the total amount of energy before is equal to the total amount of energy after (conservation of energy)

13. Sankey Diagrams Take out two pieces of paper
On the first piece of paper, create three examples of energy changes in 3 words or less
Pass it to another group
Write the corresponding energy flow diagram (including heat losses) that you receive on the second piece of paper

14. Wrap up Read the energy transfer process from your Sankey Diagram
We will guess what the situation you were describing

15. Efficiency
Although the total energy out is the same, not all of it is useful.

16. Efficiency Efficiency = useful energy output total energy input
Efficiency is defined as
Efficiency = useful energy output
total energy input

17. Example
Efficiency = 75 = 0.15 = 15% 500

18. Energy efficient light bulb
Efficiency = = 75%
100

19. Energy efficient light bulb
Efficiency = = 75%
100
That’s much better!

20. More complex examples

21. Another Sankey

22. This too shall pass
Name all the energy transformations in this video