The document discusses Sankey diagrams and their use in representing energy transfers and calculating efficiency. Sankey diagrams show the different types and amounts of energy at each stage of a process. They use thicker lines to represent greater amounts of energy being transferred. The document gives an example of a Sankey diagram for electric power production that shows how much energy is wasted versus transferred to consumers. It also provides the equation for calculating efficiency based on useful energy transferred versus total energy supplied.

1. SANKEY DIAGRAM

2. SANKEY DIAGRAM How many units of electrical energy go to consumers? 65 units are wasted in the power station. What is the efficiency of the Power Station?

3. Calculating efficiency The efficiency of any device such as a lamp can be calculated using this equation: Efficiency = ( useful energy transferred ÷ energy supplied ) × 100

4. ELECTRICAL POWER PRODUCTION Starter Activity GCSE 2009 A331/02 This question is about different ways of generating electricity. (a) Some ways of generating electricity use renewable sources. Put a ring around each of the two renewable sources. Coal, natural gas, oil, wave, wind [2 Marks] b) Explain the term renewable and non-renewable energy.

5. LESSON 11 Electrical Power Production – Discuss Sankey Diagrams. Use Presentation IP3.9 The cost of electricity , link back to Lesson 1 and introduce criteria against which different types of power station can be compared

6. ELECTRICAL POWER PRODUCTION Aims To know how to use block and Sankey diagrams in relation to electricity generation To show how relevant criteria can be used to compare different ways of generating electricity

7. Useful Energy Different types of energy can be transferred from one type to another. Name the ‘useful energy’ and ‘waste energy’ in the above diagram and explain why?

8. Sankey diagram for an electric lamp below shows that most of the electrical energy is transferred as heat rather than light.

9. SANKEY DIAGRAM Energy transfer diagrams show each type of energy, whether it is stored or not, and the processes taking place as it is transferred.

10. SANKEY DIAGRAM What is a Sankey diagram? Sankey diagrams

11. SANKEY DIAGRAM What is a Sankey diagram? Sankey diagrams Sankey diagrams summarise all the energy transfers taking place in a process. The thicker the line or arrow in a Sankey diagram, the greater the amount of energy involved.

12. SANKEY DIAGRAM How many units of electrical energy go to consumers? 65 units are wasted in the power station. What is the efficiency of the Power Station?

13. Calculating efficiency The efficiency of any device such as a lamp can be calculated using this equation: Efficiency = ( useful energy transferred ÷ energy supplied ) × 100